Ongoing evaluation of soil management practices on any site is essential to determine which actions/inputs have value.
By referencing back to the goals set, and soil management practices undertaken, results of soil management were evaluated below. By carrying out further soil testing and assessment, modifications to practices were determined and any improvements noted.
Evaluate the actions you have carried out to date, to improve soil quality. In your report, include what has worked, what has not, ease of implementation. Make note of any improvements that you have identified, summarise what you have done prior to each evaluation and record any recommendations. Make reference to organic standards and compliance. Give evidence for any claims you make.
Initial soil testing was completed on 31st August. A visual soil assessment was carried out to establish an understanding of the health of the soil in the market garden site before any soil management practices had been made. The soil of the market garden site ranked moderate with a VSA score of 18. There was good drainage and well formed aggregates with a fine-medium friable structure. Soil colour was a medium-light brown, slightly darker in places, overall revealing lower amounts of organic matter seen in rich dark soils. Water retention was okay, small amounts of moisture could be felt. There was one section of the garden in the top right hand quadrant that was different structure. Much more compacted, wet, dense and had a off scent of sulphur, indicating stagnation and bacteria and unwanted microbe populations. There was also minimal worm life, less than 4 worms recorded in the VSA 20cm of top soil. There was also minimal visible strands of fungi to be seen.
With those results, there is massive room for improvement in soil health for this site. Organic matter definitely needed to increase, as well as worm life, microorganisms, mycorrhizal fungi networks, working symbiotically to improve over all structure and health of the soil and plant life.
SOIL + NUTRIENT MANAGEMENT ACTIONS:
3/10/23 First steps carried out was to remove perennial weeds and aerate the soil with the least amount disturbance. This was done by broad forking the entire market garden site from left to right, top to bottom. Broad forking was necessary to loosen deep rooted perennial weeds: as well as aerating and loosening any compacted patches of soil. Whilst this is still in effect disturbing the soil, it is not being inverted and completely mixed, disrupting soil layers as seen in other methods such as tilling and digging. Plus, it is a one off action to remove aggrevating weeds that threaten to over take the garden if not removed such as wandering dock and oxalis. A small broad fork was gently placed into the soil and lifted to create air pockets and to remove weeds. Starting in one corner, I worked my way along from north to south broad forking. With another student helping, we met in the middle. We were very attentive not to stand back on where we had just forked the ground so we were not compacting the soil thereafter.
The first amendment of organic matter was adding medium texture woodchip which was sourced from trees onsite at WITT. Layers of wood chip were added to establish pathways around the growing beds. These would be to walk on, to not disturb the beds and create compaction within the growing zones. Wood chip will provide cover and protection for the soil, as well as food and host substrate for mycorrhizal fungi networks to establish. Woodchip mulch will be excellent for moisture and water retention and will eventually break down over the season adding a layer of organic matter to the top soil. Worms also thrive in this moist organic matter rich environment and will encourage their activity and breeding cycles within the soil also.
4/10/23 The next day the rest of the woodchip was applied to fill up all paths. Once completed, management of the growing beds started with adding in nutrient amendments to boost the nutrient levels in the soil. All naturally based, no synthetics were used in compliance with organic standards used in Organic farm NZ. Two of the 4 products applied were certified organic. 1. Tui Chicken & Sheep pellets (non organic) 2. Tui Blood & Bone (non organic) 3. Cert Organic Yates Potash 4. Cert Organic Yates Garden Lime. Ideally all of these amendments would have been certified organic, however I was using what I had access too with the WITT garden supplies, moving forward I would recommend organic sheep pellets along with an organic blood and bone to adhere to organic standards. Refer to the swaps I would use for compliance here:
The combination of these amendments will provide a wide array of essential nutrients (NPK) as well as micronutrients and mineral content to boost initial growth of plants whilst they establish. The hope is to not rely on these amendments as the quality and health of the soil improves. Instead, between the fungi, microorganisms, worms, plant roots and their exudates and organic matter from fallen plants and added compost/mulches will feed each other to create a closed loop reciprocal nutrient system where everything supports eachother, known as nutrient cycling. This will take some time to build, so plant performance will be monitored to adapt nutrient application while the soil health is still building.
A fresh load of 2 cubic metres of compost was delivered and added to the garden beds after all amendments were evenly distributed. This compost was sourced from return 2 earth "Return 2 Earth's All Natural Composted Soil Conditioner is produced from blends of recycled greenwaste, woodchip, stable, goat and chicken manures and an added humate". Not a certified organic compost, however this is what we had access to logistically and financially. The compost appearance is a beautiful dark, rich colour and fine, fluffy texture. It appears to be of good quality, although we will see how plants respond over the seasons. (Please refer to soil page) A full heavy metal analysis was carried out by the company, which passed all safe ranges of metal levels.
Overall 5-8cm thick layer of compost was added to the initial bare soil beds. This creates a blanket and well established layer of organic matter that will protect the soil below and provide a plethora of nutrients for plants to access.
26/10/23 Three weeks later, the beginnings mycorrhizal fungal networks were visible weaving their hyphae through the layers of wood chip and compost (see here for photographic evidence) this provided positive feedback that these amendments and protective layers of woodchip & compost were creating the right environment for these beneficial fungi to thrive. It is a really good sign that the soil health is starting to improve. I noted, that particularly in the woodchip were these fungal hyphae present. I look forward to seeing signs of worm activity as the season progresses.
To summarise, a one off broad forking to aerate and help remove perennial weeds was carried out, from now on minimal disturbance of the soil will be made. All bare soil was covered with organic matter, woodchip for pathways, compost for the beds. Providing protection from harsh sun, wind and rain that threatens to degrade soil health further over time. Nutrients were amended with non-synthetic fertilisers, providing an initial boost to nutrient availabilty for plant roots to access and for soil microbes, fungi and organisms within the soil food web to access over time.
The next management techniques will be to get plant roots into the soil and further protect the growing beds with plant life that can feed soil life via exchanging exudates (sugars) and recieving minerals and nutrients. Plant matter will also be added back into the soil during sucessions of plantings. My goal is to keep the soil covered as often as possible to protect the life that is building within it's ecosystems.
What I would do differently:
Set up a data collection document to track soil health with regular VSA's to keep track of any improvement overtime and to refer back at anytime.
Get a soil sample to analyse under the microscope to get the foundational understanding of the existing soil food web and ecosystem within the soil to track increasement in populations of bacteria, fungi, protozoa, nematodes to compare with further soil improvements.
I would have planted much sooner that I was able to, by direct sowing straight after the fresh compost was laid and the beds were formed to get the plant roots in and developing sooner and to develop a crop rotation plan to ensure soil is not left bare for long periods.
I would water more often in dry spells to ensure soil moisture levels were kept at an even level. Consistent soil moisture levels need to be maintained for plant health and for the health of the soil food web in particular worms, as worms will migrate to subsoil and lower, rather than brining the organic matter and plant excretions through the topsoil which we need to improve soil structure and health.
Moving the compost and woodchip was very laborious. Possibly getting the compost and woodchip placed closer to the market garden site would cut down on labour time and lugging the heavy compost bags after they were hand filled and wheel barrowing them over to the site. I was lucky enough to have help from my tutor and a couple other students from the level three course to help me. It was definitely achievable with 2-3 extra helpers, but if this was on a commercial/fast turn over market garden this labour would cost a lot. However, this was the initial set up of the market garde space, so a lot of it was a one off full on effort to establish the foundations that would need to be maintained. More woodchip and compost will have to be added in the future, possibly once a year, so creating a plan to have this process more efficient and easy will be crucial.
Evaluate the actions you have carried out to date, to improve soil quality. In your report, include what has worked, what has not, ease of implementation. Make note of any improvements that you have identified, summarise what you have done prior to each evaluation and record any recommendations. Make reference to organic standards and compliance. Give evidence for any claims you make.
Actions carried out to improve soil quality:
Plant roots covering soil. The main soil and nutrient management technique carried out over the growing season was to ensure there were plant roots consistently within the soil without long periods of bare soil. Planting began on 19/10/23 with seeds sown direct and seedlings planted out a couple weeks later. These plantings were completed much later than I had planned originally. Busy schedule and cool snaps over the season meant that seedlings had grown a little slower than expected and planted out much later than intended. This mean that the soil was bare for just over two weeks with another three weeks after this to plant out majority of other seedlings. In terms of ease of implementatation, it was definitely a lot easier to direct sow seeds, directly into the beds and covering them with micromesh to protect and lock in moisture. Seedlings took a lot of time and effort, but proved their worth upon planting as they had a head start. These particularly worked really well for large fruiting crops such as cucumber, zuchini, tomatoes, peppers, eggplant. It meant I could get these ready a lot earlier before the season started.
Fully covering the soil took time. Where plants were direct sown and planted in closer rows, they covered the soil earlier than seedlings. However once the season picked up, larger fruiting crops and salad crops filled in there space in good time. This mean at peak season, majority of the soil was covered, with a plethora of living plant roots in the ground providing protection of the soil from the elements and consistent exudate excretion into the soil via these roots. The aim was to keep the soil covered with living plant roots as much as possible and this was achieved peak season.
The benefits of the constant high level of roots and plant coverage of the soil revealed itself in plant health. Due to the consistent coverage of soil and roots in the soil, moisture was locked into the soil and the soil food web was provided for and therefore able to carry out it's reciprocal nature with the plants by providing nutrients via fungi and in turn improving plant health. This was evident in the lack of disease and pest pressure throughout the season. Minimal imputs were needed (only 3 seaweed soakings were under taken) and no form of intensive weed or pest control was needed. IPM and IWM was carried out with only minor incidences of powdery mildew and aphids, both on curcurbits - these has little effect on the productivity of the plants over all. The health of these plants was a direct reflection of the health of the soil and the work that had gone in from the beginning to weed well, release compaction and to include organic amendments to provide the initial boost for plant growth. These combined with the woodchip and fresh compost created a solid foundation with clear results of healthy, robust and productive plant growth throughout the season.
I would definitely be more on time and proactive about getting plants into the ground as soon as possible after initial garden bed set up as this prolonged the time before necessary plant roots needed to be in the ground to protect the soil from the elements and to feed the soil foodweb/microbiome. This was an unfortunate time management pitfall that will need to be remedied in the future for productivity and to ensure optimal health of the soil without leaving it bare for extended periods.
The action of adding new organic matter via fresh compost and mulch via woodchip, did help to mitigate the effects of long exposure to the elements and lack of plant roots. This mean atleast the exsisting soil was covered and had supplied organic matter for worms to break down and fungi to settle in and there was available food and nutrient cycling able to be carried out for a period without active plant roots. However, plant roots will be prioritised via a sound crop plan and rotation in the future to ensure a cycle of plant exudates are being pumped into the soil and to feed microrganisms and increase overall soil health and nutrient availability. This first season was a great way to trial which species worked well in a polycrop bed and which would be the least amount of maintenance whilst still providing a productive and cost-effective market garden crop.
Despite a longer duration that had been originally planned, by the 14th December, majority of seeds and seedlings had been planted and sown so there were active plant roots within the soil pumping out root exudates to improve nutrient availability to organisms that cycle these excretements throughout the soil. Soil was being covered by living plant folige, providing shade and moisture protection within the soil.
To back this up, I carried out 4 different VSA's with varying results, which overall reflected the improvement in soil health. While there was still significant progress to be made in soil structure, worm activity and nutrient availability via organic matter, there was still a long way to go with improvement in soil structure and overall soil health.
What I'd do differently:
WATER, WATER, WATER! We were defintiely lucky with the higher amount of rainfull during the summer season of 2023/24. This provided majority of the irrigation needs of the plants and kept soil moist for ample plant growth. I was also able to go down 1x - 2x a week depending on rain levels to hand water with a hose to increase water application when the plants needed it. I did find initially the soil was retaining moisture really well, especially at a good depth, I tested with my hands to feel the level of moisture. (Next time I will tract with moister and temperature meter). I could feel the soil was still relatively moist even after a week without water. However, as the season went on I noticed even after watering for a long period, water penetration was decreasing and would only access the surface of soil. This meant the other layers of top soil were still very dry and soil was not retaining moisture. Worms would retreat much lower into the subsoils as the moisture levels were not supportive of their wet/moist environment needs. Lack of worms in this layer near plant roots meant that nutrient cycling would be highly interupted and organic matter was not being cycled along with nutrients throughout the layers of soil. This also became evident in plants that were showing signs of wilting and therefore significant water loss via transpiration due to lack of soil moisture.
To mitigate moisture loss I would make sure to set up a consistent watering timetable or include a self timing irrigation system. This would involve a lot of cost up front, however will pay off a lot in future, especially during the dryer and hotter summer months to ensure maintenance of soil health and plant health. Either that, or I would need to make time to ensure watering was carried out 2-3 times a week and stay very consistent with this application to ensure optimal soil moisture levels.
I would be more consistent with following a crop plan and succession sowing straight after a harvest of crops. This would continue to ensure that the soil remained covered and meant mitigation of bare soil at regular intervals. Due to time and resource constraints, as well as a consistent crop plan with adjacent timings, I lacked in replacing crops after harvest. This was in part due to inexperience also, and learning what crops worked well, when they needed to be harvested and spacing. I will be using what I learnt in the following seasons to ensure regular and consistent successions to keep soil health utmost priority.
Include more seaweed soil drenchings, I would carry these out on more of a regular basis every 2 - 3 weeks to improve microbial activity within the soil to support the soil foodweb and in turn plant health.
Evaluate the actions you have carried out to date, to improve soil quality. In your report, include what has worked, what has not, ease of implementation. Make note of any improvements that you have identified, summarise what you have done prior to each evaluation and record any recommendations. Make reference to organic standards and compliance. Give evidence for any claims you make.
At the time of this report, we are in autumn and the garden has reached it's slow phase and transition form summer. Whilst most crops remain, their vitality has diminished as the days get shorter and the nights get colder. Majority of soil surface area remained covered in either living or decaying plant matter which contriubted to protecting soil health.
What's worked, improvements, notes and evaluations:
Maintaining a high level of living plant roots in the soil. This has been achieved for probably 60-70% of the garden with living plant roots within a biodiverse polycrop to ensure there was constant exchange of root exudates and the plant - microbe relationship kept strong. This is the easiest implement tation in terms of a little bit of neglect and a lack of time available to spend in the garden and maintain a good succession planting plan. I was able to maintain a high level of plants in the ground, however after harvest of crops such as beets and carrots, a lot of soil was left bare and therefore inflicting a negative effect on soil health due to weather erosion and lack of living plant roots. Next steps to ensure protection of soil health is to create a strong succession sowing and planting plan to avoid bare soil at all costs.
COMPOST. This has single handledly transformed the soil of the market garden site. Return 2 Earth compost, whilst not certified organic has provided a wealth of organic matter and nutrient availability to both plants and fungal and microbial health. The most positive signs were reflected in the health of plants and their prolificness. As well as the most noticable visual signs of fungal activity and networking within the soils and compost
There was astounding levels of fungi visible both interlaced into the soil and coating plant roots. Particularly interwined in the wood chip, as well as embedded throughout the top soil of the beds, large white patched and tiny hyphae networks stretching throughout large patches of soil. This finding was incredibly reassuring and exciting to see the progress of fungal, microbial and worm activity beginning to flourish in just a short period of time.
I carried out visual soil assessments during this time in five different patches of the garden,
1 in the right hand end of the tomato bed which included mostly compost and a
2 at the end of bed 1 in the woodchipped area, 3 as well as another patch between bed 1 & 2
4 Under roots of lettuces and rocket in bed 3
5 In between tomato plants (rupunzel and yellow pear) in the left hand side of the tomato bed*
Most of these VSA's conveyed similar results, high fungal network activity and visbility, find texture crumb especially due to the compost and areas of sticky aggregates and clay-like textures in areas, especially that in the end of bed 1 & 2 where the soil is very dense and compacted. There was good colouring and minimal mottling throughout the soil assesmenets, rich dark colours ranging from copper brown - dark slate brown indicating good organic matter presence in the top soils.
However, there wasn't as many worms as I had anticipated and hoped for. Averaging at 10 worms, which still is a good condition score and a considerable improvement when compared to the initial soil assessment taken back in August before any changes were made
Most notibly, a count of 44 worms was taken in *VSA 5 between tomatoes. This is an interesting correlation as these tomatoes were the one's impacted by an unusual elongating and curling leaf disorder.
The VSA's relayed clear evidence that the soil health of the market garden site had defiinately improved with notable levels of fungal networks and activity, worm activity, strong root structure and plant health
Worm tunnels were visable throughout compacted clayey soil near bed 1 & 2, this was poorly draining, thicker and sticky soil that had minimal crumb texture, it was evident it needed more organic matter, nutrient cycling and fungal, microbial and worm activity to improve its quality. It was amazing to see the worms beggining this process by weaving tunnels and bringing organic matter throughout the thick clods and providing aeration and nutrients.
Additives?
Nothing else has been added to the soil apart from sporadic seaweed soil drenches during summer to the soil for nutrients. These seaweed drenchs were to encourage foliar plant health and improve microbial populations.
This means the soil health has been thriving on the initial layers of compost, living plant roots, fungal, worm and microbial activity and the small array of organic ammendments we applied at the beginning back in october of blood & bone, chicken & sheep pallets, lime and potash. No other nutrient amendments of fertilsers have been added.
I plan to work in organic vermicasts, more liquid fish/seaweed drenches in the coming months
Results from popsicle test: photos will be found in final report
I had left a large popsicle stick from a label of a seedling grown in the ground to track microbial and fungal activity, as another way to test and assess the soil health. This was planted along side it's apple cucumber back on November 11th. These are the results below:
Evidence of strong microbial and fungal activity. This popsicle stick was put in the ground on november 11 2023. These photos below were taken April 11 2024, 5 months later. The bottom of the stick was already degrading and has been saturated with microbial and fungal exudates and enzymes that have broken down the wood, decomposing fragments via the poop loop.
This is awesome visual and biofeedback that tells me there is positive soil food web activity happening in the soil. It is yet another layer of evidence and indicator of good soil health forming.
Fungal networks have also been visible via fungal network evidence in soil and on plant roots, as well as microbial evident in nitrogen nodules forming on legume species.
Overall, from the main growing season over summer into autumn now, there is clear evidence that soil health has improved from our initial VSA soil testing at the beginning analysis of the site
This is your final soil evaluation. By looking back over the growing season, summarise the successes of your soil and nutrient management practices over the year.
What improvement in soil quality and fertility has there been?
Have some actions worked better than others, which would you expand, which might you not use?
Have the methods and actions used improved crop production and the overall 'health' and resilience of the site?
Also look at what could be done better. Provide recommendations for the future management of the soil on the site. Give evidence for any claims you make.
Looking back at the beginning of the market garden, and now a year later, a significant and positive evolution on soil health is evident. Soil and nutrient management is a journey, and there is a long way to go in regenerating our soil health within this site. However a lot can happen in a year and it has been exciting to explore these findings over this course below.
Soil history - THE FOUNDATION
Before Te Henui lodge was established, the land was once dense forested area with a mix of indigenous natives and intoduced species. This was removed after 2013 and slowly cleared to make space for the Te Henui lodge residents garden and WITT garden spaces.
Te Henui lodge was established between 2001 - 2005 and the area slowly evolved, ebbing and flowing from less dense to lush forested area, then to the cleared patch that exists. Earth moving/clearing and a long history of spraying weed killers in this area. External gardening companies are hired outside of WITT gardening team to take care of this area. There is minimal knowledge as to what has been used and sprayed in this area overtime. Evidence is seen in spray strips around perimeter of tree lines (shelter belt) as well as edges of beds and market garden area. Soil testing via VSA, microbial microscopic viewing has been undertaken by us to analyse and determine any impacts of soil health, which we explore below.
Before 2001, soil history and land use is unknown, however this is likely to have had impact on soil health thereafter and ongoing effects to this day.
Consensus: The origins of the soil on this site indicate that there was a strong and fruitful foundation from the lush forest that once existed on site. This was rich with biodiversity in tree and bush canopies and would have supported a healthy ecosystem above and below soil. High organic matter from years of leaf litter and plant decay and a host of fungal networks and soil food web communities would have been present. Unfortunately this would have been severely impacted by the earth moving/clearing to create the site, destroying the ecosystem, soil structure, fungal networks and life beneath the soil. This will have ongoing ramifications for decades to come. Ongoing use of weed killers ie glyphosate and other broad spectrum pest, disease and weed in the area has contributed to ill health in sections of the garden also.
2001
2005
2010
2012
2013
(Today, from 2013 onwards)
Close up of site
2024 Google Maps view
Sources: NPDC GIS Viewer https://geo.npdc.govt.nz/portal/home/index.html & Google Maps
TYPIC ORTHIC ALLOPHANIC SOILS
Taranaki is well known for its rich allophanic (Volcanic soils) as seen in the pale pinky colour above that are resilient and adept for growing pasture and cropping. Taranaki region is coated in these lush soils, including the New Plymouth district. However, New Plymouth itself is classed as Anthropic soils due to being drastically changed and disturbed by human intervention, as it is our industrialised CBD with high residential population. This means the naturally occuring allophanic soils have been exposed and a lot of their highly beneficial properties have been extensively altered.
Allophanic soils have a very dark top soil with great structure, highly permeable, crumbly and free draining. They contain high amounts of allophane (volcanic ash) along with a vast bank of minerals. Te Henui lodge, WITT gardens are therefore classed as Allophanic, but Anthropic soils. Allophanic soils that have been drastically altered by humans, clearly seen in the contruction of Te Henui lodge. Allophanic soils often have stable structures with good recovery rates after disturbance, the soil both shrinks when dried and swelled when wet with good water retention and good drainage due to the subsoil rock. Fertility is high and well suited for a variety of growing operations.
While there will be site specific nuances in soil health on my site due to anthropic intervention, it is great to have an understanding of the bigger picture of soil type and to have insight into the existing structure and nutrient availability of the Taranaki allophanic soils.
References below: https://www.trc.govt.nz/assets/Documents/Research-reviews/Land/SoilReport2018.pdf
https://soils-maps.landcareresearch.co.nz
Another Soil NZ regional analysis, classing New Plymouth amongst the Typic Orthic Allophanic Soil type. These soils are well drained and permeable with high fertility and are suited to a wide variety of horticultural and agricultural operations, as well as forestry. This is evident in the current business and industries that dominate in the Taranaki region, especially agriculture. Taranaki as a region has huge potential for more widespread horticulture oppportunities and development.
The wider outlook on Taranaki region soils, majority cast in rich Allophanic soils due to our remarkable central volcano, Mt. Taranaki.
Sourced: https://soils-maps.landcareresearch.co.nz
THE BEGINNING - What I arrived to, my history with the soil
Below is what I arrived to at my chosen site...
BARE, NEGLECTED, SUN-SCORCHED, MINIMALLY DIVERSE, SPARSE, EXPOSED, DEGRADED & UN-LOVED SOILS.
Basically, I had a lot of work to do. My knowledge of the site was that it was a communal garden of Te Henui lodge residents and WITT students. There have been many different species of crops grown in these soils in the past, which means there has been variety and diversity to provide these soils with life. However, crop rotation and consistent planting has evidently not been frequent or upkept. This has left us with visually, a sub-par looking soil that is being exposed to the elements above and deprived below, with minimal-none diverse level of plant roots to feed microbial and fungal activity in the soil. The results a depleted looking and performing soil above and below. Take a look below.
*Note: During my level 3 horticulture course in 2022 with my fellow students and tutor, we helped to take care of this area where we could, sowing and growing multiple crops including summer tomatoes. During this experience, we noticed that many of our crops, particularly the tomatoes struggled to grow. There was a lot of speculation around why this happened, whether that was overall poor soil health or what was actually the cause, whether it was a type of toxicity or lack of nutrients. I found out more over the course of this year, more to follow.
The degradation of soil health was backed up by our initial VSA's of the site below.
Initial VSA taken August 2023 - VSA Ranking score of 21
Friable, fluffy texture, much lighter in colour, lacks organic matter
Minimal worm count <4, poor worm population numbers
Soil colour, medium- slightly dark brown in this section, notable of degree of organic matter, greyish hue, needs improvement to achieve rich dark colour reflecting high organic content
Moderate clods forms, some tacky and dense, with a slick feel. Odd sulphur smell was revealed in the right hand area of soil in the market garden
VSA Ranking score of 21 - This is where we began.
MINIMAL WORMS, ODD SULPHUR SMELL, DENSE, COMPACTION, FINE TEXTURE, LACKING AGGREGATES, LOW ORGANIC MATTER - MODERATE QUALITY SOILS.
A VSA score of 21 left us with a moderate level of soil quality. This translated exactly what we could see above ground too, a soil that has been struggling to reach it's optimal potential, a soil that was slowly being degraded even more due to a lack of care in multiple areas. The most notable issues that we evident was the lack of worm populations, soil colour and structure.
A severe lack of worms was alarming evidence in this VSA. This was a key factor that reflected the low level health of the soil at this beginning phase. A low count of worms <4 in this VSA, means that soil health was poor. Poor meaning a variety of factors including lack of moisture, possible toxic substances, compaction, PH above or below 6.5 and low organic matter for them to feed. Worms are an integral part of the soil food web system, cycling nutrients, oxygenating and aerating via tunneling, improving soil drainage, their castings provide vital nutrients and microbial populations that feed into the poop loop. The lack of worms in this soil meant there was serious remediation of soil needed, in particular increasing the organic matter levels in the soil.
The VSA revealed a moderately healthy soil with friable, fine texture, with both coarse firm clods and friable fine aggregates.
Soil porosity being moderate condition, with micropores between aggregates visible upon close examination and root penetration fairly easy with moderate-good consolidation and soil structure.
Soil colour was decent, medium-slightly dark brown colour representative of the level of organic matter within the soil. Some patches much lighter than others, including an amber/rusty hue and grey colouring also. Definite improvement to the darkness and depth of the soil colour via organic content being added and created in situe
Soil mottles were generally absent, no notable orange and grey mottling, even colouring throughout soil sample
Earthworm counts were sadly disappointing with <4 worms spotted in each of the 3 areas that we assessed. It was clear that the soil was not the most hospitable environment for the worms to be thriving and reproducing regularly. Major improvement to soil health and organic matter content needs to be made to encourage worm activity and their crucial benefits to soil health also, supporting a thriving soil ecosystem
Extremely minimal - no tillage pan is visible which is a positive sign, however reflects that this area has had minimal-no heavy machinery tilling and compressing the soil. Foot traffic, compost bags/woodchip, bricks, wheel barrows and lighter landscaping tools the only means of compaction leaving no tillage pan visible. Only some areas shows slight compaction and dense wet soils.
Clod development, moderate clods were identified,
Degree of soil erosion is minimal, however, the top layer of exposed soils is being eroded by elements and left dry, which will eventuate into severly degraded, dusty and eroded soils
CAVEAT: In hindsight, I wish I had recorded more data and carried out more testing to determine more of the foundation of soil health at the beginning. What I would have done differently, and what I will do going into the future will be having a chemical soil analysis done, as well as microbial, soil food web analysis. This will provide a strong and comprehensive level of data and knowledge needed to derive the best understanding of soil health as possible. I have carried out the latter tests at the end of this year, which we will explore below.
What this means in terms of nutrient health
From what we can analyse from the initial VSA and soil observations above
This proves the importance of inital soil chemical testing on any site. It is crucial to determine what nutrients are lacking, what this means in terms of soil health via the soil food web and what you need to add to improve nutrient levels, rather than guessing and in turn risking throwing things severely out of balance. It means potentially throwing money and resources at the soil in an attempt to improve nutrient levels and soil health, without acutally understanding the specifics behind what's there and then what's needed to fine tune and optimize nutrient levels and soil health. Blinding applying nutrient amendments, including organic inputs whether these are naturally occurring such as compost, vermicasts, blood & bone, lime etc or BioGro organic compliant fertilisers. These all pose the ability to drastically impact the balance of nutrition in the soil and actually causing more damage and worsening soil health and nutrient availability than was actually present in the first place.
Soil nutrients and soil health work in tandem. Plants require a large spectrum of minerals and nutrients in order to grow and survive. They are a crucial element of soil and many soils can be and are deficient in many of these minerals and nutrients. So it is important that we work to correct these deficiencies to contribute to overall plant health. This is where a soil nutrient panel and chemical test comes in, it saves us from all the guess work.
However, whether a soil is nutritionally balanced or lacking, a plant cannot access any of these nutrients without microbial activity, the most vital factor and bridge between soil nutrients and bioavailability for plant uptake. The poop loop, which is a result of the soil food web is the crown jewel of soil health, without sufficient populations of soil microbes ie bacteria, along with beneficial (mycorrhizal) fungi, worms, protoza, nematodes, protozoa and arthropods (+ more, see diagram below) , plants can't access these nutrients in the soil. It is the poop loop, the microbial bridge that allows plants to access these bioavailable nutrients, via fungi and bacteria organic matter decomposition (metabolic and enzymatic processes), nitrogen fixation and Phosphorus, Potassium and Iron mobilization as one small example of their capabilities.
Sourced: Academic Paper on The Function of Root Exudates in the Root Colonization by Beneficial Soil Rhizobacteria https://www.mdpi.com/2079-7737/13/2/95
INITIAL SOIL PREP:
3/10/23 *First steps carried out was to remove perennial weeds and aerate the soil with the least amount disturbance. This was done by broad forking the entire market garden site from left to right, top to bottom. Broad forking was used loosen deep rooted perennial weeds: as well as aerating and loosening any compacted patches of soil. Starting in one corner, we worked our way along from north to south broad forking. With another awesome student helping, we met in the middle. We were very attentive not to stand back on where we had just forked the ground so we were not compacting the soil thereafter.
The first amendment of organic matter was adding medium texture woodchip which was sourced from trees onsite at WITT. Layers of wood chip were added to establish pathways around the growing beds. These would be to walk on, to not disturb the beds and create compaction within the growing zones. Wood chip will provide cover and protection for the soil, as well as food and host substrate for mycorrhizal fungi networks to establish. Woodchip mulch will be excellent for moisture and water retention and will eventually break down over the season adding a layer of organic matter to the top soil. Worms and fungi also thrive in this moist organic matter rich environment and will encourage their activity and breeding cycles within the soil also.
4/10/23 The next day the rest of the woodchip was applied to fill up all paths. Once completed, management of the growing beds started with adding in nutrient amendments to boost the nutrient levels in the soil. All naturally based, no synthetics were used in compliance with organic standards used in Organic farm NZ. Two of the 4 products applied were certified organic. 1. Tui Chicken & Sheep pellets (non organic) 2. Tui Blood & Bone (non organic) 3. Cert Organic Yates Potash 4. Cert Organic Yates Garden Lime. Ideally all of these amendments would have been certified organic, however I was using what I had access too with the WITT garden supplies, moving forward I will be adhering to 100% compliance by only using certified organic amendments when needed. More discussed further down the report.
It was thought that the combination of these amendments would provide a wide array of essential nutrients (NPK) as well as micronutrients and mineral content to boost initial growth of plants whilst they establish. The hope is to not rely on these amendments as the quality and health of the soil improves. Instead, between the fungi, microorganisms, worms, plant roots and their exudates and organic matter from fallen plants and added compost/mulches will feed each other to create a closed loop reciprocal nutrient system where everything supports eachother, known as nutrient cycling or the 'poop loop'. This will take some time to build, so plant performance will be monitored to adapt nutrient application while the soil health is still building.
A fresh load of 2 cubic metres of compost was delivered and added to the garden beds after all amendments were evenly distributed. This compost was sourced from return 2 earth "Return 2 Earth's All Natural Composted Soil Conditioner is produced from blends of recycled greenwaste, woodchip, stable, goat and chicken manures and an added humate". https://return2earth.co.nz/index.php?route=product/category&path=71 Not a certified organic compost, however this is what we had access to logistically and financially. The compost appearance is a beautiful dark, rich colour and fine, fluffy texture. It appeared to be of good quality, with a full heavy metal analysis was carried out by the company, which passed all safe ranges of metal levels.
Overall 5-8cm thick layer of compost was added to the initial bare soil beds. This created a blanket and well established layer of organic matter that will protect the soil below and provide a plethora of nutrients for plants to access.
Seedlings were grown and seeds sown, planting began 19th October 2023
**In hindsight, there is a lot I would have changed about this initial soil preparation which will be discussed later in this report below.
1.Broad forking and handweeding perennial and annual weeds
2. Almost there!
3. Measuring out paths and beds
4. Laying woodchip on paths
5. Adding organic amendments to soil under beds
6. Adding thick layer of fresh compost on top
7. Compost spread out and beds formed
8. Let the planting begin!
This was the foundation and driving force for the market garden system in terms of supporting soil health amongst a variety of other factors. Diversity in plant species means diversity in root exudates being fed into the soil via plant roots. The soil food web relies on a rich and diverse range of root exudates which feed various microorganisms such as bacteria and fungi within the soil. Diverse plants, diverse root exudates means diverse species of bacteria and fungi, resulting in an overall robust ecosystem above and below soil, excellerating soil and plant health. A diverse range of soil microbiota creates a resilient and robust soil system allow plants to access ample bioavailable nutrition needed for growth and protection against disease. Diverse bacteria and fungi, mean there will be a ripple effect in the diversity of nematodes and protozoa, impacting the entirety of the soil food web and poop loop. Nutrients are cycled efficiently and both plant and soil life support the protection of each other and therefore their ability to thrive.
The plan is to include as many species via polycropping as possible that space and light allows to ensure the above systems develop within the soil, increasing overall soil health.
As discussed above, the main aim in supporting soil health is a microbial first approach and this is carried out by ensuring a rich diversity in different plant species and their root exudates. Instead of successively planting the same crops over and over in each bed, all crops will be rotated whether that be line by line during the growing season, but certainly completely rotated during the change of seasons, ensuring each bed gets a drastic change in plant species and therefore the soil in each bed receiving a plethora of different root exudates to encourage vast diversity in microorganisms, overall enhancing soil health.
Is another fancy term for polycropping, extensively used in pasture and market gardening systems to bolster soil health, I too will be using these cover cropping methods of diverse species to enhance and support soil health during the cooler seasons. Cover cropping invites a rich variety of root exudates and also allows the development of organic matter in the top soil when crimped or chopped and dropped on top of soil. This organic matter then supports worm activity, amongst the full spectrum of soil microbiology, with one of their main functions being decomposition and nutrient cycling. Feeding the poop loop, enhancing the soil health.
Woodchipped paths have been layed to avoid stepping on soils in beds to minimise compaction and disturbance to the beds. Broad forking was used at the beginning and in hindsight potentially regretfully used and will not be used in the future to mimise disturbance to fungal networks and the entirety of the soil food web. Since this initial learning curve, minimal tool use has been carried out to ensure the protection of the structure and life within the soil. Gentle hand tools for planting, along with a long stick to create divots for planting seeds have since been the only forms of disturbance to ensure soil health is protected.
In adherance to organic compliance via OFNZ, zero chemical pesticides, fertilisers and any sprays have been used. This has minimised and protected soil health in terms of not being extremely detrimental to soil life by using these deleterious chemicals. Organic based fertilisers and intergrative management systems have been employed to ensure that there is no damaging substances used that will harm the soil food web and causing catatrophic changes to soil health and structure. This will always be strictly adhered to to ensure optimal soil health and protection.
Plant matter has been left behind when plants have been removed, leafs, flowers and stems dropped and left to be decomposed via the soil food web system and worms, adding dead and decaying plant matter for these soil health organisms to feed on and proliferate. Adding to organic matter levels and enhancing soil structure. Leaf litter from the alder trees during autumn will add a rich layer of leaf mould to the beds, increasing microbial and worm populations and supporting overall soil health. Woodchip has been layed on top of pathways to ensure moisture retention and protection of beds, prevent soil degradation and supporting fungal and worm activity. Covering the soil with plant residues is a key method that is being used to support and enhance soil health.
Compost (along with organic amendments) was added at the beginning to increase organic matter availability for the soil food web system, encouraging microorganism activity as well as increase worm populations that were lacking at the beginning. Compost comes rich with its own microbiology and will add a diversity in species to the exsisting soil food web, enhancing each other ecosystems and supporting soil health. Compost is adored by worms for it's high level of organic matter and microbiology. The compost added also acts as its own mulch, blanketing existing soil with rich materials that will slowly incoporate into the soil and enhance it's overall organic matter levels and soil food web systems. *Next time I would ensure to get a chemical analysis done to ensure adding compost is the right choice for my soil and it's health.
Soil testing has been carried out in multiple pathways to monitor and analyse plant and soil health. Regular testing via VSA has been critical in tracking soil health and gathering data on what is happening in the soil to ensure soil health practices are working and what could be changed. This has been backed up by popsicle testing to asess fungal and bacterial activity, along with microscopic soil food web analysis for gathering professional and quantifiable data, along with a chemical soil analysis to be conducted. These regular tests will be carried out on a season and yearly basis to ensure soil health is being well cared for and improved. It allows any nuances and problems to be picked up and addressed, ensuring top quality soil health.
https://herbi.nz/how-to-improve-the-fungi-bacteria-ratio-in-soil
https://botanicgarden.wales/2022/09/growing-with-mycorrhizal-fungi/#:~:text=Provide%20living%20roots,are%20maintained%20in%20the%20soil.
Very moist under the mulch, fungal hyphae present, dense soils with good aggregate formation
Mostly dry and friable texture in growing beds, not enough moisture or glomalin in soil from fungal activiy to make moist and fell formed aggregates
Again, better soil texture under mulched areas, alot moister and with fluffy aggregates
Nice dark colour, good layer of organic matter, with fine roots and hyphae growth. Good moisture retention
Sampled in growing bed again, alot drier, seen in cracking and fine texture of soil
On path way, good worm activity, aerating and creating holes throughout large clods, helping to break down compacted areas.
Results from the second VSA carried out in March 2024, after main growing season were interesting. I dug 5 20cm cubes holes in various spots in the market garden site to carry out the VSA's, each of them revealed similar results, without drastic variation in visual score. The main variability between the holes was soil structure, colour and earthworm count.
soil under pathways presented itself with more moisture, more aggregate formation and held together better during the drop test. It often had a darker colour, with a few mottles seen. It was clear to see fungal and work activity, with hyphae present, especially in decomposed materials found in the wood chip from paths, that is being broken down. There were also visible worm tunnels within soil clods of these pathed areas. Improving aeration and soil structure. There were some areas that felt very dense and slick, possibly resembling the presence of clay. The darker colour indicated a good level of organic matter intertwined within the soil particles, with the works helping to cycle more organic matter from the topsoil into sub soil layers. Overall, dispite being a little boggy and sticky in some areas in path ways (a little compaction) the soil structure of the mulched pathways was sound, with a decent level of aggregate formation, fungal presence and earth worm count exceeding the previous <4, which is a very positive sign and indicator of soil health improving in these areas.
The soil dug for VSA's in the cropping beds did vary alot in comparison to the soil of the path ways. This suspectedly is due to the large layer of compost that was added to these beds at the beginning of the season. There was still ample presence of fungal activity, with hyphae woven throughout the topsoil, along with patches of earthworks present, ranging from 11 - 45 worms, the latter being found in bed 5, left side near tomatoe plants, a large population of worms were found in the small area. This overall was fantastic feedback that soil health had been improving. Despite the fungal presence and worm counts, soil structure was not as strong compared to the path ways. Overall texture was a lot finer, withi minimal aggregates forming, and not even forming a cube of soil when digging the hole for the vsa and drop test. The soil lacked that 'glomulin' or glues, as well as moisture to hold the soil structure together and form defineable aggregrates and large clods.
This is likely due to the large amount of compost used, it had not yet incorporated with soil particles, leaving the compost to become dry and loose. It lacked moisture retention, especially as I was retrieving this soil in areas left bare and exposed to sun during the summer, after harvesting of crops. Overall, it lacked that moist, gluey and robust aggregrate structure of a soil at optimal health.
It was clear that in both sections of the site under paths and beds, that yes there had been an improvement of soil health, most significantly in worm count, however there was still a long path ahead to achieve a high level of soil health. Next steps were to replant for autmun/winter and get more diversity back into the soil, along with living roots to support the soil food web system and nutrient cycling.
VSA ranking score climbed from 21 to 25 over a 202 day period from when the last VSA was carried out. This was an encouraging result, with visible improvements, some minor, but resulting in a continued score of Moderate Soil quality. Still a lot of improvements need to happen and this will be a long journey to reach optimal soil health.
Next VSA will be carried out in the last week of June below.
Fungal fruiting bodies, part of the fungal cycle
Another species of fungi present
Nitrogen fixing nodules on red clover root system, showing presence of N fixing bacteria
Deep root growth and presence of fungal hyphae systems
More nitrogen nodules on juvenile pea shoot, N fixing bacteria presences is highly evident
Good, deep root penetration on bush beans
Worm presence, navigating via worm holes, improving aeration, good clod development
high worm presence in correlation of woodchip, organic matter
Dark humus, organic matter level forming on top soil, rich dark and fluffy texture with fungal hyphae visible
Fungal hyphae presence is prolific, often in tandem with roots
Cluster of worms in bed (compost) by tomatoes
Large earthworm and fungi present in pathway near where cucumbers were planted and legumes are about to grow.
POPSICLE STICK TEST - Fungal icecream party?
A fungal and microbial test was carried out by placing a popsicle stick in the ground back on November 11th 2023. The stick was then retrieved 5 months later on the 11th April 2024. The images below depict the astounding fungal growth on the soil and on the popsicle stick itself, along with the bottom end of the stick, coated in moist soil. The end of the popsicle stick crumbled when touched, indicating it's status of being broken down and decomposed, indicating strong microbial activity in the soil to break down the wooden fibers (cellulose) within the popsicle stick.
This was a really encouraging result and another piece of a data and evidence that suggests and backs up that there is both microbial and fungal activity in the soil that are actively working together in the poop loop of microorganisms to decompose organic matter within the soil. This is further backed up by Dr Carolines evidence in microscopic food web analysis below.
Below is Carolines full analysis and panel of species of soil food web microorganisms present in my soil samples.
In Carolines report, it is clear that there is ample presence of bacteria within my soil, with a level of almost 4000 μg/g (Micrograms per gram). This was backed up by the visibility of bacteria when we were with Caroline in person, we could spot vast populations of bacteria cells in amongst soil particles which were often very dense, which crammed in a lot of these bacteria, but they seemed to be thriving in that enviroment (see in videos belows) Bacteria are vital to plant health, unlocking nutrition from soil particles via enzymatic breakdown, playing an important role in carbon cycle, nitrogen fixation and a host of other activites that bolster soil health and therefore plant health.
Actinobacteria was present, which was such an exciting result. Actinobacteria are spore-forming aerobic bacteria that play a fascinating and crucial role in cycling organic matter, breaking down complex polymers in dead plant, fungal and animal tissue, inhibit growth multiple plant pathogens in the rhizosphere, stabilising organic matter levels, neutralise polluted soils and contribute to plant health via extracellular enzymes that assist in crop productions. A.K.A they're the bees knees. It's fantastic to see their presence in my soils. Caroline mentions that they will also support brassica growth. Picture of Actinomycete below.
It was very fortunate and reassuring that there was no/minimal signs of anaerobic activity and no disease forming organisms spotted in the soil samples. This means less detriment to the soil food web and beneficial microrganisms as a whole, as well as drastically minimising potential negative impact on plant health from the lack of disease forming organsisms.
During our in person analysis, we spotted multiple strands of fungal hyphae, these was very encouraging and great to see these crucial organisms present in the soil. Caroline later found to be 3 -5 difference species, an important indicator of soil health, with the beginnings of diversity in fungal presence. Fungi play an integral role in decomposition of organic matter, expanding a plants root system via hyphae which means more access to water and nutrients as well as delivering bio-available nutrient to plants in a symbiotic relationship amongst a host of other remarkable functions in soil health. It's reassuring to know that at least there is a presence of fungal activity in the soil.
Caroline also found that there was a few testate amoeba present, another indicator of soil health. Testa amoeba are a group of shelled protozoa and are key predators of microbes in the soil food web system, because of this they have impact on carbon and nutrient cycling via modifying the compositions microbial communities in soil. They are often found in freshwater and soils, such as peatlands and wetlands, being an important biomarker for water and soil quality as a whole. Having them present in the soil indicates there is good microbial presence for them to consumer also, further proving that there is a high level of soil microbes such as bacteria present.
Whilst the above findings are relatively indicative of positive soil health, and there is clear evidence of the presence of these various microorganisms and their positive impact on soil, there is still a lot to improve on in terms of soil food web health. F:B (Fungal:bacteria ratio is 0:11, with bacteria outweighing fungal presence. This is likely due to fungal networks being wiped out by broadforking and tilling of the area, bacteria have since then dominated. Other than testate amoeba, no other protozoa are present, nor nematodes, all playing a critical role in the overall sybiosis and regulation of soil health within the soil foodweb.
It is clear from these results, that there is positive happenings in the soil, but a lot that needs to be done to support further proliferation of fungal species, protozoa, nemotodes and continued support of bacteria. Caroline has suggested the need to build fungal biomass and improve protozoa and nematode populations.
Due to it being the first year of imput and change to support soil health, I am pretty happy to be notified of the visible positive biomarkers in soil health with a range of different microrganisms present in supporting the soil and therefore plant health. The next steps on how to keep improving soil health will be discussed below.
Resources:
http://www.soilhealth.com/soil-health/organisms/fungi-bact/#2 https://soil.evs.buffalo.edu/index.php/Testate_amoebae#:~:text=Due%20to%20their%20variability%20from,as%20a%20whole%20%5B6%5D. https://pubmed.ncbi.nlm.nih.gov/24529779/
https://www.iucn-uk-peatlandprogramme.org/species-showcase-testate-amoebae-0#:~:text=They%20are%20key%20predators%20and,composition%20of%20the%20microbial%20community.
https://www.cropnutrition.com/resource-library/the-role-of-soil-bacteria-in-crop-nutrition/
https://pubmed.ncbi.nlm.nih.gov/28923606/#:~:text=They%20play%20major%20roles%20in,are%20conductive%20to%20crop%20production.
https://www.rhs.org.uk/biodiversity/mycorrhizal-fungi
https://www.mdpi.com/2079-7737/13/2/95
Unfortunately a 'kill circle' from a history of spraying on site.
Long strand of fungal hypahe is amongst soil structures
Fungal spores! (The large bobbled structure and oval)
Testate amoeba (circular structure)
Very large and dense particle structure with organic matter and crystaline mineral components in the soil
another healthy strand of fungi
**Unfortunately, I was squeezed for time to get a chemical soil analysis done in time for the final report. However this is something I will definitely do next season via Eurofins lab, as well as in the future beginning an any new site.**
No upgrade from previous VSA 2, about the same state. A little less worm count at 8 worms. This leaves the VSA still at 25, resulting in the same moderate soil health level. Wasn't quite what I had hoped for, but at least there has defintley been some improvement in comparison to the very first VSA completed.
There's still a long way to go in regards to soil health, as there has been a lot of degradation to the soil that needed to be remedied, but it is very reassuring to see these positive signs listed here and in this final evaluation to see that our methods are beginning to work and we are seeing positive improvements towards soil health.
Initial broad forking of the entire market garden site
Extensive weeding of the area post broad forking
Application of blood & bone, lime, potash, chicken & sheep pellets as organic nutrient amendments
Liquid feeding with organic seasweed and nitrosol
Mulching paths with woodchip
Application of compost to all beds
Intensive planting, polycultures
Missing succession sowings
Leaving patches of bed soil bare
Leaving crops to go to seed
Carrying out intermitted VSA's
Avoiding stepping on beds
Microscopic soil analysis
Popsicle testing
Allowing plant residues to be left on the soil and leaf mold during autumn/winter
Get a comprehensive soil analysis done - chemical and microbial to determine baseline of nutrient levels and overall soil health.
Review soil health and recommendations from professional agronomist.
Assess if compost or amendments are needed. Purchase and apply only what is required.
Chopping and dropping onto beds where ever possible
Hand weeding, using hand tools to retrieve deep rooted weeds. Avoid broadforking or raking
Continue with mulches paths, assessing different material options such as pea straw, ramial woodchip
Focus on foliar feeding, microbial and bioavailable nutrition for plants and soil microorganisms
Inoculating all seeds and seedlings put into the soil with micorrhizal fungi
Having a robust planting calendar, to ensure swift succession sowings and minimising bare soil
Continuing with polycropping planting methods, diversifying and moderating species that work well together
Green manure/cover cropping, incorporating more diverse cover crops over slower cold seasons
Implementing a sound watering system via irigation or hand watering time table
Introduction of worm castings and 'cow pat pit' biodynamic microbial amendments
Tui Blood and Bone (non organic)
Tui Chicken and sheep pellets (non organic)
Yates Natural Garden Lime (certified organic)
Yates Potash (certified organic)
Tui organic liquid seaweed (certified organic)
Nitrosol Tomato liquid feed (non organic)
Return 2 Earth Compost (non organic)
Here are the nutrient amendments I used this year to help provide a full spectrum nutritional boost organically. These were added at the beginning on the year back in October, underneath the fresh compost put on beds. Liquid soil drenches of the liquid seaweed and nitrosol were used monthly over summer.
What is tricky with nutrient management, is that it's hard to determine the quaintifiable nutrient levels without a chemical soil test, which unfortunately I ran out of time to have completed before this final report. A chemical soil test helps to determine what nutrient levels there are in the soil and then you can cater your specifici amendments if needed to optimise and balance nutrient levels.
What we know of Taranaki and New Plymouth soils is that are mineral rich due to volcanic ash and its important that we cultivate microbial activity to unlock these nutrients for plants.
For what I observed over the year, growth of crops was exponential and there we no signs of stunted growth or nutrient deficiency such as yellow leaves etc. This is likely to be from the additions of the amendments above and prexisting nutrient levels, as well as soil foodweb microorganisms making nutrient bioavailable for plants
In the coming seasons, I will begin first with a chemical soil analysis to get insight and data on nutrient levels and focus will be on correcting specific deficiences and enhance microbial activity and optimising fungal networks, worm populations for nutrient cycling.
Currently organic compliance in terms of supporting and restoring soil has been adhered to with the use of diverse polycropping systems and the regulations met and needing to be worked on below:
Soil and Fertility 3.1
"Sustain and enhance the fertility and life-supporting ability of the soil" Emphasis on soil organic matter, soil flora and fauna and achieving cycles and flows of nutrients.
Soil testing
Regular soil testing has been carried out via VSA soil assessments taken at the beginning of soil rejuvenation, getting the foundation of soil health before any amendments were made, see results here: Plans for regular VSA will be put in place to coincide which each report to keep an eye visually on soil health. However soil chemical testing and analysis is required within 3 years of applying for organic certification so this will need to be achieved to gain certification via a ISO 17025 accredited laboratory. Eurofins lab in NZ provides comprehensive soil testing and scientific analysis required for organic certification standards: hill-labs.co.nz/testing-services/soil-testing/organic-farming/
I plan to send off samples for heavy metal testing to Soil Safe Aotearoa Soilsafe Aotearoa | Kia mōhio ki o oneone. (auckland.ac.nz)
Organic matter
Organic matter has been assessed and will be monitored by VSA and will need to be chemically assessed via soil laboratory tests in orders to meet biogro (ofnz) standards. Soil samples would need to be sent off for testing, which I can include in my next steps to achieve for certification.
Soil Health
I had planned to begin the season back in august/september with a cover crop, however by the time compost arrived and beds were prepped, it was too close to the growing season to complete this. Over winter and early spring season, cover crops will be planned to be applied. In the interim, peas and beans will be incorporated into the crop growing plan to provide nitrogen fixing species into the system.
Fresh soil composts will be applied at the beginning of the system set up in formation of each bed. A thick layer of 6-7cm will be applied to each bed, creating a blanket of foundational organic matter in the system. (return 2 earth compost was used, which is not certified organic, so other certified sources will need to be used in the future for compliance and certification).
Composts and Vermicasts
Return 2 Earth compost used - not BioGro approved, will need to locate and research approved compost sources for future used or look into setting up an onsite approved composting system, as this must be heated, aerated , mixed and matured sufficiently. Vermicasts have not yet been incorporated into the system, but will definitely be part of the plan in the future.
Leaching
Leaching losses will be mitigated by minimal applied composts and organic fertiliser inputs to ensure proper nutrient cycling and minimal losses to leaching. Emphasis will be placed on little to no input and to created a closed looped self - feeding system via optimal soil health via root exudates and their role in feeding and nurturing the soil microbiome and food web. Soil will be kept covered as much as possible with live plant roots to help with nutrient cycling and absorption to prevent leaching also.
Nitrogen Rates
As above, nitrogen rates will be kept very minimal with little to no use of organic fertilisers added and will not exceed 170kg limit per hectare. A one off input regime at the start of the season before compost was laid was carried out including:
- Blood and Bone (Non certified, can easily be swapped for biogro cert)
- Potash (Biogro cert)
- Lime (Biogro cert)
- Chicken and Sheep pellets (Non certified, can easily be swapped for biogro cert)
Compost was then laid on top. Official nitrogen rates will be confirmed with a chemical soil analysis.
Raw Manures
Were not applied and not planning to be applied and will be composted if planned to use in future.
Sewage by-products
Will never be used.
Industrial by-products
Textile waste have not been used, neither of food waste so far. With no intention outside of compost and carboard to be used in the system as of this moment.
Mulches
Mixed mulch was used from onsite trees that were felled and chipped. Various species across the WITT grounds, native and introduced. Medium sized chip, bagged and transported from carpark to site. Unfortunately this source is not BioGro certified, however, this might be able to be signed off with evidence that no prohibited substances were applied directly to them and residue tests may be required. I will look into BioGro cert sources in the future and if I am unable to find them will look into getting this source form WITT approved. This woodchip mulch was used to line paths and provide a substrate for mycorrhizal fungi growth.
Seeds, seedling and vegetative propagative materials
A mix of certified organic seeds were used. I used seeds from companies I had on hand to experiment and get the garden established and to see what worked well. Koanga seeds (heritage) Setha's Seeds (Heritage) Eco seeds (cert organic) Kings seeds (cert organic range) were all compliant companies I will continue to source seed from for compliance in the future and replace any non cert organic companies I have used - and if I am unable to find certain varieties organic, I will discuss their possible used with OFNZ. I grew majority of my crops via direct seeding and seedling propagation. However I did source and use non certified organic seedlings also, which I will completely avoid moving forward, focus on my own successions with cert organic seeds and seedlings to meet requirements moving forward. I used Tui BioGro cert seed raising mix to ensure compliance.
Genetic Engineering
Will never be used.
Green Manure crops and crop residues
Green manure crops have not yet been used, but will be planned for and of great use during slower seasons in winter and to increase soil fertility in the first few years of production. Polycropping will be maintained to ensure coverage of soils. VSA's and soil testing bi-monthly and annually to assess nutrient and organic matter levels achieved in soils. Crop residues from falled crop matter and roots left in soil will be incorporated back into the soil and gentle raking and occasional broadforking to achieve a smooth and fluffy planting surface will be used. Emphasis on keeping roots and organic matter and crop residues in the soil will be maintained in each bed to increase and maximise organic matter levels.
Fertility and crop rotation plan
Crop rotation will be at the forefront of the crop plan to ensure different species are rotated throughout the system and different root exudates, root length, plant structure and nutrients are cycled throughout the system as a whole. Fertility and crop plan must be documented for at least the next two seasons. So far, I have planned out the crop plan for summer and will soon plan out the autumn and winter plan. Restorative phases via green manure crops will be incorporated over slower growing seasons to maintain overall fertility and enhanced. Polycropping will ensure a diverse range of crops are rotated and cycled throughout the system to rejuvenate and increase soil fertility over time also.
Soil Structure
Soil structure will be monitored via regular VSA's to assess compaction, worm populations, organic matter levels and more. Damage to soil structure and compaction has been actively mitigated. An initial broadforking of the entire market garden space was undertaken to increase aeration and to remove annual and perennial weeds. Careful consideration and placement was carried out to ensure we were not stepping on the areas we had broad forked. Paths were laid out with woodchip, these were to be the only areas in the garden that were allowed to be stood on. NO standing on beds at any time will be enforced to mitigate soil bed compaction and impact on soil structure. No heavy machinery has been used only broadforking and gentle raking on top to smooth out beds. Adding compost and the intention of green manure cropping will offset any damage done to soil structure and polycropping to improve soil structure will be prioritised at all times.
Biological Activators
Have not yet used, but will definitely look into their use for the future.
Permitted Fertilisers
Refer Appendix B.
Blood and Bone (Non certified, can easily be swapped for biogro cert)
- Potash (Biogro cert)
- Lime (Biogro cert)
- Chicken and Sheep pellets (Non certified, can easily be swapped for biogro cert)
The only fertilisers used to far, along with Tui liquid seaweed (BioGro cert)
Restricted Fertilisers
Refer Appendix B.
Fertiliser Supply
Tui:
-Chicken and Sheep pellets (Non certified, can easily be swapped for biogro cert)
- liquid seaweed (BioGro cert)
- Blood and Bone (Non certified, can easily be swapped for biogro cert)
Yates:
- Potash (Biogro cert)
- Lime (Biogro cert)
Liquid fertilisers including vermicast liquids and compost teas
-Tui organic seaweed fertiliser has been used for topical and soil soaking so far. Used for overall plant health, microbial support and health.
- No used of vermicast or compost teas at this stage, will definitely be looked into in the future for use.
Sewage
Will never be used.
Miscellaneous Fertilisiers
Blood and Bone (Non certified, can easily be swapped for biogro cert)
- Potash (Biogro cert)
- Lime (Biogro cert)
- Chicken and Sheep pellets (Non certified, can easily be swapped for biogro cert)
The only fertilisers used to far, along with Tui liquid seaweed (BioGro cert)
Thermal Sterilisation
Have not needed to use.
Burning vegetation
Have had no need to be used and no plan to use in future as of now.
Salinization
Soil testing will help to identify any salinization effects and to monitor water supply coming from the tap used for hose irrigation. We are a long way away from the ocean and high up, so there is minimal risk of salinization from seawater, storms and run off. It will be water supply monitoring and fertilisation inputs that need to be monitored the most.
After one whole year of drastically changing operations and inputs into the soil on site, I am happy to say there is definitely positive changes in soil health happening with small improvements in such a small amount of time.
It was clear from the very beginning that this would be a mountain to climb in terms of rejueventating the poorly cared for soils that I arrived to at the beginning of the course. They were degraded and in dire need of some TLC! With a moderate VSA score of 21, soil health seemed to be okay, but it was clear that on the surface, it was far from optimal being left bare and exposed with minimal living plant roots and organic matter in put for a long time.
The soil restoration methods carried out above, with a focus on polycultures and high density planting, adding organic matter, mulching and adherance with organic compliance with no harmful inputs or sprays used, has contributed to a positive change in soil health and the signs of health slowly returning to the soil. Later VSA tests found the score reaching 25, just on the cusp of a "good" soil health rating of 25+. Worm populations were slowly increasing, with better drainage, soil colour and layer of organic matter on topsoil were amoungst the variables that showed positive improvement. The visible signs of worms, fungal hyphae and fruiting bodies, healthy plants which showed minimal signs of disease and had strong growth even in the cooler seasons, were evidence that soil health is now on the upward incline with clear indication of health slowly returning to the soils.
That being said, there is still a long way to go with soil health on the site. There is only so much progress that can be made in a year and whilst it has been very encourage of the positive biofeedback from the soil, full soil restoration will be a long journey and one that will be ongoing with the life of the market garden site. It was evident in Carolines microscopic soil food web analysis that the food web itself is still lacking in all species, mainly that of nematodes which were non existent in the test, along with more species of protozoa, as well as fungi, amongst other microorganisms were needed to create a fully functional soil food web which synthesises nutrient availabilty for plants, along with a whole host of plant and soil supportive mechanisms that contribute to optimal soil health. The positives being that yes, there is the beginnings of the soil food web coming to life with a few fungal species, lots of bacterial activity, including actinobacteria, as well as testate amoeba (protozoa) and no disease forming organisms visible. With these positive signs we can at least gather that soil health is going in a positive direction, yet with a long way to go by increasing fungal biomass and encouraging more species development of nematodes and protoza. There is a need to balance the fungal to bacterial ration that is currently sitting at 0:11 (bacterial dominance).
Ways to improve this would be maintaining high density, polycropping planting systems, keeping a high level of living roots within the soil at all times via a well planned crop planting and succession sowing schedule, as fungi are dependent on plant derived lipids (exudates) for their survival and proliferation. Including fungal composts such as woodchip as a substrate (which we have done) and it has been clear that it has been innoculated and having a positive impact on soil health. Innoculating each seedling and seed with micorrhizal fungi before planting, and there fore innoculating the soil with these beneficial fungi. Minimal disturbance of soil, minimising harmful physical distrubance such as tilling, broadforking etc to avoid destroying fungal networks.
Another step moving forward, and to adhere to OFNZ organic compliance will be to include chemical soil analysis to retrieve information and critical data on organic matter levels, nutrient availability and how these nutrients are interacting in the soil and impacting the soil food web. These tests will help guide decisions moving forward on if there is need for more organic matter (ie compost) or not and if there is any specific nutrient deficiences to be fixes or any imbalances to be corrected. This is something I wish I had completed at the beginning, but it is something I will definitely do next season. https://biologix.co.nz/collections/consultant with a certified lab and agronomist to analyse data.
Moving forward, I will be continuing with the soil restoration methods listed above, with the adherance to organic compliance via certified imputs where needed and reducing imputs whenever possible. However with the current methods used this is all the needs change, along with chemical soil testing, as the polycropping and biodiversity first planting methods are currently ticking a lot of the requirements of organic certification with OFNZ. Including livng roots in the soil at all times with high diversity will continue to contribute to postitive changes in soil health via plants critical root exudates required for the soil food web to thrive. In addition, I will be including a new foliar feedling and inoculation regime with beneficial microbes, and micorrhizal fungi strains to ensure the plant is being sybiotically introduced to the soil with a plethora of microbial activity from the time it germinates, to the time it is planted in the soil. This is likely to have a profound impact on soil health and will be a new crucial method for improving soil health moving forward.
I look forward to seeing soil health continue to improve over the next few seasons, in compliance with organic standards, increasing soil health will be an important step towards profitiabiliy, organic certification and site resilience for the future. Following organic standards, soil improving methods listed above and introducing microbial and fungal imputs in the soil health regime will be another significant step towards optimising soil health and creating a site fit for a robust future of growing healthy, nutrient rich organic crops with strong biodveristy and ecosystem resilience.