Soil fertility refers to the ability of the soil to support plant life growth.
There are several practices that improve and maintain soil fertility. These practices include:
Mulching
Adding organic matter
Cover cropping
From top to bottom:
a) Benefits of mulching
b)living mulch
c)sheet mulching
d) spot mulching
e)green mulching
f)vertical mulching
Mulching is a practice which involves the application of materials such as dried grass and leaves, which are placed on the surface of the soil. Mulching:
Covers the soil,
provides nutrients and organic matter,
moderates temperature and climactic effects,
suppresses weeds,
retains water,
builds soil and
prevents erosion.
Mulch may be made of organic material such as hay, grass clippings, leaves and the like or inorganic material such as plastic.
Mulch should not touch the base of the plants.
There are several types of mulch:
Living Mulching: This term describes perennial herbaceous plants that are planted along with other crops (typically orchard crops) to cover the soil. In addition to the benefits provided by mulch, living mulches improve the soil by breaking it up with their roots, allowing greater water infiltration and retention and often provide bee forage and attract beneficial pests. They can also be cut or scythed, living mulches return nutrients to the soil.
Sheet Mulching: This refers to forming alternating layers of newspaper/cardboard, hay, organic matter, manures, liquid fertilizer and other biodegradable materials. It is a great way to build new soil.
Heavy Mulching: This refers to adding a thick layer of mulch sufficient to suppress weeds.
Spot Mulching: This refers to mulching only around a specific plant and not across a broad area.
Green Mulching: Also called "chop and drop" mulching refers to the practice of growing plants on the soil and then cutting them at the base and dropping them on the surface of the soil so that they are not touching the plants.
Vertical Mulching: This refers to cutting a channel into the soil and putting in mulch and then planting into it. This refers to digging holes in the soil around a stressed plant and filling it with mulch in order to assist the plant.
Complete this practical activity that demonstrates how mulching can reduce soil erosion.
Organic matter refers to biological material in the process of being decomposed. Decomposition is the physical and chemical breakdown of complex organic molecules into simpler organic and inorganic compounds.
It:
helps to hold the particles of soil together.
is a source of plant nutrients.
improves soil porosity.
improves soil tilth.
improves the rate of water percolation.
Sources of organic matter include:
groundwater.
wastes of living plants and animals.
dead plants and animals.
compost.
manures.
Soils rich in organic matter are very suitable for agricultural activities.
However, adding organic matter increases soil acidity. Care must therefore be taken to ensure that the soil does not become too acidic. Limestone can be used to reduce acidity.
Complete this activity on preparing compost.
This refers to the planting of vegetation on the surface of the soil to protect it from the impact of the rain and bind the soil together with their roots. When these crops die or drop dead material to the soil, they can increase soil organic matter. They also give the same benefits as mulch. Leguminous cover crops can also be used to add nitrogen to the soil.
Watch the following video to learn more about crop rotation.
Complete the following practical activity on crop rotation.
Two other means of maintaining soil fertility is to:
Channel surface Runoff into Gullies
Planting trees and grass barriers that slow down the rate of run-off
Answer the following questions in your portfolio. You can also fill out the same quiz in the form below if you have the data.
What is Mulching?
List three benefits of mulching.
What are the two types of mulch? Give one example of each type.
Define each of the following: living mulch ,sheet mulching, spot mulching and vertical mulching.
What is organic matter?
List five benefits of adding organic matter to the soil.
What is one disadvantage of adding too much organic matter to the soil?
List three sources of organic matter.
What is cover-cropping?
How is it different from mulching?
List two benefits of cover cropping?
What is crop rotation?
Why is it important?
Which four types of crops are usually planted in crop rotation?
What order are these crops usually planted in?
How can surface run-off be channelled into gullies?
How would this maintain soil fertility?
In what way would planting trees and grass between barriers improve and maintain soil fertility?
Let's do a review of the lesson...
Post under the appropriate topic in the Forums what you learnt, what you would like to learn and what you do not understand.
References:
Grade 9 SCCP Manual
Amy, (May 8 2020), Mulching in the Permaculture Garden. Tenth Acre Farms. <https://www.tenthacrefarm.com/mulching-in-the-permaculture-garden/ >
Aternative to sheet mulching. Permies.com Forum <https://permies.com/t/56931/Aternative-sheet-mulching >
Sheet mulching — aka lasagna composting — builds soil, saves time. Oregon State University extension Services. <https://extension.oregonstate.edu/gardening/techniques/sheet-mulching-aka-lasagna-composting-builds-soil-saves-time >
Heavy Mulching. Erosion Control Technique <https://www.catchmentsandcreeks.com.au/docs/MH-1.pdf >
Image of Benefits of Mulching <https://www.google.com/url?sa=i&url=https%3A%2F%2Fplantingup.co.uk%2Finfo%2Fwhy-mulch%2F&psig=AOvVaw2TAhCSWS5mAjeRn9ra4inj&ust=1590346272062000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCIj5iOjTyukCFQAAAAAdAAAAABAD>
Image of Sheet Mulching: <https://tobyhemenway.com/resources/how-to-the-ultimate-bomb-proof-sheet-mulch/ >
Image of Spot Mulching: <https://aimmedianetwork.com/wp-content/uploads/sites/15/2015/08/web1_Mulch-Circles.jpg>
Organic matter <https://en.wikipedia.org/wiki/Organic_matter >
Advantages of Cover Cropping Images <https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.alltech.com%2Fblog%2Fincorporate-cover-crops-plant-and-soil-health&psig=AOvVaw12FrxdP3VuaUVuO1or5khb&ust=1590509798695000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOjA6oi1z-kCFQAAAAAdAAAAABAO>