Farm blog

June 2022

Recently quite a few people have asked me for further updates about what is happening on the farm. I have tried to write these over recent months, but they have just turned into a weather diary and I felt they didn’t actually convey much information, so the draft still sit on my iPad. They only really serve to backup the theory that farmers are never happy with the weather. Which is not true.

So I think I will try to explain a farmers fickle relationship with the weather and the climate.

It is simply impossible to farm without rain. Light will always come, sometimes more and sometimes less. But crops simply do not thrive without rainfall. For many people rain is seen as bad. Indeed the weather forecasters sometimes seem apologetic that it is going to rain. After all, we all feel better on a bright sunny morning. But what is a good rain? After a recent shower, during which I get drenched, I checked my automatic weather station and it was less than 2mm, which in a dry season such as this is of little use. A shower like this barely wets the surface and is evaporated back to the atmosphere within an hour or 2 as the sun returns, especially if there is a strong breeze.

A good rain is typically 10mm or more. Ideally followed by a overcast dull period. This means the rainfall can soak into the ground and become usable to the crop. The unwelcome rainfall for many of you over the jubilee weekend was in fact most welcome by all farmers. The total over the two nights was 23mm and a dull drizzly day helped to preserve the moisture in the soil.

The next most important ingredient for producing a crop is sunshine and plenty of it. I see the fields as solar panels. We aim to produce lots of green leaf so that the plant has as much photosynthetic area as possible. The leaf captures the light and the chemistry of the plant converts this solar energy into carbohydrates that we can harvest and sell. The quality of the crop is always better in seasons where the sunlight intensity is high. We do get dull years and the crop yield is always lower.

Temperature is another key factor. When the mercury rises above 22 or 23C a wheat plant will start to shutdown. The stomata on the leaf surface will close to prevent excessive moisture loss. This limits photosynthesis and makes the plant less effective. This becomes more acute when temperatures exceed 30C and is quite damaging to the crop. At 35C and above the plant just dies in front of your eyes.

I googled “what is a drought” and there were four types of drought. Most notable was an “agricultural drought”, which was when seed planted in the soil surface receives little or no rain and is unable to grow and access reserves of water held in the deeper layers of soil. This is what has happened this year. The autumn sown crops have developed extensive root systems over the mild winter and have had a plentiful supply of moisture to see them through the dry spring. Sadly the spring sown crops received little or no useful rainfall after planting and have not been able to tap into this water supply. Some spring sown crops have really struggled. I have always considered that the best thing that can ever possibly happen when you plant a crop is 5 or 6mm of rain that evening. When this does happen you get such a rapid and even germination of the seed.

Moving through the growing season regular rainfall is vital at all stages of the crops development. A good rain immediately after applying fertiliser is always welcome as it washed the nutrition into the soil and makes it available to the plant.

Excessive and persistent rainfall leads to water logging of soils. This restricts root development and the uptake of nutrients. The wet autumns of 2019 and 2020 lead to water logged soils. The crops came through those drenching winters with very restricted root systems that did not cope at all well with the droughts that followed in the spring of the following years.

So the ideal weather for the farmer is one of prefect and pleasant English summer days, with a useful drop of rain every now and again. Provided the rain comes then excessive amounts of sunshine are welcome. Wheat is a temperate plant suited to a temperate rather than a Mediterranean climate.

Does that explain anything? I hope so. A nice moderate weather pattern with the correct weather in the correct season please. Frost is good in the winter, sun is good all year as too is rainfall. Heat is great in august as that assists a speedy and dry harvest.

What is most unwelcome is unseasonal weather. Climate change seems to be driving this. Unseasonal weather can be frost in May, excessive monsoon like rainfall in the summer, drought in the spring and indeed the summer, flood in the winter, hailstorms in the summer and many other weather related issues. Sadly, with the ever increasing effects of climate change these are all becoming more frequent and seemingly more severe.

Without doubt, even in these times of huge uncertainty of input prices, output prices and supply chain security, climate change represents the biggest and most difficult challenge for agriculture.

John Jefferies