August 2020 Update from Castleton Farm

Ross continues to make positive strides towards regenerative farming, focusing on his green manure mixes and cover crop establishment. This is the recent update from Castleton Farm from 14th August 2020.

Sown too soon

Although not his finest crop, the spring barley sown straight after a cover crop, causing a green bridge, has grown better than expected. Ross experimented with a number of fallow periods between his covers and his cash crops with one field having no space between desiccation and sowing. Ross hopes that maintaining a living root at all times will improve the biological activity in his soil, however, balancing this with the increased weed and pest burden is challenging.

Green manure desiccation

Desicated green manure crop at Castleton

Ross has several fields of green manures on his farm. Green manures differ from cover crops in that they are grown for whole seasons and not just for a short period between cash crops. Ross established two mixes, a purchased mix consisting of eight species and a homemade mix containing: phacelia, daikon tillage radish, berseem clover, spring vetch, black oats and also some spring beans broadcast onto the top.

Due to the cost of seed and establishment, Ross tries to leave his green manures as long as possible to ensure he gets the greatest benefit. However, desiccating the mixes prior to viable seeds being set is important to prevent the increase off a weed seed bank which will cause problems in future years. Alongside this, the debate surrounding glyphosate and whether it will be revoked has also made Ross turn to alternative desiccation methods. Ross has trialled a crimper-roller and also tried mulching fields. Reducing chemical use wherever possible is important for all of the Regenerative Ag farmers and this is one trial which is looking for viable alternatives.


The photo on the right shows the mulched crop on the left and the crimped crop on the right. The mulching has left much smaller trash on the surface compared to the crimper-roller which has flattened all the plants in the same direction. Sowing into the crimped trash may result in hair pinning around the drill, making the direction of sowing important for the next crop, although Ross is confident that his disc drill will be up to the task. Both desiccation methods appear to have been effective, with little regrowth with the exception of a flush of weeds. Additionally, the soil remains well covered due to the high quantity of biomass on the surface. (Photo below left shows a mulched green manure; photo on bottom right shows a crimped green manure crop.)

Mulched green manure crop
Crimped green manure crop

Pros and cons of a crimper…

A crimper-roller is a slatted, tractor mounted roller designed to flatten and cut cover crops. This cultural method of control is versatile and designed to reduce chemical requirements while promoting the rapid decomposition of cover crops and green manure crops. However, diverse species mixes can have a wide variety of plant architecture and growth stages making the effective termination challenging and the regrowth of grass species can be problematic. Although Ross used a crimper roller in late summer to reduce seed set, it can also be used on cover crops when it is frosty as brittle frozen plants can be damaged more, making the termination more successful. Furthermore, as Ross hired a machine, many of the plants in his green manure were not just crimped but cut right through the stem. This may be due to the weakness of the stems, the sharpness of the blades on the demo machine.

Broadcasting cover crops

Ross has also modified a sprayer in order to establish his cover crops into standing crops. Due to the colder climate Ross has found that sowing covers after harvest results in little biomass growth and he decided to trial establishing into covers last year. This method of establishment is not often used in England as there is not enough moisture for covers to germinate, however that is not a problem in South Aberdeenshire. Ross has broadcast a variety of seeds into his crops, with many emerging within a few days. Ross plans to chop his straw at harvest across the top of the covers, hoping that they will continue to grow through the chopped straw.

Seeds which have recently been broadcast into spring barley at Castleton
Germinated cover crops several days after broadcasting in spring barley crop at Castleton


The Regen Ag farmers have all been trying to diversify their rotations to improve soil health. At Castleton, Ross has been growing winter beans, however, areas of his beans have not grown well due to the very wet winter. Furthermore, Ross’ beans began to flower when they were very short which has resulted in many pods being close to the ground, a challenge for the combine driver.

Close up of the small root structure and the nodules present on a typical bean plant at Castleton
Bean pods located very close to the ground on a typical bean plant at Castleton. The beans began to flower when the plants were very short, resulting in this pod formation

Find out more about what the other Soil Regenerative Agriculture Farmers are up to.

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