Cover Crops
The wet weather hasn’t only held back our crops but also our cover crops which haven’t established and developed as well as they usually would. The lack of green growth does mean that following these covers there will be less stored nutrients for the following crop.
Benefits of Cover Crops (Even with Poor Establishment)
Poor green cover is still more beneficial than no cover, we are still utilising photosynthesis and therefore producing sugars to feed soil microbiology, creating organic matter to feed our wonderful livestock of worms, sequestering some of the nutrients that would have otherwise leached out in the wet and allowed some soil remediation to the structure in the form of roots to reduce the risk of soils slumping and degrading.
Managing Soil with Poor Cover Crop Establishment
Due to the lack of rooting and establishment though, it may be that we do need to consider each field for management and whether we can direct drill, strip till, cultivate, sub-soil or plough. Movement of the soil is not to be considered bad if its ‘thoughtful’ tillage, as little as possible and as much as necessary.
Understanding Soil Structure and Tillage
Soils need 50% pore space for the structure to hold 25% air and 25% water. Now tillage is key in managing this ratio if soil is too tight and those percentages are too low, but it is also key to know that over-tillage can make this worse as well.
Best Practices for Tillage
It all needs to be done in the right conditions, considered carefully to make sure we are doing the correct job to benefit long term. Do not rush in with machinery just to get jobs done early, be patient and go when the conditions allow. Be open to the plough if it’s needed.
Potential Drawbacks of High Nitrogen Cover Crops
Be aware though that integrating green covers if they consist of high nitrogen, can lead to degradation of current organic matter levels as the organic matter content in the soils can be used to balance the high nitrogen from the green cover for microbes to degrade the plant debris. This can be offset by spraying on humates and carbon food source to offset the organic matter burn-off but do be aware that if this is used as a regular practice, organic matter levels may decrease over time instead of increase even with cover crops in the rotation.
