Friday, 2 January 2015
Interest In Cover Cropping
In the run up to Christmas I hosted almost 100 farmers on three different visits to look at the Cover Crop trials that we planted back in August and September. The seed was generously supplied by Kings and used in a trial to look at the benefits and costs of using cover crops in the farm rotation. Cover crops have only recently come to my attention through my Nuffield Farming Scholarship Trust award to look at increasing wheat yields n the UK. Although we have been using turnips and forage rape for years as a sheep feed through the winter period, there is so much more a cover crop can deliver other than feeding ewes or lambs through the winter. The cover crop idea has also sprung into life as they can count towards Ecological Focus Areas (EFA's) in the the new Common Agricultural Policy. In total we have planted 11 different mixes or single variety species to see what benefits or negative effects can be measured..
Paul Brown (above) from Kings, demonstrating the tap rooting ability of radishes to push down into the soil to break up compaction caused by farm machinery. The ability of all of the mixes to scavenge for nitrogen and phosphate that would otherwise be lost from the field is tremendous, and if your include vetches into the mix their ability to fix nitrogen form the atmosphere is staggering. The plot of straight vetch analysed at over 30% protein and was holding over 200Kg/Ha of nitrogen that will be available for the following crop! Species in the various mixes included, mustard, forage rye, vetch, radish, oat, berseem clover, phacelia, buckwheat and linseed. The mixes have been assessed by NIAB as part of our Kellogg's Origins Group, looking at ways in which we can farm in a more environmentally and financially sustainable way.
The crops certainly tick all of those boxes by: intercepting sunlight through the autumn and winter, turning it into carbon (plant matter) to improve soil organic matter levels (when decomposing); help remove compaction by aggressive rooting; locking up nutrients that would otherwise be washed through the soil into the environment; provide valuable late season pollen and nectar sources (bees using ours until November), provide a nutritious balanced diet for overwintering stock: stabilise and protect the soil surface from heavy rainfall events. It is almost all positive effects form these crops bar the creation of a lovely slug habitat. This will need watching and monitoring through the winter and into the drilling period to keep on top of the slippery problem!