Thursday 28 July 2011

Adding a bit of spice to the soil

What’s green, grows around 5ft in 60 days, recycles nitrogen, potassium, phosphate and organic matter to the soil, attacks herbicide-resistant weeds and kills pests?  Mustard – that’s what.

But this isn’t any type of mustard; new varieties, bred in the US, are catching on around the world as a great way of reducing nutrient loss in the autumn and reducing herbicide and pesticide use in following crops.  They not only add considerable bulk and recycle nutrients to the soil which would otherwise potentially be lost via runoff and leaching, but they can also attack weeds like blackgrass, as well as killing pests such as nematodes and slug eggs.

One Northamptonshire firm, Norman and Spicer (Agriculture) Ltd, a member of the Crest Group is nationally marketing a number of different blends of two specific mustard varieties – Pacific Gold and Idagold – at different sectors, aimed at attacking weeds in the cereals sector and nematodes, eel worm and other pests and diseases in the potato, root and vegetable sectors.

According to agronomist Mark Spicer, “Mustard blends are sown or broadcast immediately post-harvest and then left for 60 days.  At the end of this period, the crop is flailed to break it up and then incorporated with a plough or set of discs.  The compounds within the plants fumigate the soil, killing weeds and other pests, and the soil is ready for drilling or seedbed preparation after another 15 days.

“The treatment also adds significant nutrient and organic matter benefits to the soil, potentially giving the equivalent of up to 80kg N/ha and an increase of up to +2% SOM.  This, and the savings in subsequent pesticide applications, means that the use of these mustards can really stack up.  Of course, it’s not an appropriate treatment for every soil, crop or situation, but as an important tool in the ‘agricultural sustainability toolbox’ it has a great deal of potential to offer.”