Put some structure back into seedbeds


There is now time, in the run up to harvest, to contemplate those bits of soil husbandry that have been needing attention. Following on from a wet winter some land drains will have been running, hopefully, for the first time in a year or two? If not then the first port of call might be to look at ditch levels, are they sufficiently low enough so not to cover the outlets and, if so, then some remedial work with the digger needs to be planned after harvest.

There could be some fields in which the crop doesn’t look too good, maybe has a thin patch or two or, worse still, some completely bare areas. These could be caused deep down by poor drainage, or just by compaction preventing the surface water getting down into the subsoil. That compaction could also be causing poor root development and, in those areas where it has been dry this spring, that lack of top soil moisture could also now be showing up as a crop under stress. Good root depth is paramount in being able to keep a crop going in dry times as well as making sure the plant is able to draw up as much nutrient as possible, thus maximising yields, whereas poor penetration means that the crop is always going to struggle.

What’s the secret to checking things out? Well, in the first instance, it isn’t rocket science; it just needs a bit of manual graft with the spade. Digging a soil profile pit is ideal at this time of year, not too dry to make it hard work but with peak crop activity it enables a check to be made as to just how deep rooting this year’s crop is and a scrape against the wall of the soil pit with the trusty penknife can reveal a multitude of sins when it comes to compaction/rooting issues. These could be caused by a number of factors such as inappropriate traffic on waterlogged soils, soil types that are generally prone to slumping, a lack of organic matter in the soil, poor straw incorporation leading to pockets of rotting crop residues, poor earthworm populations, plough pans, etc.

Thinking further ahead and after harvest, for those looking to expand their knowledge of the farm - and what is going on down under - yet further, then a session of soil electrical conductivity testing might be the answer with regard to seeing the bigger picture. Soil EC testing can pinpoint top soil depth, compaction, soil moisture levels, soil type, pH levels and soil organic matter content to name but a few. A GPS-based, site specific soil conductivity analysis can be used to create soil texture maps that can be laid against combine generated yield maps. Here the correlation between yield potential and soil structure can be used to help decide what the limiting factors were to yield potential and to what can be done differently in the future to mitigate any issues that are preventing yield. Seed rates can also be calculated from this increased knowledge so as to even out the effects of poor seedbed preparation, seed/soil contact, and soil moisture levels have on germination to even up the LAI post-drilling.

Remember that although Precision Farming techniques can be used to improve returns, there is often no better option than to dig a hole and have a look for yourself, this can but only help to maximise your returns from every acre. When it comes to cultivations, too much depth is often not necessary and so don’t forget the old adage of ‘only a deep as necessary’.