When I was farming in Zimbabwe, moisture retention, deficit irrigation, minimum tillage, trash incorporation, controlled traffic, were all tools we used to boost the water holding capacity of our soils, along with a very active soil testing regime to monitor lime, organic matter, and P&K's. The Agricultural Research Trust Farm (ART Farm as it was known) sponsored by the Commercial Farmers Union and other producer groups, was way ahead of it's time in carrying out research and testing techniques to boost grain production in a way that boosted the bottom line on the balance sheet, rather than pure out and out yield. The attention to detail was scary, something we struggled to get our heads around at the time as we saw it as a huge burdensome amount of paperwork and record keeping. However, they could tell you to the nearest cent how much a field of maize, soya, grass, etc, had cost to grow, how much it had produced and what the margins were over a wide range of parameters. This wasn't a small little research unit either of 50 acres either, but a commercial unit. There was focus, right from the very top, all the way down to tractor driver level on getting the basics right.
The soils we farm with here in UK aren't wildly different to some of those I farmed in Zim, some of the red clay loams around Crediton, or parts of Shropshire are similar to the best soils we had, however most of our soils would be classified as green sands, or vlei sands as we called them, grade 4 and 5 stuff. Easily compacted, very little organic matter, easily capped and really easily eroded in heavy rain. We had contour drains on all arable ground with a gradient steeper than 1 in 50 just to control erosion, as well as manage moisture retention. In the USA and Canada, they call this strip farming and can be seen clearly in the photo below.
Photo by Tim McCabe, USDA Natural Resources Conservation Service
So why do we not see the same level of care of soils here in the UK as in other parts of the world?
Photo by Rodney Burton, Wigborough, Somerset.
Land near Launceston
The maize harvest is going great guns now, some of it is fit and some not quite ready. Soils vary in the amount of moisture in them, but with the cooler weather, there is less evaporation and drying out taking place, so even small showers are keeping some areas saturated and making traveling conditions difficult with harvesting machinery resulting in deep ruts and compaction areas being created. So all the sponginess will have disappeared in these areas, less air in the soil, less absorbtion capacity, poorer rooting potential for the following wheat crops where going in, as running a ripper tine through wet soil has little benefit and will lead to greater soil slumping in the spring. A deep hard frost would do more to restore some structure than a tine. Most farmers will be ploughing these spots in the hope that this will help, however in my experience this just results in the compacted blocks being inverted with little restoration of structure and doesn't solve the issue of the deeper compaction problems. Really, these can only be tackled after harvest next year, you just have to live with the consequences of this late maize harvest and possibly look at better, lighter, south facing, sheltered fields for next year.
And since we are talking about lifeblood, how many farmers are soil testing regularly, accurately and correcting the issues as they arise in a timely manner? Below is an example of the type of pH soil testing I do, the importance of this method was drummed into me by R&T Agricultural Liming, long before the likes of other companies that went on to develope an electronic method using computer software to predict and interpret soil tests and plot them in multicoloured maps.
 |
| Spring Barley near Bodmin struggling on a pH of 5.6 in 2009 |
With the push for bigger dairy units, one has to ask what the long term consequences of very high concentrated levels of slurry will be on the micro organisms in the soil profile on these units. For sure, every arable farmer in the east would probably gladly want a dairy farmer next door where he can rotate, or share field rotations with so he gets organic manure back into his soils. In the last three years I have managed to demonstrate to a number of cereal growers just how important chicken muck is and how putting back organic matter into the soils where continuous wheat is being grown is vital in maintaining yield and grain quality. On one unit in particular we have taken average yield from 2.6t/ac in years 2006-2009 to over 3.7t/ac this year. It has been interesting to physically see how the soil structure has changed, it is far more friable, works easier, doesn't cap so easily straight after heavy rain, nor does it slump as much during the winter. With the addition of using Nickerson original seed too, there are no big bare patches where there is nothing growing like there used to be in the past as the wet areas don't compact and slump like they used too and the film coated seeds allows faster, bigger root systems to develope quickly to take advantage of the nutrients on tap making winter kill less of an issue, even though last year was one of the coldest in a very long time.
However we have a few cases now developing of the opposite starting to occurr, very large dairy units with very high stocking rates/ac (3+ cows/ac) as the animals are housed most of the year round. That means there is a lot of slurry to spread on quite a tight area of ground, with the result that the ground is being drowned in slurry, literally. Lots of dead worms littering the top soil, large bare patches developing in between grass plants where they have been suffocated by slurry, sward quality and grass yields falling as a result. Sward lifters, slitters and slotters can only do so much in the short term to alleviate these issues, the longer term damage is the more worrying problem that is being stored up for the following generations.
We need to start looking at farming in a much more holistic manner, indeed Allan Savoury who conducted trials in grazing and land management first in the Karoo many years ago in South Africa and subsequently has started a foundation in the USA following extensive work in Texas and other ranching states has laid out some key principles in this area. I would recommend farmers read some of his work, or look at this website http://www.holisticmanagement.org/ especially those in drier parts.
We are all players in the food chain, whether consumers, or producers. We need to ensure that we look after our primary resource, the soils we grow our food off.
If you eat, you are involved in agriculture.
