Landwards Spring 2021
Practice: Long term soils trial
Soils work for sustainable intensification How to feed the growing population which is estimated to increase by over 2 billion in the next three decades? Since additional expansion into natural habitats, like forests and grasslands should be avoided as it causes numerous adverse effects on global climate and might lead to permanent loss of various habitats and species, the intensification of farming seems to be the solution. Until now farming has brought a sustained increase in productivity providing food security around the world and paved the way to a green revolution in the early post World War 2 years. In the UK between the 1960’s and 2014 cereals productivity increased two-fold. This resulted from machinery innovation, fertilisers, crop varieties, agrochemicals and irrigation.
Soil degradation
increasing machinery size and weight, since the increase in axle load and tyre pressure inevitably leads to soil compaction. For many years, tillage has been viewed as a measure to alleviate soil compaction, at the same time improving soil aeration and water infiltration. However, recent studies suggest that cultivation can lead to soil structure degradation, organic matter loss and erosion. Ultimately this can lead to re-compaction, since deeper tillage often requires more subsequent tractor passes to prepare a seedbed. Consequently, soil compaction can extend to greater depths in the soil profile, which may then require further deep tillage such as sub-soiling.
A potential reason for this is degradation of soil resulting from
Does it mean that humanity is doomed to failure? Is there any way
Economy of scale led to constant increase in farm machinery power, and consequently machinery size and weight. Recently the productivity curve has flattened, and crop yields are not increasing.
16
we could keep farming to maintain the soil in good condition so it can deliver for future generations?
Long term trial To address these issues, a unique long-term experiment began in 2011 at Harper Adams University in Shropshire, UK. This study is investigating the effects of three contrasting traffic management systems on soil managed for three different tillage depths (250mm, 100mm and zero tillage) on soil physical and biological properties, and crop yields, explains Dr Paula Misiewicz, who leads the research programme. The contrasting traffic systems are random (non-controlled) traffic with standard and low tyres pressures (STP and LTP) and controlled traffic farming (CTF). Magdalena
