Soils fertile but structure may be suffering
While soils used for brassica growing in the Lincolnshire belt are among the most fertile in the country, their structural integrity is among the least resilient, says Hutchinsons technical manager Dick Neale.
The soils in the Boston area dominated by silt with variable clay content and, in line with their geology, they have low levels of natural organic matter.
“These soils are marine and estuarine in origin, which means there is a good level of calcium (Ca). However, the limited level of historic organic matter is concerning as there is not much to fall back on in difficult times.”
These fertile soils are subjected to aggressive and frequent cultivation, with double cropping quite possible in some years, harvesting is not always carried out in the best of environmental conditions and cultivations to rectify damage are needed.
Addressing these issues calls for long-term strategies, and Dick advocates considering how alternative soil management strategies fit into rotations, including the use of cover crops and management of residues to stabilise soil while avoiding disease carry-over.
“There is not much you can do in the short term, and it is likely that soils have already been ploughed for this year’s spring crops.” But as soils increasingly lose resilience to weather extremes cultivations alone may not always be the answer, he warns. He encourages growers to consider the fast-developing alternatives to ploughing as the base cultivation.
“Strip tillage is increasingly viable for plug plant brassica or wide row sown crops like sugar beet or maize.” Crops in the rotation which need less soil movement, such as peas, onions and cereals can work with shallow tillage.
Taking a spade to have a look at the structure is always a good idea, he says. “Our healthy soils assessment helps to benchmark soils against key metrics of what a good soil structure is and measures to counter the areas identified as requiring improvement for the long term benefit of the soil, the growing crop and the growers profit margin.”