On Tuesday last I attended a field meeting facilitated by BASE Ireland for the European Conservation Agriculture Federation (ECAF). BASE is a voluntary group of Irish farmers who trial and develop methods to improve their land. The focus of BASE is to improve soil health with the establishment of crops with minimal soil disturbance (no ploughing), protecting soil with either growing crops or crop residue and using a combination of crop rotations and catch crops to improve soil structure.
Pesticide and fertiliser usage is kept to a minimum so as to enable financially viable crops with least damage to soils and the environment.
Crop nutrition is the key to minimising the need for fungicide usage for disease control. It is managed first with comprehensive soil analysis followed with sap analysis of the growing crop, prior to routine spray applications, so as to include minor or trace elements when necessary.
Soil nutrition without a good root system to take up both nutrients and moisture will not give a healthy crop. Good root systems can only develop in healthy soils. Healthy soils are those with a wide range of bacteria and fungi and with a ratio of approximately 1:1 to produce many of our arable crops.
The living organisms in soil determine its productivity and create the conditions under which good soil structure is generated. When crops and crop residues are removed, the food for the living organisms is removed and soils deteriorate. The BASE field walk showed the direct opposite where one field with a difficult soil was transformed to a lovely friable soil by sowing a summer catch crop immediately after an autumn sown catch crop.
While the work of BASE is driven by farmer strategies to improve soil potential, it is complementary to proposed EU legislation to enhance soils and reduce pesticide usage. Healthy soils are deemed essential to meet climate and biodiversity targets for 2030.
Many of you will recall that in 2009, arable farmers were obliged to get soil samples for Soil Organic Matter (SOM). Farmers that had soils with a SOM of less than 3.4pc (or 2pc carbon) were obliged to seek advice on improving organic matter content. The threshold of 3.4pc was deemed to provide adequate soil structure.
The findings from the analyses, as far as I can recollect, was that less than 1pc of arable soils were at risk and that there was no need to carry out further analyses. Now the Commission is seeking to use soils as a carbon sink — increase carbon content in soils and keep it there. So not alone will the Commission be looking for us to rewet bogs but also to the increase carbon content in arable soils — as indeed we are currently attempting with the Straw Incorporation Scheme.
Soils act as a tremendous carbon store. It is estimated that there are 70 billion tonnes of carbon stored in the earth. That is equivalent to 50 times the EU’s annual emissions. Every time we get rain, our rivers turn brown as a result of loss of soil from land to water. The soil losses come from erosion of river banks and from overland flow of water from fields, which in extreme cases results in gullies in fields. The average annual loss of soil from land to water in the EU (2010) was 2.46t/ha. It takes 500 years of natural processes to generate 2cm of soil cover. The average rate of soil formation in Europe is 1.4 t/ha /yr so the net loss in Europe is 1 t of soil/ha/year.
Here in Ireland, we are losing an average 0.96 t/ha /year and on tillage lands 1.32 t/ha/yr. That figure is 1.52t/ha /year on tillage lands which are not being managed in accordance with Good Agricultural and Environmental Condition (GAEC). The GAEC requirements are therefore resulting in a 16pc reduction in soil losses from tillage lands.
Soil is critical for food production, clean water, retention of nutrients and as reservoir for carbon. Perhaps if we spent less time arguing about cow numbers, fossil fuels and the impacts of heavy industry and made a concentrated effort to improve our soils, as BASE is doing, we will go further to improve our environment, make farming more sustainable and improve our incomes.
PJ Phelan is a tillage advisor based in Tipperary; he is a member of the ACA and ITCA