Nitrogen leaching to the sea is a natural process, it exists whether
we have farming activity or not and whether there are people on
earth or not. Nitrogen leaching is part of the Nitrogen Cycle which
is shown in the picture below. Due to human activity the leaching
CDI technique is an efficient technique to counteract the leaching process. Leaching is reduced by controlled draining and and plant nitrogen uptake is promoted by irrigation (presence of water in soil) which in turn lead to less nitrates in soil which reduces nitrogen leaching even more. Leaching reduction and plant increase uptake are depicted in picture below.
The CDI technique is one example of how farms can reduce leaching and still be productive to serve the human population. The technique is copied from United States, Canada and Finland and is adapted locally to match Swedish conditions.
To summarize, an estimate on reduction of nitrogen leaching of up to 25 kgN/ha and year at farm level and crop sequence can be achieved when
combining CDI with Catch Crops (CC) and Spring Tillage (ST)*. When
scaling up above figure on an effective area at a country level,
let's say 20000 ha, it will have a great impact on health status on
the Baltic Sea. Figure is based on calculations of
drainage/leaching models from "Focus on Nutrients" (**) national
program. No measurements have been taken in outgoing waters from
In short the CDI has increased effectiveness in crop production on Ragnabo farm and at the same time reduced nitrogen leaching the the Baltic Sea. Clearly a win-win situation!
Note*: There are no synergy effects between CDI, CC and ST per se. However
they have all nitrogen reduction in common and therefore belong to the same agri-environmental
program. Reason to incorporate CC and ST here is to get a reduction figure on a
farm level for benchmark comparison with other farms. CDI is only applicable to
flat land while CC/ST is more general. The latter will not be any further
discussed on this web site except for inclusion in nutrient balance and leaching
Note**: Focus on Nutrients is a joint venture between The Swedish Board of Agriculture, The County Administration Boards, The Federation of Swedish Farmers and a number of companies in the farming business.