The Dutch programme on soil ecology of arable farming systems : farm management monitoring programme and general results

A comparison was made between conventional farm management (CONV) and integrated farm management (INT) on a calcareous silty clay loam soil, with a crop rotation of winter wheat, sugar beet, spring barley and potatoes. Both types of management were started at two levels of soil organic matter, 2.2% and 2.8%, respectively, resulting from a previous experiment with different inputs of organic matter. Farm management and sampling strategies for soil variables, including soil organisms, and crop development are described. In INT, 20% less nitrogen and 90% less pesticides (mainly as a result of the lack of soil fumigation) were added than in CONV. The soil tillage depth was reduced from 20–25 cm in CONV to 12–15 cm in INT. INT crop yields were on average 90% (83–102%) of CONV crop yields and INT crop N uptake was on average 85% (74–103%) of CONV crop N uptake. INT management with the partial replacement of mineral fertiliser N by compost and manure, conserved the original levels of soil organic matter, but under CONV these levels decreased. The total N in soil increased under INT and did not change appreciably under CONV.