THE DUTCH PROGRAM ON SOIL ECOLOGY OF ARABLE FARMING SYSTEMS - FARM-MANAGEMENT MONITORING PROGRAM 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.