CARBON, NITROGEN, AND PHOSPHORUS CONTENT IN SOIL FOLLOWING PIG-SLURRY APPLICATION TO CROP ROTATIONS WITH DIFFERENT INPUT LEVELS

A multi-year experiment was started in 1993, the aim being to evaluate the suitability of selected crop-ping systems to receive pig slurry applications, whilst limiting the negative effects on the environment. The organic carbon (C), total nitrogen (N), and available phosphorous (P) concentration in soil at 0 to 0.8-m soil depth was measured in plots of sugar beet–sorghum–winter wheat and soybean–barley+sorghum second crop rotations, at 3 technical input levels: traditional, reduced and minimal. The leguminous- and second crop-including crop rotation, supplied with a more intensive application of pig slurry, was more effective in allowing the maintenance of good soil fertility levels