Effect of cultivation on the mineralization of nitrogen in soil

The effect of cultivation (ploughing followed by rotavation) on the mineralization of soil nitrogen was measured at 2 sites on a silt loam soil. Both sites had a predominantly arable cropping history but one had been under grass for the previous 2 years and the other had carried wheat. Mineralization of N was slightly faster in cultivated soil but the difference was only significant at the site previously under grass. At this site cultivated soil contained 7 kg ha−1 more mineral N than uncultivated soil 2 weeks after treatment, and 9 kg ha−1 after 6 weeks. The corresponding figures for the site that had grown wheat were 4 and 6 kg N ha−1.