Relationships between enzymatic activities and chemical indicators in a brown luvic soil

Actual and potential dehydrogenase and phosphatase activities and nitrate, ammonium and mobile phosphorus contents were determined in the 0–20–, 20–40– and 40–60–cm layers of a brown luvic soil submitted to a complex tillage and crop rotation experiment.Each activity and each chemical content in both non-tilled and conventionally tilled soil under crops of both rotations decreased with increasing sampling depth. It was found that no-till – in comparison with conventional tillage – resulted in significantly higher soil enzymatic activities and nitrate, ammonium and mobile phosphorus contents in the 0–20– and in significantly lower activities and chemical contents in the deeper layers. The soil under maize or wheat was more enzyme-active in the 6– than in the 2–crop rotation. In the 2–crop rotation, higher enzymatic activities were registered under wheat than under maize; nitrate and ammonium contents were significantly higher under wheat excepting mobile phosphorus content. In the 6–crop rotation, higher enzymatic activities were registered under wheat; nitrate and mobile phosphorus contents were significantly higher under maize, while ammonium content was significantly higher under wheat. There were positive correlations between enzymatic activities and chemical indicators under each crop of both rotations.