Soil phosphatase activity and phosphorus content as influenced by catch crops cultivated as green manure

In a 3-year experiment, the effect of catch crop management [catch crop incorporated in autumn (A) or mulched (B) vs plots without a catch crop (C)] on soil acid (PAC) and alkaline (PAL) phosphatase activities as well as on the available phosphorus content (PAVAIL) were investigated on typical Alfisol. The catch crops were sown at the beginning of August and ploughed in the autumn in 2008, 2009, and 2010, or left as mulch during the winter. Soil samples were taken four times a year from spring barley plots that were grown in 2009, 2010, and 2011. Generally, catch crop treatment significantly influenced the enzymatic activity as compared to the control. The PAC activity was significantly greater with a mulched catch crop than in a ploughed one only in I and II sampling dates, whereas the PAL activity was not influenced by the method and time of field pea management. The time of sampling significantly influenced the PAL activity in 2011 and the PAC activity in 2009 and 2011.