Assessment of soil nitrogen and related enzymes as influenced by the incorporation time of field pea cultivated as a catch crop in Alfisol.

Anna Piotrowska-Długosz,Edward Wilczewski

doi:10.1007/s10661-014-4014-0

Anna Piotrowska-Długosz, Edward Wilczewski

Open Access

https://doi.org/10.1007/s10661-014-4014-0

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Abstract

The effect of the time of catch crop (field pea) incorporation [catch crop incorporated in the autumn (A) or in the spring (B) versus plots without a catch crop (C)] on the soil enzymes related to N transformation (urease – UR, protease – PRO, nitrate reductase – NR, arginine ammonification rate – AAR), the total N and mineral N as well as microbial biomass N (MBN) contents were investigated in a 3-year experiment. The catch crop was sown at the beginning of August and plowed in the autumn in 2008, 2009 and 2010 or left as mulch during the winter. Soil samples for microbial activity were taken from spring barley plots that were grown in 2009, 2010 and 2011 before sowing (March), during the tillering phase (May), shooting (June) and after the harvesting of spring barley (August). The use of catch crop significantly increased the soil mineral and MBN contents as well as the activities of PRO and NR as compared to the control soil. The spring incorporation of the field pea significantly increased the MBN content in contrast to the autumn application, while the activity of N-cycle enzymes were clearly unaffected (UR and AAR) regardless of the time of the incorporation of field pea or else the results were inconsistent (PRO and NR). When the catch crop was incorporated in the spring, a significantly higher content of mineral N as compared to autumn incorporation was noted on only two of the four sampling dates. The enzymatic activity (PRO and AAR) was about 1.3-2.8 times higher in May and June as compared with March and August. Both spring or autumn incorporation of catch crop can be a useful management practice to increase the soil mineral N content and enhance the soil biological activity.

Highlights

Nitrogen fertilization has played a major role in the global food production over the past sixty years, and about fifty percent of total N comes from fertilizer supply (Zhaohui et al 2012)
Our study showed that use of field pea as a green manure, in contrast to the control soil, significantly increased the soil mineral and microbial biomass N content as well as the activities of protease and nitrate reductase during the growing period of the following crop
The spring incorporation of the catch crop significantly increased the microbial biomass N (MBN) content in contrast to the autumn application, while the activity of N-cycle enzymes was clearly unaffected by the time of the incorporation of field pea or the results were inconsistent

Summary

Introduction

Nitrogen fertilization has played a major role in the global food production over the past sixty years, and about fifty percent of total N comes from fertilizer supply (Zhaohui et al 2012). The effectiveness of nitrogen utilization from fertilizers is, very low and does not exceed 10–50 percent for crops grown in fields (Ribaudo et al 2011). The reasons for this low efficiency are the loss of N through leaching, runoff, ammonia volatilization or denitrification, which results in the pollution of the groundwater and atmosphere (Zhaohui et al 2012; Zarabi and Jalali 2012). The incorporation of a biomass of catch crops increases the immobilization of soil nitrogen (N), prevents leaching losses of N into the environment and improves the N supply for succeeding crops (Thorup-Kristensen et al 2003; Thomsen 2005). The decomposition of their organic matter is easy due to their low carbon to nitrogen (C:N) ratio (Fageria et al 2005)

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