Effects of plastic mulch duration on nitrogen mineralization and leaching in peanut (Arachis hypogaea) cultivated land in the Yimeng Mountainous Area, China

The Yimeng Mountainous Area is one of the most typical regions in the rocky area of northern China. In this area, plastic film mulching is one of the important measures to increase the crop yield. Using an in situ soil N mineralization device, this paper explored the situation of soil N mineralization and mineral N leaching under different durations of plastic film mulching. This work was carried out on the widespread sandy loam of this area with conventional peanut (Arachis hypogaea) cultivation. The field experiment contained a non-mulched treatment (M0) and four mulching time treatments from sowing to the end of peanut seedling stage (M1), flowering stage (M2), pod setting stage (M3) and pod filling stage (M4). Results showed that mulching increased the soil temperature at the seedling stage and soil water content during the whole growing season. In general, the total N mineralization and soil mineral N content increased with the increase of mulching duration. The largest N mineralization was observed in the M4 treatment with 139.7 mg kg−1, and the lowest was measured in the M1 treatment with 32.3 mg kg−1. Mineral N content in the M0, M1, M2 and M3 treatments were 29.7%, 34.9%, 31.6% and 8.4% less than in the M4 treatment, respectively. On the other hand, the lowest cumulative mineral N leached was measured in the M4 treatment with 14.0 mg kg−1; secondly was the M3 treatment with 14.3 mg kg−1 and the highest cumulative mineral N leached was 16.3 mg kg−1 in the M1 treatment. The highest pod and haulm yield, 1588 kg ha−1 and 1963 kg ha−1, respectively, were recorded in the M3 treatment. This study indicated that plastic film mulching from peanut sowing to the end of the pod setting stage (M3 treatment) resulted in higher N mineralization, less mineral N leaching and the highest peanut yield, and it can be widely used in peanut planting in the Yimeng Mountainous Area.

► We studied the effects of plastic mulching durations on N mineralization and leaching.
► Soil net N mineralization was higher in mulching treatments.
► Plastic mulching reduced soil mineral N leaching.
► Mulching from sowing to pod setting stage resulted in the largest peanut yield.