The Fate and Balance of Nitrogen on a Sloped Peanut Field on Red Soil

Abstract

To comprehensively evaluate the fate of nitrogen (N) through erosion and leakage, and to reveal the constitution of the whereabouts for fertilizer N on a sloping red soil cultivated with peanut, two treatments with three repetitions of conventional fertilization and no fertilization were set up according to the N-balance method. Lysimetric devices were adopted to observe the output of N in terms of loss, plant use, and residual N under natural rainfall in 2017 and 2018 in De’an, Poyang Lake Basin, China. The results showed that (1) leaching water was the main pathway of N output from runoff (including erosion and leakage), and the TN (total N) concentration of each surface runoff exceeded surface water Class V standard value of 2.0 mg L−1. (2) The fertilizer N use rate, the residual rate, and the apparent loss rate were 25.19–27.87%, 9.92–14.79%, and 60.02–62.21%, respectively. The apparent fertilizer N loss rate caused by soil erosion and leakage was 0.11–5.90% and 4.27–16.27%, respectively. (3) N losses from surface runoff and leakage were higher in the wet year (2017), whereas the amount of residual N in the soil profile was higher in the dry year (2018). This study provides a scientific basis for the adjustment of crop N fertilization in the study area.