Determining optimal water and nitrogen management under different initial soil mineral nitrogen levels in northwest China based on a model approach

Xinrui Shi, William D. Batchelor, Hao Liang, Sien Li, Baoguo Li and Kelin Hu

Agricultural Water Management, 2020, vol. 234, issue C

Abstract: Determining the best management practices (BMPs) under different initial soil mineral N (ISMN) levels is helpful to improve water and N use efficiencies (WUE, NUE) and protect the environment. In this study, a two-year field experiment of spring maize was conducted from 2014 to 2015 in northwest China. Five treatments were designed, including one local farmer practice (I480-4N280, 280 kg N ha−1 fertilizer and irrigated 480 mm with four irrigation events) and four conservation treatments (I420-4N200, I420-5N200, I420-6N200 and I420-7N200, standing for 200 kg N ha−1 fertilizer and irrigated 420 mm with four to seven irrigation events, respectively). Measured yield, leaf area index, soil water content and soil nitrate concentration were used to evaluate a soil-crop model (WHCNS, soil Water Heat Carbon Nitrogen Simulator), which was then used to simulate the effects of water and N management practices on water consumption, N fates, and crop growth. Then, the integrated index considering the agronomic, economic, and environmental impacts was simulated using 35,100 combinations of irrigation and fertilizer N scenarios, which were designed to develop BMPs under different ISMN levels (ranging from 0 to 625 kg N ha-1 in a 1.8 m-soil profile) and seasons of weather data (from 2001 to 2015). Results showed I420-5N200 was the best with a high yield, WUE and NUE, and low N loss among five treatments. The optimal irrigation amount (ranging from 350−600 mm) was related to precipitation amount. The optimal N rate decreased linearly with the increase of ISMN when ISMN was <384 kg ha−1, and reached a plateau (0 kg N ha−1) when ISMN was >384 kg ha−1. In this study, we developed a simple linear model to determine the best N application rates under different ISMNs. This method is important to help farmers achieve multiple goals of high yield, resource conservation and reduced environmental impacts simultaneously.

Keywords: Irrigation scheduling; Residual soil nitrogen; Nitrogen leaching; Best Management Practices; WHCNS model (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377419322772
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:234:y:2020:i:c:s0378377419322772

DOI: 10.1016/j.agwat.2020.106110

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().