Open AccessSimplicity on the far side of complexity: optimizing nitrogen for wheat in increasingly variable rainfall environments
Author(s) -
Zvi Hochman,
François Waldner
Publication year - 2020
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/abc3ef
Subject(s) - environmental science , nitrogen , cropping , yield (engineering) , crop , agricultural engineering , arid , crop yield , agronomy , simulation modeling , variable (mathematics) , nitrogen balance , food security , agriculture , mathematics , geography , ecology , engineering , chemistry , mathematical analysis , materials science , mathematical economics , metallurgy , biology , archaeology , organic chemistry
The increasingly chaotic nature of rainfall in semi-arid climates challenges crop growers to balance nitrogen fertiliser inputs for both food security and environmental imperatives. Too little nitrogen restricts yields and runs down soil organic carbon, while too much nitrogen is economically wasteful and environmentally harmful. The degree to which crop-water and crop-nitrogen processes combine to drive yields of rainfed wheat crops is not well understood or quantified. Here we investigate two comprehensive Australia-wide data sets, one from commercial wheat growers’ fields and the other from systematic simulation of 50 sites by 15 years using a comprehensive mechanistic cropping system model. From these data, we derived a simple model combining water use with available nitrogen and their interaction. The model accounted for 73% of the variation in the simulated yield data and 46% of the variation in the growers’ yield data. We demonstrate how the simple model developed here can be deployed as a tool to aid growers’ in-crop nitrogen application decisions.