Optimum Water and Nitrogen Management Increases Grain Yield and Resource Use Efficiency by Optimizing Canopy Structure in Wheat

Excessive nitrogen (N) application rates and serious over-exploitation of groundwater under farmer practice threatens the sustainable use resources in North China Plain (NCP). Crop canopy structure affects light distribution between leaves, which is important to determine crop growth. A field experiment conducted from October 2016 June 2019 NCP was designed examine whether optimum water management could optimize characteristics improve yield resource efficiency. Field treatments included: (1) an example local farming practices, include addition 330 kg N ha?1 irrigated twice (FP), (2) a reduced rate 270 (T1), (3) 210 once (T2), (4) no applied (0 ha?1) (T3). Results showed that highest T1 treatment during 3 years’ winter wheat growing seasons. Water efficiency (WUE), (NUtE), partial factor productivity (PFPN) were significantly higher T2 than FP, three-year average 9.4% at FP. Optimum (T1 T2) improved characteristics, with less relative photosynthetically active photon flux density (PPFD) penetrated population uniformity as well leaf area index, coordinate within maximize interception, resulting Leaf index (LAI) specific (SLA) closely correlated grain WUE, while PPFD negatively WUE. The results indicate especially are good indicators