Do reduced water and nitrogen input in rice production necessarily reduce yield?

Chuanhai Shu, Feijie Li, Q. Tang, Yuemei Zhu, Jinyue Zhang, Yongjian Sun, Na Li, Jun Ma, Zhiyuan Yang

International Agrophysics（3区，IF= 2.317），2022，36,47-58

https://pdfs.semanticscholar.org/4cdb/937d9924778ec0d510df2921079a0e83776a.pdf 

Abstract

This study explored the effects of water andnitrogen management on yields, as well as water and nitrogen useefficiency, in the production of rice (Oryza sativa L.). The studyaimed to provide theoretical and technical support for high yieldpractices and efficient resource utilization. Three replicate split-plot experiments were conducted in the field using floodingirrigation and controlled irrigation as the primary treatments. Thesecondary treatments included no nitrogen application, the farm-ers’ usual nitrogen management, optimized nitrogen treatment,and uniform nitrogen application. Uniform nitrogen achieved thehighest yield (11.91-14.12 103 kg ha-1) with controlled irrigation,in which case 20% less nitrogen is applied than in the case ofoptimized nitrogen treatment and farmers’ usual nitrogen mana-gement. Controlled irrigation + uniform nitrogen required 24.18-35.82% less irrigation than flooding irrigation. Controlled irri-gation + uniform nitrogen yielded the lowest reduction (18.52-20.00%) in the dry weight of deep roots (20-30 cm) within 30days after heading. Comparatively, this reduction was 27.54-30.26and 38.71-42.11% under controlled irrigation + optimized nitro-gen treatment and controlled irrigation + farmers’ usual nitrogenmanagement, respectively. At the heading stage, light interceptionwas highest under uniform nitrogen. Nitrogen recovery efficiencyunder uniform nitrogen was 8.53-17.88 and 46.77-60.79% higherthan that under optimized nitrogen treatment and farmers’ usualnitrogen management, respectively. Furthermore, nitrogen useefficiency under uniform nitrogen was 19.84-29.70 and 76.16-94.44% higher than that under optimized nitrogen treatment andfarmers’ usual nitrogen management, respectively, low-intensity/high-frequency nitrogen application combined with water-sav-ing irrigation can greatly reduce water and nitrogen input whilemaintaining a stable yield to achieve food security and efficient resource utilization in rice production.

Kerwords：rice ( Oryza sativa L.), water management,nitrogen fertilizer management, water and nitrogen use efficiency, yield