Optimizing the Nitrogen Fertilizer Management to Maximize the Benefit of Straw Returning on Early Rice Yield by Modulating Soil N Availability
Juan Hu,
Xianjiao Guan,
Xihuan Liang,
Binqiang Wang,
Xianmao Chen,
Xiaolin He,
Jiang Xie,
Guoqiang Deng,
Ji Chen,
Xiuxiu Li,
Caifei Qiu,
Yinfei Qian,
Chunrui Peng,
Kun Zhang,
Jin Chen
Affiliations
Juan Hu
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Xianjiao Guan
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Xihuan Liang
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Binqiang Wang
Institute of Red Soil and Germplasm Resources, Nanchang 330000, China
Xianmao Chen
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Xiaolin He
Jiangxi Agricultural Technology Extension Station, Nanchang 330046, China
Jiang Xie
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Guoqiang Deng
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Ji Chen
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
Xiuxiu Li
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Caifei Qiu
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Yinfei Qian
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Chunrui Peng
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Kun Zhang
Institute of Red Soil and Germplasm Resources, Nanchang 330000, China
Jin Chen
Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Key Laboratory of Arable Land Improvement and Quality Improvement of Jiangxi Province, National Engineering and Technology Research Center for Red Soil Improvement, National Agricultural Experimental Station for Agricultural Environment of Yichun, Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
Straw returning has gradually been adopted as an effective approach to address the serious degradation of farmland. However, the carbon/nitrogen (C/N) ratio of rice straw is generally too high for microorganisms to decompose the organic materials and release nutrients, which may minimize the benefits of straw returning to the agricultural production system. This study aimed to investigate the effects of straw returning on rice production and propose optimum nitrogen (N) management for early rice production under a straw returning system. The total N fertilizer that was evaluated was 165 kg N ha-1, urea (46% N), applied in different proportions in three stages of rice cultivation: basal, tillering, and panicle. Using no straw returning with the N fertilizer ratio of basal:tillering:panicle = 5:2:3 treatment (T1) as the control, four different N fertilizer ratios of basal:tillering:panicle, including 5:2:3 (T2), 5:2:2 (T3), 5:4:1 (T4), and 5:5:0 (T5) were set under straw returning. The return of straw decreased the available N in the soil at the tillering stage, and impeded root growth and the crop canopy from establishing, which decreased the effective panicles by 10.1% compared with that of T1, limiting the increases in rice grain yield. Increasing the N fertilizer ratio 10–20% (T3 and T4) at the tillering stage effectively increased the content of soil ammonium and nitrate nitrogen, improved the root growth, and increased the root activities by 16.0–40.5% at the tillering stage. As a result, the effective panicle number increased by 5.1–16.2%. Among these, T4 treatment maximized the benefits of straw returning the most. Additionally, increasing the N fertilizer ratio at the tillering stage increased the shoot uptake across the early rice growing season and synchronized crop N uptake with the accumulation of carbon assimilates, which enhanced the crop growth rate and increased the rice yield by 13.5–25.1%. It is concluded that increasing the N fertilizer ratio by 20% at the tillering stage is a promising strategy to increase the availability of N in the phases of high demand for this nutrient.
