【论文题目】 Nitrogen management for optimum potato yields and low environmental impact in northwest China
通过氮肥管理优化中国西北地区马铃薯产量和环境影响
【作者】 Haibo Yang, Yunfei Di, Hailin Zhang, Fei Li
杨海波，邸云飞，张海林，李斐
【摘要】
【Abstract】Understanding the changes in nitrate nitrogen (NO3−-N) content in the rooting zone is crucial for reducing nitrate leaching and improving nitrogen (N) use efficiency. The main objective of this study was to investigate the effects of N management strategies on NO3−-N dynamics in the main root zone (0–60 cm) at critical growth stages of drip-irrigated potatoes and to quantify the retention capacity of NO3−-N at harvest in an intensive potato cropping system. Three field experiments with no N application (CK), optimized management (OM) based on a realistic yield goal and soil mineral N content (Nmin) and farmer practice (FP) for three potato cultivars were conducted in Inner Mongolia of Northwest China from 2014 to 2016. A total of 52 farmers with over 3000 ha of potato fields were also investigated at harvest. The results showed that OM treatment improved N use efficiency and reduced the environmental risk of N loss while ensuring potato yields compared with FP treatment. Overusing N fertilizer in farmer fields was common, but these N fertilizers only caused a temporary accumulation of NO3−-N during the growing season, then it was reduced to the same level as the optimal treatment at harvest. The NO3−-N retention was about 70 kg ha−1 at harvest in the drip-irrigated potatoes with higher yield, and the data from farmers’ fields confirmed the universality of the NO3−-N retention content. Although retentional NO3−-N content in the main root zone at harvest was similar between FP and OM, obvious accumulation of NO3−-N content was observed during the growing season in FP treatments increasing N loss risk to the environment. The characteristics of soil NO3−-N accumulation in the root zone of drip-irrigated potatoes help to improve management strategies to maximize potato yield while minimizing environmental risks due to N fertilization.
【Keywords】Drip-irrigated potatoes, Environmental risk, Optimum nitrogen management, Soil nitrate nitrogen
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