Optimal nitrogen rate strategy for sustainable rice production in China
Optimal nitrogen rate strategy for sustainable rice production in China
复制标题
中国水稻可持续生产的最优施氮策略
DOI：
10.1038/s41586-022-05678-x
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发表时间：
2023-02-22
期刊：
影响因子：
64.8
通讯作者：
Yan, Xiaoyuan
中科院分区：
文献类型：
--
作者：
Cai, Siyuan;Zhao, Xu;Yan, Xiaoyuan
避免在不影响产量的情况下过度使用农业氮肥一直是中国(1，2)研究和政府政策的优先事项。尽管提出了许多与水稻有关的战略(3-5)，但很少有研究评估其对国家粮食自给自足和环境可持续性的影响，考虑到数百万小农面临的经济风险的研究更少。在这里，我们建立了一个基于最大化经济(ON)或生态(EON)性能的最优N速率策略，该策略使用新的特定于次区域的模型。然后，我们利用一个广泛的农场数据集，评估了小农产量损失的风险，以及实施最佳氮素水平策略的挑战。我们发现，在实现2030年全国水稻生产目标的同时，ON和EON的全国氮素消耗分别减少10%(6-16%)和27%(22-32%)，反应性氮(Nr)损失减少7%(3-13%)和24%(19-28%)，氮素利用效率提高30%(3-57%)和36%(8-%)。这项研究确定了对环境影响不成比例的次区域，并提出了N率战略，以在不损害土壤N存量或小农经济利益的情况下，将国家Nr污染限制在建议的环境阈值以下。之后，基于经济风险和环境效益之间的权衡，将优选的N策略分配给每个区域。为促进通过每年修订的次区域氮素水平战略，提出了若干建议，包括监测网络、施肥配额和小农补贴。
Avoiding excessive agricultural nitrogen (N) use without compromising yields has long been a priority for both research and government policy in China(1,2). Although numerous rice-related strategies have been proposed(3-5), few studies have assessed their impacts on national food self-sufficiency and environmental sustainability and fewer still have considered economic risks faced by millions of smallholders. Here we established an optimal N rate strategy based on maximizing either economic (ON) or ecological (EON) performance using new subregion-specific models. Using an extensive on-farm dataset, we then assessed the risk of yield losses among smallholder farmers and the challenges of implementing the optimal N rate strategy. We find that meeting national rice production targets in 2030 is possible while concurrently reducing nationwide N consumption by 10% (6-16%) and 27% (22-32%), mitigating reactive N (Nr) losses by 7% (3-13%) and 24% (19-28%) and increasing N-use efficiency by 30% (3-57%) and 36% (8-64%) for ON and EON, respectively. This study identifies and targets subregions with disproportionate environmental impacts and proposes N rate strategies to limit national Nr pollution below proposed environmental thresholds, without compromising soil N stocks or economic benefits for smallholders. Thereafter, the preferable N strategy is allocated to each region based on the trade-off between economic risk and environmental benefit. To facilitate the adoption of the annually revised subregional N rate strategy, several recommendations were provided, including a monitoring network, fertilization quotas and smallholder subsidies.