中国小麦生产的磷肥用量优化潜力及其对产量、籽粒营养和环境效应的影响

为探究农田磷肥施用对中国小麦产量、生态环境、人体健康的影响,搜集已发表文献,整合分析磷肥施用对小麦产量的贡献及其影响因素,并基于环境能值分析和三变量锌吸收模型综合评价磷肥施用的环境效应和对籽粒锌营养品质的影响。研究表明:在全国尺度上,磷肥施用致小麦增产21%,实现小麦高产的施磷量(以P₂O₅计,下同)阈值为58.9 kg·hm^-2。不同麦区在土壤条件、气候因素限制下实现小麦高产的施磷量阈值有所不同:华北、西北、长江中下游、西南麦区分别为71.6、58.1、47.8、60.0 kg·hm^-2。与当前的施磷量相比较,在施磷量阈值下,中国小麦生产系统每年可节省磷素投入(以P₂O₅计)82.07万t,可节省由于磷肥导致的综合环境成本3 600万元,提高籽粒锌质量分数3.83 mg·kg^-1,增加锌生物有效性2.87 mg·d^-1。

Optimization potential of phosphorus input in wheat production in China and its effects on yield,grain nutrition and ecological environment

In order to explore the effects of phosphorus (P) fertilizer application on wheat yield, ecological environment and human nutrition health in China, a meta-analysis was conducted by collecting published literatures to evaluate the contribution of P input to wheat yield, grain zinc (Zn) nutrition and ecological environment by using environmental energy analysis and Zn absorption model. It was shown that the application of P fertilizer averagely increased wheat yield by 21% on the national scale compared to no P applied, and the threshold of P input (based on P₂O₅, the same as below) for high yield production of wheat was 58.9 kg·hm^-2. Different regions had different thresholds due to various soil conditions and climatic factors. The threshold of P input in north China, northwest China, the middle and lower reaches of the Yangtze River, and the southwest China was 71.6, 58.1, 47.8, 60.0 kg·hm^-2, respectively.Compared to the present P input, the application of threshold of P input could save P fertilizer in the wheat production system in China by 82.07×10⁴ t per year, and it would decrease the comprehensive environmental cost more than 36 million yuan per year. In addition, the Zn mass fraction and bioavailability in wheat grain could be enhanced by 3.83 mg·kg^-1 and 2.87 mg·d^-1, respectively, under thethreshold of P input.