配方施肥对水稻生产和经济、环境效益的影响

Effects of formulated fertilizer pattern on rice production,economic and environmental benefits

苏州市吴中区是农业面源污染防控的重点区域,推行配方施肥模式是该区实现种植业肥料减量的主要手段。但是,测土配方施肥模式的制定以作物产量的提升和保障为侧重,缺少对经济、环保等多方综合性需求的回应。针对该区已沿用4 a的水稻配方施肥模式,本研究设置包含配方施肥模式和常规施肥模式的缺素试验,测定水稻养分利用、农田氮磷排放、农户经费收支等指标,分析配方施肥模式的经济、环境效益。研究结果显示,现有配方施肥模式在减少养分投入的条件下仍能够保障水稻产量,且提高磷钾肥利用效率6.35~28.59个百分点,降低氮流失量36%,减少用于肥料购置的经济投入35%,增加农户净利润2558元∙hm^(-2),实现生产、经济和环境多方效益的兼顾。基于养分利用效率,现有配方施肥模式仍有进一步减少肥料投入的余地。为保障土壤生产力的可持续性,建议增加一定比例的有机肥投入,且以4~5 a为周期,对配方肥养分配比和配方施肥模式进行调整,构筑生产中的动态物质平衡,为农业绿色发展提供技术支撑。

The Wuzhong District in Suzhou City is a key region that requires the control of agricultural non-point source pollution.The formulated fertilizer pattern established from soil testing is the main pathway to reduce the fertilizer input required for planting in this region.The aim of the formulated fertilizer pattern was to improve or maintain a high yield,as opposed to being informed by a comprehensive consideration of including agricultural production,economic profit,and environmental protection.Based on the present formulated fertilizer pattern used in rice cultivation over the last 4 years,a field experiment was carried out using the formulated fertilizer and implementing traditional fertilizer patterns for the different nutrient elements that were lacking in the soil.Economic and environmental benefits analysis was undertaken on the nutrient use efficiencies of rice,nitrogen and phosphorus loss from field,and the cost of production.The results showed that the formulated fertilizer pattern was able to maintain rice yield with a lower nutrient input compared to the traditional fertilizer pattern.This meant that the cost of fertilizer was 35%lower,increasing profits by 2558 yuan∙hm^(-2).Higher(6.35~28.59 percentage points)phosphorous and potassium use efficiencies and lower(36%)nitrogen runoff loss was also observed in the formulated fertilizer pattern.Based on the nutrient use efficiencies,there was still space to further reduce fertilizer input;organic fertilizers should be used to replace a portion of the chemical fertilizer usage.The formulated fertilizer pattern was updated every 4~5 years to maintain mass balance during agricultural production.A properly formulated fertilizer pattern would be conducive to an environmentally friendly agricultural practice.