优化施肥对小麦-玉米轮作体系产量、养分平衡与生态环境效益的影响

Effects of optimized fertilization on yield,nutrient balance,and eco-environmental benefits in wheat-maize rotation system

小麦-玉米轮作是华北平原主要的种植模式,对保障我国粮食安全起着关键作用。本文系统研究了不施肥(CK)、优化施肥(OPT)和农户习惯施肥(FP)方式连续8年对小麦-玉米轮作体系产量、养分平衡、温室气体排放和经济效益的影响。结果表明,小麦季、玉米季和周年轮作中,OPT较FP产量分别提高4.3%、5.3%和4.8%;氮肥偏生产力分别提高39.1%、31.7%和35.9%;磷肥偏生产力分别提高39.1%、40.4%和39.8%;钾肥偏生产力分别降低47.8%、47.3%和47.6%;温室气体排放量分别降低21.7%、21.1%和21.4%;温室气体排放强度分别降低27.0%、27.5%和27.3%;净收益分别提高11.2%、11.4%和11.3%,农业生产成本分别降低3.7%、2.1%和3.1%,环境修复成本分别降低28.4%、17.3%和22.1%。周年轮作中,OPT较FP氮素盈余量降低105 kg·hm^(-2)(46.3%);磷素盈余量降低48 kg·hm^(-2)(53.3%);钾素从亏缺1 kg·hm^(-2)变为盈余59 kg·hm^(-2),满足了作物生长需求。连续8年,OPT较FP土壤有机质含量提高5.3%,速效钾提高12.3%,有效磷降低27.8%。综上所述,与农户习惯施肥(FP)相比,优化施肥(OPT)具有高产、高收益以及环境友好的优势,为华北平原小麦-玉米轮作体系高效绿色生产提供了科学依据。

The wheat-maize rotation system in the North China Plain is the main planting pattern that plays a key role in ensuring food security in China.An 8-year positioning experiment with a randomized block design was performed,comprising three treatments:no-fertilizer application control(CK),optimized fertilizer(OPT),and farmers’practices(FP).The experiments analyzed the effects of OPT and FP on the yield,nutrient balance,greenhouse gas emissions,and economic benefits of the wheat-maize rotation system.The results showed that the yields of OPT increased by 4.3%,5.3%,and 4.8%compared to FP in wheat,maize,and yearround rotation,respectively.Accordingly,the partial factor productivity of N increased by 39.1%,31.7%,and 35.9%,respectively.The partial factor productivity of P increased by 39.1%,40.4%,and 39.8%,respectively.The partial factor productivity of K was reduced by 47.8%,47.3%,and 47.6%,respectively.The greenhouse gas emissions were reduced by 21.7%,21.1%,and 21.4%,respectively.The greenhouse gas emission intensity was reduced by 27.0%,27.5%,and 27.3%.Net profits increased by 11.2%,11.4%,and 11.3%,respectively.Agronomy costs were reduced by 3.7%,2.1%,and 3.1%,respectively.The environmental costs were reduced by 28.4%,17.3%,and 22.1%,respectively.Compared with the FP treatment,the year-round OPT treatment reduced the surplus of nitrogen by decrement of 105 kg·hm^(−2),i.e.,46.3%.The surplus phosphorus was reduced by 48 kg·hm^(−2)i.e.,53.3%.The surplus of K of OPT and FP was 59 kg·hm^(−2)and−1 kg·hm^(−2),respectively.OPT met the requirements of crop growth better than FP.At the end of 8 years of wheat-maize rotation,the soil organic matter content in OPT treatment increased by 5.3%compared to that in FP.Compared to that of FP,available K increased and P reduced by 12.3%and 27.8%,respectively.In conclusion,compared with FP treatment,OPT treatment has the advantages of high yield,high profit,and environmental friendliness.Therefore,this study provides a scientific basis for the efficient and green product.