山东省小麦玉米秸秆资源分布与还田减肥潜力

Distribution of Wheat and Maize Straw Resources in Shandong Province and Fertilizer Reduction Potential Under Straw Return

【目的】山东地处华北地区,是我国小麦玉米主产省份。明晰其秸秆资源的空间分布特征及秸秆还田的养分替代潜力,可为推进全省秸秆综合高效利用和农田化肥合理减量增效提供决策依据。【方法】基于统计年鉴资料和文献调研数据,利用草谷比法对2019—2021年山东省不同地区小麦玉米秸秆年均产量及还田情景下的化肥可替代量进行测算。【结果】2019—2021年山东省小麦和玉米秸秆年均产量分别为2928万t和2252万t,两种秸秆资源的区域占比表现为鲁北(34.9%、34.7%)>鲁西南(27.6%、24.9%)>鲁中(20.2%、21.4%)>鲁东(9.1%、11.3%)>鲁东南(8.2%、7.8%)。单位面积小麦秸秆可收集量排序为鲁北(5573 kg·hm^(-2))>鲁西南(5380 kg·hm^(-2))>鲁中(5361 kg·hm^(-2))>鲁东南(5088 kg·hm^(-2))>鲁东(4968 kg·hm^(-2)),玉米秸秆可收集量排序为鲁西南(5121 kg·hm^(-2))>鲁北(5034 kg·hm^(-2))>鲁东南(4807 kg·hm^(-2))>鲁中(4790 kg·hm^(-2))>鲁东(4709 kg·hm^(-2))。秸秆产量较高的菏泽、德州、聊城、济宁和潍坊五市的小麦和玉米秸秆总占比分别为57.5%和55.5%,而秸秆产出较少的东营、淄博、日照和威海四市的两种秸秆总占比分别仅为7.2%和8.0%。全省小麦秸秆N、P2O5、K2O养分年均资源量分别为13.94万t、5.13万t和50.90万t,玉米秸秆N、P2O5、K2O养分资源量分别为16.65万t、6.58万t和36.60万t。区域尺度上单位面积小麦秸秆还田当季的N、P2O5、K2O养分理论可替代化肥的量分别为16.7—18.7、7.8—8.7和110.4—123.8 kg·hm^(-2),玉米秸秆还田的N、P2O5、K2O养分可替代化肥的量分别为25.4—27.6、11.8—12.8和83.2—90.5 kg·hm^(-2)。【结论】山东省不同地区的小麦玉米秸秆资源总量及单位面积可收集量存在一定差异,应因地制宜加强秸秆高效利用;秸秆还田利用情景下需考虑还田秸秆的替代化肥潜力,以促进化肥减量增效和农业绿色发展。

【Objective】Shandong Province is the main wheat and maize producing province in North China.Clarifying the spatial distribution characteristics of wheat and maize straw resources and nutrient substitution potential of straw return of this province could provide the decision support for comprehensive utilization of crop straw and fertilizer reduction.【Method】In this research,the wheat and maize straw yield and substitution potential of nutrient by straw return in different areas of Shandong Province were estimated by straw-to-grain ratio method,based on statistic yearbook data and published literature review.【Result】The annual outputs of wheat and maize straw were 29.28 and 22.52 million tons,respectively,in Shandong Province during 2019-2021.The proportions of wheat and maize straw resources in different regions were ranked as follows:North Shandong(34.9%and 34.7%)>Southwest Shandong(27.6%and 24.9%)>Central Shandong(20.2%and 21.4%)>East Shandong(9.1%and 11.3%)>Southeast Shandong(8.2%and 7.8%).The order of collectable wheat straw per unit area was North Shandong(5573 kg·hm^(-2))>Southwest Shandong(5380 kg·hm^(-2))>Central Shandong(5361 kg·hm^(-2))>Southeast Shandong(5088 kg·hm^(-2))>East Shandong(4968 kg·hm^(-2)).The order of collectable maize straw per unit area was Southwest Shandong(5121 kg·hm^(-2))>North Shandong(5034 kg·hm^(-2))>Southeast Shandong(4807 kg·hm^(-2))>Central Shandong(4790 kg·hm^(-2))>East Shandong(4709 kg·hm^(-2)).At the municipal level,the straw resources were mainly distributed in Heze,Dezhou,Liaocheng,Jining and Weifang.The wheat and maize straw yields of these cities accounted for 57.5%and 55.5%,respectively.However,the proportions of wheat and maize straw outputs from Dongying,Zibo,Rizhao and Weihai were only 7.2%and 8.0%,respectively.In Shandong Province,the amounts of nutrient from wheat straw were 0.1394 million tons of N,0.0513 million tons of P2O5,and 0.5090 million tons of K2O.For maize straw,the outputs of nutrient were 0.1665 million tons of N,0.0658 million tons of P2O5,and 0.3660 million tons of K2O.In the regional scale,the substituting potentials of N,P2O5 and K2O through wheat straw return were 16.7-18.7,7.8-8.7 and 110.4-123.8 kg·hm^(-2),respectively.The maize straw incorporation could substitute chemical fertilizers of N 25.4-27.6,P2O511.8-12.8 and K2O 83.2-90.5 kg·hm^(-2)theoretically.【Conclusion】In summary,there were some differences in total straw yield and collectable straw per unit area among different wheat-maize rotation areas of Shandong Province.Therefore,these appropriate policies should be formulated based on local conditions to promote efficient utilization of wheat and maize straw resources.The fertilizer replacement potential of returned straw should be considered for nutrient management in wheat-maize rotation system,which was conducive to chemical fertilizer reduction and green agricultural development.