辽宁省主要粮食作物秸秆还田对化肥替代潜力分析

Analysis of Fertilizer Substitution Potential of Main Grain Crop Straw Returning to Field in Liaoning Province

为明确辽宁省主要粮食作物秸秆养分资源量及其还田对化肥的替代潜力,推进全省秸秆资源化利用及化肥减施,基于统计数据和文献资料,对辽宁省水稻和玉米2种主要粮食作物的秸秆产量,秸秆N、P_(2)O_(5)、K_(2)O养分资源量,以及还田条件下的养分带入量进行估算,评估其对化肥替代减施的潜力。结果表明,2018—2020年辽宁省玉米和水稻秸秆年均产量分别为2130万、440万t。2种作物秸秆养分资源总量年均67.6万t,其中,N、P_(2)O_(5)、K_(2)O分别为22.2万、7.8万、37.6万t;玉米和水稻秸秆养分资源量分别占秸秆养分资源总量的79.4%、20.6%。单位面积水稻秸秆还田的养分当季归还量为N 23.7~40.1 kg/hm^(2)、P_(2)O_(5)5.3~9.0 kg/hm^(2)、K_(2)O 98.8~167.0 kg/hm^(2);玉米秸秆还田的养分当季归还量为N 26.2~50.6 kg/hm^(2)、P_(2)O_(5)4.4~8.4 kg/hm^(2)、K_(2)O 45.5~87.8 kg/hm^(2)。水稻秸秆全量还田对氮肥(N)、磷肥(P_(2)O_(5))替代潜力分别为13.2%~17.6%、6.3%~9.6%,可全部替代钾肥(K_(2)O);玉米秸秆全量还田对氮肥(N)、磷肥(P_(2)O_(5))、钾肥(K_(2)O)替代潜力分别为12.7%~23.7%、4.80%~9.0%、46.7%~87.3%。

In order to clarify the amount of straw nutrient resources of main grain crops in Liaoning Province and the substitution potential of straw returning for chemical fertilizer,and to promote the utilization of straw resources and the reduction of chemical fertilizer application in the whole province,based on statistical data and literature,the straw yield of two main grain crops of rice and corn in Liaoning Province,the amount of straw N,P_(2)O_(5)and K_(2)O nutrient resources,and the amount of nutrient brought in under the condition of returning to the field were estimated,and the potential of substitution and reduction of chemical fertilizer was evaluated.The results showed that the average annual yields of maize and rice straw in Liaoning Province from 2018 to 2020 were 21.3 million and 4.4 million tons,respectively,mainly distributed in the Liaohe Plain and Western Liaoning.The total amount of straw nutrient resources of the two crops was 676000 t per year,of which N,P_(2)O_(5)and K_(2)O were 222000,78000 and 376000 t per year,respectively.Corn and rice straw nutrient resources accounted for 79.4%and 20.6%of the total straw nutrient resources,respectively.The nutrient returning amount of rice straw per unit area was N 23.7—40.1 kg/ha,P_(2)O_(5)5.3—9.0 kg/ha,K_(2)O 98.8—167.0 kg/ha.The nutrient returning amount of maize straw in the current season was N 26.2—50.6 kg/ha,P_(2)O_(5)4.4—8.4 kg/ha,K_(2)O 45.5—87.8 kg/ha.The substitution potentials of total rice straw returning for nitrogen(N)and phosphorus(P_(2)O_(5))fertilizers were 13.2%—17.6%and 6.3%—9.6%,respectively,and it could completely replace potassium(K_(2)O).The replacement potentials of total maize straw returning for nitrogen fertilizer(N),phosphorus fertilizer(P_(2)O_(5))and potassium fertilizer(K_(2)O)were 12.7%—23.7%,4.80%—9.0%and 46.7%—87.3%,respectively.