河北省主要作物秸秆养分资源量及替代化肥潜力的空间分布特征

Spatial distribution of nutrient resource of main crop straws and its potential to replace chemical fertilizer in Hebei Province

明确河北省的主要粮食作物秸秆养分资源量和替代化肥潜力,旨在为高效利用全省秸秆资源和实现化肥减量增效提供科学依据。本研究基于《河北农村统计年鉴》和文献资料数据,估算了河北省各市的玉米、小麦、水稻及大豆秸秆总产量及养分资源量、养分当季释放量和替代化肥潜力。结果表明:2016—2020年河北省年均作物秸秆总产量为5490.21万t,呈现中南高、东北低的分布特征。玉米、小麦、水稻及大豆秸秆年均产量分别为3440.62万t、1965.81万t、50.57万t和33.21万t,其中玉米和小麦秸秆所占比例达62.67%和35.81%,是全省农作物秸秆资源的主要构成部分。河北省主要作物秸秆可提供的钾(K_(2)O)、氮(N)和磷(P2O5)养分量分别为75.73万t、45.49万t和15.72万t,分别占养分资源总量的55.30%、33.22%和11.48%,全省秸秆氮磷钾养分资源量可观,以钾养分资源量为主。河北省主要作物秸秆还田当季可为土壤提供的钾(K_(2)O)、氮(N)和磷(P2O5)有效养分量分别为67.62万t、25.38万t和11.10万t,相当于钾(K_(2)O)、氮(N)和磷(P2O5)化肥施用量的104.38%、15.54%和14.52%。不同区域来看,秸秆替代化肥潜力呈现东部>南部>中部>北部的分布规律。综上所述,河北省全量秸秆还田时,在有效养分数量上,可全部替代当前区域化学钾肥投入,可部分替代氮肥和磷肥投入,在统筹管理秸秆资源时应充分考虑区域差异,以实现全省秸秆资源高效利用和化肥减施增效。

This study aimed to quantify the nutrient resources in primary grain crop straws and assess their potential for fertilizer substitution in Hebei Province,China,which is important for promoting the efficient utilization of straw resources and reducing chemical fertilizer usage in the region.Based on data from the Hebei Rural Statistical Yearbook and the literatures,the annual production,nutrient resources,nutrient release amounts during the season,and potential for substituting chemical fertilizers of corn,wheat,rice,and soybean straws in each city of Hebei Province were estimated.The results showed that the average annual production of crop straws in Hebei Province from 2016 to 2020 was 54.90 million tons,with a distribution pattern of high in the central and southern regions,and low in the northeast region.The average annual productions of corn,wheat,rice,and soybean straws were 34.41,19.66,0.51,and 0.33 million tons,respectively,with corn and wheat straw accounting for 62.67%and 35.81%of the total straw resources in the province.The nutrient resources of potassium(K_(2)O),nitrogen(N),and phosphorus(P_(2)O_(5))provided by major crop straws in Hebei Province were 757.3,454.9,and 157.2 thousand tons,respectively,indicating a considerable quantity of nutrient resources in crop straws.The nutrient resources that could be provided by straws when returned to the soil during the season were 676.2,253.8,and 111.0 thousand tons for K_(2)O,N,and P_(2)O_(5),respectively,which were equivalent to 104.38%,15.54%,and 14.52%of the chemical fertilizer application amount.The potential for straw to substitute chemical fertilizers showed a distribution trend of east>south>central>north.Therefore,when the total straw is returned to fields,the nutrients brought to soils could replace all the K_(2)O and some of the N and P_(2)O_(5)in chemical fertilizers.Regional differences should be completely considered in the comprehensive management of straw resources to achieve efficient utilization of straw resources and reduce chemical fertilizer usage in Hebei Province.