Field residue of field crops and its temporal distribution among thirty-one provinces of China | 中国各省大田作物田间秸秆资源量及其时间分布

Chinese. 准确评估中国秸秆资源量及其时空分布对秸秆资源化利用具有重要意义。本研究采用各省市区不同作物的最新田间秸秆系数评估田间秸秆资源量,确定各作物秸秆热值合理取值折算标煤量,并依据中国主要大田作物田间秸秆成熟期,对各省各作物田间秸秆的时间分布进行研究。结果表明：2007―2009年中国年均秸秆量为7.35亿t,包括田间秸秆6.46亿t（折标煤量3.41亿t,占总量87.36%）和加工副产物0.89亿t（折标煤量0.50亿t,占总量12.64%）。三大粮食作物是田间秸秆的主要来源,其中水稻田间秸秆为19 865.13万t,折标煤9 177.69万t,占总量26.90%;玉米田间秸秆为14 947.83万t,折标煤量8 266.15万t,占总量24.23%;小麦田间秸秆为14 373.43万t,折标煤7 833.52万t,占总量22.96%。秸秆量最大的10个省份由高到低依次为河南、山东、江苏、黑龙江、安徽、四川、广西、湖南、河北、湖北,变化范围为3 772.15～7 295.06万t,折标煤为1 908.83～3 999.61万t,这10省总量占全国总量62.46%。田间秸秆成熟时间分布不均,第三季度（7―9月）最多,秸秆折标煤占总量44.49%;其次为第四（10―12月）和第二季度（4―6月）,分别为25.26%和24.27%;第一季度（1―3月）最少,只占总量的1.37%。

English. To accurately assess the quantity and spatio-temporal distribution of crop residues is essentially important for its sustainable utilization in China.The residue quantities of all the field crops among 31 provinces in mainland China were evaluated by using the latest crop residue index（CRI） based on different province or region.The residue quantities were calculated as standard coal equivalence（SCE） according to the heating value of each crop residue from original papers.During 2007 and 2009 in China,the annual crop residue production was estimated as 735 Mt which was composed of 646 Mt field residues（341 Mt SCE,87.36% SCE） and 89 Mt process residues（50 Mt SCE,12.64% SCE） based on air dried weight.The field residue of cereal crops was evaluated to be 492 Mt（253 Mt SCE） annually,accounting for 74.10%（SCE） of the total field residue,which was including three main crops,i.e.rice residue weight 198.65 Mt（91.78 Mt SCE,26.90%SCE）,maize residue weight 149.48 Mt（82.66 Mt SCE,24.23% SCE） and wheat residue weight 143.73 Mt（78.34 Mt SCE,22.96% SCE）,respectively.Changes in crop residue quantity was varied from 37.72 Mt（19.08 Mt SCE） in Hubei to 72.95 Mt（40.00 Mt SCE） in Henan province,and the top ten provinces were Henan,Shandong,Jiangsu,Heilongjiang,Anhui,Sichuan,Guangxi,Hunan,Hebei and Hubei.Moreover,the highest field residue quantity was harvested between July and September,accounting for 44.49%（SCE） of crop residues;and only 1.37%（SCE） between January and March.