我国水稻秸秆磷分布及其还田对土壤磷输入的贡献

Distribution of rice straw phosphorus resources in China and its utilization potential under straw return

  • 摘要: 我国水稻秸秆资源丰富,水稻秸秆还田是向土壤输入磷素的重要途径之一。对我国各省区不同季别水稻秸秆还田的土壤磷输入贡献进行测算,可有针对性地为水稻秸秆还田条件下土壤磷素优化管理及平衡调控提供科学参考和指导。本研究基于《中国农村统计年鉴》中水稻生产统计资料和文献调研参数,对2013—2018年我国主要稻区不同季别水稻秸秆磷养分资源时空分布特征以及单位播种面积水稻秸秆还田的土壤磷素输入量进行分析。结果表明,2018年我国主要稻区早稻、双季晚稻和中晚稻秸秆产量分别为2327万t、2783万t和13 527万t,长江中游和长江下游稻区的水稻秸秆资源量居于全国前列,分别占33.6%和21.8%。2013—2018年我国水稻秸秆磷(P2O5)养分产量呈缓慢增长的趋势,从2013年的59.7万t增加到2018年的62.8万t。2018年水稻秸秆磷养分资源主要分布在黑龙江(15.0%)、湖南(12.5%)、江苏(10.0%)、湖北(9.9%)和江西(9.6%)等省份。2013—2018年我国主要稻区早稻、双季晚稻及中晚稻秸秆还田的年均土壤磷养分输入量分别为13.9~15.1 kg(P2O5)·hm-2、16.0~20.9 kg(P2O5)·hm-2和19.3~29.3 kg(P2O5)·hm-2。从全国范围来看,早稻、双季晚稻和中晚稻秸秆还田下的土壤磷养分输入量平均分别为14.4 kg(P2O5)·hm-2、18.2 kg(P2O5)·hm-2和24.4 kg(P2O5)·hm-2。基于上述测算结果,建议我国主要稻区各省份在水稻特别是中晚稻秸秆还田条件下,基于秸秆磷素携入量适当调整磷肥投入量,以实现土壤磷养分收支平衡,控制农田磷养分盈余及流失风险。

     

    Abstract: Large amounts of rice straws are produced in the main rice-cultivating areas of China. Rice straw returning is a major contributor of phosphorus input in the field. Clarification of the contribution of rice straw returning to soil phosphorus input could provide scientific references and guidance for the optimization of phosphorus management and the regulation of soil phosphorus balance. Based on the rice production statistics from China Rural Statistical Yearbook and related data from a literature survey, the temporal and spatial distribution characteristics of rice straw phosphorus resources from 2013 to 2018 and the amount of straw phosphorus returning to soil per unit sown area were estimated for different rice-cultivating provinces and regions of China. In 2018, the amounts of straw from early rice, double cropping late rice, and medium and late rice in the main rice-cultivating areas of China were 23.27, 27.83, and 135.27 million tons, respectively. Rice straw was mainly produced in the Middle Reaches and the Lower Reaches of Yangtze River, accounting for 33.6% and 21.8% of the total national rice straw yields, respectively. The rice straw phosphorus resources was tended to increase from 2013 to 2018, increasing from 0.597 million tons phosphorus pentoxide (P2O5) in 2013 to 0.628 million tons P2O5 in 2018. The rice straw phosphorus resources were mainly distributed in Heilongjiang (15.0%), Hunan (12.5%), Jiangsu (10.0%), Hubei (9.9%), and Jiangxi (9.6%) in 2018. During 2013-2018, the annual average phosphorus inputs by straw incorporation in the main rice-cultivating provinces of China were 13.9-15.1 and 16.0-20.9 kg(P2O5)·hm-2 for early rice and double cropping late rice, respectively. For medium and late rice, the annual average phosphorus inputs by straw incorporation reached as high as 19.3-29.3 kg(P2O5)·hm-2. Nationally, the soil phosphorus inputs from straw incorporation were 14.4, 18.2, and 24.4 kg(P2O5)·hm-2 for early rice, double cropping late rice, and medium and late rice, respectively. Based on the results of this study, the application rate of phosphate fertilizer in different rice-cultivating provinces should be adjusted according to the contribution of rice straw returning to the soil phosphorus input. This will help to maintain the soil phosphorus balance and reduce surplus phosphorus accumulation and phosphorus loss to surface water.

     

/

返回文章
返回