摘要
【目的】研究秸秆和地膜覆盖旱作冬小麦田土壤团聚体分布规律及与有机碳的关系,为探讨覆盖方式对土壤团聚作用的影响,优化黄土高原旱作农田耕作措施提供理论依据。【方法】冬小麦覆盖试验开始于2008年,试验设计4个处理:冬小麦种植期间无覆盖对照(CK)、全年覆盖秸秆9000 kg/hm^2(M1)、全年覆盖秸秆4500 kg/hm^2(M2)和全年地膜覆盖(PM)。利用干筛法和湿筛法筛分了2014年收获期0-10 cm和10 20 cm土层中>5 mm、5~2 mm、2~1 mm、1~0.5 mm、0.5~0.25 mm和<0.25 mm粒级的团聚体,计算团聚体平均重量直径(MWD)和几何平均直径(GMD),并分析了覆盖方式对土壤总有机碳的影响及其与土壤团聚体的关系。【结果】1)秸秆覆盖显著提高了0-10 cm土层>0.25 mm土壤机械稳定性团聚体含量m1和M2处理较CK处理分别提高了5.1%和2.0%;秸秆和地膜覆盖均可提高10-20 cm土层>0.25 mm机械稳定性团聚体含量,M1、M2和PM处理较CK处理分别提高了7.6%、4.3%和3.1%。2)秸秆覆盖有利于0-10 cm土层>0.25 mm水稳性团聚体的形成M1和M2处理较CK处理分别提高了6.8%和5.0%PM处理与CK处理无显著差异;覆盖处理对10-20 cm土层水稳性团聚体影响不显著。3)秸秆和地膜覆盖均有利于0-10 cm土层土壤团聚体稳定性的提高,M1、M2和PM处理平均重量直径值较CK处理分别提高47.8%、24.7%和24.6%几何平均直径值分别提高了48.9%、34.8%和31.6%。4)秸秆覆盖有利于提高土壤有机碳含量在0-10 cm土层M1和M2处理较CK处理有机碳含量分别提高了11.9%和6.3%在10 20 cm土层分别提高4.2%和4.5%,地膜覆盖对土壤有机碳的积累无促进作用。在0-10 cm土层土壤有机碳含量与>0.25 mm水稳性团聚体含量呈显著正相关。【结论】秸秆覆盖处理可提高土壤大团聚体含量提高团聚体的水稳性,改善土壤结构,同时可增加土壤有机碳含量提高土壤肥力,且覆盖量越大效果越明显。地膜覆盖对土壤结构
[Objectives]Study on the effect of different mulching treatments on soil aggregates and their relationships with soil organic carbon,will help selecting the sustainable mulching measures for the loess hilly region of China.[Methods]The field experiment was carried out in 2008.Four treatments were included as control without mulching treatment（CK）,straw mulching at a rate of 9000 kg/hm2（M1）,straw mulching at a rate of 4500 kg/hm2（M2） and plastic film mulching（PM） during winter wheat growing season.Soil samples were collected at layers of 0-10 cm and 10-20 cm in 2014 after crop harvest,soil aggregates were separated into 5mm,5-2 mm,2-1 mm,1-0.5 mm,0.5-0.25 mm and 0.25 mm and were determined by using dry sieving method and wet sieving method.The mean weight diameter（MWD） and geometric mean diameter（GMD） were calculated and the content of soil organic carbon was also measured.[Results]1） Compared with CK,soil mechanical-stable macroaggregates content was increased by straw mulching,the increase in the 0-10 cm soil layer was 5.1%in M1 and 2.0%in M2 treatment,respectively.Both straw and plastic film mulching improved the macroaggregate contents in 10-20 cm soil layer,with significant increase of 7.6%,4.3%and 3.1%in M1,M2 and PM,respectively.2） Compared with CK,the contents of water-stable macroaggregates（0.25 mm） in M1 and M2 were increased by 6.8%and 5.0%in 0-10 cm soil layer,respectively,mulching with plastic film had no significant effect.3） All the straw mulching and plastic film mulching treatments improved the values of MWD and GMD in 0-10 cm soil layer significantly.Compared with CK,the soil MWD was increased by 47.8%,24.7%and 24.6%,and the GMD was by 48.9%,34.8%and 31.6%in M1,M2 and PM treatments.4） Soil organic carbon content was increased by straw mulching.Soil organic carbon content was in turn 11.9%and 6.3%higher in 0-10 cm layer,and 4.2%and 4.5%higher in 10-20 cm layer in M1 and M2 than in CK,respectively.Plastic film mulching had no effect on soil organic carbon sequest
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2015年第6期1423-1430,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(31270484
31570440)
西北大学研究生自主创新项目(YZZ13006)资助
关键词
秸秆覆盖
地膜覆盖
土壤团聚体
土壤有机碳
straw mulching
plastic film mulching
soil aggregates
soil organic carbon
