秸秆还田对瘠薄红壤水稻土团聚体内酶活性及养分分布的影响  

Enzyme Activities and Soil Nutrient Status Associated with Different Aggregate Fractions of Paddy Soils Fertilized with Returning Straw for 24 Years

作　　者：李委涛 李忠佩[1,2] 刘明[1] 江春玉[1] 吴萌[1] 陈晓芬[1,2] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008 [2]中国科学院大学,北京100049

出　　处：《中国农业科学》2016年第20期3886-3895,共10页Scientia Agricultura Sinica

基　　金：国家自然科学基金(41171233);国家重点基础研究计划(2013CB127401)

摘　　要：【目的】研究秸秆还田配施粪肥与化肥对红壤水稻土水稳性团聚体粒级组成、团聚体微域空间内养分及酶活性分布的影响,为提高秸秆还田在改造中低产田中的利用效益提供理论依据。【方法】依托于鹰潭农田生态系统国家野外科学观测研究站24年(1990—2014)的长期定位试验,施肥处理包括:不施肥处理(CK)、全量秸秆还田配施粪肥(SM)、全量秸秆还田配施粪肥与氮肥(NSM)、全量秸秆还田配施粪肥与氮磷钾肥(NPKSM)。利用湿筛的方法得到5个粒级的水稳性团聚体:>2 mm、1—2 mm、0.25—1 mm、0.053—0.25 mm和<0.053 mm。测定水稳性团聚体内C、N、P养分含量以及转化酶、脲酶和酸性磷酸酶活性。【结果】长期秸秆还田配施粪肥尤其是配施化肥显著增加了大团聚体(>0.25 mm)含量,降低了微团聚体(<0.25 mm)的含量,增大了水稳性团聚体平均当量直径,显著改善了土壤团粒结构。秸秆还田配施粪肥与化肥显著提高团聚体微域空间内的酶活性,NSM处理对团聚体内转化酶和脲酶的活性影响最为显著,NPKSM处理对团聚体各粒级内酸性磷酸酶活性影响最为显著。与CK相比,NSM处理的转化酶在5个粒级内增加量是20.3%—396.2%,脲酶的增加量是58.6%—372.1%。NPKSM处理的酸性磷酸酶在各粒级的增加量是48.9%—94.5%。与CK相比,NSM处理下,有机碳在各个粒级的增量是31.6%—65.1%;全氮在各粒级内的增加量是19.8%—51.9%;NPKSM处理下,速效磷含量在各粒级内的增加量最大是:7.4—10倍;集成推进树(ABT)分析表明,有机碳对转化酶活性影响最大,占40.6%。团聚体粒级组成对脲酶活性的相对影响最大,占44.9%;速效磷对酸性磷酸酶的活性影响最大,占41%。非度量多维尺度(NMDS)对团聚体样本排序结果显示,与CK、SM和NSM相比,NPKSM处理对土壤理化性质的影响更为显著,SM及NSM处理的肥效性相似。【结论】秸秆还田与粪肥、化肥配合施用[Objective] Paddy soils in subtropical China derived from Quatemary red clay are generally deficient in available nutrients, and fertilizers have long been identified as dominant contributors to increase of crop production. Therefore, a long-term experiment was set up in a paddy field that used to be a wasteland earlier to study the distribution of nutrients and enzyme activities in water stable aggregates under long term application of fertilizers, and the findings will provide a sound basis for rational application of fertilizers to ensure sustainable crop production. [Method] Soil samples were collected from a 24-year long-term field experiment, which was established in 1990 in the Yingtan Red Soil Ecological Experiment Station. The experiment included four treatments： CK （without fertilization）, SM （straw application plus manure）, NSM （straw application plus manure and nitrogen fertilizer）, NPKSM （straw application plus manure, nitrogen, phosphorus and potassium fertilizers）. Undisturbed bulk soils were separated into five aggregate-size classes （〉2 mm, 1-2 mm, 0.25-1 mm, 0.053-0.25 mm and 〈0.053 mm） by wet sieving. Three soil enzymes, invertase, urease, and phosphatase, in water-stable aggregates （WSA） and total nitrogen （TN）, available phosphorus （AP）, and soil organic C （SOC）were determined. [ Result ] Application of fertilizers to infertile paddy soil significantly increased the percentage of macro aggregates （larger than 0.25 mm）, decreased the percentage of micro aggregates （smaller than 0.25 mm）, and increased the mean weight diameter （MWD） of WSA, which could improve soil structure. The combined application of straw, manure and inorganic fertilizer significantly increased the soil enzyme activities in each size fraction. NSM treatment had the largest impact on invertase and urease activities. NPKSM treatment had the most significant impact on acid phosphatase activity. Compared with the control, NSM treatment increased invertase activity in five si

关 键 词：红壤性水稻土 秸秆还田 水稳性团聚体 土壤养分 土壤酶活性 

分 类 号：S141.4[农业科学—肥料学]