不同保护性耕作措施对三种土壤微生物氮素类群数量及其分布的影响  

Effects of different conservation tillage on amount and distribution of soil ammonifying bacteria,nitrobacteria and nitrogen-fixing bacteria

作　　者：赵有翼[1,2] 蔡立群[1] 王静[1] 张仁陟[1] 

机构地区：[1]甘肃农业大学资源与环境学院,甘肃兰州730070 [2]兰州城市学院,甘肃兰州730070

出　　处：《草业学报》2009年第4期125-130,共6页Acta Prataculturae Sinica

基　　金：国家科技支撑计划项目(2006BAD15B06);国家自然基金项目(40771132)资助

摘　　要：通过设置在陇中黄土高原丘陵沟壑区的长期定位试验，研究了不同保护性耕作措施下旱作春小麦一豌豆轮作系统中土壤氨化细菌、硝化细菌和自身固氮菌数量及其分布的差异。结果表明，无论是小麦地还是豌豆地，土壤氨化细菌、硝化细菌、自身固氮菌数量在0～5，5～10和10-30cm土层中均呈现免耕秸秆覆盖〉秸秆还田〉免耕不覆盖〉传统耕作的趋势，且随着土层的加深，在小麦地中，免耕秸秆覆盖处理的氨化细菌数量比免耕不覆盖处理分别增加了76．21％，146．92％和67．82％，且差异均达到5％的显著水平，在豌豆地中，各处理自身固氮菌数量逐渐减少，而硝化细菌数量呈先增加后减少的趋势，免耕秸秆覆盖、秸秆还田处理土壤氨化细菌数量逐渐下降，而免耕不覆盖、传统耕作处理的土壤氨化细菌数量先增加后减少。Field experiments were conducted in Dingxi, in the western Loess Plateau, on the effects of tillage on soil ammonifying bacteria, nitrobacteria and nitrogen-fixing bacteria under a rotation system with spring wheat and pea. The treatments were conventional tillage and three conservation agriculture patterns. Conventional tillage （T）, conventional tillage with stubble incorporation （TS）, no till with no straw cover （NT）, no till with straw cover （NTS） The amount of soil ammonifying bacteria, nitrobacteria and nitrogen-fixing bacteria from high to low was NTS, TS, NT, and T in the 0-5, 5-10, and 10-30 cm depths of soil under two rotation fields. The amounts of soil ammonifying bacteria in NTS at these three depths was 76.21%, 146.92%, 67.82 % respectively, higher than that in NT. Soil nitrobacteria and nitrogen-fixing bacteria initially increased, then decreased in all treatments in spring wheat fields. However, soil nitrogen-fixing bacteria decreased with soil depth, while nitrobacteria initially increased, then decreased in pea fields. Ammonifying bacteria decreased with soil depth in NTS and TS, but initially increased, then decreased in NT and T.

关 键 词：保护性耕作措施 土壤氨化细菌 硝化细菌 自身固氮菌 

分 类 号：S154.36[农业科学—土壤学]