覆膜对春小麦农田微生物数量和土壤养分的影响  

Effect of Various Mulching Durations with Plastic Film on Soil Microbial Quantity and Plant Nutrients of Spring Wheat Field in Semi-arid Loess Plateau of China

作　　者：宋秋华[1] 李凤民[1] 王俊[1] 刘洪升[1] 李世清[1] 

机构地区：[1]兰州大学干旱农业生态国家重点实验室,兰州730000

出　　处：《生态学报》2002年第12期2125-2132,共8页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目 (G2 0 0 0 0 1 860 3 ) ;国家基础研究重大项目前期研究专项资助项目

摘　　要：研究了黄绵土区不同覆膜时期对旱作麦田土壤微生物数量及其与土壤碳、氮、磷含量的关系。丰水的 1 999年 ,土壤微生物数量增长早 ,延续时间长 ,覆膜 60 d微生物数量最高 (3 3 .93 8× 1 0 6 /g dry soil) ,其次为全程覆膜 (3 2 .2 5 9× 1 0 6 ) ;干旱的 2 0 0 0年微生物平均数量只有 1 999年的 3 6.5 % ,在后期有一定降水后微生物数量才出现高峰 ,以全程覆膜数量最高(1 4.83 6× 1 0 6 ) ,覆膜 60 d次之 (1 1 .5 2 9× 1 0 6 )。 1 999年各类群微生物数量同土壤有机碳之间均呈显著或极显著负相关。2 0 0 0年相关系数几乎全面下降 ,氨化细菌、硝化细菌和反硝化细菌 ,甚至微生物总量同土壤有机碳之间都已不再显著相关。 1 999年土壤全氮同氨化细菌、硝化细菌、亚硝化细菌、解磷细菌及微生物总量均呈显著或极显著负相关 ,2 0 0 0年只与氨化细菌、亚硝化细菌、微生物总数显著负相关。土壤速效磷含量在 1 999年与解磷细菌显著负相关 ,而在 2 0 0 0年相关已不再显著。两年试验结束后 ,全程覆膜处理有机质下降 2 1 .2 % ,覆膜 60 d处理下降 1 7.2 % ,覆膜 3 0 d和不覆膜处理下降相对较小 (4 .3 %和 6.7% )。由于施用化肥 ,土壤全氮有明显升高。速效磷在 1 999生长季和随后的休闲期都有升高 ,在干旱的 2 0 0 0?Effect of various mulching durations with plastic film on soil microbial quantity and plant nutrients of the spring wheat field was investigated in semi\|arid Loess Plateau of northwest China for two years. Four treatments were employed: M 0\|no mulching, M 30 \|mulching for 30 days from sowing, M 60 \|mulching for 60 days, and M\|mulching for whole growth period. In 1999, a wet year with rich precipitation, the total soil microbial quantity increased faster and the higher level of soil microbial quantity lasted for longer time in the mulching treatments than in control. The highest quantity of soil microbes in total was recorded in the M 60 treatment with 33 938×10\+6/g dry soil, the secondary was in M treatment with 32 259×10\+6/g dry soil at the harvest stage. In 2000, a dry year, the mean quantity of all the microbes for all treatments decreased by 63 5% compared with that in 1999. Because rich precipitation occurred in the latter growth period of this year soil microbial quantity for all the treatments increased significantly, and reached the highest in M treatment with 14 836×10\+6/g dry soil, and the secondary was in M 60 with 11 529×10\+6/g dry soil at the harvest stage of spring wheat. \;Significantly negative correlation was noticed between soil organic carbon contents and the microbial quantities of various physiological properties which included ammonibacteria, nitrite bacteria, nitrate bacteria, denitrobacteria, cellulose decomposing bacteria,phosphorus bacteria and actinomycetes in 1999. In 2000, however, the correlation coefficients decreased between soil organic carbon contents and the quantities of almost all the microbes above mentioned. No significant correlation was found between soil organic carbon contents and some soil microbes such as ammonibacteria, nitrite bacteria, denitrobacteria, even the total quantity of soil microbes. Significantly negative correlation was shown between soil total nitrogen contents and the soil microbial quantities of ammonibacteria, nit

关 键 词：覆膜 春小麦 农田微生物数量 土壤养分 土壤微生物 半干旱黄土高原区 有机质 养分 

分 类 号：S154[农业科学—土壤学] S15[农业科学—农业基础科学]