土壤微生物量氮的动态及其生物有效性研究
The dynamics of soil microbial biomass nitrogenand its biological availability
-
摘要: 采用盆栽试验和15N示踪技术对玉米生长期间不同施肥处理黑土土壤微生物量氮的动态变化及其与土壤氮素组分、玉米吸氮量之间的关系进行研究。结果表明,在玉米生长期间,施肥并没有影响土壤微生物量氮的变化趋势,但不同施肥处理土壤微生物量氮的含量明显不同。玉米植株残体的加入,增加了土壤微生物量氮的数量,降低了土壤微生物对肥料15N的释放率。土壤微生物量氮与土壤全氮含量呈极显著的正相关(r=0.727**),与土壤碱解氮及玉米吸氮量之间均呈显著正相关(相关系数分别为0.528* 和0.536*)。土壤微生物量氮和土壤氮素组分对作物吸氮量的通径分析表明,土壤微生物量氮的有效性近于土壤矿质态氮、高于土壤酸解有机氮和非酸解氮。土壤微生物量氮是作物吸收氮素的有效来源。Abstract: Based on pot experiment and isotope 15N tracer, the dynamics of soil microbial biomass nitrogenduring different corn growing stages in black soil was investigated and its biological availability was discussed The results indicated that the content of soil microbial biomass nitrogen of different treatments was different and its changes followed the similar trend during corn growing period Corn stalk and stubble rationing application of chemical fertilizer, in comparison with single application of chemical fertilizer, would result in the increase of the rate of fertilizer 15N immobilization and decrease of the rate of release of fertilizer 15N by microbes There existed significant correlations between soil microbial biomass nitrogen and soil total nitrogen, alkalihydrolysable N, corn uptake N( correlation coefficient were respectively 0.727**, 0.528* and 0.536*) Path analysis showed that the availability of soil microbial biomass nitrogen was similar to soil mineral nitrogen, above acidhydrolyzed organic nitrogen and acidinsoluble nitrogen The soil microbial biomass nitrogen was an available pool corn absorbing nitrogen from soil
下载: