微生物菌肥对高寒草甸土壤养分的影响

Soil nutrient variation at using microbial fertilizer on alpine meadow in Qing-Tibet plateau

采用纤维素分解菌肥、联合固氮菌肥、EM混合菌肥3种微生物菌肥配以水分添加和划破草皮等方法对退化高寒小嵩草草甸进行土壤养分改良,以土壤中速效养分含量及pH变化评价改良状况。结果表明,退化高寒小嵩草草甸土壤中添加微生物菌肥＋划破草皮处理与对照相比,没有明显改变0~20cm土层速效磷含量、速效钾含量和pH剖面分布特征;不同微生物菌肥＋划破草皮处理明显改变土壤中速效氮含量的分布特征,其中,EM处理明显提高土壤表层硝态氮含量,CD处理明显提高土壤中表层氨态氮含量,CD和EM处理可以显著提高土壤表层速效氮（硝态氮＋氨态氮）含量,但单纯划破草皮G处理只能改变不同形式的速效氮在土壤垂直剖面中的分布格局,没有明显提高土壤中速效养分含量。因此,采用EM和CD处理均可以改善土壤中速效氮缺乏的现状,但作用微弱,可能同选用的微生物菌肥在青藏高原高寒恶劣气候条件下活性变弱有关。筛选或分离适应高寒草甸生态系统生存的微生物菌肥再配以适宜的施用方法可改善退化草地土壤养分状况。

Utilizing cellulose decomposition,nitrogen fixation and EM microbial fertilizer and other alpine meadow soil improvement methods such as water addition and cut the mattic epipedon to investigate how the degradation alpine meadow soil nutrient dealt with those improvements,the results showed that：microbial fertilizer and other alpine meadow soil nutrients improvements methods did no effects on ameliorating available phosphorus,available potassium and pH value condition in 0~20cm soil layer.While there were some effects on available nitrogen.EM microbial fertilizer＋ cut mattic epipedon treatment could enhance the nitrate content,cellulose decomposition microbial fertilizer＋cut mattic epipedon treatment could increase the ammonia content in 0~5cm soil layer.And cellulose decomposition microbial fertilizer＋ cut mattic epipedon treatment and EM microbial fertilizer＋ cut mattic epipedon treatment could raise the available nitrogen including the sum of ammonia and nitrate content.And cut mattic epipedon treate could not enhance the nitrogen in the 0~20cm soil layer,but could chang the distribution on different soil layer.So using microbial fertilizer on soil and using the cut mattic epipedon method could improve the degradation alpine soil nutrient,but the effects were so little,maybe it was decreased the active of the microbial fertilizer in alpine meadow environment,because the environment was so bad,and the most of microbial could not live in those environment.So in the next research,to choose the microbial fertilizer which can adapt alpine meadow environment is the most important study both in improving soil nutrient condition,and in restoring the degradation alpine meadows.