外源碳磷的加入对农田土壤微生物碳磷比及磷素有效性的影响  

Effect of Additional Carbon,Phosphorus on the Soil Microbial Biomass Carbon Phosphorus Ratio and Phosphorus Availability

作　　者：李春越[1,2,3] 王益[4] Philip Brookes 党廷辉[3] 王万忠[3] 

机构地区：[1]陕西师范大学西北国土资源研究中心,西安710062 [2]英国洛桑研究所农业与环境中心,英国赫特福德郡AL52JQ [3]西北农林科技大学水土保持研究所,陕西杨凌712100 [4]中国科学院地球环境研究所,西安710075

出　　处：《西北农业学报》2012年第11期113-117,共5页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：国家自然科学基金青年项目(41201259);陕西省科学计划自然基金项目(2011JQ5014);陕西师范大学中央高校基本科研业务费专向资金项目(10SZYB27)

摘　　要：设置室内培养试验,在较低养分和碳素质量分数的农田土壤中,通过加入外源的高、中、低质量分数的无机磷和碳源黑麦草基质的方式,研究不同梯度的磷素质量分数和不同培养时间序列的土壤微生物磷、微生物碳磷比的变化规律以及磷素利用的有效性。结果表明,低养分条件下外源无机磷的加入对土壤微生物碳的影响不大,黑麦草的加入引起微生物碳的巨大变化,即碳素的多少对于微生物碳的变化起着重要作用。低碳条件下,无机磷的加入对微生物磷的影响不大,而加入黑麦草后较高碳素质量分数下,微生物磷出现巨大变化,说明碳源多少对于微生物磷起着重要作用。微生物磷具有较快的周转周期。微生物碳磷比波动比较大,加入外源物质以后,分别在第5天和第25天出现高峰,大多数在第10天前后出现低谷,也就是第10天前后微生物活性较大,微生物磷质量分数较高,磷素利用较为活跃。可见,速效磷与微生物磷和微生物碳磷比具有很好的相关性,分别呈对数函数和二项式函数关系。The soil microbial biomass phosphorus is an extremely important source of plant phosphorus nutrition. It plays an important role in soil phosphorus supply and regulation and its changes are influ- enced by many factors. In this study, try to know the different gradient phosphorus pigment mass fraction and different culture time series of soil microbial phosphorus, microbial carbon-phosphorus ratio variation, as well as the validity of the use of phosphorus by indoor culture experiments and by adding exogenous high, medium and low mass fraction of inorganic phosphorus and the carbon source ryegrass matrix in lower nutrient and carbon mass fraction of farmland soil. The results show that,ex- ogenous inorganic phosphorus in low nutrient conditions added little effect on soil microbial carbon, but the adding of ryegrass caused tremendous change on the microbial carbon. That＇s to say, how much of the carbon plays an important role in the changes of microbial carbon. The adding of the inor- ganic phosphorus has little influence on the microbial phosphorus in low-carbon conditions, while in the higher carbon mass fraction by adding ryegrass, microbial phosphorus change greatly. So how much of the carbon source plays an important role on microbial phosphorus. Microbial phosphorus has a faster turnaround cycle and microbial carbon-phosphorus ratio is fluctuated greatly, peak in 5 d and 25 d respectively, the trough in 10 d mostly after the addition of exogenous substances. That is about the tenth day, larger microbial activity, higher microbial phosphorus mass fraction and more active phosphorus utilization. Available phosphorus, microbial phosphorus and microbial carbon-phosphorus ratio have good correlations and are respectively logarithmic function and binomial function.

关 键 词：土壤微生物生物量 碳磷比 农田 磷素有效性 

分 类 号：S154.3[农业科学—土壤学]