间作白三叶促进苹果园土壤碳循环的机制

Mechanism of intercropping white clover to promote soil carbon cycling in apple orchard

【目的】为了探明间作白三叶对苹果园土壤碳循环的影响机制。【方法】设置平邑甜茶幼树间作芳香植物白三叶处理,清耕为对照,在种植白三叶120 d后,分别取清耕处理平邑甜茶根际土(CF)、间作白三叶处理平邑甜茶根际土(TF)和白三叶根际土(TT),对土壤基本理化性质、微生物生物量、碳循环相关酶以及不同形态碳等养分指标进行检测。【结果】结果表明,间作白三叶能够显著降低平邑甜茶幼树根际土的pH和含水量,提高微生物总生物量,降低真菌和革兰氏阳性菌生物量,提高纤维素酶和脲酶活力,降低转化酶和淀粉酶活力,提高可溶性有机碳、易氧化有机碳含量和碳库活度指数,进而提高了全氮、全磷、全钾、碱解氮、速效磷、速效钾以及锰含量,降低C/P比以及钙和钠含量。【结论】结果表明,间作白三叶可以通过改变平邑甜茶幼树根际土微生物生物量来影响转化酶活力,从而提高土壤中易氧化有机碳含量,促进果树根际土壤碳循环和养分供应。

[Objective]In order to explore the effect mechanism of intercropping white clover on soil carbon cycle in apple orchard.[Methods]The Malus hupehensis Rehd were treated Trifolium repens L.intercropping,and the clear tillage was the control.After 120 days of planting white clover,the clear tillage Malus hupehensis Rehd rhizosphere soil(CF),the Trifolium repens L.intercropping treatment Malus hupehensis Rehd rhizosphere soil(TF),and the Trifolium repens L.root rhizosphere soil(TT)were selected.Soil's basic physical and chemical properties,microbial biomass,carbon cycling-related enzymes,and different forms of carbon were tested.[Results]The results showed that interplanting Trifolium repens L.could significantly reduce the pH and water content of rhizosphere soil of young Malus hupehensis Rehd,increase the total microbial biomass,decrease the biomass of fungi and G+,increased the activity of cellulase and urease,reduced the activity of invertase and amylase,increased the content of dissolve organic carbon,readily oxidizable carbon and carbon pool activity index,which in turn increased the content of total nitrogen,total phosphorus,total kalium,Alkali-hydrolyzable nitrogen,available phosphorus,available potassium and Mn,and reduced the content of C/P ratio,Ca,and Na.[Conclusion]These results suggest that intercropping Trifolium repens L.can influence the activity of invertase by altering the rhizosphere soil microbial biomass of young Malus hupehensis Rehd,thereby increasing the easily oxidizable organic carbon content of the soil and promoting rhizosphere soil carbon cycling and nutrient supply in fruit trees.