含铜有机肥对土壤酶活性和微生物群落代谢的影响

Abstract

Composted manure has been used for centuries in Chinese agricultural production,however,only in recent year,there has been growing concerns over the problem caused by manure amendment,such as the buildup of salt in the soil and the potential introduction of hazardous trace elements into human diet.The objective of this experiment was to investigate the influence of Cu containing organic manure on soil enzyme activity and the functional diversity of microbial community.A pot experiment was conducted by incorporating same quantity of composts with a range of Cu concentrations,which were produced by composting the raw materials of swine manure and wheat straw spiked with 3 levels of Cu: 0 mg/kg(control),300 mg/kg(low Cu,referred to L thereafter) and 900 mg/kg(high Cu: H).The resulted soils after the cabbage harvest were used to investigate the soil enzyme activities and the diversity of microbial community function(Biolog #).The results showed that,the soil dehydrogenase activity declined by 64.75% in the low Cu containing compost treated soil and 90.66% in the high Cu compost treated soil as compared to the control treatment,suggested high Cu concentration in compost inhibits the soil dehydrogenase activity.The result of Biolog test showed that the average well color development(AWCD) of the control soil was greater than that of both the L and the H treatments during the process of the Biolog-ECO incubation.Compared with control treatment,AWCD of L and H treatments at 96 h had dropped by 3.55% and 36.59%,respectively.AWCD of H treatment was significantly lower than that of control(P0.01).The most microorganisms in control soil had higher ability to use carbon source than those in L and H treatments.The soil microbial community diversity indices had different responses,the highest Shannon index was observed on L treatment,the highest Simpson index was on H treatment,and the highest Mclntosh index and Mclntosh evenness index on control treatment.The principal component analysis demonstrated that the significant difference between the three treatments mainly depend on carbohydrate and carboxylic acids dominated carbon sources.The results indicated that the Cu contained in the composted manure significantly inhibited the soil enzyme activity and microbial metabolism.