Tillage and manure effect on soil microbial biomass and respiration, and on enzyme activities

Application of liquid pig manure on soil for agricultural use increases the organic matter content and constitutes an important input of nutrients into the soil, increasing microbial activity through the direct addition of nutrients and microorganisms. The objective of this study was to determine the influence of both tillage and liquid pig manure application on soil microbial biomass, enzyme activities and microbial respiration in a meadow soil. The results obtained did not show any significant effect of tillage and manure on microbial biomass carbon (C) and nitrogen (N) nor on soil acid phosphatase activity. However, these treatments significantly increased microbial biomass P, urease, alkaline phosphatase and ammonification rates. The maximum microbial activity was observed in surface soil layer both under conventional tillage and zero-tillage. In fact, microbial respirations (CO2) of bacteria and actinomycetes were higher in the surface soil and increased with the level of manure. Tillage and manure application had no significant effect on fungal respiration but interaction between tillage and manure application significantly influenced soil urease and ammonification rates. Hence, we suggested that soil microbial biomass and enzyme activities were closely correlated to the N mineralization potential, N and C mineralization rates, total amounts of C or N, soil pH, ammonification rates and soil structural stability.Keywords: Microbial biomass, enzyme activities, respiration, pastures soi

Soil DNA Purification and Isolation

There is an increased interest in the extraction of nucleic acids from various environmental samples, since molecular techniques allow less biased access to a greater portion of uncultivable microorganisms. Two strategies have been developed to improve DNA recovery in terms of yield, purity and unbiased representation of the microbial diversity. Amplification of DNA from soil is often inhibited by co-purified contaminants. DNA is also suitable for PCR amplification using various DNA targets. This review presents an overview of the available methods to achieve this challenging objective. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation

Article has been reomved on author's request

Article has been reomved on author's reques