Soil Microbial Activity and Biomass as Influenced by Tillage and Fertilization in Wheat Production

Abstract

Tillage systems and fertilization play an important role in crop growth and soil improvement. This study was conducted to determine the best tillage and fertilization system for wheat production. Experiments were arranged in a split plot based on randomized complete block design with three replications in 2008-09 and 2009-10 growing seasons. Main plots consisted of no tillage (T1), minimum tillage (T2) and conventional tillage (T3). Six methods of fertilization including (N1): farmyard manure; (N2): compost; (N3): chemical fertilizers; (N4): farmyard manure + compost; (N5): farmyard manure + compost + chemical fertilizers and (N6): control were arranged in sub plots. Addition of compost or farm yard manure significantly increased soil microbial biomass carbon in comparison with chemical fertilizer. No tillage system increased microbial biomass carbon compared to other tillage systems. The dehydrogenase, phosphatase and urease activities in the N3 treatment were significantly lower than in the farm yard manure and compost treatments. Urease activity under T1N4 treatment in the two years of our study was the highest of all treatments. N5 treatment had a significant difference with other treatments. The highest rate of grain yield was produced in minimum tillage system.