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

A FIELD experiment was conducted in Burg El Arab region, Egypt,.to investigate the influence of five fertilization treatments and three tillage systems on wheat productivity, soil microbial biomass and some enzymes activity. Fertilization treatments were control (without treatment) (F1), Farmyard manure (F2), Compost (F3), Mineral fertilizers (F4) and a mixture of farmyard manure + compost + chemical fertilizers (F5). Tillage systems were no-tillage (NT), minimum tillage (MT) and conventional tillage (CT). Experiments were designed in a split plot based on randomized complete block design (RCBD) with three replications in 2010-11 and 2011-12 growing seasons. Main plots were the tillage systems while the fertilization treatments were arranged in sub plots. The highest rate of grain yield was produced in MT system under F5 treatment. CT system showed the average reduction in grain yield of about 17% than MT; while CT showed average increasing of about 4% than NT in wheat grain yield. MT and NT systems increased soil microbial biomass compared to CT. Farm yard manure or compost applications increased soil microbial biomass significantly compared with mineral fertilizer. The urease, dehydrogenase and phosphatase activities in the F4 treatment were significantly lower than in the other fertilizer treatments F2, F3, and F5. The highest value of urease activity was under NT + F2 treatment in the two years of this study.