Integrated Effect of Mineral, Compost and Biofertilizers on Soil Fertility and Tested Crops Productivity

Poor performance of nitrogen and micronutrients availability is one of the major factors related to crop productivity in the calcareous soil . . Maize (Individual hybrid 10) and wheat (C.V. Giza 168) cropping sequence grown on a calcareous sandy clay loam soil under field conditions of El Nubaria region, Egypt to evaluate the benefit effect of organic manure (composted rice straw) and bio-fertilizer (bio1: Azotobacter sp. and bio2: Azotobacter sp, Asosprillum sp.Bacillus negatherium and Pseudomonas sp.) for improving nitrogen and some micronutrients availability. To achieve this target, two rates of mineral N were applied, i.e., 75% and 100% of recommended N. Both two rates of applied N were obtained equally from mineral N and organic one at ratio of (1:1). The investigated maize and wheat grains were either grown without inoculation or inoculated with separate kind of bio-fertilizers (1,2). The results obtained clearly showed that the availability of N,P and K in the soil increased as well as some micronutrients availability in a calcareous soil as compared to the initial soil and consequently increased in grains and straw of maize & wheat. Concerning the nutrients content in plants, data revealed that an increasing trend of nutrients responses for the abovementioned elements in plant tissues of the studied two crops with superiority of mineral fertilizer and compost combined with bio-fertilizer at the first and second season. This is may be due to the addition of organic compost which improved the physical and chemical properties of the soil, as well as the mixture of bio-fertilizer enrich the soil by nitrogen fixation which increase soil fertility. As for, increased the supplying power of available nutrients to plants. The positive effect of bio-fertilizer may also be due to optimum soil pH which facilities maximum utilization of applied micronutrients to crops.