Integrated Effects of Bio and Mineral Fertilizers and Humic Substances on Growth, Yield and Nutrient Contents of Fertigated Cowpea (Vigna unguiculata L.) Grown on Sandy Soils

A bio-fertigation trial was conducted at the experimental farm of National Research Centre, Noubaria, Egypt during May to August of 2010 to study the relative efficacy of bio-fertigation of liquid formulation of N-fixer (Azospirillum sp. and Azotobacter sp.) and P-solubilizer (Basillus megatheriumion with bio fertigation and humic substances gave rather equal yield. Injection of 50% recommended dose NPK as drip fertigation in combination with biofertigation of liquid formulation and humic substances was better and comparable way than the other treatments. Bio fertigation of microbial inoculums and humic substances could be used as a complementary for mineral fertilizers to improve yield and quality of cowpea under sandy soil conditions which protect the environment chemical pollution and its harmful effect on human and animal health.