Influence of Nitrogen Sources and Bio-fertilizer on Soil Nutrients, Yield and Quality of Cowpea under Saline Soil Conditions

Two field experiments were conducted at El-Rod village at Sahl El-Houssinia, El-Sharkia governorate, (32°15' 00" N 30°50' 00" E), Egypt. The study investigated evaluations of different nitrogen fertilizers sources (calcium nitrate, ammonium sulphate and urea fertilizers) and rates (0, 47.6, 71.4 and 107 kg N/ha) alone or combined with bio-fertilizer (using bio-fertilization with Rhiobium radiobacter sp strain on improve nutrients available and contents in cowpea productivity and quality in newly reclaimed saline soil conditions during two summer seasons 2017 and 2018. The studies treatments were disturbed among the experimental pelts in split design with six replicates. The obtained results cleared that the used ammonium sulphate fertilizer was increase effect with increasing rate in EC, pH, and available N, P, K , Fe, Mn and Zn content in soil. Moreover data recorded the applied 71.4 kg N /ha was increase of plant height, weight of 100 seeds, weight of pods (g/plant) , weight of seeds (g)/plant and seeds yield (ton ha-1) have been affected by inoculation with bio-fertilizer combined with nitrogen sources fertilizers and different rates than other treatments. The highest values of N, P , K, Fe, Mn and Zn concentrations and uptake in seeds treated with ammonium sulphate at rate 71.4 kg N/ha than other treatments. The decrease of the soil salinity to increased content of cowpea plant of chlorophyll and protein, but increased salinity of the soil led to increase the content of the plant of proline. The application of ammonium sulphat at 30 kg N/fed combined with bio-fertilizer was improve soil properties and cowpea productivity and quality under saline soils conditions.