The Effect of Using Chemical Nitrogen Fertilizer and Biological Fertilizer on Seed Yield and Protein Percent of Cowpea (Vigna unguiculata L.)

To study the possibility of reducing the consumption of nitrogen fertilizer using biological fertilizer on yield and yield components of cowpea. A factorial experiment in a randomized complete block design with three replications was conducted at Darreb Shahr in 2012. The first factor, which was at 3 levels of urea nitrogen, containing 0, 50 and 100 kg nitrogen per hectare, and the second factor was the biological fertilizer Nitroxin at 3 levels containing no inoculation, inoculation rate of 1 ml per 60 kg seeds and spraying a rate of 3 liters per ha. The results showed that protein content of seed inoculated with bio-fertilizer nitroxin was 24.96 percent which is one percent more than non-inoculated seeds. The amount of protein obtained in application of nitrogen was also more than non-application treatment and the difference between them was significant. The interaction of urea fertilizer and bio-fertilizer, resulted in highest and the lowest yield in seeds inoculated with 50 kg of urea fertilizer and no fertilizer application biological fertilizer no fertilizer urea in 2046 and 1336 kg per hectare, respectively. All levels of nitrogen in the highest and the lowest yield was in a state of inoculation and non-application. Generally the results showed that the use of biological fertilizers can be used as part of the nutrients needed by cowpea, Also, if Nitroxin was supplemented with lower amounts of urea fertilizer seed yield may be increased seed yield may be improved.