The Effect of Inoculation with Azotobacter and Nitrogen Levels on Grain and Corn Yield Components at Simultaneous Cropping System with Legumes

Corn has been regarded as one of the important crops from the view point of both human and animal feeding resource. Intercropping defined as cultivation of two or more species together. The advantages of intercropping can be included: efficient use of water and sunlight, exchange of nutrients, weed competition reduction, reduction of pathogens and the increase of soil fertility. Research shows that intercropping combinations of legume–grass will increase forage quality. Because, grasses Grains have a lot of carbohydrates and legumes are rich in protein and vitamins. This study was conducted to evaluate the effect of inoculation with azotobacter and nitrogen levels on grain and corn yield components at simultaneous cropping system with legumes under the weather conditions of Markazi province.
This study was carried out at agricultural research field of Payame Noor University, Arak Branch during 2011. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Methods of plant nutrition (M0= inoculation with azotobacter, M1= inoculation with azotobacter 37/5 Kg ha-1 of rare nitrogen with foliar application method, M2= inoculation with azotobacter 150 Kg ha-1 of rare nitrogen mix with soil) and simultaneous cropping treatment of legumes, [S1= corn alfalfa (Medicago sativa L.), S2= corn bitter vetch (Lathyrus sativus L.), S3= corn mung bean (Vigna radiata L.), S4= corn chickpea (Cicer arientinum L.), S5= corn vetch (Vicia ervillia L.) ] were assigned in plots. Each sub plot consisted of 4 rows, 6 m long with 60 cm between rows space and 20 cm between plants on the rows and S.C Apex hybrid was used. In this study characteristics such as: plant height, earing height, the number of grains per m-2, the number of rows per ear, the number of grains per row, surface of ear leaf, grain yield of corn, 1000 grain weight, harvest index of corn, nitrogen use efficiency, dry weight of legumes were assessed. After analyzing the data, the means by Duncan multiple range test were compared to five percent. All of the correlation coefficients were calculated and their significance was determined by Mstat-c software.
Results indicated that the effect of nutrition methods on corn characteristics such as: plant height, the number of grains per m-2, the number of grains per row, surface of ear leaf, grain yield of corn, 1000 grain weight, nitrogen use efficiency and dry weight of legumes was significant. The impact of simultaneous cropping treatment on the characteristics such as: plant height, the number of grains per m-2, the number of grains per row, corn grain yield, 1000 grain weight, corn harvest index, nitrogen use efficiency, dry weight of legumes was significant, too. Maximum and minimum grain yield (4237 and 1973 kg ha-1) were obtained with the (inoculation with azotobacter 150 Kg ha-1 nitrogen fertilizer Simultaneous cropping system of vetch and corn) and (inoculation with azotobacter Simultaneous cropping system of corn and alfalfa) treatments, respectively. Inoculation with azotobacter 37.5 Kg ha-1 nitrogen fertilizer simultaneous cropping system of vetch and corn with 51.7 kg kg-1 and inoculation with azotobacter 150 Kg ha-1 nitrogen fertilizer simultaneous cropping system of corn and chickpea with 10.1 kg kg-1 were the highest and lowest amount of nitrogen use efficiency.
Over the past few decades, global approach to modern agriculture, as in other human activities has been causing damage to natural resources, polluting and destroying the environment and causing ecological imbalance. Inorganic fertilizers used in agriculture cause the destruction of natural ecosystems. Therefore, combined use of bio-fertilizers, chemicals manures and nitrogen fixation by the legume will increase the quantity and quality of agricultural products. It can also be one of the most effective ways to achieve sustainable agriculture. But, application of chemical fertilizers causes soil degradation and increase the production cost.