The effect of biological fertilizers on quantitative and qualitative characteristics of bean (Vigna unguiculata L. Walp) in drought stress condition

Introduction One of the principles of sustainable use of bio-fertilizers and livestock in agricultural ecosystems in order to eliminate or reduce the use of chemical inputs.bio-fertilizers as an alternative and in most cases as a complement to chemical fertilizers can ensure the sustainability of agricultural systems (Han et al., 2006). Bio-fertilizers consisting of micro-organisms are useful that each one are produced for a specific purpose, such as nitrogen fixation, release of phosphate ions, potassium, iron, etc.These microorganisms are usually deployed around the roots, and plants will help nutrient absorption (Wu et al., 2005) and reduce plant disease, improve soil structure, further stimulate plant growth and increase in quantity and quality and to are increase its resistance to environmental stresses (Nagananda et al., 2010). Material and Methods The study in year 2014 with split plot experiment in a randomized complete block design with three replications. Main plot include drought stress with 3 levels (control, 50% water deficit, 90% water deficit and 75% water deficit) and sub plot was bacteria inoculation with tree levels (control, Azotobacter, Phosphate Barvar 2). Before conducting the experiment and to inform the physical and chemical soil sampling soil from a depth of zero to thirty centimeters and meters.Each plot consists of 4 lines of planting 3m in length and line spacing was 50 cm. Bean seeds, bio-fertilizers based treatments were impregnated and then planted. Based on experimental treatments of bio-fertilizers on the basis of 100 grams per hectare were impregnated and then cultivation. Results and disscussion The results were indicated that bio fertilizer on grain yield was significant. The results of the data analysis were showed that plant height is influenced by inoculation with biofertilizers and different levels of drought stress was significant. Bio-fertilizer was increased plant height, so that the maximum height of Phosphate Barvar 2 fertilizer treatments with an average of 75 cm -2 showed that compared to control and Azetobacter 40.34 and 16.79 percent respectively. Drought stress reduced plant height so that the maximum height of 50 percent of water deficit with an average 67.44 cm and minimum height was achieved of 90 percent of allowable deficit with an average 60.67 cm. The hight of pod length was obtained in biological phosphorous with an average of 13.11 cm was achieved compared to the control (no bio fertilizer) and Azotobacter fertilizer consumption increased by 135 and 31.89 percent. Also, the maximum of pod length was obtained at 50% water deficit that compared to other treatment (70 and 90% water deficit) was increased 8.12 and 20.67 percent respectively. Analysis of variance was showed that bio fertilizer in 1% level and drought stress treatments at 5% level was significant different on biological yield of bean. The highest and lowest biological yield was obtained of 50 % water deficit with 3704.11 kg/ha and 90% of the water deficit with 3505.78 kg/ha.The highest of economical yield obtained of biological phosphorous and 50% water deficit 2344 kg/ha.The greatest number of seeds per pod obtained in treatment of biological phosphorous an (9.76) that compared to the control (no bio-fertilizer), was increased 70.55%. The highest seed weight was observed in biological phosphorous with 16.95 grams and the lowest seed weight was obtained with 10.60 grams of control treatment. Overall, the results indicate that the seed inoculation with biological phosphorous can increase biomass, grain yield and components yield.