Effects of application of Kara biological fertilizer on the grain yield of Hashemi rice variety

Nitrogen has known as a key element that affects rice grain yield more than other nutrient elements. To satisfy nitrogen requirement of crops, chemical fertilizers specially urea are used in which can tend to pollution of surface and underground water resources. Application of biological fertilizers cotaining N-fixing bacteria is one of the most interested approach to reduce chemical fertilizers application and supply some part of plant nutrient demand. A famous and important group of these bacteria is known as Rizobacteria. Thus to evaluate the effect of Kara biological fertilizer application on the grain yield of Hashemi rice variety , this research was conducted in RRII adopting a RCBD with three replicates at 1388. The treatments were as follow: 1- Control (without any fertilizer) 2- application of chemical fertilizers as recommended rates (without biological fertilizers) 3- application of 70% recommended urea + inoculation of rice seedlings with Kara biological fertilizer 4- application of 70% recommended urea + foliar application of Kara biological fertilizer every 8 weeks interval 5- application of 60% recommended urea + inoculation of rice seedlings with Kara biological fertilizer and 6- application of 60% recommended urea + foliar application of Kara biological fertilizer every 8 weeks interval. In the ripening stage the rice crop have harvested from 5 m2 and rice grain yield have measured at 14% moisture content. The results have shown that application of Kara biological fertilizer had significant effects on grain yield and harvest index at 1% level, and on straw yield and tiller number at 5% level, while had no significant effect on plant height. According to obtained data and statistical analysis it can be concluded that inoculation of rice seedlings with Kara biological fertilizer when 60% of recommended N for Hashemi rice variety applied, regarding to heighest yield production is recommendable.