جستجوی مقالات مرتبط با کلیدواژه « promoting rhizobacteria » در نشریات گروه « زراعت »

In order to investigate the effect of bio-fertilizers on the effective physiological characteristics and to improve the performance of common bean (Phaseolus vulgaris L.) and black cumin (Nigella sativa L.) in different ratios of intercropping, a field experiment was conducted as a factorial based on a randomized complete block design with three replications; this study was carried out at the research farm of the Faculty of Agriculture, Urmia University, Iran, in 2016. Treatments included two levels of bio-fertilizers (consumption of nitrogen, phosphorus, potassium supplier bacteria) and non bio-fertilizers, and 5 planting ratios (0:100, 25:75, 50:50, 75:25 and 100:0) of common bean- black cumin. The maximum seed yield and the biological yield of black cumin (54.20 and 118.40 g m-2) were obtained by sole cropping with the use of bio-fertilizers. The percentage of oil and chlorophyll b of the black cumin was increased by 17.34 and 14.36%, respectively, in the 50:50 planting ratio; On the other hand, chlorophyll b and carotenoids of bean were increased by 13.74 and 10.38%, respectively, in the 50:50 planting ratio, as compared to the sole cropping systems. The highest yield of oil (1.24 g m-2) and essential oil (0.51%) of the black cumin belonged to sole cropping with the application of bio-fertilizers. The highest land equivalent ratio (1.50) was also obtained in the 50:50 planting ratio with the application of bio-fertilizers. This means that seed yield per unit area in intercropping was improved up to 50%, as compared with seed yield by sole cropping. With respect to the higher yield (the quantitive and qualitive yield of both two species) and sustainable agricultural objectives, the 50:50 planting ratio along with application of bio-fertilizers could be appropriate.

A considerable portion of chemical N fertilizer in rice field is lost through denitrification, volatilization, leaching, causing environmental pollution problems. It seems that incorporation of winter legume crops in rotation with rice and using plant growth-promoting rhizobacteria can be alternative approaches in reducing N chemical fertilizer and increasing sustainable crop production in rice fields. This experiment was conducted at Rice Research Station of Tonekabon, Mazandaran province, during growing season of 2013-2014 to evaluate the effect of crop rotation, Azotobacter chroococcum inoculation and N rates on rice (Oryza sativa L. cv. Shiroudi) paddy yield.
The experiment was conducted as split-factorial arrangement based on a Randomized Complete Blocks with three replications. Main plots were crop rotation [berseem clover - rice, faba bean- rice, and fallow – rice (control)] and subplots were the factorial arrangement of Azotobacter chroococcum (inoculated and un-inoculated) and N rate (50, 75, and 100 percent of N recommended rates which were 50, 75 and 100 kg N ha-1, respectively) levels.
Analysis of variance showed that rice paddy yield was significantly affected by crop rotation, Azotobacter chroococcum and N rate. Rice paddy yield in faba bean – rice crop rotation (6174.8 kg ha-1) was significantly lower than fallow – rice (7352.3 kg ha-1) and berseem clover – rice (7554.8 kg ha-1) crop rotations. Moreover, there was no significant difference in paddy yield between fallow – rice and berseem clover – rice crop rotations. Rice paddy yield was significantly increased by 8% after Azotobacter chroococcum inoculation. Rice paddy yield was significantly increased from 6628.8 to 7340 kg ha-1 as N rate increased from 50 to 75 kg ha-1, but further N application (100 kg ha-1) had no significant effect on paddy yield. Of the yield components, panicle number per m2 was significantly affected by crop rotation, Azotobacter chroococcum inoculation and N rate, while grain number per panicle was significantly affected only by crop rotation. Moreover, 1000-grain weight was not significantly affected by any factors. The highest panicle number per m2 was observed in berseem clover – rice crop rotation (352.1 panicles), N fertilizer at the rate of 100 kg ha-1 (362.0 panicles) and Azotobacter chroococcum inoculation (353.2 panicles). The highest grain number per panicle (105.8 grains) was observed in berseem clover – rice crop rotation, while the lowest one (96.3 grains) was observed in faba bean – rice crop rotation.
Based on the result of this experiment, in all crop rotations with rice, the highest paddy yield was obtained in nitrogen application at the rate of 75 kg ha-1 and plants inoculated with Azotobacter chroococcum.

Incorporation of winter legume crops in rotation with rice and using plant growth-promoting rhizobacteria can be a proper alternative approach in increasing sustainable crop production in rice fields. A split factorial field experiment using randomized complete block design with three replications was conducted at the Rice Research Station of Tonekabon, Mazandaran province, Iran, in 2014 to evaluate the effects of previous crop, Azospirillum lipoferum inoculation, and N rate on growth and seed yield of rice (Oryza sativa L. cv. Shiroudi). Main plots were consisted of previous crop [berseem clover, faba bean, and control (fallow)] and subplots of Azospirillum lipoferum (Inoculated and Un-inoculated) and recommended rate of N applications (50, 75, and 100 kg.ha-1). Analysis of variance showed that rice paddy yield was significantly affected by previous crop, Azospirillum lipoferum and N rate. Result also showed that rice paddy yield was increased only by 3% when rice was planted after berseem clover as it compared with rice plant after fallow. However, rice paddy yield was significantly reduced by 16% when it was planted after faba bean as compared to that it was planted after fallow. Rice paddy yield was significantly increased by 14% after Azospirillum lipoferum inoculation. Rice paddy yield was significantly increased by 11% when N application increased from 50 to 75 kg N ha-1, and further N application (100 kg N ha-1) did not affect paddy yield significantly. Based on the result of this experiment, planting rice after berseem clover, Azospirillum lipoferum inoculation and application of kg N ha-1 of recommended rates can be used to obtain highest paddy yield in the experimental site.