Abstract

Biofertilizers are important for sustainability of agriculture and have the potential to reduce the environmental costs of nitrogen (N) and phosphorus (P) fertilizers in modern intensive farming practices. Field experiments were conducted on two promising strains of P-solubilizing bacteria (PSB) viz. RB-1 (Pseudomonas argentinensis) and RB-2 (Bacillus aryabhattai) identified in the lab studies, in conjunction with N-fixing Mesorhizobium, for improving symbiotic efficiency, growth and productivity of irrigated desi chickpea. An experiment comprised of four biofertilizer seed inoculation treatments (uninoculated control, Mesorhizobium, Mesorhizobium + RB-1 and Mesorhizobium + RB-2), and four P levels (0, 15, 20 and 25 kg P₂O₅ ha⁻¹) was conducted. Dual inoculation with Mesorhizobium + RB-1 and Mesorhizobium + RB-2 proved more effective in increasing nodulation in chickpea at lower dose of P of 15 and 20 kg ha⁻¹ as compared with Mesorhizobium + 25 kg P ha⁻¹. Chickpea with Mesorhizobium + RB-1 recorded similar leghaemoglobin content in nodules and chlorophyll content in leaves as achieved with Mesorhizobium + RB-2; however, both of these attributes improved significantly over Mesorhizobium alone. Improved plant growth with both Mesorhizobium and PSB resulted in significant grain yield increase up to 7% as compared with Mesorhizobium alone. Investing additional US $0.74 ha⁻¹ on PSB to current growers’ practice of single inoculation with Mesorhizobium resulted in additional net returns increase of US $53-71 ha⁻¹. Therefore, biofertilizers that promote N-fixation and P-solubilization need to be adopted in conjunction with each other in chickpea to reduce chemical fertilizer usage and improve profitability.

摘要

生物肥料对于农业的可持续性很重要，并且有可能降低现代集约化农业实践中氮 (N) 和磷 (P) 肥料的环境成本。对两种有前途的溶磷菌 (PSB) 菌株进行了田间实验，即。实验室研究中鉴定出的RB-1（阿根廷假单胞菌）和 RB-2（Bacillus aryabhattai）与固氮中生根瘤菌一起用于提高灌溉德西鹰嘴豆的共生效率、生长和生产力。由四种生物肥料种子接种处理（未接种对照、中生根瘤菌、中生根瘤菌）组成的实验+ RB-1 和中生根瘤菌+ RB-2)，并进行了四个 P 水平（0、15、20和 25 kg P ₂ O ₅ ha ^-1）。与Mesorhizobium  + 25 kg P ha ^-1相比，用Mesorhizobium + RB-1 和Mesorhizobium + RB-2双重接种证明在15 和20 kg ha ^{-1 的}较低P 剂量下在增加鹰嘴豆结瘤方面更有效。含有中生根瘤菌+ RB-1 的鹰嘴豆记录的根瘤中豆血红蛋白含量和叶片中的叶绿素含量与中生根瘤菌+ RB-2相似；然而，这两个属性都比Mesohizobium显着提高独自的。与单独使用中生根瘤菌相比，使用中生根瘤菌和 PSB改善植物生长导致谷物产量显着增加高达 7% 。向目前种植者单次接种中生根瘤菌的做法额外投资 0.74 美元 ha ^-1的 PSB导致额外净回报增加 53-71 公顷^-1。因此，在鹰嘴豆中需要结合使用促进固氮和增溶的生物肥料，以减少化肥的使用，提高盈利能力。