Effect of Rhizobium Inoculation and Tillage Practices on Fodder Cowpea (Vigna unguiculata)

Abstract

Background: Agriculture and its allied sectors is an important sector in employment, income and food security. The increasing demands for food grains and cash crops, the area under fodder crops has been static since last 3-4 decades (8.4 mha) resulted in to a net deficit in dry and green fodder is around 10 and 35%, respectively making livestock rearing more challenging. Conventional agriculture has largely been characterized by conventional tillage which caused soil degradation and negative impacts on soil physical and biological activity. To mitigate these negative effects, resource conservation technologies (RCTs) was tested and adopted to save substantial quantity of irrigation water, reducing the cost of cultivation, timely sowing, improve input use efficiency and left indirect effect on mitigating the adverse effect of climate changes. Biological N2 fixation (BNF) can make plants self-sustaining for N nutrition and avoiding the need for mineral N fertilization. The current study aimed enhancing fodder production by adoption of modern tillage practices and efficient N management. Methods: In this field-laboratory investigation during 2017-18, experiment was laid out in the split plot design consisting of three tillage practices zero tillage (ZT), conventional tillage (CT) and raised bed (RB) and six N management viz., N0, N75, N75+Rhizo,N100, N100+Rhizo and N125%. The soil of the experimental field was clay loam in texture having pH 7.30, EC; 0.35 dS/m, mediumin organic carbon (0.63%), low in nitrogen (188.48 kg/ha), medium in phosphorus (23.56 kg/ha) and potassium (271.12 kg/ha). The recommended dose of fertilizer and other cultural practices was applied as per treatments with standard process. The crop was harvested at 60 days after sowing and weighed for green fodder yield. The observations growth, yields and quality parameters was recorded as per the standard method. Statistical analysis was done using analysis of variance in split plot design. Result: ZT practices significantly improved growth attributes, fodder yield and available nitrogen. Higher fodder yield of cowpea was recorded with ZT as compared to CT and it was statistically similar in RB. The nitrogen management practices had significant effect on root length and root nodules, plant growth attributes, fodder yield and available N, P and K. The significant fodder yield was increase with successive increase of N application up to 75% N + rhizobium, over 0 and 75% N alone. The present work shows that adoption of ZT and inoculation of rhizobia had significantly improved soil health and stabilized fodder yield of cowpea besides decrease fertilizer nitrogen requirement in the irrigated agro-ecosystem of T-IGP.