Supplementing Nitrogen in Combination with Rhizobium Inoculation and Soil Mulch in Peanut (Arachis hypogaea L.) Production System: Part II. Effect on Phenology, Growth, Yield Attributes, Pod Quality, Profitability and Nitrogen Use Efficiency

Peanut (Arachis hypogaea L.) is adorned as the one of the important sources of vegetable oil, protein, vitamins and several minerals, which could mitigate the nutritional gap worldwide. However, peanut cultivation in winter suffers from low temperature stress and knowledge lacuna regarding the optimum dose nitrogen. Therefore, the present investigations were carried out during the winter seasons 2015-2016 and 2016-2017 at the district seed farm of Bidhan Chandra Krishi Viswavidyalaya, an agricultural university in West Bengal, India (23 degrees 26' N, 88 degrees 22 ' E, elevation 12 m above mean sea level) to facilitate the comprehensive study of plant growth, productivity and profitability of an irrigated peanut crop under varied levels of nitrogen: with and without a rhizobium inoculants and with and without polythene mulch. Quality traits and nutrient dynamics were also itemized. Fertilizing with 100% of the recommended dose of nitrogen combined with rhizobium inoculant and polythene mulch significantly enhanced peanut plant growth, yield and yield-attributing traits, while resulting in the maximum fertilizer (i.e., nitrogen, phosphorus and potassium) uptake by different plant parts. The greatest number of root nodules occurred in the treatment that received 75% of the recommended dose of nitrogen with rhizobium supplementation under polythene mulch, while 50% of the recommended dose of nitrogen with no rhizobium resulted in maximum fertilizer nitrogen use efficiency. Applying the full recommended dose of nitrogen with the rhizobium inoculants and mulch resulted in maximum profitability in the peanut crop.