Effect of Nitrogen and Phosphorus Application Rate on Peanut (Arachis Hypogaea L.) Phenology, Yield and Soil Nutrient Status

Abstract

Purpose: Over and under dose application and of nitrogen (N) and phosphorus (P) leads to inferior growth and yield reduction in field crops. Different nutrients have synergetic and antagonistic effects according to soil properties, climate, crop type and management practices at the same time. Research Methods: In this field study, we tried to explore the combined effect of N and P on peanut phenology, yield and soil N and P status. Three N (N₁=20, N₂=40, N₃=60 kg ha^-1) and three P (P₁=60, P₂=80, P₃=100kg ha^-1) application rates were applied in a split-plot complete randomized design in 2016 and 2017 growing seasons of peanut, while after harvesting of peanut field was fallow. Findings: Our results demonstrated that combined or individual application of N and P not affected phenophases of peanuts (germination, flowering and pegging) except physiological maturity, and a low rate of N application increased maturity duration time in peanut. While pod production in low N doses was more as compared to high dose application of N and P, except N₃P₂ in both years, a greater number of pods attained less grain weight and lower yield. Concurrently, a higher dose of N and P individually produced higher yield (2614, 2647 in N₃, 2549, 2527 kg ha^-1 in N₂) and lower yield was quantified 2216 and 2205 in N₁ in both years (2016-2017) respectively. Similarly, 2658, 2647, and 2496, 2507 kg ha^-1 were weighted in P₃ and P₂ respectively. But their combined effect was non-significant (P>0.05). In the case of soil total N and available P, N increment doubled (~0.8 g kg^-1) as compared to initial N status regardless of N application rate but P had no effect on available P contents in upper soil (0-15 cm) surface. So, peanut cultivation can be a promising strategy for N increment in a semi-arid area of Pakistan. Limitations: Due to the limited availability of funds, we analyzed areas of topsoil (0-15). It will be better to do soil analysis in depth for further studies. These findings are valuable for researchers, farmers, and regional agriculture departments, because alternation in nitrogen rate application didn’t change the soil N level with the combination of phosphorus in peanut. So, Findings suggested that low N application was enough for peanut cultivation. Nitrogen and phosphorus have a significant effect on the growth and yield of peanuts. Peanut crop needs the half amount of nitrogen than phosphorus because it is a leguminous crop and has nitrogen factories in the root nodules.