Influence of different nitrogen levels and harvesting stages on nutrient uptake and available nutrients in ashwagandha (Withania somnifera L. Dunal)

The field experiment was carried out at at Krishi Vigyan Kendra, University of Agricultural Sciences, Raichur, Karnataka in medium black clayey soil during 2021-22 to study the influence of different nitrogen levels and harvesting stages on nutrient uptake and available nutrients in Ashwagandha [Withania somnifera (L.) Dunal). Experiment was laid out in split plot design with treatment combinations. The main plot consists of four nitrogen levels (N) viz., N₀: 0 kg N ha, N₁: 20 kg N ha, N₂: 40 kg N ha and N₃: 60 kg N ha. Whereas, sub plot consists of four different stages of harvest (H) viz., H₁: 90 DAS, H₂: 110 DAS, H₃: 130 DAS and H₄: 150 DAS. The nutrient uptake by the plants and available nutrients in the soil after harvest were significantly influenced and varied by the combination effect of different nitrogen levels and harvesting stages. The highest nitrogen, phosphorus and potassium uptake and maximum soil available nitrogen, phosphorus and potassium were recorded with the application of 40 kg N ha-1 and harvested at 150 DAS (N₂H₄).