Tree spacings and nutrient sources effect on turmeric yield, quality, bio-economics and soil fertility in a poplar-based agroforestry system in Indian Himalayas
摘要
The tree-based farming system is one of the finest options for crop diversification, ecological stabilisation and economic upliftment in the Indian Himalayan regions. Keeping this scenario in mind, an on-field experiment was conducted to assess the effect of Populus deltoides ‘G-48’ tree spacings (S1:6 m × 4 m, S2:4 m × 4 m) with open-field condition (S0) and different nutrient sources [T1:Control; T2:100% RDN (recommended dose of nitrogen); T3:75% RDN + 25% FYM (farmyard manure); T4:50% RDN + 50% FYM; T5:25% RDN + 75% FYM; T6:100% FYM; T7:100% Vermicompost); T8:Jeevamrut (10%), each replicated thrice] on agronomic performance of Curcuma longa at Solan, India during 2019–2021. The results revealed that C. longa grown under tree spacing S1 coupled with the application of T3 treatment showed marked enhancement in growth, quality attributes of C. longa and post-harvest soil nutrient status whereas, yield attributes were better in S0. The yield of C. longa was curtailed by 22.5 and 31.6%, whereas curcumin content was enhanced by 13.4% and 12.2% under S1 and S2, respectively over S0. The vegetation carbon density (66.38 Mg ha−1), total ecosystem carbon density (119.04 Mg ha−1), and total carbon sequestered (436.47 Mg ha−1) was found to be higher under S1, whereas soil carbon density (55.68 Mg ha−1) was maximum under S2 being at par with S1. Maximum net returns (14,693 US$ ha−1 yr−1) were realised under S1 tree spacing and T3 treatment. Overall, the study concluded that in P. deltoids–C. longa system, application of 75% RDN + 25% FYM at 6 m × 4 m spacing of poplar have demonstrated efficacy in getting a better quality of turmeric, maintaining soil fertility, and combating climate change.