ABSTRACT Drip fertigation has potential to reduce fertilizer dose in comparison to surface application in coconut (Cocos nucifera L.) by increasing its’ use efficiency in the Eastern Gangetic plains of South Asia. A long-term field experiment (2007–2013) was conducted on Inceptisol to evaluate 100% of the soil test-based recommended fertilizer dose (RDF; N:P2O5:K2O applied at 500:250:750 g palm−1 year−1) in soil with ring basin irrigation as conventional, 100%, 75%, 50%, 25%, and 0% of the RDF through drips. The fertigation level of 75% RDF resulted in 32%, 19%, 39%, and 16% higher copra yield, energy productivity, net return, and benefit-cost ratio, respectively, over conventional. Increasing trend of nutrient use efficiency was observed with decreasing dose of N, P and K. Use efficiencies decreased from 50.4 kg copra kg−1 N, 230.7 kg copra kg−1 P, and 40.5 kg copra kg −1 K (with 25% of the RDF through drip) to 6.1 kg copra kg−1 N, 27.8 kg copra kg−1 P, and 4.9 kg copra kg−1 K (with 100% RDF through ring basin irrigation). Fertigation with 75% RDF in drip had the highest copra yield (3.19 t ha−1), energy output (206082 MJ ha−1), energy productivity (187 g copra MJ−1), net returns (US $ 3073 ha−1), and benefit–cost ratio (2.36) compared to others.

中文翻译：

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施肥对南亚东部印度恒河平原椰子 (Cocos nucifera L.) 栽培养分利用效率、能源生产率和经济性的影响

摘要 与表面施用椰子（Cocos nucifera L.）相比，滴灌施肥有可能通过提高其在南亚东恒河平原的使用效率来减少肥料用量。对 Inceptisol 进行了一项长期田间试验（2007-2013 年），以评估 100% 的基于土壤测试的推荐肥料剂量（RDF；N:P2O5:K2O，施用量为 500:250:750 g 棕榈−1 年−1 ) 在采用常规环盆灌溉的土壤中，100%、75%、50%、25% 和 0% 的 RDF 通过滴灌。75% RDF 的施肥水平使椰干产量、能源生产力、净回报和效益成本比分别比传统方法高 32%、19%、39% 和 16%。观察到养分利用效率随着 N、P 和 K 剂量的减少而增加的趋势。利用效率从 50.4 kg 椰干 kg−1 N, 230 下降。7 kg 椰干 kg-1 P 和 40.5 kg 椰干 kg -1 K（RDF 的 25% 通过滴注）到 6.1 kg 椰干 kg-1 N、27.8 kg 椰干 kg-1 P 和 4.9 kg 椰干 kg-1 K（通过环盆灌溉使用 100% RDF）。滴灌含 75% RDF 的灌溉施肥具有最高的椰干产量 (3.19 t ha-1)、能量输出 (206082 MJ ha-1)、能源生产力 (187 g 椰干 MJ-1)、净收益 (US $ 3073 ha-1) )，以及与其他人相比的收益成本比 (2.36)。