Sustainable groundnut production in arid region with drip irrigation and sulphur fertilization

In India, groundnut is the third most important oilseed crop after soybean and mustard; however, its productivity remains suboptimal due to inefficient irrigation scheduling and inadequate sulphur (S) nutrition. To address these constraints, a study was planned to evaluate the impact of different drip irrigation (DI) regimes based on pan evaporation (PE) levels (0.6, 0.8, 1.0 PE, and their stage-specific combinations) and graded S fertilization (0, 20, 40, and 60 kg S ha⁻¹) on growth, yield, quality, and resource use efficiency of groundnut. The results demonstrated that higher DI levels, particularly 1.0 PE and 0.8+1.0 PE (moderate irrigation during vegetative and higher during reproductive stage), significantly enhanced pod and kernel yield (up to 7-fold) and haulm yield (up to 10-fold) compared to the lowest irrigation regime (0.6 PE). Although 1.0 PE yielded the highest, the 0.8+1.0 PE treatment reduced evapotranspiration by 10.7% and saved approximately 60–70 mm of water without compromising yield, thereby improving water productivity and energy efficiency. This regime also recorded the lowest carbon footprint per unit yield (CFy), indicating better environmental performance. Sulphur fertilization had a significant influence on yield and quality parameters. While groundnut responded positively up to 60 kg S ha⁻¹, the response was most economically and environmentally efficient up to 40 kg S ha⁻¹. The 40 kg S ha⁻¹ level reduced carbon footprint by 2–3% and energy consumption by 3–4%, while providing comparable yields and higher benefit-cost ratios than 60 kg S ha⁻¹. The combination of 0.8+1.0 PE irrigation with 40 kg S ha⁻¹ emerged as the most efficient and sustainable strategy, offering a favourable balance between productivity, input use, economic returns, and environmental impact. These findings underscore the importance of optimizing irrigation and nutrient management practices for enhancing groundnut productivity, resource use efficiency, and environmental sustainability.