The scarcity of water resources has posed serious threats to the sustainable development of agriculture and promoted the need for water-saving technologies. Deficit irrigation has been widely used as a water-saving practice globally. Although it does facilitate the improvement in crop water productivity (WP), its influence on crop yield varies considerably. Therefore, a global meta-analysis was conducted to systematically and quantitatively analyze the responses of both WP and seed cotton yield to deficit irrigation, and explore the optimal conditions for the better application of deficit irrigation in practice. It was found that, although deficit irrigation averagely increased WP by 5.3% compared with full irrigation, it caused a significant decline in seed cotton yield by 20.2% on average. Overall, deficit irrigation performed best at the seedling+blooming stage of cotton under 80–100% full irrigation, in regions with seasonal precipitation ≥ 120 mm and average annual temperature ≥ 10 ℃. Cotton planted in medium textured soils with bulk density ≥ 1.35 g cm⁻³ obtained highest seed cotton yield and WP. Seed cotton yield and WP were increased by ridge planting with film mulching. Additionally, drip irrigation was most beneficial for seed cotton yield than sprinkler and furrow irrigations. Deficit irrigation throughout the whole growing season of cotton was the most undesirable measure. Seed cotton yield and WP were significantly affected by fertilization rate, and the appropriate nitrogen, phosphorus and potassium application rates were 300–400 kg N ha⁻¹, 79–105 kg P ha⁻¹ and 100–133 kg K ha⁻¹, respectively. In conclusion, higher WP was obtained with acceptable reduction in seed cotton yield under deficit irrigation. However, to optimize deficit irrigation in practice, irrigation method and amount, deficit stage, climate condition, soil property, mulching mode and fertilization rate must be further considered.

水资源的稀缺对农业的可持续发展构成了严重威胁，并促进了节水技术的需求。亏缺灌溉在全球范围内被广泛用作节水措施。虽然它确实有助于提高作物水分生产力 (WP)，但它对作物产量的影响却大不相同。因此，进行全球荟萃分析，系统、定量地分析可湿性粉剂和籽棉产量对亏缺灌溉的响应，探索在实践中更好地应用亏缺灌溉的最佳条件。结果表明，虽然亏缺灌溉比全灌平均提高了5.3%的WP，但导致籽棉产量平均下降了20.2%。全面的，80%~100%全灌条件下，棉花苗期+开花期亏灌效果最好，季节降水量≥120mm，年平均气温≥10℃。棉花种植在中等质地土壤中，容重 ≥ 1.35 g cm^-3获得最高的籽棉产量和WP。地膜覆盖垄作提高了籽棉产量和可湿性粉剂。此外，滴灌比喷灌和沟灌对籽棉产量最有利。棉花整个生长季节的灌溉不足是最不受欢迎的措施。籽棉产量和WP受施肥量影响显着，氮、磷、钾的适宜施用量为300-400 kg N ha ^-1、79-105 kg P ha ^-1和100-133 kg K ha ^-1， 分别。总之，在亏缺灌溉条件下，籽棉产量降低可接受，获得了更高的可湿性粉剂。但要在实践中优化亏缺灌溉，还需进一步考虑灌溉方式和灌溉量、亏缺期、气候条件、土壤性质、覆盖方式和施肥率。