Effects of irrigation on alfalfa yield in arid and semi-arid regions of China:A meta-analysis

REN Huipeng; NING Songrui; YAN An

doi:10.13522/j.cnki.ggps.2025139

Abstract：[Background]Alfalfa is a key forage crop in the arid and semi-arid regions of China,where water availability is a major limiting factor for productivity.This paper aims to assess the effects of irrigation on alfalfa productivity in these regions.[Method]We analyzed publicly available alfalfa yield data under different irrigation treatments from 2000 to 2025 that met the inclusion criteria.Statistical and meta-analysis methods were used to explore the variations in annual yield and yields per cutting under different irrigation management practices.[Result]Annual alfalfa yield decreased with increasing latitude from 35° to 46° N.The mean annual yield of alfalfa in the 35°-39° N latitude zone was 33.96%and 40.05%higher than that in the 39o-43o N and 43o-46o N zones,respectively.For irrigation quotas in the range of 2 500 to 5 000 m3/hm2,the highest mean annual yield was 16 491 kg/hm2,and its average yield increase was by 58.90%(p＜0.05)compared to rainfed conditions.The yields of the first,second,and third cuttings increased as irrigation quota increased from 0 to 5 000 m3/hm2.When irrigation quota was the same,increasing cutting number reduced yield.Among all irrigation methods,drip irrigation resulted in the highest mean annual yield(15 425 kg/hm2)and an average yield increase of 67.30%(p＜0.05),compared to rainfed cultivation.Compared with flood and sprinkler irrigation,drip irrigation achieved the highest yield for all cuttings,although the yield decreased progressively with increasing cutting number.[Conclusion]Sustaining high alfalfa yields in arid and semi-arid regions of China requires selecting suitable varieties for different latitude zones.Drip irrigation is most effective for the 35°-39° N and 39°-43° N zones,with optimal irrigation amounts of 3 830 and 2 152 m3/hm2,respectively.In the 43°-46° N zone,drip irrigation with an optimal irrigation amount of 5 227 m3/hm2 can ensure stable yield.These findings provide optimal irrigation strategies for improving alfalfa productivity in water-limited regions of China.