滴灌条件下不同灌水下限对甘蔗生长发育及产量的影响分析OA

By conducting field comparison experiments,four different irrigation lower limits(low limit A,medium-low limit B,medium-high limit C,and high limit D)were set based on field water-holding capacity(hereinafter re-ferred to as FC).This study analyzed the irrigation lower limits under drip irrigation across different growth stages of sugarcane,as well as the effects of different irrigation lower limits on the growth and yield of sugarcane.The re-sults indicate:① Under drip irrigation,the irrigation lower limit significantly affected the irrigation frequency,irri-gation water volume,and the irrigation initiation time.As the irrigation lower limits were gradually increased from treatment A to treatment D,the number of irrigation times were 6,8,9,and 11 times,with the irrigation volumes be-ing 5.538,7.426,8.432,and 10.446 m3 respectively,and the irrigation initiation times advanced by 3 to 9 days.②The key water regulation strategy for sugarcane drip irrigation was clarified:maintaining the lower limit at 65%～70%FC during the seedling and tillering stages to ensure the quality of seedling emergence and tillering;increasing the lower limit to 70%～75%FC during the elongation stage to meet the high water demand;reducing the lower limit back to 65%～70%FC during the maturity stage to promote sugar accumulation.③ Among different irrigation lower limits,treatment D had the highest yield and is suitable for regions with abundant water resources;treatment C ex-hibited the optimal economic benefits and water use efficiency,making it the recommended treatment for sugarcane drip irrigation in Qinzhou,Guangxi and similar ecological areas;treatment A achieved the highest water use efficien-cy and is suitable for drought-prone or water-deficient areas;treatment B performed moderately and can serve as a transitional option.