根区水分空间匹配的深层灌溉促进柑橘增产提质OA

To investigate the effects of deep subsurface irrigation on soil water storage,fruit yield,and quality in citrus orchards in hilly red soil regions,an experiment was conducted in a typical citrus or-chard in Jiangxi Province.The experiment included three irrigation depths set as follows:D1(25 cm),D2(50 cm),and D3(100 cm);three irrigation levels were used as follows:W3(full ir-rigation:upper limit of 100％θf,where θf is field capacity),W2(mild deficit irrigation,75％of W3),and W1(severe deficit irrigation,50％of W3),resulting in a total of nine treatments.The re-sults show that D2W2 treatment(50 cm irrigation depth combined with mild deficit irrigation)creates a stable moist zone in the 0-120 cm soil layer that effectively covers the main root zone of citrus(0-80 cm).The root zone water storage under this treatment increases by 8.74％and 16.43％compared to D1W2 and D3W2 treatment,respectively.This treatment also achieves the highest yield per plant(58.13 kg/plant),the highest sugar content(15.93％),the lowest acidity(0.46％),and the optimal sugar-acid ratio(34.63).D2W1 treatment has the highest irrigation water use efficiency at 11.15 kg/m3,which is slightly higher than that of D2W2 treatment(11.03 kg/m3).TOPSIS comprehensive evaluation indicates that D2W2 treatment is the optimal irrigation mode with the highest score.The study recommends promoting a deep irrigation mode with a 50 cm depth combined with mild water defi-cit in citrus orchards in hilly red soil regions to synergistically achieve water conservation,yield in-crease,and quality improvement.