基于多目标综合评价的滴灌苹果水肥协同调控研究

Cooperative Regulation of Water and Fertilizer in Drip Irrigation Apple Based on Multi⁃objective Comprehensive Evaluation

为探寻滴灌水肥一体化条件下北方半干旱地区苹果树种植的最佳水肥协同调控制度,设置灌水与施肥2个试验因素,滴灌灌水量设4个水平,根据田间持水率θf的不同百分比确定灌水下上限:75%θf~90%θf(W1)、65%θf~80%θf(W2)、55%θf~70%θf(W3)、45%θf~60%θf(W4);滴灌施肥量设3个水平,N、P_(2)O_(5)、K_(2)O与风干土质量比分别为:0.9、0.3、0.3 g/kg(F1);0.6、0.3、0.3 g/kg(F2);0.3、0.3、0.3 g/kg(F3),分析滴灌施肥协同调控对苹果树生长生理指标、生物质量与产量、果实品质以及水肥利用效率的影响,最终基于TOPSIS法建立以高效、高产、高品为目标的苹果综合指标评价模型。结果表明,滴灌施肥协同调控下苹果树植株生长量、基茎生长量和叶面积最大值均出现在F1W2处理,苹果树净光合速率、蒸腾速率和叶绿素含量基本上随灌水量和施肥量的增加而增加,最大值均出现在F1W1处理,全生育期干物质量和产量在F1W1和F1W2处理下差异不明显,水分利用效率和水分生产率最大值均出现在F1W2处理,与F1W1处理相比,分别提高10.6%和11.1%,肥料偏生产力基本上随灌水量的增加和施肥量的减少而增加,增加灌水量有利于提高苹果着色指数、果形指数和糖酸比,增加施肥量有利于提高苹果单果质量、维生素C含量和可溶性糖含量。综合4类17个指标建立TOPSIS多目标综合评价模型,代入各指标最终权重计算得出F1W2处理贴近度最大,为0.7653,此处理条件下苹果综合指标评价最优,而F3W4处理最差,仅为0.2583。综上,本试验水肥协同调控下灌水量下上限控制在田间持水率的65%~80%,施N、P_(2)O_(5)、K_(2)O与风干土质量比分别为0.9、0.3、0.3 g/kg是苹果树的最佳水肥管理制度。

In order to explore the best water⁃fertilizer cooperative control system for apple tree planting in semi⁃arid northern China under the condition of integrated drip irrigation and fertilization,two experimental factors(irrigation and fertilization)were set,among which irrigation was 75%θf~90%θf(W1),65%θf~80%θf(W2),55%θf~70%θf(W3)and 45%θf~60%θf(W4)of field water capacity,respectively,and fertilization mass ratio of N,P_(2)O_(5),K_(2)O to air⁃dried soil was 0.9 g/kg,0.3 g/kg,0.3 g/kg(F1),0.6 g/kg,0.3 g/kg,0.3 g/kg(F2),and 0.3 g/kg,0.3 g/kg,0.3 g/kg(F3),respectively.The effects of cooperative regulation of drip irrigation and fertilization on the growth physiological indexes,dry matter quality and yield,fruit quality and water and fertilizer use efficiency of apple trees were analyzed.Finally,an apple comprehensive index evaluation model aiming at high efficiency,yield and fruit quality was established based on TOPSIS method.The results showed that under the cooperative control of drip irrigation and fertilization,the maximum values of apple tree growth,basal stem growth and leaf area appeared in F1W2 treatment.The net photosynthetic rate,transpiration rate and chlorophyll content of apple tree were basically increased with the increase of irrigation amount and fertilizer application rate,and the maximum values appeared in F1W1 treatment.There was no significant difference between F1W1 and F1W2 in dry matter quality and yield during the whole growth period,and the maximum value of water use efficiency and water productivity appeared in F1W2 treatment,which was increased by 10.6%and 11.1%compared with that of F1W1 treatment,respectively.Fertilizer partial productivity was basically increased with irrigation increasing and fertilizer decreasing.Increasing irrigation amount was beneficial to increase apple color index,fruit shape index and sugar⁃acid ratio,and increasing fertilizer amount was beneficial to increase apple fruit quality,vitamin C content and soluble sugar content.The TOPSIS multi⁃objective comprehensive evaluation model was established by synthesizing 17 indexes of four categories,and the final weight value of each index was taken into the calculation.It was concluded that the closest degree of F1W2 treatment was 0.7653,and the comprehensive index evaluation of apple was the best under this treatment,while that of F3W4 treatment was only 0.2583.In conclusion,F1W2 treatment under the cooperative control of drip irrigation and fertilization was the best water and fertilizer management system for apple trees.