The Combined Effect of Water and Fertilizer on Yield and Quality of Mini Chinese Cabbage in Cold-cool Irrigation Area

Abstract

【Objective】 Mini Chinese cabbage is a cash crop in Hexi Corridor in northwestern China, but its production relies on irrigation and fertilization. The objective of this paper is to investigate the combined effect of water and fertilizer on its yield and quality. 【Method】 The experiment was conducted in a film-mulched field, with the variety Golden Queen used as the model plant. The crop was drip irrigated. There were three irrigation treatments and three fertilization treatments, which combine making total nine treatments. In each treatment, we measure yield and quality of the cabbage. The key indexes was screened using the principal component analysis, and comprehensive evaluation of the combined effect of water and fertilizer was analyzed using the membership function and the weighted standard deviation coefficient method. 【Result】 Irrigation and fertilization jointly affected growth index, yield and quality of the cabbage, albeit the effect varied with their combinations. Combination of water and fertilizer affected crop growth and yield more greatly than irrigation and fertilization working independently. Moderate irrigation and fertilization increased the net weight per plant, net vegetable rate, yield, soluble solids, Vc content and heading compactness, but reduced nitrate content. Principal component analysis reduced the 12 indicators into three independent comprehensive indicators, with their cumulative contribution rate being 91.87%. The comprehensive score for the coupled effect of water and fertilizer was the highest when irrigation and fertilization were both at moderate level. 【Conclusion】 Comprehensive analysis showed that a suitable irrigation and fertilization for autumn mini Chinese cabbage in Hexi Corridor region is: keeping soil water content higher than 70% of the field capacity, and applying 330 kg/hm2 of N, 195 kg/hm2 of P2O5 and 450 kg/hm2 of K2O.

Keywords

• cold-cool irrigated areas of hexi corridor
• brassica pekinensis
• water and fertilizer coupling
• principal component analysis
• membership function method