Effects Of Water And Fertilizer Coupling On Yield, Quality And Nutrients Uptake Characteristics Of Cabbage

Field experiment was carried out to study the effects of water and fertilizer couplingon the yield, quality, sample absorption and water use efficiency of cabbage (Brassicaoleracea L. var.capitata L.) mainly cultivated in north west area of China. The main resultssummarized as follows:1. Compared with the treatment of local irrigation and fertilization (CK), thecombination of reducing10%irrigation and saving20%fertilizer (W2F1) was morebeneficial to dry matter accumulation of cabbage; the combination of tradition irrigationand saving20%fertilizer (W1F1) had the highest economic yield (100131kg hm-2), andthe treatment of CK and W2F1was lower than W1F1, but no significant difference wasfound among them. The CK had the highest biological yield (147010kg hm-2). However,there was no significant difference between CK and W1F1and W2F1.2. Fertilization can significantly affect nitrate, VCand free amino acid contents in leafball of cabbage, and the suitable irrigation could significantly reduce the content of nitrate.The contents of Vc, soluble sugar and free amino acids in the treatment of reducing10%irrigation combined with saving20%fertilizer (W2F1) were the highest, while the nitratecontent was the lowest. This treatment was significantly better than the local traditionirrigation and fertilizer amounts (CK). Relative low irrigation treatment was moreconducive to increase compactness of leaf ball. The leaf of cabbage was relatively small inW2F1.3. The different water and fertilizer supply to cabbage had significant effects on thenitrogen, phosphorus and potassium absorption. High fertilizer could improve the plant N,P and K absorption. The highest mineral element absorption capacity was exist in leaf ball,leaf lower and root was least. The highest content and absorption of N, P and K were foundin the product organ in each treatment. In the whole growth stage, low water and fertilizerwas not conducive to improving the accumulation of N, K in plants, while the effect ofwater and fertilizer on the P accumulation in different organs of cabbage was differentfrom N and K accumulations. High fertilizer could promote the N, P and K absorption, while the effect of low irrigation was adverse. The N, P and K harvest index in W2F1wassignificantly higher than CK.4. Different water and fertilizer combinations had significant effects on soil nutrientcontents. High fertilizer could significantly increase the soil total nitrogen and availablenitrogen contents, while too much irrigation amount could reduce these contents. With thefertilization increasing, soil available phosphorus and potassium contents increased. Withthe amount of irrigation appropriately decreasing, the effective P content decreased whilepotassium content decreased first and then increased. The soil urease activity in W2F1washighest, and significantly increased by85%compared with CK; the soil sucrose activitywas significantly higher than other treatments, and it reduced with the fertilizer andirrigation decreasing; The soil phosphatase activity in treatment of tradition irrigationcombined with saving30%fertilizer （W1F2） was highest and W2F1was lower, andthese were significantly higher than CK.5. The highest utilization efficiency of water and apparent nitrogen was found in thetreatment of W2F1. Compared to local tradition irrigation and fertilizer combination, thetreatment of W2F1was beneficial to save water and fertilizer and protect environmental.To sum up, the treatment of reducing10%irrigation（1960m3hm-2）combined withsaving20%（N304kg hm-2, P2O5204kg hm-2å'ŒK2O72kg hm-2）fertilizer is moreappropriate to the local cabbage growth, and this measure could be applied in a similar areaof the test conditions.