Study on the Cucumber N Application Parameters in Greenhouses

The pot and plot experiments in greenhouses showed that certain amount of N application increased the yield and improved the quality of cucumber. High N application brought the ratio of N fertilizer absorbed by cucumber down. The Vc contents in friut of cucumber reduced and the nitrate increased when the Nwas applied at high levels. The Stanfort's formula,F=Nc-NsRf, is useful for calculating the amount of N fertilizer in cucumber field in the greenhouse. In the experiumental conditions, the formula is N=Ym·C-NaRs·2 2Rf in which N is the amount of N fertilizer for cucumber growth; Ym is the yidle of cucumber from 75 to 106t per ha according to the fertility of the soil; C is 3.0 that is the Kilograms of N absorbed by cucumber when harvesting one ton fresh fruit; Na is alkakine hydolytic N of soil and Rs is the ratio of N absorbed by cucumber from soil that is 0.36; Rf is the ratio of N assimilated by cucumber from N fertilizer with the range from 0.40 to 0.29.