Effects Of Nutrient Solution Supply On Growth And Mineral Nutrient Absorption Of Cucumber In Separate Root Zones With Multiple Salts

Soilless culture has many advantages,such as water saving,fertilizer saving,high yield,good quality,avoiding soil-borne diseases and insect pests,and being suitable for application in non-cultivated areas,and it has been widely used in the world.However,in the traditional nutrient solution cultivation system,there is nutrient solution waste,which not only leads to the waste of nutrients and water,but also leads to environmental pollution.Therefore,it is of great theoretical and practical significance to study the technology of prolonging the using of nutrient solution in soilless culture in order to reduce the waste of nutrient solution.This experiment choosing cucumber as experimental material,adopted Ca(NO3)2·4H2O、KNO3、KH2PO4、MgSO4·7H2O 4 kinds of salt which dissolve and prepare nutrient solution respectively to build the multi-salt independent supply method which the trace elements was added separately according to the general formula.The root system of cucumber was divided into 4 parts and put into 4 kinds of salt independent circulation system to compare with the traditional mixed nutrient solution supply method,we determined morphological indicators of the cucumber plant,mineral nutrition in the nutrient solution,the yield of cucumber,mineral nutrition content of cucumber plant and fruit.The effects of liquid supply on growth,yield and mineral nutrient absorption of cucumber were studied.The preliminary results were as follows:1.Over time,the growth of cucumber with the solution of the multi-salt independent supply method was better than that with mixed nutrient solution supply method,and there was no significant difference in the photosynthetic characteristics of leaves between them.At 49 days after transplanting,the leaves of the plants supplied with mixed nutrient solution supply method began to show symptoms of deficiency,while the plants supplied with liquid from multi-salt independent supply method did not show symptoms of deficiency until 84 days after colonization.2.Compared with mixed nutrient solution,the consumption of P,K,Ca,Mg and S could be saved by 60.86%,17.99%,15.08%,7.29%and 33.07%,in the multi-salt independent supply method.The multi-salt independent supply method,has obvious effect of fertilizer saving.In The multi-salt independent supply method,the coefficient of variation of each element in nutrient solution was smaller than that in mixed nutrient solution supply method,and the coefficient of variation of N,P,K,Ca,Mg and S contents were 66.53%,64.08%.40.44%,68%,33.78%and 56.04%lower than that in mixed nutrient solution supply method,respectively.The content of nutrient elements was more stable and the recycling time was longer in the multi-salt independent supply method.3.In the multi-salt independent supply method,the content of Ca in cucumber stem and Ca and Mg in cucumber leaves were increased by 15.74%,9.86%compared with mixed nutrient solution supply method,respectively.Compared with mixed nutrient solution supply method,the root fresh weight of cucumber in the multi-salt independent supply method was increased by 12.91%and 10.92%,respectively.4.Compared with mixed nutrient solution,in the multi-salt independent supply method the number of fruit per plant,the weight of fruit per plant and the yield per plant increased by 25.37%,1.54%and 23.07%,respectively.5.The multi-salt independent supply method has obvious water-saving effect.Compared with mixed nutrient solution supply method,the multi-salt independent supply method could save water by 25.21%...