| By Intelligent greenhouse soilless culture pattern we compared the effects of high N composition, mid N composition and low compositions in hydroponics tomato and pepper, and the changes of nutrient solution nature and the dynamic change laws of nutrient in soilless culture, and carried out research on the nutrient demand law of the vegetables, to offer basis on selecting soilless culture vegetables nutrient solution and scientifically managing the nutrient solution in Anhui Province. The results of study are as follows:1. Different Intelligent greenhouse nutrient solutions have different effects on soilless culture tomato and pepper. In the formula of nitrogen in tomato yield was the highest, no significant difference among other treatments. Soilless cultivation of hot pepper in low nitrogen nitrogen formula the highest yield, the lowest yield formula. In terms of quality between the VC content of tomato without significant difference, reducing sugar to nitrogen in the formula was the highest, and nitrate to nitrogen in the formula of minimum; The contents of pepper’s Vc and reducing sugar among four treatments are not significant, and the nitrate content of pepper in mid N composition is the lowest, but the nitrate contents of tomata and pepper in all treatments do not exceed the environment-friendly food standard. Considering comprehensively, the best treatment in hydroponics pepper and tomato is mid N composition.2. There are greater changes in the nature of the Intelligent greenhouse nutrient solution in the course of culture. Soilless cultivation of tomato and pepper the nutrient solution pH values show a clear upward trend in one day, rose by 6.5 to 7.5 above; dissolved oxygen in the nutrient solution decreased significantly, one day rapidly by 6mg/L dropped to below 3mg/L; nutrient solution EC values in a vegetative cycle showed obvious decreasing trend, a decline in different period is different.3. There are significant linear positive correlation between the EC value and the content of NO3--N, P, K in the nutrient solution. Intelligent greenhouse hydroponic tomato EC value down to 2/3 of the initial value, the nutrient solution in nitrate nitrogen, soluble potassium decreased to one-third of the initial value, soluble phosphorus depletion, at this time to replace or supplement nutrient solution is more appropriate.4. The exhaustion speed of nutrients is connected with vegetables kind, the periods and the density of the nutrient in nutrient solution. The exhaustion speed of nutrients in hydroponics tomata is greater than pepper; The exhaustion speed of nutrient of bearing fruit period is greater than other periods; The mid N composition speed that its nutrient exhausts is relatively fast.5. The absorption amount of N, P, K is different in different crops and in different nutrient solution as well as in different growing period. Tomato nutrient absorption is higher than the results of nutrient uptake of pepper, the highest. Tomato on nutrient absorption of potassium, nitrogen, phosphorus, absorption ratio in different periods and different, generally K:N:P=103.7:72:15.21... |
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