| Soilless culture can effectively solve the problems of continuous cropping obstacles,soil borne diseases and low fertilizer utilization rate in traditional agriculture,so it is widely used in the world.However,whether open or closed substrate soilless cultivation has the problem of nutrient solution scrapping.Nutrient liquid membrane cultivation is welcomed by growers and has a better development prospect because it does not need substrate and has the advantages of small investment.However,the traditional nutrient liquid membrane cultivation uses the mixed nutrient solution composed of various compounds for circulating supply,which also has the problems of regular replacement and nutrient solution scrapping.In this experiment,the compound which provides a large number of medium elements in the nutrient solution formula is set separately.The nutrient liquid membrane experiment of tomato was carried out with the traditional mixed liquid supply method as the control.The morphological indexes of tomato plants,the contents of nutrient elements in each zone and mixed nutrient solution,the contents of mineral elements in plants and fruits,the yield and quality indexes of tomato were measured and analyzed The effects of different liquid supply methods on the growth and yield of Spring Tomato in plastic greenhouse were studied.The results are as follows :1.The way of supplying liquid in different areas was more beneficial to the growth and development of tomato.After 35 days of tomato planting,the stem diameter,leaf area and leaf color value of Tomato in the partition liquid supply mode were significantly higher than those in the mixed liquid supply mode after 28 days of tomato planting.When tomato topping,the stem diameter,leaf area and leaf color value of regional liquid supply mode were increased by 37.30%,11.08% and 142.05% respectively compared with that of mixed liquid supply mode;the fresh weight of leaves,dry weight of leaves,fresh weight of stem,fresh weight of root and dry weight of root of Tomato under regional liquid supply mode were increased by 19.19%,12.65%,8.07%,33.10% and 43.01% respectively.2.The method of regional liquid supply was more conducive to increase the single fruit weight and yield of tomato.The results showed that the average fruitweight and the average yield per plant increased by 13.16% and 9.97% respectively.3.The method of regional liquid supply was beneficial to improve the quality of tomato fruit.The contents of soluble protein,vitamin C and organic acid increased by0.6%,76.79% and 18.7%,respectively,and the content of nitrate nitrogen decreased by 59.77%.4.The way of regional liquid supply was beneficial to the absorption of mineral elements by tomato plants.The contents of K,CA,Mg and P in leaves,K,Ca and Mg in stems,K and P contents in roots,and Mg contents in fruits were significantly higher than those in mixed solutions.5.The use time of nutrient solution can be effectively prolonged by the way of partition liquid supply.When the ratio of potassium to calcium in nutrient solution was less than 0.1,it could be used as a qualitative indicator of nutrient deficiency symptoms.After 7 days of this index,the leaves of plants showed obvious yellowing symptoms,and the time of obvious nutrient deficiency symptoms appeared in partitioned feeding solution was 21 days later than that of mixed solution. |
