| Tomato is one of the most widely grown and most popular edible crop in the world,with large growth,long resulting and harvesting period,high yield,high fertilizer demand,therefore,sufficient nutrient supply was needed,so as to meet the requirement of its stems and leaves growth,flowering and fruiting.At present,the supply of nutrient to most of the greenhouse tomato production was finished by fertigation,but little was known for the requirement law of nutrient by tomato under fertigation.Based on the study results of absorption of N,P,K,Ca,Mg and trace elements by tomato plants as well as their distribution within tomato plants,the amont of water soluble fertilizer used by grower normally was taken as CK,the effects of different gradients of water-soluble fertilizer fertilization on the growth,yield,fruit quanlity as well as their influence of soil nutrient status in different soil layers were studied,so as to establish an optical fertilization model.The main re sults are as follows:1.The absorption law of tomato to N,P,K,Ca,Mg,Fe,Mn,Cu and Zn was basically the same as the growth characteristics of the plant.the absorption rate of each nutrient in the tomato flowering period was low,the absorption of N,P and K only accounts for about 10%of the total absorption,the absorption of Ca and Mg only accounts for about 8%of the total absorption of the whole fertility period,the absorption of Fe,Mn,Cu and Zn only accounted for 5-16%of the total absorption of the whole fertility period,the early fruit-sitting late tomato plant absorption rate of N,P and K was higher,the absorption scored 63.4 kg·hm-2,27.4 kg·hm-2 and 115.6 kg·hm-2 respectively;Ca and Mg absorption was 20.97 kg·hm-2,2.72kg·hm-2;Fe,Mn,Cu and Zn absorption was 4589.5g·hm-2,360.5g·hm-2,109.5 g·hm-2,190.4g·hm-2.2.With the development of tomato,the distribution rate of N,P,K and trace elements in roots,stems and leaves decreased,while the distribution rate of all elements in fruits continued to increase.The distribution rates of N,P and K were 44.89%,56.73%,54.25%,respectively;Ca and Mg were 19.9%and 53.9%,respectively;Fe,Mn,Cu and Zn were 31.8%,19.0%,27.8%and 9.0%,respectively.The absorption ratio of N,P and K is 3.0:1.0:4.7;the absorption ratio of Ca and Mg is 8.1:1;the absorption ratio of Zn and Mn is 38.6:2.9:1:2.0.3.Compared with the blank treatment,the content of N,P and K in the plants increased significantly in each fertilization treatment;compared with the blank treatment,the yield of constant application of special water-soluble fertilizer was the highest?86.7%increase in yield?,followed by farmers'habit of fertilization,54.5%increase in yield.The total acid content,Vc content and nitrate content of tomato increased by 30%were higher,lower and higher.The quality of tomato fruit was better under constant fertilization.4.The application of special water-soluble fertilizer and commercial water-soluble fertilizer can improve the soil properties and the content of available nutrients.The total nitrogen,available phosphorus and organic matter of each layer of soil showed a trend of surface>middle>deep... |
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