| Tomato has a long period of growth, higher yield and great amount of fertilizer absorption. Previous findings of tomato fertilization varied consider -ably for different cultivations, different fertility level and different breeds. In recent years, gragting of tomato has a rapid development for the seriousness of soil-borne diseases. While grafting changed the root of tomato which is the main organ of nutrient absorption, its absorption and distribution characteris -tices of elements must be changed, at the same time, we must consider the differences between different stocks. So in this paper we studied the optimiza -tion fertilization program first, then the effects of grafting and fertilization on the yield, quality and nutrient absorption and using characteristics of tomato were studied, to make the increase mechanism of production clearly and to provide a reference of high efficiency of grafted tomato fertilization. The main findings are as follows:1. N, P and K significantly influenced tomato yield and quality, and there were significant interactive effects between every two factors. Among the three factors, K had the greatest effect on the yield and quality of tomato. At the lower level, the yield and quality were improved along with the increase of N, P and K. When N, P2O5, K2O reached 790.74, 346.25, 1223.93 kg·hm-2, the effect value of marginal quality was 0. Obtained by computer simulation, in this experiment, when the fertilizer rates were N at 520.2-758.4 kg·hm-2, P2O5 at 294.75-367.25 kg·hm-2, K2O at 1051.5-1299.75 kg·ha-2 yield reached 140 t·hm-2 and quality grade passed 95. The most suitable ratio of N:P2O5:K2O was about 1:0.52:1.84.2. The growth of all the organ and the absorption of nutrient of grafted tomato were highly improved, and 30.76% average yield raising compared to the self-rooted, at the same time the using efficiency of N, P and K was 25.67%, 20.41% and 20.97% increased each. When applying the mixture of N, P and K, the yield can be increased and more nutrients can be uptook and the using efficiency of the relevant element can be improved highly comparing to use single element. The average yield of tomato using N, P and K was 42.58%, 68.68% and 50.16% improved than using single fertilizer and the using efficiency of N, P and K were 103.03%, 272.86% and 93.71%imporved too. In the grafted treatment the soil provision ability of N, P and K was 27.63%, 29.80% and 29.17% improved each compared to the self-rooted while the other elements were enough.3. The grafted tomato had a high speed of growth and development. With the growth of tomato, the differences of the amount of dry matter in root, stem, leaf and fruit were increased between the grafted and non-grafted and at the end of the stages, the amount of dry matter in root, stem, leaf and fruit of grafted tomato were 32.0%, 27.2%, 36.4% and 33.8% higher than the self-rooted. The yield of grafted tomato reached 67736.1 kg·hm-2, 22.4% higher than the self-rooted. The incidence of root knot nematodes of grafted tomato was 9.17% while the incidence of the self-rooted was 100% and the disease index of the tow treatments were 8.75 and 81.0. At the same time, the amounts of dry matter, soluble protein and rigidity of fruit in grafted tomato were slightly higher compared to the self-rooted one and the amount of Vc, soluble sugar and organic acid were slightly fewer but the sugar-acid ratio was higher. So grafting can enhance the resistibility on root knot nematodes, raise the yield obviously and influnence the quality of fruit unobviously.4. The active of enzymes were enhance and the content of MDA was reduced in the leaves of tomato after grafted. Compared to the self-rooted tomato, the liveness of SOD, POD and CAT are 53.4%, 72.9% and 61.2% increased and the content of MDA is 60.2% declined at most. And the root activity of grafted tomato is enhanced extraordinary, 49.8% higher than the self-rooted. The content of chlorophyll and photosynthetic rate are raised highly after grafted, about 80.4% and 55.1% increased.
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