Abstract: A field split plot experiment was set up, in which tomato was planted and bare field, two irrigation levels were 2.25×10³ t/ hm² （W1） and 4.50×10³ t/hm² （W2）, and two application nitrogen levels were 450 kg/hm²（N1） and 675 kg/hm²（N2） in the sub plot. The growth and yield of plants in each treatment were measured in the growth period, and the soil physical and chemical properties in all treatment root zone was measured after harvest. The results showed that compared with different water and nitrogen treatments, the chlorophyll content and total biomass of tomato leaves were the highest in W2N2; Compared with different treatments, the yield of W1N2 was higher than that of W1N1, W2N2 and W2N1, but there was no significant difference among the latter three. Compared with bare field, in planted tomato field the soil moisture and pH decreased by 17.3% and 2.08%; The concentration of nitrate nitrogen and EC increased by 29.2% and 84.4%. In planting zone under the same irrigation amount, the trend of nitrate concentration was the same, the higher the irrigation amount was, the higher the nitrate nitrogen concentration was 10~20 cm; The EC value of 0~50 cm in W1N2 treatment was significantly higher than that in other treatments. In bare field W2N2 of the concentration of nitrate nitrogen in different soil layers was significantly higher than that of W1N2, W2N1 and W1N1, and the EC value of 0~10 cm of N2 was significantly higher than that of N1.

Key words: irrigation amount, nitrite nitrogen, salinity, tomato