Impact Of Different Irrigation And Nitrogen Levels On Growth, Development, Quality And Soil Environment Of Solar-Greenhouse Tomato

Impact of 2 water levels (4541.0, 2270.6 m3/hm2) and 3 nitrogen levels (747.4, 373.9, 0 kg/ hm2) reciprocally supply on tomato yield, fruit quality, water and nitrogen utilization coefficient and respiratory microbial, enzyme, etc. in soil were studied through autumn to spring in solar greenhouse. Results show:1) Tomato yields is not distinctly affected by irrigation supply, but affected by nitrogen supplies. The yields increased prominently along with nitrogen increasing, though its growth not affected obviously under different water and nitrogen levels.2) Soluble protein, free amino acid, organic acid in tomato fruit are effectively improved according to the nitrogen increment along nitrate increment in tomato fruit. The shortness and excessiveness of nitrogen supply would reduce ascorbic acid (Vc) content, but not affected by water supply. Content of nitrate in different truss is increased from 1st to 4th truss, but decreased significantly with its ripening. Nitrogen and water affect nitrate content obviously in fruit.3) Chlorophyll, nitrate nitrate reductase activity and catalase activity in stem or leaf significantly increased and reduced along with nitrogen and water levels raising.4) Significant positive correlation at level 0.01 between leaf nitrate and stem nitrate, soluble protein, free amino acid in fruit were found; Nitrate is significantly positive correlated with Vc, free amino acid, at level 0.01, and with soluble sugar at level 0.05; Vc is significantly positive correlated to soluble sugar, but negatively to organic acid at level 0.01.5) The optimum results derived from nitrogen747.4kg/ hm" and water 2270.6 m~ supply by using Grey Relativity Analysis on yields and quality characters.6) The activity of urease and phosphatase are inhibited under excessive water or excessive nitrogen supply. The invertase activity and soil microbial quantity and soil respiratory intensity were advanced under the coordination between water and nitrogen. EC in soil is significantly affected by water and nitrogen, but not for pH.7) Soil water content is mainly affected by the amount of irrigation and less affected by the amount of nitrogen. Irrigation mainly affected soil layer of 0-60cm. Soil water content, water store and their range of variation increased with the amount of irrigation increasing, and affected soil deep layer. Under the same amount of nitrogen, larger irrigation led to larger nitrate leaching in soil surface layer, under the same amount of irrigation, larger nitrogen led to larger nitrate leaching.8) Water utilization efficient was distinctly increased alone with the increment of nitrogen, but decreased with water increment. N loss percentage was not distinctly affected by water, but strongly affected by the amount of nitrogen. Rational water and nitrogen can reduce N loss percentage effectively.