Response Of Greenhouse Tomato With Drip Irrigation Under Plastic Mulch To Water-nitrogen Coupling

Greenhouse vegetable plays an important role in the development of the rural economyand increasing farmers’ income and riching people’s food. As overuse of fertilization andirrigation, quality of vegetable crops got worse. With the development of irrigationtechnology, drip irrigation technology had gradually been applied into the greenhousevegetabl cultivation, due to its benefits in water-saving, increasing yield and reducing pests.However, the scientific application of irrigation technology still lack of in-depth research. Inthis thesis, experiment was performed in a greenhouse with the material of tomato, inYangling District, Shaanxi Province. Different water-nitrogen coupling treatments were set inordre to explore their effects on tomato yield, quality and soil. The main conclusions are asfollows:1. Tomato plant height, stem diameter and leaf area significantly increased following theincrement of nitrogen. The suitable nitrogen and water could significantly add the leafphotosynthesis, while too much nitrogen may reduce the leaf photosynthesis,.2. The increment of irrigation water contributed to the cumulation of dry matter, whilethe increment of nitrogen had less effect on dry matter cumulation. Add irrigation andsuitable nitrogen increased the tomato root length, surface area, volumn, mass, but too muchnitrogen could induce anti-effect on root growth.3. Tomato yield increased with the add of irrigation water, while water use efficiencyhad negative relationship with the amount of irrigation water. However, tomato yiel and wateruse efficiency as well increased increment of nitrogen. Rich water and medium nitrogentreatment generated the highest yield.4. Medium nitrogen treatment promoted the add of tomato soluble sugar, organic acid,Vc and sugar-acid ratio. Medium water treatement could induce similar effect on tomatosolube sugar, organic acid and Vc. The quantity of soil nitrate positively related to theapplication of nitrogen fertilizer, while was negative with irrigation water. Based on thesynthesis judgement of tomato quality, low water and rich nitrogen treatment produced thebest quality tomato. 5. Soil moisture and nitrate nitrogen fluctuated greater within the soil layer0~20cmthan0~60cm. In the experiment end, soil nitrate nitrogen in rich nitrogen treatment was morethan other treatments. The cumulation of soil nitrate nitrogen had posive relationship with theapplication nitrogen fertilizer and negative with irrigation.6. Water-nitrogen coupling treatment had no significant effect on soil PH. Soil electricconductivity could be improved by add of nitrogen and degraded by high water irrigation. Itcould be conclude that the relationtship between soil nitrate cumulation and electricconductivity was significantly positive.