Study On Physiological Characteristics And Water Consumption Rule Of Tomato Under Crop Rootzone Non-pressure Subirrigation

Crop rootzone non-pressure subirrigation is a new water-saving irrigation method. The research on it at present was only restricted to the water-saving mechanism, irrigation indexes, and parameters. Moreover, little research was done on the growth of plants and whether it's good or bad when compared with other irrigation methods. For this we used the materials of No.1 DongSheng tomato, carried out the experiment in the greenhouse, explored the effect of different water levels(-3cm, 0cm, 3cm, and 6cm) and different irrigation methods (non-pressure, drip, furrow irrigation)on the growth, fruit quality, yield, and water consumption rule of tomato. The results show as follows:(1) Using -3cm water elevation during seeding stage can optimize the proportion between plant heights and stem diameter, which was good for plants and make plants grow healthier. Using other water elevations during flowering stage can enhance the yield of tomato, because it can supply more water to plants after a long time water deficit during seeding stage. -3cm water elevation was not suit for irrigation during fruit-setting stage.(2) Water elevations had significant effects on the growth of tomato. 0cm treatment was not only got a proper dry mass of each plant, but had a reasonable root/top, which was in favor of the growing of plant root and enhance the ratio of flowering and fruit-setting. Root water conductance displayed a trade of 6cm>0cm>3cm>-3cm treatment, the leaf water content had a similar trade because of the effect of root water-suck. The results showed that the soil water content had conic relations with photosynthetic rate, transpiration rate, stomata conductance and intercellular CO₂ concentration. Soil water content had thrice relations with leaf water use efficiency.(3) Water elevations had significant effects on the yield and quality of tomato. The ascorbic acid displayed a trade of 6cm>3cm>0cm>-3cm treatment, but the soluble solids and the sugar/acid all presented the trade of 0cm>-3cm>3cm>6cm, all these showed us that 0cm treatment can harmonize the proportion between sugar and acidity, and make tomato more delicious without the reduction of nourishment. 0cm treatment was superior to other treatments on tomato quality. The yields of two planting time were 6cm>0cm>3cm>-3cm, but the water use efficiency were -3cm>0cm>3cm>6cm(tomato planted in autumn)and 0cm>6cm>3cm>-3cm(tomato planted in spring).(4) The water consumption in the growing stages was seeding>flowering>fruit-setting stage during winter time. When the tomato planted in spring, the water consumption showed the trade of fruit-setting > flowering > seeding > the last growing stage. The water consumption intensity got bigger from -3cm to 6cm treatment during all growing stages. We found that the yield and water consumption, water use efficiency and water consumption have conic relations. To get the aim of saving water and getting high yield, the volume of water consumption should be in the range of 136.73mm～147.01mm(tomato planted in autumn)and 166.02mm～192.35mm(tomato planted in spring), the yield be in the range of 3090.49 kg·667m^-2～3602.95kg·667m^-2(tomato planted in autumn)and 7136.53 kg·667m^-2～7534.6kg·667m-2(tomato planted in spring).(5) We made a comprehensive appraise on all water elevations from investment and output, the results showed that the 6cm treatment got the highest economic benefit, 0cm treatment was inferior to 6cm treatment, and the -3cm treatment was the worst. Combined with the quality of tomato and water use efficiency, we can get that the 6cm treatment had the highest yield, but the water use efficiency, tomato quality and shelf life were inferior to 0cm treatment. Thus, 6cm and 0cm water elevations both can supply the plants well; you can use different water elevations under different purpose.(6) Through studying the effects of non-pressure irrigation, drip irrigation and furrow irrigation on the growth, yield and quality. et al., we found that non-pressure irrigation was superior to drip and furrow irrigations on optimizing root/top, improving healthy index, enhancing the yield and quality of tomato. From the view of investment and output, we found that non-pressure irrigation had the highest benefit, drip irrigation was inferior to it, and furrow irrigation was the worst. At the same time, non-pressure irrigation did not need any water supply pressure, which can save a lot of energy. Therefore, non-pressure irrigation can enhance the yield and quality of tomato and save water and energy, which was worth promoting in greenhouse agricultural production.