Effects of different soil management modes on rhizospheric temperature,soil properties and grape growth in the greenhouse

Abstract: 【Objective】To study the effects of different soil management modes in the greenhouse on the improvement of rhizospheric temperature and the growth and development of grapes in the spring, aiming to provide theoretical and technical support for viticulture in greenhouse.【Methods】The grafted seedlings of 2 years old wine grape‘Cabernet Sauvigon'(Vitis vinifera L.)/3309 M were used as test materials. The planting space was 1.5 m×0.7 m. The test was set to 4 treatments, namely“tent”cover, ridging cultivation, plastic film mulching and the ground cultivation control.【Results】The root zone temperature obviously delayed behind the air temperature in the greenhouse. Whether it was sunny or cloudy, the root zone temperature delayed behind air temperature for about 2 hours, and the root zone temperature of“tent”cover treatment only delayed for about 1 hour. The root zone temperature of the“tent”cover was higher than that of the ground cultivation about 1.2 ℃ to 1.5 ℃, and the root zone temperature of the ridging cultivation increased by 1.1 ℃ to 2.4 ℃, the effects of plastic film cover was the same as“tent”cover. Different effects of different management modes on improving the soil structures were found. The soil bulk of the“tent”cover and the ridging cultivation were decreased obviously, compared with that of the flat cultivation control. The plastic film cover had no significant difference, while the change trend of the soil porosity and the bulk density was opposite, after measured the soil porosity of“tent”cover and ridging cultivation, they significantly increased by 19.8% and 20.9% compared with the flat cultivation, the soil porosity of the plastic film cover was only 5.2% greater than that of the flat cultivation control. Mulching was also helpful for retaining soil moisture. On the 45 days after treatment, compared with that of the flat cultivation, the relative water content of soil under“tent”and the plastic film cover significantly increased by 23.9% and 23.5%, but there was no significant difference between them. The ridging cultivation was not conducive to water retention, and the soil water content was 16.9% lower than that of the“tent”cover. Soil oxygen diffusion rate and soil respiration intensity increased rapidly after the“tent”was covered. Especially, when sharp cooling occurred(the 30 th days),a higher root zone microenvironment temperature was maintained after the“tent”was covered, the soil respiration intensity decreased by only 20% compared with the previous peak, while that of the flat control decreased by 77.8%. With the extension of treatment the ground temperature gradually increased,and the soil enzyme activity also showed an increasing trend, and the effects of“tent”was particularly significant. When the root zone temperature reached the temperature of root germination, the activity of the underground part was accelerated, the ability of root to absorb water increased, the water content of upward transportation increased, and the relative water content of branches increased. Compared with the control, on the 45 th days, in the‘Cabernet Sauvignon'roots and buds covered by the“tent”, both the expressions of auxin synthesis-related genes(YUC1, YUC2, YUC6) and transporter genes(PIN1,PIN2, PIN3) were significantly up-regulated. The“tent”cover effectively increased the ground temperature and promoted the growth of grape root system, and the auxin content in grape root system significantly increased. The germination period was 7-10 d earlier than that of the flat cultivation control, and the leaf development period was 5 d to 7 d earlier than that of the flat cultivation control. The grapes grew neatly, and the root growth significantly increased by 32.9% compared with the control, and the root activity increased by 13.8%. For germination effects(time and uniformity), the effecs of the“tent”were the best, followed by the plastic film cover and the cultivation.【Conclusion】“Tent”cover could significantly improve the root zone temperature in the greenhouse, effectively improved soil compactness and aeration, and help to maintain soil moisture content, advance the germination process of grapes, and promote the growth and development of grapes in the spring.