Impact of fruit tree hole storage brick treatment on the growth of grape seedlings and water transport in the root zone under root restriction and subsurface drip irrigation

Abstract

Under the condition of root restriction, the fresh and dry weight of the root absorbed by grapes is reduced, the growth of the main root is hindered, and the upward movement of roots is caused by surface drip irrigation. To solve these problems, this paper designed a fruit tree hole storage brick combining organic fertilizer and polymer material. To investigate the mechanism of how the fruit tree hole storage bricks affect the root and shoot biomass, root distribution, leaf physiological function, and soil water content of grape seedlings, two-year-old ‘Summer Black’ was used as the test material, and three treatments were designed under root restriction conditions: (1) conventional drip irrigation (CK), (2) fruit tree hole storage brick a (T1), and (3) fruit tree hole storage brick b (T2). The results showed that the T1 and T2 treatments significantly increased the total dry matter mass and root-shoot ratio, well maintained the soil water content at a soil depth of 15–30 cm and enhanced the distribution of roots at different soil depths. At a soil depth of 30–45 cm, the total root length, total root surface area and absorbing root length were significantly different among the different treatments, presenting as T2>T1>CK. Under the T1 and T2 treatments, the net photosynthetic rate, transpiration rate and instantaneous water utilization rate of leaves all increased compared with CK. On the 13th day of irrigation, the difference between fluorescence intensity under the T1 and T2 treatments and that under CK increased over time. In conclusion, the fruit tree hole storage bricks made of materials such as organic fertilizer and biochar could well maintain the soil water content and promote the growth of the root system, and the T2 treatment performed the best.