Abstract:

In Chinese solar greenhouse, in order to deal with the problem of high temperature stress in sweet pepper growth period in spring, a novel cultivation method named soil ridge substrate-embedded cultivation (SRSC) was designed. In this experiment, four kinds of treatments were set such as soil ridge (S treatment), soil ridge substrate-embedded of PE (P treatment), soil ridge substrate-embedded of wire (W treatment) and single PE groove (CK) which as contrast. Root zone temperatures were observed from 12：00 to 16：00 every day in sweet pepper maturation stage (May to June), and parameters of growth and yield of sweet pepper were measured and analysed at different times. Results showed that root zone temperatures of S, P and W were 1.50, 2.17 and 1.47℃ lower than CK, respectively, and P and W could effectively buffer high root zone temperature, and the effect of P was slightly better than W. The plant height, stem diameter, chlorophyll content, dry shoot weight and fresh shoot weight of sweet pepper cultivated on S, P and W were significantly higher than that of CK, and the effect of W was the most obvious. The fresh root weight of soilless cultivation was significantly less than sweet pepper cultivated on other ridges, but dry shoot and root weight were decreased by high root zone temperature. In addition, the fruit number of S was significantly less than that of other three treatments when picking at first time, it suggested that soilless cultivation could accelerate the growth process of sweet pepper. The yield of W was 3.78kg·m^-2, and it increased by 80.9%, 31.3%, and 51.8% respectively than S, P and CK. In short, W enhanced the root zone temperature buffer capacity, and significantly improved the yield of sweet pepper, and it had important application value in the high temperature environment production in Chinese solar greenhouse.

Key words: Chinese solar greenhouse, Soil ridge substrate-embedded cultivation method, Sweet pepper, Root zone temperature, Temperature buffer capacity