Objective The deserts of our country are vast and plentiful in sunshine, large in temperature difference between day and night, and dry in climate. Since sand has the characteristics of leaking fertilizer and water, planting economic forest trees in the desert has a low survival rate, slow growth, and low economic and ecological benefits. Jujube is a drought-resistant and light-loving economic fruit tree species. Therefore, researching the cultivation technology of desert jujube trees and solving the soil-fertilizer-water problems in desert orchards will make it possible to build jujube orchards in the desert, and achieve high yield and quality to obtain high economic benefits.
Method In our work, the Maowusu Desert in Yulin, Shaanxi Province and the Taklimakan Desert in Kashi, Xinjiang of northwestern China were used as experimental bases. Observation and comparative experiments were used to study the phenophase of desert jujube, formula soil replacement, fertilization and irrigation, suitable varieties, facility cultivation, suitable tree shape, water and fertilizer integration, and ecological effects.
Result When planting jujube trees in the desert, the soil in the planting holes need to be replaced with formula soil. The formula soil was prepared by mixing high-quality soil and farm manure at a volume ratio of 7∶3, and the soil in each planting hole was replaced with 0.08 m3 formula soil. When row spacing of 3.0 m and plant spacing of 1.0 m were used for planting, the density of jujube trees was suitable and convenient for mechanized operation. Basic fertilizer (farmyard manure) was applied once a year, the fertilizer amount was 30 m3/ha, and the additional fertilizer (300 kg/ha each time of diammonium phosphate, 120 kg/ha each time of urea) was applied twice, which was applied through mixed ditching or integration of water and fertilizer. Foliar spraying fertilizer (mixture of fertilizers: 0.4% urea, 0.3% potassium dihydrogen phosphate, 0.3% zinc sulfate, 0.5% borax, 0.3% ferrous sulfate) twice a year, and drip irrigation 5 times a year. Among the cultivated varieties of fresh jujube, Qinbaodongzao, Dongzao No.2, Zaocuiwang and Fumicui were better. For dried jujube, Junzao and Huizao were better. The economic benefits of fresh jujube were higher than that of dried jujube. The crown of jujube trees was preferably a small crown, such as spindle-shaped, heart-shape, and a small crown sparse layer-shaped. If water and fertilizer integration and plastic greenhouse facilities could be used for the cultivation of desert jujube, the yield and economic benefit will be increased by 3.2 times and 6.5 times compared with open field cultivation.
Conclusion Based on the desert climatic conditions and the growth and development characteristics of jujube trees, this study overcomed the three technical difficulties of soil, fertilizer and water in the cultivation of jujube in the desert, and achieved high yield, high quality and high efficiency of desert jujube. Furthermore, desert jujube can also play the role of wind-preventing and sand-fixing, protect the ecology, and achieve economic and ecological double profit.