Microclimate, yield, and income of a jujube–cotton agroforestry system in Xinjiang, China

Abstract

The purpose of this study was to establish a jujube (Zizyphus jujuba Mill.)–cotton (Gossypium hirsutum Linn.) intercropping agroforestry system in the south and north of Xinjiang Uygur Autonomous Region and to determine the impact of intercropping systems on microclimate, yield, and income compared with sole-cropping planting. Therefore, a two-year field experiment was carried out in the Hotan and Shihezi areas to measure photosynthetically active radiation (PAR) on the space-time scale, air temperature on the time scale, wind speed and windproof efficiency on the time scale, and yield and income. Through correlation analysis, the relationship between intercropping microclimate and intercropping yield were revealed. Compared with corresponding sole-cropping cotton, the PAR of intercropping in Hotan and Shihezi was 13.04% and 12.75% lower, respectively, and the closer to the tree alley, the smaller it was. Intercropping changed the daily dynamics of air temperature, especially at high temperatures, under which the decrease range was significant. Intercropping has buffer effect and latent heat release on air temperature and the maximum temperature in Hotan and Shihezi intercropping was 13.57% and 6.49 lower than that in sole-cropping, respectively. Intercropping reduced the wind speed, the greater the wind speed in a certain range, the stronger the windproof efficiency. The maximum windproof efficiency of Hotan intercropping was 50.92%, and that of Shihezi was 48.56%. The intercropping system had advantages in land equivalent ratio (LER), yield, and income. The income of intercropping was 11622.38–12528.55 USD·hm−2, 55.41–61.91% higher than that of sole-cropping cotton and 19.19–20.37% higher than that of sole-cropping jujube. The results showed that the development of jujube-cotton intercropping could protect the growing environment of cotton and increase farmers' economic income by improving the field microclimate.