Microclimate, crop quality, productivity, and revenue in two types of agroforestry systems in drylands of Xinjiang, northwest China

Abstract

Listen

Translate article

The objective of this study was to determine the effects of agroforestry systems with narrow rows on microclimate, crop quality, productivity, and revenue when compared with that in sole-cropping in drylands. Therefore, two-year field experiments were conducted to determine the characteristics of two types of agroforestry systems in drylands of Xinjiang including photosynthetically active radiation (PAR), air temperature, crop protein content, productivity, and revenue. The two systems included (1) a jujube tree (Zizyphus jujuba Mill.) + wheat (Triticum aestivum L.) intercropping (JWI) system and (2) a poplar tree (Populus L.) + alfalfa (Medicago sativa L.) silvopastoral (PAS) system located in southern and northern Xinjiang, respectively. Variables were measured in control sole-cropping plots and in the alleys of JWI and PAS system plots at different distances from the tree row. PAR and air temperature both decreased in plots of the JWI and PAS systems. The changes in microclimatic conditions and competition for resources in the JWI and PAS systems resulted in an overall decrease in wheat grain and alfalfa hay yield and decreases in the overall protein content of wheat grain and alfalfa. In JWI and PAS systems, the yield and protein content of understory crops, PAR, and air temperature were highest at the center line of the system alley and decreased with decreasing distances from the tree row. The PAS system was more productive than the JWI system based on the calculated land equivalent ratio (LER), because no significant decrease was observed in tree yield in the PAS system. Both the JWI and PAS systems resulted in an increase in the annual total crop revenue when compared with individual crop management, indicating that the JWI and PAS systems could provide greater long-term economic benefits. Therefore, the balance between yield, crop quality, and revenue have to be taken into account in the analysis of agroforestry systems.