Effect of a jujube || alfalfa intercropping system on soil chemical properties and microorganisms in the oasis irrigation area of southern Xinjiang

In field experiments, three planting systems consisting of jujube (Ziziphus jujuba) || alfalfa (Medicago sativa) intercropping (JA), alfalfa monocropping (SA), and jujube monocropping (SJ) were applied to examine the effects of the different planting systems on soil nutrients and soil microbial properties. The results showed that under the JA system, the soil pH value tended to initially decrease, then increase; soil alkalinity nitrogen content varied in the order SA > JA > SJ; and available potassium and available phosphorus content in the soil differed in the order JA > SJ > SA. The number of soil microorganisms was the highest under the JA system, showing a pattern of an initial increase followed by a decrease. The number of soil fungi and actinomycetes peaked on July 21, and the number of soil bacteria peaked on June 19; in terms of yield, the yield under the JA system was 73% higher than that under either the SA or SJ systems. These findings show that the JA system significantly (P < 0.05) increased soil nutrient content, land use efficiency, and yield while also promoting microbial activity.