Apricot can improve root system characteristics and yield by intercropping with alfalfa in semi-arid areas

Background and aims The interaction between apricot and alfalfa will increase land use efficiency and improve the production capacity of trees, and allow the exploration of the impact of apricot intercropping with alfalfa on physiological and root morphological characteristics. Methods Four planting modes were set up: alfalfa monoculture, apricot monoculture, apricot intercropped with alfalfa with a 20 cm row spacing and apricot intercropped with alfalfa with a 30 cm row spacing. Through measurements of the plant height, soil and plant analyzer development value, root length density, root surface area, and crop yield, the above and belowground growth status of the crops under different planting modes was explored. Results In 2020 and 2021, in the horizontal direction, root length density was mainly concentrated at 60–90 cm. With the increase in the horizontal distance, root length density was mainly concentrated at 90–120 cm. In the vertical direction, root length density was mainly concentrated at 0–20 cm. In 2020, compared with the yield in the alfalfa treatment, the yield of intercropping alfalfa (30 cm) and (20 cm) decreased by 71.2% and 58.7%, respectively, and alfalfa differed significantly between apricot intercropped alfalfa (20 cm) and apricot intercropped alfalfa (30 cm). In 2021, the land equivalent ratios of apricot intercropped alfalfa (20 cm) and apricot intercropped alfalfa (30 cm) were 1.25 and 1.26, respectively. Conclusion Indicating that both planting modes have land production advantages. Under the two row spacing intercropping modes, apricot intercropped alfalfa (20 cm) is more suitable for local planting. Graphical abstract