Effect of Different Irrigation Patterns and Covering Methods on Soil Temperature of Onions Under Membrane Drip Irrigation

In order to investigate the influence of the soil temperature of onions in the West Hebei Oasis, this paper tested the soil temperature of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the soil temperature of onion was measured in each reproductive period, and the results showed that: The most significant changes in soil temperature were found in the 5 cm soil layer, where the soil temperature was more affected by external influences, and in the 10 and 20 cm soil layers, where the soil temperature was less affected by external influences. The difference in soil temperature was not significant between full irrigation and regulated deficit irrigation. The soil temperature in the black mulch layer was higher than that in the transparent mulch layer and fine sand mulch layer at the seedling and leaf development stages, while the soil temperature in the black mulch layer was higher than that in the transparent mulch layer and fine sand layer at the bulb expansion and maturity stages.The soil temperature of the onion can be best controlled by irrigation while covering the onion with black mulch throughout the growing season, which is of great significance for onion cultivation in the Hexi Irrigation Zone.