Effect of Furrow Straw Mulching and Straw Decomposer Application on Celery (Apium graveolens L.) Production and Soil Improvement

Straw mulching on wet beds is an effective method to alleviate continuous cropping obstacles in greenhouses. However, this technique cannot be applied in the production of leafy vegetables with high planting density. Straw mulching in furrows is an alternative method in this circumstance. In this study, celery (Apium graveolens L.), a vegetable that prefers a high planting density and wet soil, was used to test furrow straw mulching technology, and the effect of different straw amounts and straw decomposers on soil improvement and celery production was investigated. The results showed that straw mulching in furrows significantly reduced soil conductivity and nitrate nitrogen levels, increased the contents of soil organic carbon as well as phosphorus and potassium nutrients in the bed, and improved celery yield and quality, indicating the significant lateral movement of released nutrients between the furrow and bed. The positive effects of 15,000 kg/ha straw application were more pronounced than those of 7500 kg/ha and 11,250 kg/ha. In addition, straw decomposers accelerated nutrient release and improved celery yield and quality. A decomposer named "ZhuBang" containing Bacillus licheniformis was the most effective. We concluded that furrow straw mulching combined with straw decomposer application is an effective measure for the sustainable production of leafy vegetables in intensive vegetable production facilities.