Effect of biofumigation with different green manures on soil health and active ingredient profiling

Abstract Soil‐borne diseases significantly hinder soil health; however, biofumigation presents an environmentally friendly and cost‐effective strategy for managing these pests. Currently, research studies on the use of plants as green manures have primarily focused on their benefits for soil quality, whereas overlooking their fumigation effects on soil‐borne pests. In this study, we evaluated several soil health indicators for 11 green manures belonging to genus Brassica . Our results indicated that all 11 Brassica species function as the green manure and possess the potential to control pests, with efficacy ranging from 37.55% to 99.19%. Among them, the rapeseed varieties “Zhong Shuang 919” canola and “Hua You Za 9” canola, as well as “Niu Xin No. 3” cabbage, achieved pest control rates of 86.56%–99.19%, increased soil ammonium nitrogen content by 193.73%–252.15%, enhanced organic matter content by 2.68%–13.81%, and boosted the relative abundance of beneficial microbes, such as Bacillus species, by 59.23%–147.85%. During the biofumigation process, isopropyl isothiocyanate was identified as a novel active compound, exhibiting an LC 50 of 1.92 mg/L against Meloidogyne incognita . These findings highlight the fumigation effects of certain Brassica species, suggesting that biofumigation can effectively control soil pests while simultaneously enhancing soil fertility.