Abstract:

Background and aims

Continuous cropping of vegetable crops leads to soil degradation, increased disease incidence, and environmental impacts. Green manure or fallow are widely recognized as effective methods to address these challenges. This study investigated the effects of different green manure on soil nutrient and microbial properties, and their impact on the yield and quality of Chinese cabbage (Brassica rapa L. ssp. pekinensis).

Methods

Five treatments were evaluated: the different crops planted as green manure are canola (Brassica napus L.) (C), fallow (F), common vetch (Vicia sativa L.) (P), mixed common vetch and canola (PC), and continuous Chinese cabbage cropping as a control (CK).

Results

Treatment P achieved the highest biomass yield (185.5 t ha−1) and economic yield (97.0 t ha−1), significantly surpassing CK by 11.4% and 11.6%, respectively. Other green manure treatments (C, F, and PC) reduced the Chinese cabbage yield by approximately 20% to 30% compared to CK. Quality analysis demonstrated that treatments P and PC had the remarkably higher overall quality index (Sum (Xi)) of 4.50 and 4.54 compared to 3.65 for CK. The soil microbial community structure varied significantly across different green manure planting regimes, setting them apart from fallow and continuous Chinese cabbage cropping systems. Notably, treatment F exhibited the highest soil microbial biodiversity, as indicated by the Shannon and Sobs indices. Nitrogen availability under different green manure planting regimes appeared to influence soil microbial structure.

Conclusion

These findings suggest that planting common vetch before economic crop, significantly enhances vegetable production, providing a sustainable solution for continuous Chinese cabbage cropping systems.