Alleviating negative home plant–soil feedback in vegetables through phosphorus management

Home plant–soil feedbacks (home-PSFs) typically demonstrate negative effects in vegetable crops, substantially inhibiting their growth. Phosphorus (P), an essential plant nutrient crucial for growth, influences vegetable crop growth patterns through soil availability levels. However, the relationship between soil available P levels and home-PSFs in vegetable crops requires further investigation. This study established a home PSF system incorporating 12 vegetable crops from 6 families to examine growth responses under two P conditions (low P level: 40 mg P kg^–1 soil; high P level: 200 mg P kg^–1 soil). The findings revealed that low P conditions significantly decreased overall biomass across all vegetables, with preferential biomass allocation to root development. Furthermore, low P conditions enhanced mycorrhizal colonization and rhizosphere acid phosphatase activity while notably decreasing root length. While vegetables generally exhibited negative home PSFs, allium and nonmycorrhizal plants demonstrated positive responses under high P conditions. Wild tomatoes displayed greater variation in feedback values across P levels compared to common tomatoes. Under high-P conditions, mycorrhizal colonization showed positive correlations with feedback values of biomass and P concentration. Root diameter and mycorrhizal colonization demonstrated distinct correlations with these feedback values under low-P conditions. The research concludes that high P levels effectively mitigate negative home-PSFs in vegetables while increasing biomass production. Additionally, high P levels demonstrated superior efficacy in alleviating negative home-PSFs in wild tomatoes compared to common tomatoes.