Rotational strip peanut/cotton intercropping improves agricultural production through modulating plant growth, root exudates, and soil microbial communities

Legume-based intercropping is widely used by smallholder farmers; however, there is scarce information governing the long-term effects of interspecific interactions on the crop growth performance. Here, we present data of 5 years field experimentation on a rotational strip peanut/cotton intercropping system to uncover its beneficial effects on crop production and decipher the underlying mechanisms. Treatments included monoculture of peanut (MP), monoculture of cotton (MC), peanut/cotton intercropping (IC), and peanut/cotton intercropping with solid root barrier (SC). Averaged for 5 years, intercropping did not alter the peanut pods yield whereas the seed cotton yield was significantly increased by 52.63% compared with monoculture. Moreover, the net economic return of IC was significantly increased by 59.49%. Physiological data indicated that the leaf net photosynthetic rate, total biomass, and the accumulation of total nitrogen in peanut pods and cotton buds were significantly increased in IC compared with MP and MC. Meanwhile, the contents of total protein and oleic acid in peanut kernels were also increased by intercropping. Metabolomics evidence showed that differential metabolites from Tryptophan and Carbon pathways were significantly enriched in peanut and cotton strips of IC. Additionally, IC significantly altered the rhizosphere soil bacterial abundance composition and diversity, and the metabolic functional features of carbohydrate and amino acid were significantly enriched. Strikingly, the beneficial effects of intercropping were partially counteracted by SC as indicated by the reduction of crop production and net return. Our results demonstrated that rotational strip peanut/cotton intercropping increases production, net economic returns, and peanut quality parameters via the interspecific interactions by enhancing plant growth, regulating root exudates, and modulating soil microbial communities.

Automated summary

Legume-based intercropping, specifically rotational strip peanut/cotton intercropping, significantly increases the seed cotton yield and net economic returns without affecting the peanut pods yield. The physiological data indicate that intercropping enhances the leaf net photosynthetic rate, total biomass, and total nitrogen accumulation in peanut pods and cotton buds. Intercropping also increases the total protein and oleic acid contents in peanut kernels. Metabolomics and soil microbial community analysis reveal that intercropping influences the plant metabolic pathways and soil microbial composition and functionality. However, the beneficial effects of intercropping are partially counteracted by the introduction of a solid root barrier.