Linking maize root size to phosphorus acquisition and productivity in diversified cropping systems.

Introduction: Intercropping and mixed-cropping of plant varieties can increase yields; however, the impacts of root size and morphology on nutrient uptake and plant growth in these systems remain unclear. Methods: Two maize varieties with small root system (Shengrui 99, M1) and large root system (Zhongke 11, M2) were intercropped with soybean (D76-1609), and also grown under mixed-cropping conditions, with two phosphorus (P) levels (low P: 2.97 mg P kg Results and discussion: Results showed that both intercropping and mixed-cropping conferred advantages over monoculture, with land equivalent ratios (LER) ranged from 1.87 to 2.53. The advantage of intercropping was greater under LP conditions, average 8.65% higher, while mixed-cropping performed better under HP conditions, increased by 26.20%. Nutrient absorption equivalent ratios were also greater than 1 in inter- and mixed-cropping systems. Intercropping with soybean enhanced maize root length under LP, with M2 showing a more pronounced response. Specific nutrient uptake per unit root length and nitrogen (N) and P competition ratios were significantly influenced by P supply and planting pattern ( Conclusion: These results suggest that genetic improvement of maize root size could enhance plant growth and improve resource competitiveness in intercropping and mixed-cropping systems. Furthermore, depending on P availability, larger root systems in maize could increase overall productivity in intercropping and mixed-cropping systems.