Maize Plant Pruning Enhances Peanut Yield Through Mitigating Shading in a Maize–Peanut Strip Intercropping System

ABSTRACT Shading from taller cereal plants often reduces the growth of shorter, intercropped legumes and the productivity of cereal‐legume intercropping systems. To mitigate the effect of shade on companion crops, pruning (leaf cutting) maize plants at a seedling stage is an increasingly common practice. However, it is not clear if this leaf‐removal strategy benefits leguminous crop yield without causing a loss in cereal crop yield. A 2‐year field experiment was performed to investigate the impact of cutting maize leaves at V4 stage (T V4 ) and V5 stage (T V5 ) on the growth and yield of intercropped peanuts. Across 2 years, peanut yield was 22.9% higher in T V4 and 33.5% higher in T V5 treatments than it was in a nonleaf‐cutting control, whereas maize grain yield was not affected, with a slight increase in T V4 and a slight decrease in T V5 . Compared with uncut controls, maize plant height was reduced by 30.2 cm (23.9%) in the T V4 treatment and 49.2 cm (35.5%) in the T V5 treatment, whereas photosynthetically active radiation reaching peanuts strips increased by 16.6% and 22.8%, respectively; the net photosynthetic rates of peanuts increased by 17.4% on average. Seedling leaf cutting shortened maize roots but increased peanut root length (28.6%) and surface area (30.8%) over time. The positive effects of seedling leaf cutting contributed to an increase in nitrogen absorption by 26.6% and 20.8% greater total biomass of peanuts. Cutting leaves at stage V4 resulted in a greater intercropping‐system land equivalent ratio than cutting them at the V5 stage, whereas leaf cutting at the V5 stage contributes to a greater increase in the intercropped peanut yield. We demonstrate that cutting leaves of intercropped maize at the seedling stage improves peanut yield by optimizing the canopy light environment and modifying belowground root development of peanuts.