Crop Productivity, Economic Advantage, and Photosynthetic Characteristics in a Corn-Peanut Intercropping System

Corn-peanut intercropping is an important element of China's agricultural planting model as it confers ecological benefits and increases yield. The aim of this study was to explore the productivity differences between intercropping and monoculture by using the C-13 isotope tracer labelling method. Corn hybrid Denghai 618 (DH618) and peanut variety Huayu 22 (HY22) were used as test materials under three planting methods, single corn, SM; single peanut, SP; and corn-peanut intercropping, IM and IP, respectively, during two growing seasons. The results showed that IM increased yield by 59.7% and 62.3% compared with SM, respectively. IP reduced yield by 31.3% and 32.3% compared with SP, respectively. IM significantly increased the photosynthetic rate, leaf area, C-13 assimilation distribution, and dry matter accumulation of summer corn, which led to an increase in the kernel number and grain yield. The decrease in intercropped peanut yield was mainly caused by a decrease in the full-pod rate and number of pods per plant. The decrease in peanut yield did not affect the production of intercropping benefit due to the larger intercropping advantage and land equivalence ratio. Corn-peanut intercropping yielded greater economic benefits than monoculture. These results showed the utility of the peanut-corn intercropping model.