Abstract:

Using an optimized APSIM model and based on daily meteorological data from Fuxin, Liaoning province from 1961 to 2020, with sole maize (SM) and sole peanut (SP) as controls, eight maize−peanut row ratio configurations were established: narrow strip scenarios 2:2 (M2P2), 4:4 (M4P4), 6:6 (M6P6); medium strip scenarios 8:8 (M8P8), 10:10 (M10P10); and wide strip scenarios 12:12 (M12P12), 14:14 (M14P14) and 16:16 (M16P16). A comparative analysis was conducted to assess the effects of different maize−peanut row ratio configurations under climate change on rainfed yield, potential yield, land equivalent ratio, soil water content and soil organic carbon content. This study aimed to identify the optimal maize−peanut intercropping row ratio configuration in western Liaoning, thereby addressing the sustainable development of maize−peanut intercropping systems in the region and providing theoretical guidance for enhancing the economic and ecological benefits of grain production in western Liaoning. The results indicated that: (1) under rainfed conditions, maize yield in the maize−peanut intercropping system showed a decreasing trend across all 8 row ratio configurations from 1961 to 2020, declining from 3469kg·ha⁻¹ to 3418kg·ha⁻¹, while peanut yield increased from 746kg·ha⁻¹ to 926kg·ha⁻¹. Under fully irrigated conditions, maize yield in the maize−peanut intercropping system decreased from 4166kg·ha⁻¹ to 4156kg·ha⁻¹, while peanut yield increased from 751kg·ha⁻¹ to 1004kg·ha⁻¹ across the eight maize−peanut row ratio configurations from 1961 to 2020. Compared to the wide−strip scenario M16P16, the narrow−strip scenario M2P2 maize yield reduced by 51kg·ha⁻¹ under rainfed conditions and by 10kg·ha⁻¹ under fully irrigated conditions, while peanut yield increased by 180kg·ha⁻¹ and 253kg·ha⁻¹, respectively. (2) Under eight row ratio configurations in the maize−peanut intercropping system from 1961 to 2020, the rain−fed and potential land equivalence ratios for intercropped maize fluctuated stably around 0.56 and 0.62, respectively. The rain−fed land equivalent ratio for intercropped peanuts increased from 0.29 to 0.35, while the potential land equivalent ratio increased from 0.25 to 0.33. Both maize and peanut land equivalent ratios in intercropping systems remained <1.0. (3) From 1961 to 2020, soil organic carbon content in maize−peanut intercropping systems increased from 0.82% to 1.02%. Soil moisture content decreased from 0.26mm·mm⁻¹ to 0.14mm·mm⁻¹. From 1961 to 2020, soil moisture content in the maize−peanut intercropping system showed an interannual decreasing trend, while soil organic carbon content exhibited a significant interannual increasing trend (P<0.001). Based on the performance of total yield, land equivalent ratio, soil moisture content, narrow−strip intercropping of maize and peanuts (M2P2 and M4P4) could effectively enhance land productivity for the fragile ecosystems in western Liaoning province. This approach is economically and ecologically valuable under global warming conditions.

Key words: Row ratio, Intercropping, Maize, Peanut, APSIM model