关键词: 玉米, 花生, 种间竞争, 强势株与弱势株, 最大生长速率, 产量, 单粒播种, 磷肥

Abstract:

【Background】Maize (Zea mays) intercropping with peanut (Arachis hypogaea) (maize||peanut) has outstanding interspecific effects between aboveground and underground, and the intercropping advantage in yield is prominent, which plays an important role in alleviating the conflict between oil and grain in our country. However, peanut is at the disadvantage of interspecific competition, which becomes the bottleneck restricting the further improvement of intercropping advantage.【Objective】The objective of this study is to explore the regulation measures and mechanism of enhancing peanut interspecific competition in maize||peanut system, and to provide theoretical basis and technical support for maize||peanut high-yield cultivation.【Method】Maize ‘Zhengdan 958’ and peanut ‘Huayu 16’ were used as test materials in the experimental farm of Henan University of Science and Technology from 2021 to 2022. A completely randomized block experiment with three factors: planting pattern, peanut sowing method and phosphorus application rate was set up. In other words, planting patterns were peanut monoculture and maize||peanut, peanut seeding methods were single-seed sowing and double-seed sowing, and phosphorus application rates were 0 (P₀) and 180 kg P₂O₅·hm^-2 (P₁₈₀). Peanut double-seed sowing of maize||peanut was used as control, effects of peanut single-seed sowing on interspecific competitiveness of intercropping peanut over maize, net photosynthetic rate, maximum growth rate, dry matter accumulation and distribution, and yield advantage of intercropping were studied.【Result】Compared to the strong and weak plants with double-seed sowing peanut, single-seed sowing significantly increased the aggressivity and crowding coefficient of intercropping peanut over maize, the aggressivity increased by 29.72%-80.85% and 38.91%-87.07%, respectively, and the crowding coefficient increased by 76.59%-172.02% and 244.43%-308.70%, respectively. The net photosynthetic rate of intercropping peanut with single-seed sowing was significantly higher than that with double-seed sowing, and the maximum growth rate was significantly higher than that of strong and weak plants with double-seed sowing, respectively. The dry matter in the later growth period was significantly increased, dry matter distribution ratio to pod was increased, the contribution rate of stem and leaf dry matter to pod was improved, compared to the strong and weak plants with double-seed sowing peanut. The yield and advantage of intercropping with single seeding were higher than those with double seeding, and the yield was 18.84%-33.32% higher, the difference was significant. Compared with no phosphorus fertilizer, phosphorus application significantly increased the net photosynthetic rate and maximum growth rate of intercropping peanut, and promoted the dry matter accumulation and increased yield of intercropping peanut.【Conclusion】Peanut single-seed sowing can improve intercropping peanut yield and intercropping advantage, the key lies in the fact that single-seed sowing can enhance interspecific competitiveness of intercropping peanut compare with double-seed sowing, significantly increase the net photosynthetic rate, and promote the accumulation of dry matter and distribution to the pod. Phosphorus application promotes the growth and development of intercropping peanut under single-seed sowing.

Key words: maize, peanut, interspecific competition, strong plant and weak plant, maximum growth rate, yield, single-seed sowing, phosphorus fertilizer