Wang Ying, Han Xue, Zhao Xingyao, Zhang Yanli, Qi Bingjie, Li Lijun
College of Agronomy, Inner Mongolia Agricultural University, Hohhot, China.
Front Plant Sci. 2024 Mar 8;15:1344110. doi: 10.3389/fpls.2024.1344110. eCollection 2024.
Oat ( L.) and common vetch ( L.) intercropping in the northern regions of China has resulted in substantial production capabilities. However, there is currently a dearth of comprehensive research on whether this intercropping system can enhance productivity through increased sowing densities and underlying interspecies interaction mechanisms.
A two-year field experiment was conducted in 2022 and 2023 to investigate the yield, biological efficiency, economic efficiency, and competition indicators of oats and common vetch in a high-density intercropping system. Two cropping patterns (monocropping and intercropping) and five sowing densities (D1: 4.5×10 plants ha; D2:5.4×10 plants ha; D3:6.3×10 plants ha; D4: 7.2×10 plants ha; and D5: 8.1×10 plants ha) were arranged in a randomized block design.
At the same sowing density, the intercropped oats exhibited greater grain yield than the monocultures. Increasing the oat sowing density significantly enhanced oat yield, with the D3 level in intercropping showing the highest yield increase, ranging from 30.98% to 31.85%, compared with the monoculture. The common vetch intercropping grain yield was maximized in the D2 treatment. The land equivalent ratio was maximized at the D2 level in both years and was significantly higher than D1, with the land equivalent coefficient, system productivity index, and percentage yield difference suggesting that increasing oat sowing densities improved the productivity of the intercropping system, with the best performance observed at the D2 level. For both years, the proportionate actual yield loss of oat was the highest at the D3 level; significantly surpassing D1, proportionate actual yield loss of common vetch and actual yield loss were the highest at level D2, both significantly surpassing D1. These indicates that appropriate densification contributes to the realization of the advantages of intercropping. With an increased oat sowing density, the economic benefits of the intercropping system were maximized at the D2 and D3 levels. Regarding intercropping competition, oat was the dominant crop under different sowing densities (Aggressivity for oat (A)>0, relative crowding coefficient for oat (K)>1, competition ratio for oat (CR)>1), whereas common vetch was the inferior crop. Compared with the D1 level, the D2 level harmonized the aggressivity, competitive ratio, and relative crowding coefficients of oat and common vetch, significantly increasing crowding coefficient for common vetch (K) and competition ratio for common vetch by 19.76% to 21.94% and 4.80% to 7.51%, respectively, while reducing K and CR.
This result suggests that in the intercropping of common vetch and oat in alpine regions, rational densification can harmonize interspecific competition and thus improve the biological efficiency and economic benefits of intercropping systems.
在中国北方地区，燕麦（L.）和普通野豌豆（L.）间作展现出了可观的生产能力。然而，目前对于这种间作系统是否能通过提高播种密度及潜在的种间相互作用机制来提高生产力，尚缺乏全面研究。
于2022年和2023年进行了为期两年的田间试验，以研究高密度间作系统中燕麦和普通野豌豆的产量、生物学效率、经济效率及竞争指标。设置了两种种植模式（单作和间作）以及五种播种密度（D1：4.5×10株/公顷；D2：5.4×10株/公顷；D3：6.3×10株/公顷；D4：7.2×10株/公顷；D5：8.1×10株/公顷），采用随机区组设计。
在相同播种密度下，间作燕麦的籽粒产量高于单作。增加燕麦播种密度显著提高了燕麦产量，间作中的D3水平产量增幅最高，与单作相比，增幅在30.98%至31.85%之间。普通野豌豆间作籽粒产量在D2处理中达到最大值。两年中土地当量比在D2水平达到最大值，且显著高于D1，土地当量系数、系统生产力指数和产量差异百分比表明，增加燕麦播种密度提高了间作系统的生产力，在D2水平表现最佳。两年中，燕麦的实际产量损失比例在D3水平最高；显著超过D1，普通野豌豆的实际产量损失比例和实际产量损失在D2水平最高，均显著超过D1。这表明适当密植有助于实现间作优势。随着燕麦播种密度增加，间作系统的经济效益在D2和D3水平达到最大值。关于间作竞争，在不同播种密度下燕麦是优势作物（燕麦的竞争能力（A）>0，燕麦的相对拥挤系数（K）>1，燕麦的竞争比率（CR）>1），而普通野豌豆是劣势作物。与D1水平相比，D2水平协调了燕麦和普通野豌豆的竞争能力、竞争比率和相对拥挤系数，显著提高了普通野豌豆的拥挤系数（K）和竞争比率，分别提高了19.76%至21.94%和4.80%至7.51%，同时降低了K和CR。
该结果表明，在高寒地区普通野豌豆与燕麦间作中，合理密植可协调种间竞争，从而提高间作系统的生物学效率和经济效益。
