In some temperate climate regions, co‐cultivation of warm‐ and cool‐season perennial grass species represents a promising alternative for sustainable food production. However, managing these pastures is challenging, particularly because of intra‐annual competition, which can lead to some species suppressing others. This 3‐year study investigated the effects of different defoliation strategies on mixed pastures composed of tall fescue (Schedonorus arundinaceum Schreb; Tf) and kikuyugrass (Cenchrus clandestinus Hochst. ex Chiov; Ky). Treatments were factorial combinations (two × two) of pre‐grazing canopy heights (15 and 20 cm) and the presence or absence of a single clean‐up grazing event during the spring (SCG). Pre‐grazing canopy height and SCG significantly influenced annual forage accumulation (p < 0.05), but there was no interaction between them (p > 0.05). Swards managed at 20 cm or subjected to SCG presented a 10% greater forage production (approximately 15,432 kg DM ha−1) than those managed at 15 cm or without SCG (14,067 kg DM ha−1). All the treatments presented higher intra‐ and inter‐annual stability in forage production (<30% coefficient of variation). The greater annual forage accumulation was mostly attributed to increments in Tf leaf area index and Ky tiller population density over the seasons. Our study demonstrated that in a mixed sward of warm‐ and cool‐season perennial grasses, both the pre‐grazing canopy height and the presence of an SCG influence year‐round forage production by changing their canopy attributes.

中文翻译：

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高羊茅和菊草混合草的牧草生产受到不同的脱叶策略


在一些温带气候地区，暖季和冷季多年生草种的共作是可持续粮食生产的有前途的替代方案。然而，管理这些牧场具有挑战性，特别是因为年内竞争，这可能导致一些物种压制其他物种。这项为期 3 年的研究调查了不同落叶策略对由高羊茅 （Schedonorus arundinaceum Schreb;Tf） 和菊草 （Cenchrus clandestinus Hochst. ex Chiov;Ky） 的处理是放牧前树冠高度 （15 × 20 cm） 的因子组合 （2 2） 以及春季期间是否存在单一的清理放牧事件 （SCG）。放牧前冠层高度和 SCG 显著影响年牧草积累 （p < 0.05），但它们之间没有交互作用 （p > 0.05）。与 15 cm 或无 SCG 的草料 （14,067 kg DM ha-1） 相比，在 20 cm 处管理或接受 SCG 的草料产量（约 15,432 kg DM ha-1）高 10%。所有处理在牧草生产中表现出更高的年内和年际稳定性 （<30% 变异系数）。较大的年牧草积累主要归因于季节中 Tf 叶面积指数和 Ky 分蘖种群密度的增加。我们的研究表明，在暖季和冷季多年生草的混合草丛中，放牧前的树冠高度和 SCG 的存在都会通过改变它们的树冠属性来影响全年的牧草生产。