Diverse forage mixtures to optimise ruminant animal production, nutrient use efficiency, environmental impact, biodiversity, and resilience

牧草的生长和供应是饲养绵羊和牛的最具成本效益的方式。牧草主要由黑麦草或黑麦草与白色或红色三叶草混合组成，牧草的总量取决于气候、管理、土壤和化肥使用量。黑麦草和三叶草在潮湿凉爽的环境中茁壮成长，但由于不可预测和不断变化的气候，这些最佳条件发生的频率较低。干旱和土壤内涝都减少了可种植的牧草数量，这影响了农场的生产力，最终增加了生产英国本土牛奶和肉类的成本。植物生长需要许多必要的营养物质。这些养分大部分是通过土壤提供的，但其他养分，如氮(N)，对许多植物来说是缺乏的，因此需要以矿物质肥料的形式添加。由于依赖石油，矿物肥料的生产成本很高，而且由于它们的生产和对土壤一氧化二氮排放的贡献以及对水道的污染，对环境有害。解决这些问题的办法是使用更多多样性或多样性的饲料植物。生态系统中的植物种类越多，对不断变化的环境就越健康、更健壮和更具弹性。在典型的气候特定牧场之外，在不稳定的天气模式下，含有耐旱和耐涝植物的各种混合物可以提供高质量的饲料来源。这些多样化的植物包括豆类，它们减少了对矿物质化肥的需求，因为它们提供了牧场极好的氮源，因为它们有能力转化或‘固定’不可用的大气氮气。因此，这提高了土壤肥力，提高了牧草产量，并使N在动物和农场规模上得到了更好的利用。这一点，再加上饲喂不同饲料混合物的牲畜甲烷排放量的减少，可以减少牛奶和肉类生产的碳足迹。然而，这些好处只能通过更多的农场吸收这类饲料才能实现。该项目的最终目标是为畜牧业生产实现高产量的优质饲料，同时对环境产生积极和长期的影响。我们设想，与黑麦草或黑麦草/三叶草牧场相比，可以通过利用有潜力在更具挑战性的气候情景下生产的各种饲料混合物以及提高氮素利用效率来实现这一点。该项目将包括对各种混合饲料的性能进行一系列农学和“农场”评估，这些混合饲料是为提高肥力、弹性和抗旱性而配制的。不同的混合物配方将基于我们之前的研究和行业需求，并与传统的黑麦草和化肥进行比较。这些饲草处理将在英国南部的多个季节在一系列环境中进行比较，它们对牲畜的饲养价值和对氮素利用率的影响将通过一系列关于生长牛的营养研究来衡量。结果将利用现有农场规模的养分平衡和生态系统服务模型进行综合，以确定不同牧场在养分循环和更广泛的生态系统方面的总体效益，并通过参与性讲习班传播结果。该项目的研究成果将为提高农场在畜牧业生产系统、土壤和环境方面的可持续性提供快速、高影响的结果。

Growth and supply of pasture is the most cost effective way to feed sheep and cattle. Pasture is comprised mainly of ryegrass, or ryegrass mixed with white or red clover, with the total amount of pasture produced dependent on the climate, management, soil, and amount of fertiliser used. Ryegrass and clover thrive in a moist, cool environment, but these 'optimal' conditions are occurring less often due to an unpredictable and changing climate. Both drought and soil water-logging reduce the amount of forage that can be grown, which affects farm productivity and, ultimately, increases the cost of producing UK 'home grown' milk and meat.There are a number of essential nutrients that plants need for growth. Most of these nutrients are supplied through the soil but others such as nitrogen (N) are lacking for many plants and therefore need to be added in the form of a mineral fertiliser. Mineral fertilisers are expensive to produce through reliance on oil, and are detrimental to the environment through their production and contribution to soil nitrous oxide emissions and pollution of waterways.A solution to these concerns is through the use of a greater diversity or variety of forage plants. The more plant species in an ecosystem the healthier, more robust and resilient it is to changing environments. Diverse mixtures containing drought-tolerant and flood-tolerant plants can provide a source of high quality feed in the face of erratic weather patterns, above and beyond that of typical climate-specific pastures. These diverse plants include legumes which reduce the need for mineral fertilisers because they provide an excellent source of N for pastures due to their ability to convert or 'fix' unusable atmospheric N gas. As a result this improves soil fertility, forage production, and enables N to be better utilised at the animal and farm scales. This, combined with reduced methane emissions from livestock fed diverse forage mixtures can reduce the carbon footprint of milk and meat production. These benefits however, can only be achieved with greater farm uptake of such forages.The ultimate aim of this project is to achieve high yields of good quality forage for livestock production whilst having a positive and long term impact on the environment. We envisage that this can be achieved by utilising diverse forage mixtures that have the potential to be productive during more challenging climatic scenarios, as well as improving N use efficiency, compared to ryegrass or ryegrass/clover pastures. The project will include a series of agronomic and 'on farm' evaluations of the performance of diverse forage mixtures, formulated for fertility building, resilience, and drought tolerance. Diverse mixture formulations will be based on our previous research and industry needs, and compared to conventional ryegrass and fertiliser. The forage treatments will be compared across a range of environments over multiple seasons in the southern UK and their feeding value for livestock and effects on N utilisation will be measured in a series of nutrition studies with growing cattle. The results will be integrated using existing farm scale models of nutrient balance and ecosystems services to determine the overall benefits of diverse swards in terms of nutrient cycling and the wider ecosystem, and the results disseminated through participatory workshops. The research outcomes from this project will deliver rapid, high impact results for increasing on-farm sustainability in terms of livestock production systems, soils and the environment.