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喂养绵羊和牛的最具成本效益的方式。牧草主要由黑麦草或混有白色或红色三叶草的黑麦草组成，牧草的总量取决于气候、管理、土壤和肥料的使用量。多花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”条件不太经常发生。干旱和土壤水涝都减少了可种植的牧草数量，这影响了农场生产力，最终增加了英国“本土"牛奶和肉类的生产成本。植物生长需要许多必需的营养素。这些营养物质中的大多数是通过土壤提供的，但其他营养物质如氮（N）对许多植物来说是缺乏的，因此需要以矿物肥料的形式添加。矿物肥料的生产依赖石油，因此成本昂贵，而且矿物肥料的生产会导致土壤中一氧化二氮的排放和水道污染，从而对环境造成危害。解决这些问题的一个办法是使用更多样化的饲料植物。生态系统中的植物种类越多，它就越健康，对不断变化的环境更具活力和弹性。含有耐旱和耐洪植物的各种混合物可以在气候模式不稳定的情况下提供高质量的饲料来源，超过典型的气候特定牧场。这些不同的植物包括豆类，它们减少了对矿物肥料的需求，因为它们能够转化或“固定”不可用的大气氮气体，为牧场提供了极好的氮源。因此，这提高了土壤肥力，饲料产量，并使N在动物和农场规模上得到更好的利用。这一点，再加上减少饲喂不同饲料混合物的牲畜的甲烷排放，可以减少牛奶和肉类生产的碳足迹。然而，这些好处只能通过增加农场对这些饲料的吸收来实现。该项目的最终目标是为畜牧业生产提供高产量的优质饲料，同时对环境产生积极和长期的影响。我们设想，这可以通过利用不同的饲料混合物，有可能在更具挑战性的气候情景下生产，以及提高氮的利用效率，相比，黑麦草或黑麦草/三叶草牧场。该项目将包括一系列的农艺学和“农场”的不同饲料混合物的性能评估，制定了生育能力建设，恢复力和耐旱性。不同的混合物配方将基于我们以前的研究和行业需求，并与传统的黑麦草和肥料进行比较。饲料处理将在英国南部的多个季节的一系列环境中进行比较，其对牲畜的饲养价值和对氮利用的影响将在一系列生长牛的营养研究中进行测量。将利用现有的农场规模的养分平衡和生态系统服务模型来综合这些结果，以确定不同草地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这些结果。该项目的研究成果将提供快速，高影响力的结果，以提高畜牧生产系统，土壤和环境方面的农场可持续性。

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.