Are datasets from commercial agricultural analyses sufficiently robust for national-scale monitoring of topsoil indicators?

土壤是一种重要的自然资源，它发挥着一系列功能，包括充当食物、燃料和纤维的生长介质、过滤水、储存碳(气候调节)以及作为生物多样性的储存库。英国的农业土壤承受着一系列压力，这些压力会导致其性质随着时间的推移而发生变化，这可能(尽管农民尽了最大努力)加剧退化威胁，如侵蚀(土壤资源的损失)、压实和淡水养分流失。农业土壤还必须以可利用的形式拥有足够的养分，以确保它们能够保持大量的作物产量，以养活日益增长的人口。因此，我们必须(随着时间的推移)仔细监测英国土壤的主要性质，以确保它们能够继续有效地发挥作用，并确保土壤资源的这些性质意味着它不太可能退化。这些关键属性包括土壤的有机质含量、植物生长所需的两种关键营养物质(磷和钾)的有效数量以及土壤的酸度(酸度--对决定养分的有效性和植物的总体生长很重要)。自1971年以来，英国各地的政府管理部门(Defra、威尔士和苏格兰政府)一直在资助全国范围的研究，以监测农业表土的性质，并对各种数据进行了统计分析，以报告截至2007年的关键土壤指标的变化和趋势。随着研究预算的下降，政府部门正在考虑替代的、具有成本效益的方法来监测这些指标，其中一种方法是利用农民付费的土壤测量，由商业实验室进行。尽管与使用政府研究基金进行的测量相比，农民发起的测量要多得多，但前者没有收集到统计设计，因此需要以不同于后者的方式进行分析。农民发起的土壤测量可能不能更普遍地代表土壤，这可能导致与政府资助的研究人员领导的测量相比不同的(有偏见的)结果。我们项目的目的是对农民发起的土壤测量数据和研究主导的测量数据进行比较，以确定区域和国家范围内关键指标平均值的差异大小。我们将使用统计程序，这意味着我们可以对这两种类型的数据进行一致的比较。如果我们观察到的差异很小，就有可能使用农民发起的调查来监测土壤属性，从而避免未来国家规模的、政府资助的调查的成本。我们没有接触个别农民，而是获得了使用英国最大的商业农业土壤实验室产生的数据的许可。我们将比较近十年来两种主要农业用地类型(耕地生产和草地)的农民数据和政府资助研究数据的关键土壤指标值。我们将与那些在全国范围内负责土壤政策的政府部门合作，并将我们的发现提交给他们。

Soil is a vital natural resource which performs a range of functions including acting as a growth medium for food, fuel and fibre, filtering water, storing carbon (climate regulation) and as a repository for biodiversity. Agricultural soils in Great Britain are subject to a range of pressures which lead to changes in their properties over time that can (despite farmers' best efforts) exacerbate degradation threats such as erosion (loss of the soil resource), compaction and nutrient losses to freshwater. Agricultural soils must also have sufficient nutrients in available forms to ensure they can maintain large crop yields to feed an increasing population. It is therefore essential that we carefully monitor (over time) key properties of British soils to ensure they can continue to function effectively and also that these properties of the soil resource mean it is less likely to be degraded. These key properties include the organic matter content of the soil, the available quantity of two key nutrients for plant growth (phosphorus and potassium) and soil pH (its level of acidity - important in determining nutrient availability and plant growth in general). Government administrations across Great Britain (Defra, Welsh and Scottish Governments) have funded national-scale research to monitor the properties of agricultural topsoil since 1971 and various data have been analysed statistically to report on changes and trends of key soil indicators up to 2007. With declining research budgets, government departments are considering alternative, cost-effective ways to monitor these indicators and one approach is to utilise the soil measurements which farmers pay for, undertaken by commercial laboratories. Although there are many more of these farmer-initiated measurements in comparison to those undertaken using government research funds, the former are not collected to a statistical design and so need to be analysed in a different way to the latter. The farmer-initiated soil measurements may not be representative of soils more generally which could lead to different (biased) results in comparison with the measurements led by government-funded researchers. The aim of our project is to undertake comparisons between the data from farmer-initiated soil measurements and research led measurements to determine the size of any differences in the average values of the key indicators at regional and national scale. We will use statistical procedures which mean we can make consistent comparisons between the two types of data. If the differences we observe are small, it may be possible to use the farmer initiated surveys to monitor soil properties, thereby avoiding the costs of future national-scale, government funded surveys. Rather than approaching individual farmers, we have secured permission to use those data generated by the largest commercial agricultural soil laboratory in Great Britain. We will compare the values of key soil indicators from farmers' data and government-funded research data for the two main agricultural land use types (arable production and grassland) over the last ten years. We will work with, and present our findings to, those in government which have responsibility for soil policy at national scales.