Site-Season effects on crop productivity

组合作物的产量图谱使得识别不同田地和农场间产量的空间差异变得更加容易。绘制的土壤信息（典型剖面、底土性质、矿物学持水能力、可通行性等）以1:25万比例尺提供，但不够详细，无法有效考虑现场变化。作物产量在时间上也有显著差异，包括天气（Wreford和Adger， 2010年）、病虫害压力（Madgwick等人，2011年）以及季节性管理影响，包括种植、轮作以及化肥和农药的使用。分析和量化异质性土壤条件与作物生长和产量之间的关系往往受到缺乏数据的限制，因为与采样相关的高成本和时间要求（Heil和Schmidhalter， 2012）。在研究时间和空间变化的有限研究中，这些模式经常相互作用，即一年的高产地区下一年可能是低产地区（Blackmore et al., 2003）。

Yield mapping in combinable crops has made identifying spatial variation in yield across fields and farms easier. Mapped soil information, (typical profile, sub-soil properties, mineralogy water-holding capacity, trafficability etc.) is available, at 1:250,000 scale, which is not sufficiently detailed to allow in-field variation to be considered effectively. Crop yields also vary markedly in time, with variation in weather (Wreford and Adger, 2010), pest and disease pressure (Madgwick et al., 2011), and seasonal management impacts including cultivations, rotations and fertiliser and pesticide use. Analysing and quantifying relationships between heterogeneous soil conditions and crop growth and yield has often been constrained by a lack of data due to high costs and time demands associated with the sampling (Heil and Schmidhalter, 2012). In the limited number of studies where both temporal and spatial variation are investigated, the patterns often interact i.e. high yielding areas one year might be low yielding the next (Blackmore et al., 2003).