Assessing sampling designs for determining fertilizer practice from yield data
Assessing sampling designs for determining fertilizer practice from yield data
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DOI：
10.1016/j.compag.2017.02.002
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发表时间：
2017-04-01
影响因子：
8.3
通讯作者：
Milne, A. E.
中科院分区：
文献类型：
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作者：
Muhammed, S. E.;Marchant, B. P.;Milne, A. E.
许多农民取样测量土壤中植物养分的浓度，以决定施用多少肥料。既然肥料可以以可变的比例施用，农民想知道是否应该用网格样本或田间分区（田间分区）绘制养分浓度图：当考虑到所有成本时，这样的地图是否比对每个田地的散装样本进行单一测量带来更大的利润？我们已经研究了基于网格和基于区域的采样策略的优点，在单一的基于字段的平均使用连续的空间数据在英格兰南部6个领域的小麦收获产量和模拟土壤中的磷（P）浓度。我们考虑了小麦、磷肥的当前价格以及取样和实验室分析。产量的变异图为取样提供了指导。我们表明，变异函数具有较大的方差和长的有效范围，网格采样和映射是可行的，并具有很大的概率是成本效益。在有效范围较短的地方，取样必须密集，以揭示空间变化，而且费用昂贵，可变施肥量可能不切实际，几乎肯定不符合成本效益。我们发现，以区域为基础的采样是不太可能的成本效益在类似的情况下，当管理区与磷浓度相关性很差。皇冠版权所有（C）2017由Elsevier B.V.发布
Many farmers sample their soil to measure the concentrations of plant nutrients, so as to decide how much fertilizer to apply. Now that fertilizer can be applied at variable rates farmers want to know whether maps of nutrient concentration made from grid samples or of field subdivisions (zones within their fields) are merited: do such maps lead to greater profit than would a single measurement on a bulked sample for each field when all costs are taken into account? We have examined the merits of grid-based and zone-based sampling strategies over single field-based averages using continuous spatial data on wheat yields at harvest in six fields in southern England and simulated concentrations of phosphorus (P) in the soil. We have taken into account current prices of wheat, P fertilizer and sampling and laboratory analysis. Variograms of yield provide guides for sampling. We show that where variograms have large variances and long effective ranges grid-sampling and mapping are feasible and have large probabilities of being cost-effective. Where effective ranges are short, sampling must be dense to reveal the spatial variation and be expensive, and variable-rate application of fertilizer is likely to be impracticable and almost certainly not cost-effective. We found zone-based sampling was less likely to be cost effective in a similar situation when the management zones were poorly correlated to P concentrations. Crown Copyright (C) 2017 Published by Elsevier B.V.