Purpose

Understanding spatial and temporal variability of absolute and relative profit within fields provides a basis for site-specific management of limited agricultural inputs such as water. The objectives of this study were to evaluate the pattern of spatial and temporal variation of cotton profitability and to assess the stability of profit in management zones (MZs) created based on soil properties and topography.

Methods

This study analyzed profitability patterns in eight commercially managed fields in the Southern High Plains from 2000 to 2003. Each field was divided into 30 m grids and soil physical properties, topography, and lint yield were collected for each grid. Based on the input cost and output prices, profit was also calculated for each grid. Clusters or MZs based on soil and topographic properties were created for each field using the partitioning around medoids (PAM) clustering algorithm. ANOVA and Least Significant Difference tests were conducted to determine the difference in profit among the clusters over multiple years.

Results

In four of the eight fields, the spatial pattern of profit was consistent across multiple years, indicating the potential of using MZs for site-specific input management. For the rest of the fields, the profit pattern in clusters was inconsistent across multiple years, indicating the need for within-season dynamic MZs.

Conclusion

The variability in soil and topographic properties influenced the profitability of management zones within a field across multiple years. Hence, this study indicates that understanding the variability in profit patterns in management zones can help to determine the best strategy for field-specific and year-specific precision input management. 

中文翻译：

---

基于土壤性质和地形的管理区棉花盈利能力的时空格局

 目的

了解田地内绝对和相对利润的空间和时间变化，为水等有限农业投入的特定地点管理提供了基础。本研究的目的是评估棉花盈利能力的时空变化模式，并评估根据土壤性质和地形创建的管理区 (MZ) 的利润稳定性。

 方法

本研究分析了 2000 年至 2003 年南部高平原八个商业管理田地的盈利模式。每个田地被分为 30 m 的网格，并收集每个网格的土壤物理特性、地形和皮棉产量。根据投入成本和产出价格，还计算了每个电网的利润。使用围绕中心点划分 (PAM) 聚类算法为每个田地创建基于土壤和地形属性的聚类或 MZ。进行方差分析和最小显着差异测试以确定多年来集群之间的利润差异。

 结果

在八个领域中的四个领域，利润的空间格局多年来保持一致，表明使用混合区进行特定地点投入管理的潜力。对于其他油田，多年来集群的利润模式不一致，这表明需要季节内动态 MZ。

 结论

土壤和地形特性的变化多年来影响着田地内管理区的盈利能力。因此，本研究表明，了解管理区域利润模式的可变性有助于确定特定领域和特定年份精确投入管理的最佳策略。