Delineation of Soil Management Zones for Variable-Rate Fertilization: A Review

Different methods of management zone (MZ) delineation have been established over the past 2 decades based on approaches, which have been largely constrained by the available data collection methods that are often time consuming and expensive. This situation is being changed by recent advances in sensor technology, making a huge amount of data available. Advances in computing power make it possible to analyze and utilize this large amount of data. These current advances in technology are gradually turning MZ maps into commercially viable agricultural products for large-scale adoption. The aim of this paper is to provide a critical overview of MZ delineation approaches for precision agriculture applications, and to compare and contrast traditional with advanced sensing technologies for delineating MZs. This review illustrates how recent development in sensing technologies, geostatistical analysis, data fusion, and interpolation techniques have improved precision and reliability of MZ delineation, making it a viable strategy in commercial agriculture. Studies from the last decade showed that when MZ delineation techniques are used for variable-rate nutrient application, farm efficiency increased when this is compared to traditional uniform-rate application methods. This improved farm production efficiency is accompanied by a reduction in environmental impacts. Implementation of MZ therefore often provides financial and environmental benefits, and we can foresee an increase in the diffusion and application of precision agriculture techniques in the near future.