Submitted to: Agricultural Sciences
Publication Type: Book / Chapter
Publication Acceptance Date: November 15, 2011
Publication Date: April 27, 2012
Citation: Hatfield, J.L. 2012. Spatial patterns of water and nitrogen response within corn production fields. In: Aflakpui, G., editor. Agricultural Science. Rijeka, Croatia: Intech Publishers. p. 73-96. Technical Abstract: There is a lack of understanding of the interactions between the spatial patterns of crop water use and nitrogen (N) response. This study was conducted to evaluate the spatial and temporal patterns of crop water use and couple these observations with observations collected from N strips within fields as part of a N evaluation study. The objective of this study was to evaluate the spatial patterns within different fields observed by remote sensing and yield maps collected at harvest with yield monitors to determine the information content contained in spatial analyses of agricultural fields. Nitrogen response across agricultural fields is more complex than observing a consistent response across a change in management practices. Observations among fields has shown that when multiple soils are encountered within a production field there are spatial patterns in both water use and N impacts on crop yield. There have been few studies which have coupled water and N dynamics across corn production fields. It has been assumed that water patterns operate separately from N management practices; however, the spatial patterns within a field show there is a temporal and spatial pattern determined by the combination of the precipitation patterns during the season, the soil water holding capacity, and the crop growth (crop water use) patterns. Observations of N impacts on corn yield across production scale fields revealed that yield responses were dependent upon the soil type and within a rate strip there were a range of yields and when further dissected into the spatial patterns, these spatial patterns were related to the water use patterns and soil water holding capacity. The observations from this study revealed that N impacts on crop yield were directly related to soil water holding capacity and to improve N response an improvement in soil water availability during grain-filling would be necessary. Observations of the changes in the spatial patterns during the growing season have shown that there is complex interaction between the patterns of soil within the field and the final pattern of corn yield as a function of the patterns of soil water use and N management inputs. Agriculture will benefit from an enhanced understanding of the interactions of soil water use and N management and how these interact across a production field. The combination of remote sensing along with yield maps offers an enhanced method to evaluate field scale responses to both weather and management which will benefit production efficiency. These efforts will lead toward improved production efficiency and enhance the capability of agricultural systems to become more efficient in terms of water and N use.