Effect of weather, subsurface topography and fertilizer type on corn yields at the BARC experimental OPE3 site

Authors: Morgan, Billie; Daughtry, Craig; Dulaney, Wayne; Russ, Andrew - Andy; Pachepsky, Yakov

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2016
Publication Date: 4/27/2016
Citation: Griffith, B.J., Daughtry, C.S., Dulaney, W.P., Russ, A.L., Pachepsky, Y.A. 2016. Effect of weather, subsurface topography and fertilizer type on corn yields at the BARC experimental OPE3 site. BARC Poster Day. 27th Annual Beltsville Poster Day on April 27, 2016.

Interpretive Summary:

Technical Abstract: Availability of soil water is critical for plant growth and development. In shallow groundwater conditions, this availability may vary with the depth to the restrictive layer that is found beneath groundwater. The restrictive layer is not flat, and the presence of the relief of this layer leads to the existence of subsurface preferential flow networks. These networks hold larger amounts of water than other subsurface domains and provide a more reliable source of water for crops. It was hypothesized that the role of subsurface networks in crop development can be affected by the wetness of a year, since in dry years flow networks may degenerate to a sequence of subsurface ponds and eventually lose the ability to affect crops. Our objective was to evaluate this hypothesis with data from a multiyear experiment on the effect of fertilizer type on corn yield at the OPE3 experimental site at Beltsville Agricultural Research Center in MD. The effect of the subsurface topography on crops may depend on the wetness of a specific year. The subsurface flow network was developed using the geostatistical wizard and hydrology tools in ArcGIS. The geographically weighted regression was applied to evaluate the correlation between the corn yield and the distance to the subsurface flow network. The adjusted correlation coefficient showed a moderately-to-high relationship between the yield and the distance to the network. This relationship was less strong in dry and normal years as compared with the wet year. The least strong relationships have been seen at the manure field, and the strongest one was found at the precision agriculture field. Results of this work underscore the role of subsurface topography in crop development and yield formation. Knowledge of this topography can be useful in designing and implementing as well as evaluating precision farming crop management.