Analysis of Spatiotemporal Variability of Corn Yields Using Empirical Orthogonal Functions

Seongyun Kim,Aura Pedrera-Parrilla,Craig Daughtry,Yakov Pachepsky,Andrew Russ

doi:10.3390/w12123339

Abstract

We used empirical orthogonal functions (EOF) to analyze the spatial and temporal patterns of corn (Zea mays L.) yields at three hydrologically-bounded fields with shallow subsurface preferential lateral flow pathways. One field received uniform application of manure, the second field received the uniform applications of the chemical nitrogen fertilizer, and the third field received variable rate applications of the chemical fertilizer. The preferential subsurface flow and storage pathway locations were inferred from the ground penetration radar survey. Six-year monitoring data were analyzed. Statistical distributions of EOFs across fields were approximately symmetrical. Semivariograms of the first EOF differed between fields receiving manure and chemical fertilizer. This EOF accounted for 52 to 56% of the interannual variability of yields, and its values reflected the distance to the subsurface flow and storage pathways. The second and third EOF explained 17 to 20% and 10 to 13% of the interannual variability of yields, respectively. The precision applications of the nitrogen fertilizer minimized corn yield variability associated with subsurface preferential flow patterns. Investigating spatial patterns of yield variability under shallow groundwater flow control can be beneficial for the within-field crop management resource allocation.

Highlights

It has been demonstrated that the groundwater depth in the range from one to three meters created favorable conditions for corn crop, whereas groundwater depth less than one meter affected corn yields negatively [5,6]
Ranges of EOF1 variation were much higher than ranges of variation of EOF2 and EOF3 at all three fields
This study investigated the spatial and temporal patterns of corn yields as affected by subsurface preferential lateral flow pathways and different nutrient management practices

Summary

Introduction

Multiyear observations often show that some sections of fields are less productive than other sections This has been attributed to the spatial variation of soil fertility [2], the ability of soil to retain and transmit water [3], and interactions of the above and other environmental factors [4]. The proximity of groundwater and the capillary fringe to the soil surface and root systems can be an important control of the crop yield. The groundwater proximity and flow affect water availability that can be very important in dry years or areas, transport and availability of nutrients when water availability is not restrictive factor of crop yields, and loss of nitrogen to denitrification that can be important in wet years or areas. Tromp-Van Meerveld and McDonnell (2006) noted that networks of such lateral flow

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Discussion

Conclusion