Influence of windbreaks on crop yields in the Great Plains

Abstract

After the Dust Bowl in the 1930s, windbreaks become a more prominent way to reduce wind erosion. Windbreaks are single or multiple lines of trees and shrubs planted along the edge of agricultural lands. There are many other benefits from windbreaks, such as modifying airflow, wind speed reduction, and microclimate changes. Windbreak effectiveness in reducing wind speeds depends on the windbreak’s height and porosity. Very few recent studies have evaluated the crop yield benefits of windbreaks. The main objective of this study was to build database and evaluate the effect windbreaks have on modern crop yields. With the specific objectives to identify crops that show improved yield due to windbreaks, quantify whether the yield increase is enough to compensate for the footprint of the windbreak and characterize the impact of crop yield with the windbreak width. Yield data were obtained from protected and unprotected fields across several counties in Kansas and Nebraska over several crop years. Windbreak influences on crop yield were estimated using farmers’ pre-existing georeferenced data, generated by automated combine yield monitors, with ArcGIS 10.7.1 software. Multiple means comparisons (protected versus unprotected) through two sample t-tests were conducted to determine if the yield in protected areas of fields was significantly different from the yield in unprotected areas. Yield loss was estimated from the windbreak footprint to see if yield increases are enough to compensate for the area taken out of crop production. Results showed that wheat had the most positive response to the windbreak effect with a yield increase 63% of the time, with a 13% average yield increase. Soybean had the highest average yield increase with 21%. Yield increase from north and south windbreaks compensated for the windbreak footprint more often than east and west windbreaks. Windbreak width and crop yields showed variable trends across different crops. However, windbreaks provided inconsistent, mostly positive yield benefits across a variety of crops. Future studies in different counties and states for more crop field/years with different soil types and rainfall amounts, and intensities with different windbreak widths are recommended. More data collection is recommended for sorghum to overcome the issues due to a smaller number of crop field/years. This research would deepen our understanding of the relationship between windbreaks and crop yield and affect their future role as a conservation practice in the Great Plains.