Factors leading to spatiotemporal variability of soil moisture and turfgrass quality within sand-capped golf course fairways

Authors: Hejl, Reagan; STRAW, CHASE - Texas A&M University; WHERLEY, BENJAMIN - Texas A&M University; BOWLING, REBECCA - Texas A&M Agrilife; MCINNES, KEVIN - Texas A&M University

Submitted to: Precision Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/2022
Publication Date: 5/22/2022
Citation: Hejl, R.W., Straw, C.M., Wherley, B.G., Bowling, R.A., McInnes, K.J. 2022. Factors leading to spatiotemporal variability of soil moisture and turfgrass quality within sand-capped golf course fairways. Precision Agriculture. 23:1908-1917. https://doi.org/10.1007/s11119-022-09912-4.
DOI: https://doi.org/10.1007/s11119-022-09912-4

Interpretive Summary: The addition of a sand layer above existing native soil is called sand capping and is utilized to increase infiltration and improve the downward movement of salts and sodium in turfgrass rootzones. This trend is becoming common during renovation and construction of golf course fairways and previous research has shown that soil moisture dynamics are impacted by sand-cap characteristics. However, there is currently a lack of published data that outlines the factors that influence soil moisture and turfgrass quality variability within sand-capped fairways which could aid in irrigation management decisions, like the implementation of soil moisture sensor technology. A field study was conducted on two sand-capped golf fairways in College Station, Texas. The objective was to measure several turfgrass and soil characteristics during dry down events from either rainfall or irrigation to determine their relationship and contribution to soil moisture and turfgrass quality variability. During both dry down periods, considerable variability across space and time was observed within the two fairways. Capping depth, elevation, and thatch depth were found to have significant influence on soil moisture and turfgrass quality. However, the complexity within sand-capped golf course fairways was highlighted as many of the relationships were not consistent and were often opposite of what was expected. To most effectively incorporate soil moisture sensor technologies in to large-scale precision irrigation practices, mapping soil moisture with an understanding of contributing factors is a necessary preliminary step. This study provides a strong foundation for future research as well as information for golf course superintendents and construction companies regarding the types of variability that sand-capped systems produce.

Technical Abstract: Precision irrigation utilizing soil moisture data and valve-in head sprinkler systems may be a viable solution for sustainable water management on complex turfgrass areas. There is currently no research investigating the factors that influence soil moisture and turfgrass quality variability within sand-capped golf course fairways to aid in precision irrigation-related management decisions. Therefore, the objective of this study was to measure several turfgrass and soil characteristics from two sand-capped fairways during dry down events from either rainfall or irrigation to determine their relationship and contribution to soil moisture and turfgrass quality variability. Considerable spatiotemporal variability was observed within the two fairways during the dry down periods. Factors that were found to have a significant influence on soil moisture and turfgrass quality were sand capping depth, elevation, and thatch depth, but these relationships were not consistent between rainfall versus irrigation events, days after dry down, or even the specific fairways. Also, the direction of many of the relationships were opposite of what was expected. These findings highlight the complexity of soil moisture and turfgrass quality variability on sand-capped golf course fairways. To incorporate soil moisture sensor technologies into large-scale precision irrigation practices, mapping soil moisture with an understanding of contributing factors is a necessary preliminary step. Although there are several current practical limitations, the information presented in this study provides a foundation for future research.