Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $10,000
Principal Investigators: Saleh Taghvaeian, Sumon Datta
Abstract: Irrigated agriculture is a major contributor to the economy of Oklahoma and plays a vital role in supplying the demand in food, feed, and fiber utilizing the States limited water resources. In Oklahoma, over 400,000 acres of irrigated cropland contribute to 50% of crop revenues. A sizable portion (41%) of total water withdrawals in Oklahoma goes to crop irrigation, making it a prime consumer of water. The demand for irrigation water in agriculture is expected to increase 20% by 2060 in Oklahoma. Therefore, to meet with this increasing demand, water conservation in irrigated agriculture in Oklahoma must happen as soon as possible by improving irrigation management. Irrigation management can be optimized by implementing several smart technologies of measuring soil water content and perform a precise irrigation scheduling. This study will focus on one of the promising methods: use of soil water sensors. Currently, only 11% of Oklahoma growers use soil water sensors to schedule irrigations, whereas, this number is 23% for Nebraska and 17% for California. Thus, there is an enormous potential for improving irrigation management using soil water sensors. At least four commercially available soil water sensors will be selected. Commercial sensors will be used as opposed to research-grade sensors in Oklahoma soils to ensure the results will be usable by Oklahoma growers who may be unwilling to perform site-specific calibration. Hence, the growers can expect better accuracy by these sensors when using them in out of the box condition. A performance evaluation of these sensors will be conducted at lab firstly, and then, under field conditions. In the lab study, uniform mixture of typical agricultural soils from Oklahoma will be used to pack containers where soil water content (SWC) will be monitored by sensors over a wide range of soil water levels representing field capacity and permanent wilting point which are two extreme soil water thresholds used irrigation scheduling. Then, the same sensors will be taken out to collaborating agricultural fields and installed at variable locations/depths to evaluate their performance under actual field conditions. Undisturbed soil samples will be collected at each field to determine the hydraulic properties of different types of soil. Reference values for field study will be the sensor that had the highest accuracy in the lab study. Rain gages will be installed to record irrigation/precipitation depths and timing to the crop field. The readings of sensors will be analyzed in conjunction with irrigation management practices and yields to optimize irrigation scheduling. Participating growers will be engaged in this process to ensure improvements suggested are practical and feasible. The main objective of this study is to investigate how soil water sensors can be used under variable agro-climatological conditions of Oklahoma to optimize irrigation management. Because, other researches shown different performances of soil water sensors in different types of soils, clay content and salinity levels (Hignett & Evett, 2008). This study will address these issues. This study will also promote the adoption of these smart technologies through developing several demonstration sites across the state in direct collaboration with Oklahoma growers.