Monitoring Root Zone Salt and Water Dynamics Under Drip and Sprinkler Irrigated Cotton

This study was conducted at three Oklahoma cotton fields under subsurface drip and sprinkler irrigation systems. Different types of soil moisture and salinity sensors were installed in order to monitor salt and water dynamics in cotton root zone during the growing season. The results confirmed that soil sensors provide valuable information that can assists producers in making informed decisions. Water availability in the root zone was strongly related to the amount of applied water (precipitation and/or irrigation) as well as cotton water use (influenced by both crop condition and atmospheric demand). Comparing soil salinity levels between two adjacent fields, one under subsurface drip and another under sprinkler irrigation, revealed that soil salinization under drip irrigation may become a major issue in the future since salts tend to accumulate at the outer edges of the wetting front under this type of irrigation system.