1a. Objectives (from AD-416)
The goal of this research will be to obtain knowledge and develop tools that will enable planners, decision makers, and producers to more effectively manage, conserve, and protect water resources. Specific objectives are as follows: 1)Develop cotton and peanut production systems for humid areas that are based on site-specific water and nutrient applications, 1a)Develop water management strategies in humid areas that optimize spatial and temporal water applications, 1b)Develop and explore spatial nutrient management for irrigated and non-irrigated crops in humid areas; 2)Develop practices that increase crop water use efficiency in rainfed/irrigated cropping systems in relation to tillage, irrigation, and crop management practices; and 3) Develop practices and technologies that enhance denitrification in riparian buffers and wetlands for improving water quality in streams.
1b. Approach (from AD-416)
This 5-year project utilizes a systems approach to identify and develop strategies for improved spatial management of water and nutrients. The project explores the spatial components of irrigation, tillage, and nutrient management. In spatial irrigation, the project will focus on identifying strategies for managing a site-specific irrigation system to conserve water and nutrients while maintaining cost effective production. In tillage management, the project will focus on efficiency of water use using tillage practices that will improve infiltration and soil water-holding capacities under site-specific irrigation to determine the spatial uptake and water use efficiency to improve spatial water management. In nutrient management, the project will focus on both in-field and off-site management. In-field nutrient management will focus on spatial nitrogen applications on cotton and Coastal bermudagrass to improve crop production and reduce the impact of off-site nitrogen movement. Off-site nitrogen management will focus on understanding the spatial variability of nitrous oxide emissions from riparian buffers and treatment wetlands.
3. Progress Report
Determining Spatial Variability for Plant Water Status in Irrigated Cotton: This progress report serves to document research conducted under a non-funded cooperative agreement (6657-13000-008-01N) between ARS and Richard Rogers, a cotton producer in Marlboro County, South Carolina. Progress was monitored by telephone calls with the producer and by site visits to the producer’s farm. The objective of this cooperative research project is to evaluate spatial variability for plant growth and water status in a Coastal Plain cotton field with center pivot irrigation. An irrigated cotton field on the producer’s farm was selected for this research. Beginning in late May, measurements of plant growth, plant water status, and soil water status have been made several times per week at ten different areas within the field. At the end of the season, measurements of crop yield and fiber quality will be made at each site. The research will contribute toward developing improved precision irrigation application strategies for cotton.
Narrow-Row Corn Production with Sub-Surface Drip Irrigation: In the southeastern USA Coastal Plains, supplemental irrigation is required to reduce the impact of frequent short-term droughts and yield-reducing plant water stress. Sprinkler irrigation is commonly used to water agronomic crops in the region. In recent years, microirrigation, typically used for high value fruit and vegetable crops, combined with conservation tillage has been implemented to conserve soil moisture for agronomic crop production. We investigated feasibility of planting corn in narrow rows over subsurface drip irrigation (SDI) laterals spaced 1 and 2 meters apart. On a whole plot basis, we found no significant difference in yield or grain nitrogen (N) for either SDI lateral spacing. However, we found within the plot areas that plant biomass, whole plant N, and yield all decreased significantly with distance from the SDI laterals. We concluded that planting patterns may need to be modified to optimize yield and resources for narrow-row corn with subsurface drip irrigation. This research contributes to the goals of the Irrigation and Water Management and Security problem area of National Program 201, Water Resource Management. Soil Electrical Conductivity May be Useful in Developing Prescription Irrigation Maps on Coastal Plain Soils: Site-specific irrigation, or applying water at variable rates throughout a field, is technologically feasible, but information is needed to determine how best to use this technology. We found that a relationship exists between the timing of the onset of cotton plant water stress and electrical conductivity of the soil on a Coastal Plain field. This information will be useful in developing prescription irrigation plans for the Southeast USA that will provide a more efficient use of irrigation water. This research contributes to the goals of the Irrigation and Water Management and Security problem area of National Program 201, Water Resource Management. Turf Subsurface Drip Irrigation: In the Carolinas, the turfgrass industry has become a major component of state economies with a range of impacts from growers to tourists. A cooperative effort between ARS, Coastal Plains Soil, Water, and Plant Research Center in Florence, SC, and Clemson University has been initiated to improve turfgrass water management via subsurface irrigation. This research addresses 1) the feasibility of subsurface drip irrigation systems for turf applications and 2) irrigation management with low quality, saline waters. The system has been installed, the turf has been established, and irrigation treatments have been initiated. Results from this study should provide the turfgrass industry with improved water conservation methods and guidelines for use of saline irrigation water. This research contributes to the goals of the Irrigation and Water Management and Security problem area of National Program 201, Water Resource Management. Peanut Spatial Irrigation Management: Determining how best to use spatial irrigation technology will likely increase grower income while lowering water consumption by agriculture. An irrigation experiment was initiated to evaluate spatial peanut irrigation scheduling methods. The experiment was conducted under a center pivot with highly variable soils. We evaluated spatial irrigation scheduling using 1) soil water potentials, 2) the Irrigator Pro model for spatial management zones, and 3) the Irrigator Pro model for uniform management zones. Measurements of the crop development were conducted throughout the growing season. Crop temperatures were measured using infrared thermometers and a thermal camera at high potential stress periods to determine variations in crop temperatures in the spatial irrigation management zones. At the end of the season, crop yield will be measured using a yield monitoring peanut combine. The research will contribute toward developing improved peanut precision irrigation application strategies. This research contributes to the goals of the Irrigation and Water Management and Security problem area of National Program 201, Water Resource Management.
5. Significant Activities that Support Special Target Populations