NCSU - Protecting Water Quality and Reducing pesticide Exposure
Contents |
Resources
Alabama
Cotton Irrigation Research Results
Arizona
AZ Irrigation Scheduling System (AZCSHED)
Cotton Irrigation Consumptive Use
Determining the Amount of Irrigation Water Applied to a Field
Irrigation Efficiencies in Maricopa
Measuring Water Flow and Rate on the Farm
Measuring Water Flow in Surface Irrigation Ditches and Gated Pipe
Methods for Determining When to Irrigate
Proceedings of the Fourth Annual Four Corners Irrigation Workshop
California
California Irrigation Information System
Irrigation Management Improvements for San Joaquin Valley Pima Cotton Systems
Sample Cost to Establish and Produce Cotton
Using Saline Groundwater for Large-Scale Irrigation of Pistachios Inter-planted with Cotton
Florida
Kansas
Irrigation Formulas and Conversions - MF2404
Subsurface Drip Irrigation (SDI) Components: Minimum Requirements - MF2576
Design Considerations for Subsurface Drip Irrigation Systems - MF2578
Filtration and Maintenance Considerations for Subsurface Drip Irrigation (SDI) Systems - MF2361
Drip Irrigation of Row Crops: What is the State of the Art?
Missouri
Physiology of Cotton Irrigation
New Mexico
CR582DroughtStrategiesforCotton
NM Irrigation Scheduling for Cotton
Oklahoma
Classification of Irrigation Water Quality
Site-Specific Irrigation and Nitrogen Management for Cotton Production in the Southern High Plains
Texas
Basics of Microirrigation - B6160
Center Pivot Irrigation - B6096
Using Flexible Pipe (poly-pipe) with Surface Irrigation - L5469
Irrigation Water Quality - Critical Salt Levels for Peanuts, Cotton, Corn and Grain Sorghum - L5417
Maintaining Subsurface Drip Irrigation Systems - L5406
Utilizing Center Pivot Sprinkler Irrigation Systems to Maximize Water Savings
Irrigation Water Quality Standards and Salinity Management Standards - B1667
Irrigation Monitoring with Soil Water Sensors - B6194
Texas High Plains Evaporation Network
General
Water directly or indirectly affects all cotton production factors. Soil water is essential for successful planting, seed germination, root growth, mineral absorption by roots, soil microbiological and chemical processes, plant development and growth, fruit development and pollination as well as lint development and elongation.
Maximizing water use in crop production involves knowing critical growth stage irrigation timings, the optimization of evapo-transpiration (ET) deficit use, stress index limitations around specific growth stages as well as optimizing the sequencing of ET deficits.
Early Development of Irrigation and Water Management in the United States
Irrigation has enabled civilization to establish permanent cropping sites even in semiarid and arid lands. Around 100 B.C., the Hohokam Indians built extensive canals in the Salt River Valley where Arizona now exists. The Spanish settlers and missionaries established small irrigation projects in the Southwest during the 16th and 17th Centuries. During the mid-1800’s more modern irrigation developed along streams with settlement of the West. Early development was by private investment. However, the Desert Land Act of 1877 and the Carey Act of 1894 stimulated more private and state irrigation projects. In 1902, the Reclamation Act pulled the federal government into irrigation development. The Water and Power Resources Service, formerly part of the Bureau of Reclamation, then began to deliver irrigation water to 11% of the total irrigated areas in the 17 western states and then added supplemental supplies to another 9%. Currently, much of the irrigation and water management projects are overseen by several entities. Watershed regions manage some oversight with local irrigation districts that often share some responsibility as well as divide out roles with state engineers to manage irrigation water use, quality and quantity. More oversight, conservation or use planning is further performed through local, state as well as federal agencies such Natural Resource Conservation Service (NRCS), United States Geological Survey (USGS), university projects, water commissions, regional water projects, water committees, environmental groups, water right entities and other groups.
Irrigation and Water Use Management Changes
Irrigated areas in the United States have increased since 1939. Recently increases have even occurred in the sub-humid and humid South and Southeastern states. The largest areas with irrigation are the semiarid Central and Southern Great Plains. The largest sprinkler irrigated area is in the semiarid Great Plains and this is rapidly being changed over in some part to drip irrigation. These changes in irrigation and method of delivery are related to major fluctuations in climate. The rapid expansion of irrigation into the Texas High Plains in the 1950’s was primarily spurred by the severe drought in that region from 1953 to 1957. Efficient pumps, better well-drilling techniques and a low cost of expansion as well as available energy further stimulated irrigation into areas where groundwater supplies were available. In 1975, about 40% of irrigation water was from groundwater resources compared with 11% in 1929. The use of the center pivot, patented in 1952, in the 1970’s further expanded irrigation even to medium- to coarse-textured soils previously not suitable for irrigation. Today trickle or drip irrigation has further expanded the boundaries for irrigation by providing more water use efficiency, allowing low flow supplies and by filtering water for use despite continued bouts of drought throughout the Cotton Belt and beyond.
Many factors work into determining efficiency of water use with irrigation. Some of these factors include: the resources toward planning farm systems including the economic and environmental constraints; the soils that influence the water infiltration rate and availability; salinity and sodicity of water to be used and the problems that can result with these ions; water requirements of plants including ET and water use timing; drainage and land design criteria; land shaping particularly with current laser-controlled fine smoothing of basins and fields not practiced in the past; water delivery systems toward better mechanization and automation; pumps and pump maintenance for efficiency; farm distribution systems through lined and unlined, covered and uncovered canals and pipelines; improved surface irrigation (flood, row, sprinkle) or converted trickle or drip systems; and, irrigation water management related to yield-ET relationships and irrigation scheduling methods.
In cotton, irrigation or water management influences lint quality and quantity including lint length, micronaire, strength, length uniformity, leaf grade and even color. More work with new technology still needs to be done with irrigation and water management in cotton. Water delivery to farms can be improved through modernization and delivery policy. Development of economical irrigation systems that apply water with near perfect uniformity is desired to coincide with ET and leaching requirements for crops. Alternative energy sources for irrigation are desired due to escalating costs. Environmental and health improvements to water will provide better water use efficiency. Data on design and operational constraints to existing irrigation systems can improve efficiency to the systems as well as save on water use while increasing fiber production.
Resources on irrigation and water use management are available. One such resource from New Mexico covers the basic stages when cotton utilizes water more efficiently for better production, CR582 Drought Strategies for Cotton. There are also other resources listed at the first of this web page.
Cotton Irrigation Research
ARS
ASABE
Cotton Incorporated
Australia
