Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Improving Irrigation Scheduling And Water Use Efficiency In Cotton, Derrick M. Oosterhuis
Improving Irrigation Scheduling And Water Use Efficiency In Cotton, Derrick M. Oosterhuis
Technical Reports
Cotton (Gossypium hirsutum L) is an important crop in the southern United States. The crop is grown in both irrigated and rainfed situations and is seldom free from periods of water shortages at some stage during the season. In recent years the need for consistency in yields and a stable cash flow has resulted in a rapid expansion in the number of irrigated acres of cotton in the Mississippi Delta. Irrigation research has, however, not kept pace with this expansion. This project represents a start at meeting this urgent need. The influence of weather patterns necessitates that these studies be …
The Behavior Of Soluble Salt In Sharkey Clay- Ii, J. T. Gilmour, R. E. Baser, H. D. Scott, J. A. Ferguson
The Behavior Of Soluble Salt In Sharkey Clay- Ii, J. T. Gilmour, R. E. Baser, H. D. Scott, J. A. Ferguson
Technical Reports
Soluble salts have been shown to accumulate in Arkansas soils in sufficient quantities to impair crop plant growth. The major objective of this study was to describe the behavior of soluble chloride salt over long time periods in Sharkey clay - a major Mississippi Delta soil. Prior to flooding rice, leaching of chloride in response to rainfall was observed. The inclusion of a sandy subsoil layer reduced this effect presumably by limiting downward movement of water under unsaturated conditions. No lateral movement of the chloride salt was found during the period prior to flooding. Removal of soluble chloride salts from …
The Behavior Of Soluble Salt In Sharkey Clay, J. T. Gilmour, J. A. Ferguson, H. D. Scott, R. E. Baser
The Behavior Of Soluble Salt In Sharkey Clay, J. T. Gilmour, J. A. Ferguson, H. D. Scott, R. E. Baser
Technical Reports
Soluble salt problems do exist and are significant in Arkansas. Studies have been conducted on Crowley silt loam (Typic Albaqualfs) which have established the behavior of soluble salt in that soil. The major objective of this study was to quantify the behavior of soluble salt in a second important Mississippi River Delta soil - the Sharkey (Vertic Haplaquepts). To this end, estimation of the downward redistribution of salt and the estimation of various components of the water balance for this soil served as specific objectives. Field studies were designed to monitor the movement of salt in the Sharkey soil and …
Identification Of Critical Water Levels In Flooded Rice Fields, Carl L. Griffis
Identification Of Critical Water Levels In Flooded Rice Fields, Carl L. Griffis
Technical Reports
A mathematical model was developed to simulate the transient hydrology of a flooded rice field. With the model, users can determine the critical interlevee areas in which to monitor the water levels so that the irrigation well can be turned on at the critical low water level, and turned off at the critical high water level, in order to maximize water application efficiency. Sensitivity analysis performed with the model showed that it will be necessary to calibrate the model for each specific field. A calibration procedure has been developed.
A Survey Of Soils Irrigated With Arkansas River Water, John T. Gilmour, H. D. Scott, R. E. Baser
A Survey Of Soils Irrigated With Arkansas River Water, John T. Gilmour, H. D. Scott, R. E. Baser
Technical Reports
Interest in the use of Arkansas River water for irrigation has increased recently as land adjacent to the river is converted to crop production and river water is considered as an alternative to depleted underground supplies. Since the Arkansas River can contain elevated concentrations of sodium chloride, this study was designed to determine if soil conditions adverse to crop growth were developing where river water has been used. The impact of river water on sites where river water was used as either the sole source for up to 3 years or as a supplement to another surface source for up …
Expansion Potential For Irrigation Within The Mississippi Delta Region, Robert N. Shulstad, Ralph D. May, Jon Mark Erstine, Blake N. Phillips, Billy E. Herrington Jr.
Expansion Potential For Irrigation Within The Mississippi Delta Region, Robert N. Shulstad, Ralph D. May, Jon Mark Erstine, Blake N. Phillips, Billy E. Herrington Jr.
Technical Reports
17.6 million acres, or 73 percent, of the Mississippi Delta Region is currently cropland and possesses the physical characteristics of slope, texture and soil type which are recommended for irrigation. Economic feasibility of expanding irrigation by flood, furrow and center pivot methods were examined under 24 scenarios representing two sets of crop prices, yield levels, production costs, opportunity costs and six crop rotations. Irrigation was economically feasible for 56 to 100 percent of the cropland across all scenarios. Approximately 88 percent of the cropland can be economically irrigated with flood or furrow in its present form, 8 percent yield highest …
Subsurface Irrigation Research In Arkansas, John P. Hoskyn, Billy B. Bryan
Subsurface Irrigation Research In Arkansas, John P. Hoskyn, Billy B. Bryan
Technical Reports
A pilot study conducted in 1963 indicated that (1) cotton yields could be increased by subirrigation, (2) drilled orifices were unsatisfactory because of internal plugging caused by burrs and drilling particles, and (3) operating pressures of 5 and 10 psi were excessive, and 5 psi probably should be considered as an upper-limit pressure. A greenhouse study of a subirrigation system indicated that 2 psi should, in general, for in-wall orifices, be considered as a lower-limit pressure when orifices are built into the pipe wall. The greenhouse study also indicated that a placement depth of 12 inches was preferable to 18 …