Session 22. Microirrigation of Row Crops
Experiences with Microirrigation for Agronomic Crops in the Southeastern USA
C. R. Camp, E. J. Sadler, W. J. Busscher, R. E. Sojka, and D. L. Karlen
Microirrigation offers several advantages over sprinkler irrigation in humid areas, including ease of automation; lower water pressure and flow rate; improved management of water and nutrients; and easy seasonal start-up, especially for subsurface placement. Microirrigation system cost could be reduced and made more profitable for agronomic crops by using wider spacing and subsurface placement of microirrigation laterals. Results are reviewed from five experiments involving microirrigation of agronomic crops (corn, soybean, and cotton) and including 14 site-years of data. Agronomic crops can be effectively and efficiently irrigated in the southeastern Coastal Plain with microirrigation systems. In three experiments involving nine site-years of data, both normal (0.76 - 1.0 m) and wide (1.5 - 2.0 m) lateral spacings were used to irrigate corn and cotton; yields were equal except in one year when corn yield was reduced by about 10% for the wide spacing. With corn, there was no yield difference between surface and subsurface placement of laterals at the normal spacing (every row). Other data indicate that wider spacing of laterals in subsurface installations produces cotton lint yields similar to those for the same spacing in surface placements. Consequently, it appears that surface or subsurface placement of laterals at wider spacings (alternate furrow, 1.5 - 2.0 m) has significant potential for profitable irrigation of agronomic crops such as corn, cotton, and soybean in the southeastern USA.
Keywords: Lateral-placement, Trickle-irrigation, Lateral-spacing, Corn, Cotton, Soybean
Abstract taken from paper found on pages 638 to 644 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Drip Irrigation of Flue-cured Tobacco
Ilan Bar
Drip irrigation and plastic mulch were introduced to commercial production of tobacco to optimize yields and quality. Using this highly controlled root zone management system resulted in obtaining yields at the level of 5,100 Kg/Ha which nearly doubles the state of Georgia's average yield of 2,500 Kg/Ha. High yields, together with improved quality, can generate an additional income of $6,295/Ha which will pay for the total first year cost of a complete drip irrigation system and leave an additional profit of bout $3,000/Ha.
The data and experience obtained in the last two years are used to recommend a tentative irrigation and fertigation schedule for drip irrigation of tobacco.
Keywords: Drip Irrigation, Fertigation, Plastic, Mulch, Tobacco
Abstract taken from paper found on pages 645 to 650 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Drip Irrigation of Row Crops: An Overview
B. R. Hanson
An overview of drip irrigation of row crops in California, based on grower experiences, literature review, and current research results, is provided. Topics include a survey on types and characteristics of drip tape/tubing, installation depth of tape/tubing, irrigation frequency versus crop yield, emitter spacing, seed germination with subsurface drip systems, and clogging problems. Results of a field study on soil salinity under subsurface drip irrigation are presented. Results of side-by-side field-scale comparisons of furrow and subsurface drip irrigation are summarized.
Keywords: drip irrigation, row crops
Abstract taken from paper found on pages 651 to 655 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Potato Production Using Subsurface Drip Irrigation-Water and Nitrogen Management
Howard Neibling, Randall Brooks
Bi-wall drip tubing was buried at a depth of about 8 cm in a production Norkotah potato field near Paul, Idaho in summer 1993. Plots were managed to provide 3 levels of water stress and 3 fertility levels. Crop water stress was determined with granular matrix sensors and plant N by petiole analysis. Results of the first year of this study showed that potato yield and quality could match or exceed that of the wheel line irrigated portion of the field. Non-replicated samples at the 1/4 points of a 213 m long plot showed no clear yield trend with distance from the submain.
Keywords: Drip irrigation, Microirrigation, Nitrogen fertilizer, Water management
Abstract taken from paper found on pages 656 to 663 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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A Microirrigation System for Peanut Research Plots
J. W. Worthington and J. R. Schmidt
Irrigation studies for row crops are frequently designed using line source or other sprinkler irrigation methods of applying water at different rates. Many of these systems are subject to experimental errors due to non-uniform application by sprinklers. For more definitive studies in replicated plots of peanuts, we chose to use biwall microirrigation tubing.
The experiment conducted in 1994 nested various fertilizer treatments on two irrigation rates with a completely randomized design. In all, there were 120 plots of peanuts. Each replicate consisted of 4 rows. Rows were 4.9 m long and planted 0.91 m apart. For our system, well water was pumped into an open reservoir from whence it was repressurized and passed through media filters. The controlling mechanism for the various treatments was handled by a Motorola MIR 5000 D.C. using solar and battery power to operate the 5.08 cm hydraulic valves needed in our design. Water from the 5.08 cm main line was delivered to "lay flat" submains of like size. From the submains, water was delivered down alleyways to each replicate of treatments through 1.9 cm sub-submains. Water was delivered to individual rows in each treatment through 1.27 cm polyethylene lateral lines. While the Motorola unit has the capability of cycling based on total flow through the system, in 1994, water applications were based on time required to deliver appropriate amounts as scheduled by pan evaporation.
Keywords: Microirrigation, Irrigation amounts, Irrigation control
Abstract taken from paper found on pages 664 to 668 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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A History of Drip-irrigated Cotton in Texas
Joseph C. Henggeler
Drip-irrigated cotton (drip-cotton) was first used commercially in Texas in 1984. Since that time about 1,336 hectares (3,300 acres) of drip-cotton have been installed by about 45 individuals. The economic benefits derived from drip-cotton come from labor savings, reduced cultivation, increased yield on the drip-cotton plots and a corresponding increase in yields on the conventionally irrigated part of the farm (due to application of more water there, which was freed up by use of drip on other parts of the farm). The area drip-irrigated on the typical farm was only about 11% of the total, farmed cotton area. Chances of success using drip irrigation increased as the ratio of drip to conventionally irrigated acres on a farm increased. However, approximately 6% of all installed drip-cotton was later abandoned.
Keywords: Microirrigation, Technology adoption, Irrigation statistics
Abstract taken from paper found on pages 669 to 674 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
