|Author:||Dukes, M. D. ; Scholberg, J. M.|
|Book Group Author:||NA|
Subsurface drip irrigation (SDI) is being adopted in areas to conserve water while maintaining economical production of crops. These systems have not been evaluated on sandy soils common to Florida. An SDI system was installed on a well-drained sandy soil for sweet corn production in Florida. SDI tubing was buried under each row (76-cm spacing) at either two depths of 23 or 33 cm below the ground surface to result in two experimental treatments. Additionally, two methods of irrigation scheduling were imposed on the SDI treatments. One scheduling treatment was the initiation and termination of irrigation based on soil moisture measured by time domain reflectometry (TDR) probes installed 5 cm above the drip line. The other scheduling treatment was a daily irrigation event at rates consistent with typical practice in the region. Sprinkler irrigation scheduled similar to farmer practices in the region and non-irrigated control treatments were also established. The soil moisture based irrigation scheduling regime resulted in high frequency short duration (30-min) irrigation events to meet crop water needs. The 23-cm deep soil moisture-based treatment resulted in similar yields and similar water use in 2002 and reduced water use 11% with similar yields compared to sprinkler irrigation in 2003. This indicates that 23-cm deep SDI is feasible for sweet corn production under these conditions. The combination of optimum yield and minimum water use was achieved with soil moisture based set points of 10% to 12% by volume (on-off). The 33-cm depth SDI treatment was found to be too deep for optimal yield results on sweet corn-under the type of sandy soil in the study. Time-based SDI treatments were under-irrigated but showed evidence of considerable drainage based on soil moisture measurements due to single daily irrigation events that promoted movement of irrigation water below the root zone. Comparison of drainage calculations beneath the SDI treatments and sprinkler treatments indicated that up to 24% less drainage may have occurred on SDI plots compared to sprinkler plots largely because SDI applied water to the root zone and not the furrows.
|Pages:||89 - 101|
|Journal:||Applied Engineering in Agriculture|
automatic irrigation systems, crop production, crop yield,depth, irrigation scheduling, irrigation systems, maize, plant waterrelations, probes, sandy soils, soil types, soil water, subsurfaceirrigation, time domain reflectometry, trickle irrigation, water use,water use efficiency, Florida, USA, Zea mays, Zea, Poaceae, Cyperales,monocotyledons, angiosperms, Spermatophyta, plants, eukaryotes, SouthAtlantic States of USA, Southern States of USA, USA, North America,America, Developed Countries, OECD Countries, Gulf States of USA,Southeastern States of USA, corn, soil moisture, United States ofAmerica, Horticultural Crops (FF003) (New March 2000), Plant WaterRelations (FF062), Plant Production (FF100), Soil Physics (JJ300), SoilWater Management (Irrigation and Drainage) (JJ800) (Revised June 2002)[formerly Soil Water Management], Water Resources (PP200)