Yield and economics of shallow subsurface drip irrigation (S3DI) and furrow diking

Authors: Sorensen, Ronald - Ron; Nuti, Russell; Lamb, Marshall

Submitted to: Crop Management at www.cropmanagement.org
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2010
Publication Date: 12/21/2010
Citation: Sorensen, R.B., Nuti, R.C., Lamb, M.C. 2010. Yield and economics of shallow subsurface drip irrigation (S3DI) and furrow diking. Crop Management. DOI: 10.1094CM-2010-1220-01-RS.

Interpretive Summary: Improving water capture and infiltration into the soil may lead to less frequent irrigation and reduce irrigation expenses. Furrow diking has been proven as a successful practice when used with irrigation in the arid regions of the World to improve water capture and reduce evaporation of irrigation water. Furrow diking increases field surface area and can improve water capture to increase opportunity time for water percolation and minimize evaporation while improving infiltration, reducing erosion, and distributing water more uniformly between high and low elevation areas. Furrow diking tillage improved irrigation efficiency, improves rainfall capture, and showed a positive crop response in cotton, grain sorghum, sunflower, and corn. Furrow diking also reduced rainfall induced runoff. Drip irrigation due to its simplicity of design, has been used to irrigate vegetables and high value crops for many years. It can precisely deliver water, nutrients, and chemicals to the crop root zone. Field tests were conducted using shallow subsurface drip irrigation (S3DI) on peanut, cotton, and corn to investigate yield potential and economic sustainability. S3DI can be installed easily with low initial investment and provide flexible irrigation schedules without using large pumps and wells that are typical with overhead irrigation systems. The use of drip irrigation and furrow diking, independently, had positive effects on the yield of various crops. It is unknown how drip irrigation (S3DI) and furrow diking together would affect crop yield. In the presence of furrow diking, drip tubing would need to be removed and replaced yearly (new or re-used tubing) incurring an extra expense to the grower. Therefore the objectives of this research were to 1) document crop yield with S3DI and furrow diking, and 2) determine the economic benefit, if any, of drip irrigation in conjunction with furrow diking on peanut, cotton, and corn. This research was conducted at the USDA-ARS Multi-crop Irrigation Research Farm in Shellman, GA during the 2005 through the 2007 growing seasons on a Faceville fine sandy loam with up to 3% slope. Three areas were selected for crop rotations of cotton, corn, and peanut. Within each crop rotation, there were a total of four treatments replicated three times in a randomized complete block design. Treatments included irrigated, irrigated plus furrow dikes, nonirrigated, and nonirrigated plus furrow dikes. Crop rows were 3 ft wide planted in a single row orientation except for peanut which was planted in a twin-row orientation. At harvest the middle two rows were selected for yield except for corn which harvested the four middle rows. Harvesting procedures and data collection are described below. Land preparation was the same for all areas and for each year. Herbicides, insecticides, and plant growth regulators were applied to each crop as recommended by field scouting. Net revenue was determined by subtracting the cost of the drip system and furrow diking per acre. Each crop was analyzed individually by year and treatments. Crop yield and gross revenue were analyzed using a general analysis of variance procedure with respect to year, treatment, and year by irrigation and diking treatment. There was a positive revenue increase by installing a drip irrigation system for one year on peanut. It would require a yield increase of 1631 lbs/ac to pay for the expense of the drip system. In this research there were an average 1100 lbs/ac yield increase implying that it was not cost effective to install a drip system for one year. Overall, based on this research, the installation of a drip system on peanut for one year does not seem cost effective. The average corn yield increase of irrigated over nonirrigated treatment was 8154 lbs/ac implying that using drip irrigation for one year could be cost effective provided installation,

Technical Abstract: A shallow subsurface drip irrigation (S3DI) was installed yearly in conjunction with furrow diking to document yield and economic benefit of these techniques on peanut (Arachis hypogaea L.), cotton (Gossypium hirsutum L.), and corn (Zea mays L.). This research was conducted for three years from 2005 to 2007, inclusive. Each crop had four treatments replicated three times in a randomized complete block design. Treatments included irrigation, irrigation plus furrow diking, nonirrigation, and nonirrigation plus furrow diking. In 2005, there was no yield or gross revenue difference between treatments as precipitation was not limited for any crop. The expense of the S3DI system reduced net revenue in all irrigated crops in 2005 such that non-irrigation regimes had higher net revenues. In precipitation limited years (2006 and 2007), irrigated yield of peanut, corn, and cotton increased an average 1.3, 7.3 and 2.8 times, respectively, over nonirrigated yield. Net revenue increased for irrigated corn and cotton, but not for irrigated peanut compared with nonirrigated crops. Increased revenue received from irrigation during limited precipitation years offset the cost of the irrigation system for corn and cotton but was marginal for peanut. Yield increased numerically with furrow diking but was not significantly different from non-diked treatments. Increased yield with furrow diking did cover the expense of the treatment. Thus, installing a drip system for one year was economically beneficial for corn and cotton but not for peanut in limited precipitation years. Furrow diking may be economically beneficial but is dependent on precipitation timing and amounts.