Longevity of Shallow Subsurface Drip Irrigation Tubing under Three Tillage Practices

Abstract

Shallow Sub‐Surface drip irrigation (S3DI) has drip tubing buried about 2 inches below the soil surface. It is unknown how long drip tubing would be viable at this shallow soil depth using strip‐ or no‐tillage systems. The objectives were to determine drip tube longevity, resultant crop yield, and partial net revenue when using conventional, strip‐, and no‐tillage. Drip tubing (8, 10, and 15 mil) was buried 1.5 inches in 2006 and left in the field for five years under strip‐ and no‐till areas and removed and reinstalled in conventionally‐tilled areas. Crop rotation was cotton (Gossypium hirsutum L.) the first year, corn (Zea mays L.) the next three years, and peanut (Arachis hypogaea L.) in the final year. There was no difference in cotton lint yield by tillage treatment and irrigated lint yield was 2.4 times greater than nonirrigated. There was no difference in irrigated corn yield across year or tillage practice. Irrigated corn yield was 5.8 times greater than nonirrigated yield. Irrigated peanut yield was the same across tillage treatments but was 2.6 times greater compared with nonirrigated yield. For tube longevity, conventionally tilled areas had less tube repairs compared with strip‐ or no‐tilled practices. Thinner wall tubing (8 mil) had 3.5 times more holes compared with thicker wall tubing (15 mil). The “cost‐to‐repair” versus “cost‐to‐replace” tubing indicates average replacement time at about 5.4 years. There were less production expenses for strip‐ and no‐ till compared with conventional tillage. Both strip‐ and no‐tillage systems are recommended when installing S3DI.

Removing Peanut Foliage Adjacent Shallow Subsurface Drip Laterals to Reduce Rodent Damage

“…The use of S3DI in field crops is easily installed and economical (Sorensen and Lamb, 2008; Sorensen and Lamb, 2009; and Sorensen and Lamb, 2015). Drip tubing was left in the field for five years with a cotton–corn–corn–corn–peanut rotation.…”

“…Thinner wall tubing (8 mm) had 3.5 times more holes compared with thicker wall tubing (15 mm). The “cost‐to‐repair” versus “cost‐to‐replace” tubing indicates average replacement time at about 5.4 years (Sorensen and Lamb, 2015). Both corn and cotton have open‐type canopies such that rodents cannot hide from predators quite as easily as compared with a closed canopy structure such as peanut.…”

Crop rotation, irrigation system, and irrigation rate on cotton yield in southwestern Georgia

“…There were seven tiers orientated perpendicular to individual plot rotations (Figure 1; Balkcom et al., 2001; Lamb et al., 2010, 2011, 2015). Tiers 1, 2, and 3 were established for an SSDI system.…”

“…The alternate row middle lateral spacing would be less expensive to install by using less drip tubing while having the same yield. Both Sorensen et al (2011) and Sorensen and Lamb (2015) showed that drip tubing placed under individual crop rows did not increase yield in cotton and peanut, respectively. The S3DI irrigated cotton had greater yield than SSDI irrigated cotton at the 100% irrigation level.…”

“…Drip irrigation systems for this research include surface drip systems (SDI), where the drip tubing is placed on the soil surface; deep subsurface drip (SSDI) irrigation, which has drip tubing buried 10 to 12 inches below the soil surface; and shallow subsurface drip irrigation (S3DI), where drip tubing is buried about 2 inches below the soil surface. Surface drip irrigation is traditionally used for high‐value vegetable and truck crops were the drip tubing is replaced seasonally; SSDI is considered permanent and typically not removed until the life span of the tubing has been reached; S3DI, when used with strip tillage production systems, may last up to 5 yr or longer depending on crop rotation (Sorensen & Lamb, 2015; Sorensen, Lamb, & Butts, 2016).…”