Grain Yield of Subsurface Microirrigated Corn as Affected by Irrigation Line Spacing

Abstract

Without irrigation, crop yields are usually water‐limited on the acid soils of the southeastern USA. Economically feasible irrigation systems that require less water are needed. As part of a feasibility study of subsurface microirrigation for corn (Zea mays L.) production, the effects of irrigation line spacing and irrigation water amount were investigated in a 5‐yr study at Suffolk, VA. The soil was a Uchee loamy sand (loamy, siliceous, thermic Arenic Hapludult) with inclusions of Emporia loamy sand (fine‐loamy, siliceous, thermic Typic Hapludult). Treatments were three line spacings (0.91, 1.82, and 2.74 in apart, buried 0.38 m below and parallel to the crop row), low and high water amounts (about 41 and 62% of average pan evaporation, respectively), and a nonirrigated control. Nonirrigated grain yields ranged from 3.12 Mg ha−1 (1987) to 9.73 Mg ha−1 (1989). Irrigated grain yields ranged from 8.27 to 12.02 Mg ha−1. Except for 1987 (the driest year), there was no significant difference between the low and high water application amounts. In 1987, corn irrigated with the higher rate yielded 34% more. Grain yields were highest with irrigation lines placed under each row (narrow spacing) and ranged from a low of 8.55 Mg ha−1 (wide spacing) in 1989 to a high of 12.25 Mg ha−1 (narrow spacing) in 1990. Increased amounts of irrigation water were needed with the wider line spacing to obtain corn grain yields comparable with the other two spacings. It is unlikely that the lowered yield or increased irrigation water required with wide line spacing could offset additional installation costs for the narrow spacing. Irrigation lines spaced in alternate corn row middles (1.83 m) or under the third row (2.74 m) are recommended.

Narrow Row Corn Production with Subsurface Drip Irrigation

“…The 2-m lateral spacing had a higher slope, indicating a greater decrease in ear weight with distance from the SDI lateral. Ear length and weight results were similar to the normalized corn grain yields for those observed by Powell and Wright (1993). In a 4-year study, they found decreasing corn yields with increasing distance from the SDI laterals.…”

“…In Virginia, Powell and Wright (1993) evaluated corn yields on a loamy sand soil using SDI spacings of 0.91, 1.83, and 2.74 m. They found that additional irrigation was required for the wider lateral spacing to obtain corn yields comparable to the narrow lateral spacings. The highest observed yields were from the narrow SDI laterals that were under each corn row.…”

Pod Yield and Mineral Concentration of Four Peanut Cultivars Following Gypsum Application With Subsurface Drip Irrigation

“…Subsurface drip systems are adaptable to variations of field shape making them an important consideration in the Southeast. In recent years, drip irrigation has been expanded with good success on field crops such as corn (Zea mays L.) (Lamm et al, 1997(Lamm et al, , 2001Mitchell, 1981;Mitchell and Sparks, 1982;Powell and Wright, 1993), cotton (Gossypium hirsutum L.) (Camp et al 1997;Sorensen et al, 2004), and peanut (Jordan et al, 2002;Sorensen et al, 2001a, b;Zhu et al, 2004). Irrigation SDI laterals have been installed at 0.2 and 0.3 m soil depths (Bucks et al, 1981;Camp et al, 1989;Phene et al, 1987;Tollefson, 1985) on cotton, corn, fruits, and vegetables.…”

Cotton, Tomato, Corn, and Onion Production with Subsurface Drip Irrigation - A Review

“…However, the 2.0 m dripline spacing still increased the yield over rainfed production by 18%. Average corn yields were 100%, 93%, and 94% of the maximum yield for dripline spacings of 0.91, 1.83, and 2.74 m in the humid region of Virginia under adequate irrigation on a loamy sand (Powell and Wright, 1993). In an economic comparison of these results, it was concluded that the 1.8 m spacing was best for corn and peanut rotations (Bosch et al, 1998) in Virginia and North Carolina.…”