Corn Nutritional Properties and Yields with Surface Drip Irrigation in Topographically Variable Fields

Authors: Zhu, Heping; Lan, Yubin; Lamb, Marshall; Butts, Christopher - Chris

Submitted to: International Agricultural Engineering Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2007
Publication Date: 9/20/2007
Citation: Zhu, H., Lan, Y., Lamb, M.C., Butts, C.L. 2007. Corn Nutritional Properties and Yields with Surface Drip Irrigation in Topographically Variable Fields. International Agricultural Engineering Journal. 9(9):1-10.

Interpretive Summary: Corn is a major peanut rotation crop in the Southeastern United States. It has imposed great economic impact on farmers. Corn grain is also a major high quality feed used in dairy and beef cattle in the USA due to its high energy and easy digestibility. Current concern has increased awareness of methods to reduce excessive nitrogen in livestock manure and use genetically modified corns to increase protein and energy content of corn. Many research efforts have been aimed at improvement of corn yield, irrigation water efficiency and nutrient management efficiency. However, very little research has been done on the use of surface drip irrigation to improve corn yield and nutritional properties under undulating topographic field conditions. A surface drip irrigation system was installed and investigated to irrigate a corn field with very little topographic variation and another field with undulating terrains. Drip tapes with two lateral spacings were placed on the soil surface close to a planting row and in the middle line of two planting rows, respectively. Corn grain yield and nutritional properties with surface drip irrigation treatment were compared with the corn produced in the adjacent non-irrigated zones. With surface drip irrigation, the average corn yield was significantly higher than without irrigation the yield. There were no significant differences for yields between two drip tape lateral spacings. Compared to non-irrigation treatment, surface drip irrigation greatly reduced variations in corn yield and nutritional properties in undulating terrain field. Corn kernels with surface drip irrigation contained higher carbon to nitrogen ratio and lower protein content, crude fiber, ash and fat or oil than non-irrigation treatments. No serious problems with the surface drip irrigation system were encountered during the corn growing season.

Technical Abstract: Development of a method to effectively irrigate row crops that requires less capital investment than current methods will improve the economic feasibility of irrigation. A surface drip irrigation system was installed and investigated to irrigate a corn field with very little topographic variation and another field with undulating terrains containing 1.75% slopes. Drip tapes with lateral spacing of 0.91 m and 1.82 m were placed on the soil surface 3 cm away from a planting row and in the middle line of two planting rows, respectively. Corn grain yield and nutritional properties with surface drip irrigation treatment were compared with the corn produced in the adjacent non-irrigated zones. With surface drip irrigation, the average corn yield was 8,451 kg/ha in Plot 1 and was 10,920 kg/ha in Plot 2, while without irrigation the yield was 1461 kg/ha in Plot 1 and 450 kg/ha in Plot 2. There were no significant differences (p<0.05) for yields between 0.91 m and 1.82 m drip tape lateral spacings. Compared to non-irrigation treatment, surface drip irrigation greatly reduced variations in corn yield and nutritional properties in undulating terrain field. Corn kernels with surface drip irrigation contained higher carbon to nitrogen (C/N) ratio and lower protein content, crude fiber, ash and fat or oil (F/O) than non-irrigation treatments. No serious problems with the surface drip irrigation system were encountered during the corn growing season.