The objective of this research was to determine the influence center-pivot sprinkler irrigation methods in combination with tillage practices for corn (Zea mays L.) have on surface runoff of irrigation and rainfall. A center pivot irrigation machine was redesigned to apply water by high-pressure-impact (HPI), low-pressure-impact (LPI), and low-pressure-spray (LPS) nozzles. The center-pivot was a standard 10-tower machine, 395 meters in length and 38.4 meters tower spacing. Three tillage systems were used -- till-plant (T), disk (D), and subtill (S) which was till-plant with subsoiling between rows with straight single shanks, 360 mm deep, after last cultivation. The soil was a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudolls). Runoff was measured from two plots representing each tillage system under the span between towers 9 and 10 for HPI, LPI, and LPS. Hand samples of water were taken at specific time intervals during runoff events for sediment and nutrient analysis. The greatest average annual sediment yield within each irrigation system was for D tillage treatment (148 kg ha-1) and smallest was for S tillage treatment (2 kg ha-1). Total nitrogen in runoff followed a pattern similar to sediment with a range from 0.86 to 0.01 kg ha-I for D and S tillage, respectively. Runoff as a percentage of irrigation water applied for irrigation systems ranked LPS \u3e LPI \u3e HPI. Tractor wheel trafficked rows accounted for majority of the runoff
