Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Other
Publication Acceptance Date: June 23, 1995
Publication Date: N/A
Technical Abstract: Pullman clay loam and related soils, the predominate soil types in the Southern High Plains, are slowly to moderately permeable, and furrow wheel traffic further reduces furrow irrigation intake rates. Traffic effects were evaluated with treatments of one (1) and two (2) furrow passes with relatively light (L) and heavy (H) tractors of 4.1 and 8.2 Mg (9,000 and 18,000 lb) mass, having 75% of the mass on the rear axle. Treatments are designated 1-L, 2-L, 1-H, and 2-H. Both larger tractor mass and repeated traffic increased tillage zone compaction and reduced irrigation intake rates and total intake. Soil strength (cone penetrometer) from wheel traffic compaction was greatest at the 100 to 150-mm (4- to 6-in) depth for all treatments, which is near the bottom of the 150-mm (6-in) primary tillage zone. For the first 8-h infiltration test using a flowing furrow infiltrometer after tillage, the 1-L, 2-L, 1-H, and 2-H treatments reduced average intake by 23, 33, 38, and 43% respectively; compared with 212 mm o intake for the no-traffic check. Because of furrow surface layer consolidation after the first irrigation, intake for all treatments was about 20% less during the second tests about 60 days later when the check infiltrated 171 mm and traffic induced intake reductions were 16, 23, 28, and 36% respectively; for 1-L, 2-L, 1-H, and 2-H treatments. A better understanding of variable furrow traffic effects on irrigation intake enables producers to make management adjustments to improve water application efficiency by beneficially using traffic compaction to reduce excessive early season intake or limiting traffic where low intake is a concern later in a crop season.