Relationship of landscape position and properties to crop production

Abstract

ABSTRACT: Five locations in southeastern Nebraska were studied in 1985 and 1986 to characterize landscape positions along a hillslope and to relate the associated soil properties and topographic features to crop yields. Each location consisted of a catena possessing several soil series. However, the entire area was mapped as an eroded phase of a Crete (Pachic Arigustoll), Hastings (Udic Argiustoll), Moody (Udic Haplustoll), Sharpsburg (Typic Argiudoll), or Wymore (Aquic Argiudoll) soil series. Landscape positions consisted of upper interfluve (UI), lower interfluve (LI), shoulder (S), upper linear (UL), lower linear (U), and footslope (F). Thickness of the mollic colors ranged from 0 to 46 cm (0-18 inches) among all soils studied. A general ranking of the relative thickness of the mollic colors by landscape position illustrated that F> UI>LI>S> UL>LL. Slope gradient among sites ranged from 1% to 18%. Slope length ranged from 9 to 171 m (30-560 feet). Significant yield differences among landscape positions were identified for one of two corn crop-years, two of five sorghum crop-years, and three of three soybean crop-years. Crop production among all landscape positions was generally LI>F>UI>S> UL>LL. Corn-yield ranking was significantly influenced by position and slope length; sorghum-yield ranking was significantly influenced by position, thickness of the mollic colors, and slope gradient; and soybean-yield ranking was not significantly affected by any of the parameters evaluated.