Crop Rotation Effects on Soil Physical Quality
Open Access
- Author:
- Weaver, Jill L
- Graduate Program:
- Soil Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- May 27, 2008
- Committee Members:
- Sjoerd Willem Duiker, Thesis Advisor/Co-Advisor
- Keywords:
- penetration resistance
infiltration
bulk density
crop rotations
aggregate stability
soil quality - Abstract:
- Agricultural soil management practices influence soil physical properties. Soil physical properties as affected by crop rotation were evaluated in a long- term crop rotation experiment on a Hagerstown silt loam soil (Fine, mixed, mesic Typic Hapludalf) in central Pennsylvania. Properties observed included bulk density, penetration resistance, steady-state infiltration rate, and aggregate stability. Soil properties were measured in continuous corn (Zea mays, L.), corn-soybean (Glycine max, L.) crop rotation (in the year of corn), four years of corn followed by four years of alfalfa (Medicago sativa, L.) (in the first year of corn after alfalfa, and in the fourth year of corn after alfalfa), and the corn-oat (Avena sativa, L.)-wheat (Triticum aestivum, L.)-two years of red clover (Trifolium pratense, L.) and timothy (Phleum pretense, L.) hay rotation (in the year of corn). All soils were conventionally tilled (moldboard plow followed by disk and power rotary harrow) prior to crop establishment. Fertilization was with inorganic fertilizers based on soil test recommendations. Soil physical properties in corn monoculture did not differ from those in the corn-soybean crop rotation. After the perennial crops, improved soil physical quality was observed including lower bulk density, lower penetration resistance, and higher percentage of stable aggregates (no differences in steady-state infiltration rates were observed). The improved soil physical quality after perennial crops is attributed to decreased use of tillage and longer periods of root growth per year. The research shows that rotating crops alone does not improve soil physical quality, but rather certain crops (in this case perennials) contribute to improved soil quality in a conventionally tilled system.