Division S-6—notes Haying, Tillage, and Nitrogen Fertilization Influences on Infiltration Rates at a Conservation Reserve Program Site

Effect of haying (hayed or not hayed prior to tillage), tillage (notillage, minimum tillage, or conventional tillage), and N fertilization (0 or 67 kg ha ') on surface infiltration rates, Q(h), was evaluated for Conservation Research Program (CRP) site conversion. Soils included Amor loam (fine-loamy, mixed, superactive, frigid Typic Haplustoll) and Cabba silt loam (loamy, mixed, superactive, calcareous, frigid, shallow Typic Ustorthent). In reference plots Q(h) increased from 1995 to 1997 (27.2 ± 3.2 vs. 36.4 ± 2.9 mm h~' at 50-nun tension, 10.9 ± 1.2 vs. 20.6 ± 1.4 mm h" at 100-mm tension, and 4.1 ± 0.6 vs. 10.9 ± 1.1 mm h ' at 150 mm-tension) under permanent vegetation. Plots hayed prior to tillage exhibited higher Q(h) when no fertilizer was applied than plots hayed and fertilized or not hayed (31.9 ± 2.9 vs. 23.3 ± 1.3 mm h' at 50-mm tension and 18.1 ± 1.3 vs. 13.5 ± 0.6 mm h ' at 100-mm tension). As tillage intensity increased, Q(h) at 50-mm tension increased (20.1 ± 2.6 mm h ' under no-tillage, 25.5 ± 1.6 mm h~' under minimum tillage, and 30.1 ± 2.0 mm h" under conventional tillage). Q(h) did not change from 1995 to 1997