Affiliation:
1. Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1, Canada.
2. Agriculture and Agri-Food Canada, 2585 County Road 20, Harrow, ON N0R 1G0, Canada.
3. Department of Renewable Resources, University of Alberta, Room 751, General Services Building, Edmonton, AB T6G 2H1, Canada.
Abstract
Long-term (58 yr) cropping and fertilization effects on soil water repellency were determined for a clay loam soil in southwestern Ontario, Canada by measuring soil organic carbon (SOC), soil water repellency index (RI), and soil hydrophobicity (SH). The 12 treatments (non-replicated) included fertilized and non-fertilized legume-based crop rotation (ROT) with four phases (corn–oat–alfalfa–alfalfa), continuous corn (CC), and continuous Kentucky bluegrass (KBG). We hypothesized that SOC, RI, and SH would be greater for each phase of the ROT versus CC, KBG versus CC and ROT, and fertilized versus non-fertilized treatments. Surface (0–10 cm) soil samples were collected in the spring of 2017. Laboratory measurements were conducted to determine SOC, RI (ratio of soil sorptivity to ethanol and water), and SH (ratio of hydrophobic CH– to hydrophilic CO– functional groups). Mean SOC and SH were greater (P ≤ 0.05) for each phase of the ROT versus CC (33% to 2.4 times), KBG versus CC (3.2–6 times) and each phase of ROT (2.2–2.8 times), and fertilized versus non-fertilized rotation oats and KBG (15%–30%). Mean RI was greater for KBG versus CC (4.8 times) and KBG versus each phase of the ROT (3.0–5.5 times) under fertilization only, greater for fertilized versus non-fertilized KBG (6.8 times), but similar for each phase of ROT versus CC. In general, legume-based rotations, perennial grass, and fertilizer enhanced SOC and SH, and to a lesser extent soil RI.
Publisher
Canadian Science Publishing