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Grayson, Carinthia Alden

Plant and Soil Science

1993

M.S.

Reduced tillage and rye cover crops may reduce management and environmental problems associated with corn production in New England. Currently, only 5% of Vermont farmers use conservation tillage to produce corn and few farmers use cover crops. A 3 year study was established on a Kingsbury clay (fine, illitic, mesic, Typic Eutrochrept). The objective was to compare the effect of four tillage trreatments (no-till (NT), ridge-till (RT), chisel plow (CH) and moldboard plow (MB) in combination with residue and cover crop management (grain harvest (GR), silage harvest (SIL) and silage harvest with rye cover crop (SIL-R)), on soil properties (surface cover, moisture, temperature and nitrate) and corn growth, silage and grain yields. The results of the first 2 years are reported here. On the Kingsbury soil early growth was affect by both tillage (MB > RT > CH > NT in 1988 and RT > MB > CH > NT in 1989) and residue/cover (SIL > SIL-R and GR). No differences in final grain and silage yields were found on the Kingsbury soil. On the Palatine soil MB treatments (P=0.10) in 1988 and NT-SIL and CH-SIL treatments had lower grain yields than other treatments in 1989. No-till-GR and CH-GR treatments had more soil surface cover, had 0.01 to 0.02 kg kg⁻¹ more soil moisture (on both soils), and 1 to 3 °C cooler temperatures and less soil NO₃-N than other SIL treatments (on the Kingsbury soil). These GR treatments also had the lowest biomass production in the early season on the Kingsbury soil. Tillage treatment significantly affects corn residue cover but did not affect soil moisture or temperature on either soil. Rye treatments also had less soil NO₃-N and had lower biomass production than SIL treatments in early season on the Kingsbury soil. Rye provided significantly more surface cover than SIL treatments on the Kingsbury soil but grew unevenly on the Palatine soil. Tillage did not effect rye cover. Some SIL treatments had significantly more soil NO₃-N at the end of the growing season than in SIL-R treatments on the Kingsbury soil.