Corn Response to Compost and Manure Amendments Combined with No-Till or Plow Tillage
Livestock producers in the United States are increasingly aware of environmental issues associated with production, storage, treatment and utilization of animal wastes. It is well known that fresh and composted manure can be effectively used to sustain corn production. Rarely studied, however, is the conversion from mineral to more organic based systems of nutrients under contrasting tillage systems. We conducted a field study where uncomposted and composted cow (Bos taurus) manures (C/M) were applied at three different 'loading' rates of 28, 56, and 112 dry Mg ha-1 in the first year, followed by three years of maintenance rates of 11 Mg ha-1. Amendments were applied in the autumn to a clay loam Hoytville (H) soil and in the spring to a silt loam Ravenna soil at Wooster (W), OH and either immediately plowed down (PT) or left on the surface as part of the no-tillage (NT) treatment. Controls consisted of a no-amendment treatment and a mineral fertilizer only treatment. Stand counts and grain yields were recorded and soil cores analyzed after three (W) or four years (H) years of treatments. Planting immediately after fresh manure application lowered stand counts when NT was used, but this was not always reflected in grain yields. Delaying planting by a month, or manure incorporation or composting reversed the detrimental effects of fresh manure on seedling emergence. Carbon and other plant nutrient (N, P, K) concentrations were generally significantly greater for the surface soil layers of NT than PT, but the reverse was true at depth. We conclude that high loading rates of manure and composts, followed by annual maintenance rates, are effective in maintaining high corn grain yields. However, care must be taken to first compost the manure or to apply it with incorporation if seeding is immediately conducted.
Poster presented at the ASA/CSSA/SSSA annual meetings in Indianapolis, Indiana in Nov. 2006
stand count, grain yield, carbon, nitrogen, phosphorus, potassium, soil pH, no-tillage, nutrient management