Conservation Tillage and Wildlife Modified by the GA Agriculture Education Curriculum Office July 2002
Tillage practices greatly influence wildlife habitats in agricultural landscapes.
Conservation Tillage - Any tillage and planting system in which at least 30 percent of the soil surface is covered by plant residue after planting to reduce soil erosion by water; or where soil erosion by wind is the primary concern of at least 1,000 pounds per acre of flat small grain residue equivalent are on the surface during the critical erosion period. [NRI-92] Conventional Tillage- Tillage types that leave less than 15 percent residue cover after planting, or less than 500 pounds per acre of small grain residue equivalent throughout the critical wind erosion period. Generally involves plowing or intensive tillage. [CTIC-97] Reduced Tillage - Tillage types that leave 15-30 percent residue cover after planting or 500 to 1,000 pounds per acre of small grain residue equivalent throughout the critical wind erosion period. [CTIC-97]
Conservation Tillage – Increasingin Popularity for its Conservation andEconomic Benefits. Conservation Benefits: • Soil • Conservation • Water • Quality • Wildlife • Habitat 1996 CTIC data
Tillage Practices Affect Wildlife in 4 Primary Ways: • Amount of cover provided by crop residues • Availability of wildlife in food crop residues • Timing and frequency of disturbance • 4. Toxicity of nutrient inputs and pesticides
Crop Residue Provides Wildlife Cover In general, the higher the amount of crop residue, the greater the value for wildlife cover. Standing crop residue is particularly important. Nesting cover Winter cover Small mammal diversity increases with crop residue
Crop Residue Provides Wildlife Food Waste grain provides food for: Waterfowl, songbirds, upland game birds, deer, small mammals, etc.
Tillage-Associated Disturbance and Wildlife Adverse effects on nesting birds in crop fields: • Direct mortality •Nest abandonment • Nest destruction
Bird species found to nest in conventionally-tilled (T) and no-till (NT) corn and soybeans (from Best 1986) Corn Soybeans Species T NT T NT Ring-necked pheasant x x x Killdeer x x Mourning dove x x x x Horned lark x x American robin x Common yellowthroat x Bobolink x Eastern meadowlark x Western meadowlark x x Red-winged blackbird x x Brown-headed cowbird x x x x Dickcissel x x Savannah sparrow x Grasshopper sparrow x Vesper sparrow x x x x Field sparrow x x
Vesper Sparrow Nesting Season # Nests May June July Aug
Reduced tillage (e.g., mulch and ridge till) systems may provide enough cover to attract nesting birds, but the level of disturbance during the crop cycle offers little chance for nest success, creating ecological traps. Frequency of disturbance may be more important than the amount of nesting cover available - no-till provides the best cover with the least amount of disturbance. In general, tillage systems that reduce the number of equipment passes and leave standing crop residue improve nest success except when:
Pesticides and Wildlife Risks: Mortality Factors Contact transfer from adults to young Direct spraying on eggs and young Ingesting poisoned insects and granular pesticide products
Insecticides are Generally More Toxic to Wildlife than Herbicides, but Both May Cause Adverse Affects Producers can use scouting and other IPM measures and can select the least toxic pesticide to use where needed
Conservation Tillage Benefits In the absence of natural grasslands, croplands can provide “surrogate” grassland environments for many grassland birds and other wildlife. By providing food and cover, conservation tillage on croplands enhances habitat quality for many species. Any shift in tillage practices that increases crop residue and/or decreases disturbance is beneficial. For example: conventional to reduced tillage ridge-till to no-till
Conservation Tillage, and Especially No-Till, in • Conjunction with: • Integrated Pest Management, • Crop rotation • Nutrient management • Conservation buffers • Greatly improves wildlife habitats in cropland • agricultural ecosystems.
For more information on Conservation Tillage and Wildlife See comprehensive literature review on the WHMI website www.whmi.iastate.edu