Wildlife Damage in Conservation Tillage Agriculture: a New Challenge

Conservation-tillage farming systems have changed agriculture and brought new challenges to the wildlife damage field. Associated minor problems may result from the presence of rattlesnakes (Crotalus viridis) or badgers (Taxidea taxus), but sprout-pulling damage by birds has not been reported. Rodents dig and consume newly planted corn. At least 14 small mammal species have been captured in notillage cornfields, some species throughout fields and others primarily at edges. Deer mice (Peromyscus maniculatus) generally have been the most abundant, comprising 71 to 93% of total captures. Small mammal populations in no-tillage fields are generally no higher than in conventionally tilled fields, but they may be more diverse, and possibly more stable. Rodent damage to newly-planted corn is variable among fields and years but is at times substantial, possibly resulting in annual losses of up to $16 million in Nebraska. Six rodent species have been implicated in the damage problem but the overall amount of damage caused by each species is unknown. Currently, there are no satisfactory control methods. A new zinc phosphide grain bait is being developed; other potential controls include cultural methods, alternate feeding, and repellents. Benefits of small mammals such as their consumption of crop-damaging cutworms should be considered in control decisions. Wildlife damage problems in conservation-tillage systems, particularly rodent problems, challenge further research to better quantify associated impacts and to develop appropriate control measures.