The following guest article is by Craig Romary, environmental program specialist, and Tim Creger, pesticide program manager, for the Nebraska Department of Agriculture; and Mike Kucera, agronomist, NRCS National Soil Survey Center; Soil Quality and Ecosystems Branch
Once a pesticide is used in a cropping system, the restrictions on the label must be followed for the original crop it is used on, and any succeeding crops, until all restrictions on that label have been met. One of these is called the plant-back restriction. Plant-back restrictions exist for two reasons:
- To avoid carryover pesticide injury to the subsequent crop (such as with herbicides).
- To protect humans and livestock from elevated levels of pesticide residues that a succeeding crop may accumulate.
Because cover crops are re-emerging as an important practice for conserving soil, increasing soil water, and improving soil health and function, one needs to be aware of these restrictions and include them in the planning process. However, many of the plant species used in today's cover crop mixtures may not be specifically listed on the label to ensure establishment of the stand or the safety of the feed or forage. The following points highlight scenarios that may affect what is planted for cover crops and how they are used. Cover crops serve different purposes than forage crops although they may actually be the same species or mixture. The crop's end purpose — either cover or forage — affects plant-back and forage/harvest restrictions.