Understanding the Practice ‘Planting Green’ for Alfalfa Establishment

By Josh Kamps, Extension Crops and Soils- Grant, Green, Iowa, and Lafayette

Agriculture has a long tradition of associating the color of paint with each farmer’s preferred tractor brand. Even within a certain color hue multiple brands are represented, for example the hue of green is associated with John Deere, Oliver, Deutz-Fahr, Fendt and Claas tractors. We have all heard the jokes, song refrains and directed ridicule based on the color of paint which represents a particular tractor brand. The term ‘planting green’ is not describing the paint color of the tractor in the field. Rather, this term defines the action taking place in the field. ‘Planting green’ is planting the seed of an intended cash crop directly into a green and growing cover crop. In Wisconsin, a popular cover crop option used for this practice is winter cereal rye.

Extension and UW-Nutrient and Pest Management along with local collaborators designed, established and evaluated the practice of establishing alfalfa by ‘planting green’ with winter cereal rye to better understand the level of stand establishment, yield and forage quality for this practice. The management practices studied include no-till vs. tillage, cover crop vs. no cover crop and herbicide vs. forage harvest cover crop termination. Fall planted cereal rye was followed by spring planted glyphosate tolerant alfalfa into the living cereal rye. Early terminated treatments of rye biomass with herbicide yielded .5-ton dry matter of biomass per acre. Late terminated treatments of rye biomass with forage harvest yielded 1-ton dry matter of biomass per acre. The first cutting of alfalfa at the Lafayette County plot was harvested at the mid-bloom maturity stage. Table 2 (above)lists the average treatment data for the first cutting of alfalfa. This data set implies that tradeoffs for each management practice exist with the first crop of alfalfa new seeding. Fall alfalfa stand assessment indicated maximum yield potential for the first full production year across all treatments as the presence of a rye cover crop did not appear to affect stand establishment in 2022.

Based on infield observations of ‘planting green’ and the data collected during year one of this study, the following list shares some of the positive and negative effects of this practice.

  • Positive- reduced risk of soil erosion during early spring compared to traditional alfalfa establishment
  • Positive- cover crop biomass is an additional feed source
  • Positive- soil carrying capacity increases and risk of field rutting during the seeding year decreases
  • Negative- requires alfalfa seeding field identification 6 months in advance
  • Negative- forage quality and yield penalty for the first alfalfa crop of the seeding year

Thank you to the 2022 collaborators for your support! The collaborators include LASA, Curt and Debbie Miller, Reddy Ag/Ross Soil Service, Rockie Miller, Tom Douglas Family, Gretchen Kamps and Dan Smith.

The ‘planting green’ alfalfa establishment study is scheduled again for 2023 in Lafayette County and at the Lancaster Research Station. Learn additional information about this practice during a presentation at the 2023 LASA Annual Meeting.