Preliminary Observations of Perennial Lupine as a Cover Crop in Field‐Planting Sites and Forest Nurseries in Wisconsin

Plantings of perennial lupine ( Lupinus perennis ) were observed over a 4‐year period on 12 field‐planting sites in northeastern Wisconsin and in 2 forest nurseries. On nonirrigated field plantings production varied considerably by sites. On sites of reasonably good nutrient content and moisture relations oven‐dry weight of the crop per acre was in the range of 3,136 to 3,762 pounds per acre in the fourth year, with a nitrogen equivalent of 60 to 73 pounds per acre. On dry or very infertile sites the species was a failure, producing only a few hundred pounds of bulk dry matter per acre. In irrigated nurseries it produced an average of 3,203, 4,792, and 12,180 pounds per acre of oven‐dry material in the first, second, and third years, respectively. Average nitrogen content on a per‐acre basis ranged from 55 pounds the first year to 311 in the third year. Seed production in a second‐year nursery planting was 480 pounds per acre and in a third‐year stand, 812 pounds per acre.