Establishment of Legumes as Influenced by the Rate of Sowing the Oat Companion Crop¹

Abstract

LARGE proportion of the stands of small-seeded legumes A in the North Central Region of the United States is established with a conipanion crop of spring grain. This spring grain is principally oats. In Wisconsin, over 90% of the legume seedings are mad? in this manner. A companion crop such as oats competes with the legume seedlings in varying degrees for light and moisture, and for mineral nutrients if soil fertility has not been properly ndjusted. Limitations of light may become the dominant factor in competition on the heavy, fertile soils while on the lighter or sandy soils, competition for moisture may limit or eliminate the growth of the small-seeded legume seedlings. The study reported here deals primarily with the influence of spring oats sown at different rates on the establishment of stands of alfalfa and medium red clover. The observations were made over a 4-year period, 1947-1950, at four Experiment Stations in Wisconsin.

Competition Between Wheat and Undersown Pasture in the Year of Sowing and the Effect of Undersowing on the Yield of Pasture in the Following Year

“…Stahler (7) showed that the suppression of bindweed by crops was mainly due to shading. Smith et al (6) and Klebesadel and Smith (3) have shown that the shade cast by cereal crops results in a considerable reduction in the growth of pasture species.…”

Comparison of the Uptake of P32 and K42 by Intact Alfalfa and Oat Roots

“…SEEGMILLER The growth of a legume grown as a companion with a grass has been shown by many workers (3,4,5,8,10,11,15) to he less than when the legume is grown in pure stand.…”

“…Explanations for this growth reduction of the legume include competition for light (5,6), soil moisture (11,15), nutrients (1,4,7,9,10,13), excretion of toxic materials (2,12,14), and effects of the microflora (12).…”

Establishment of vegetation on highway backslopes in Iowa

“…After three years, the cover percentages were 13,6, and 4 for birdsfoot trefoil and 89, 59, and 77 for crown vetch, respective to the above grasses.…”

“…Although advice against using too much rye grass in a mixture has been offered (44,45), ryegrass has not been found a problem in other instances (15). Either rye grass or a small grain have been used as cover crops in other instances (3,30,39,40,47,59). …”