Use of Minimum Tillage and Herbicide for Establishing Legumes in Kentucky Bluegrass (Poa pratensis L.) Swards¹

Abstract

Factorial experiments were conducted for three successive years with plantings of alfalfa (Medicago sativa L.) made in spring, mid‐and late summer of each year. White clover (Trifolium repens L.) was sown only in spring. Tillage levels were none and strips tilled to a depth of 1.9 cm with widths of 0.6, 1.9 and 5.7 cm. Herbicide levels were none and paraquat, l:l‐dimethyl‐4, 4'dipyridylium dichloride, applied at 1.11 kg a.i./ha in bands of 5.1 and 10.2 cm over the seeded rows. Seeds were placed either on or below the soil surface. Spring plantings were most successful, late summer ones were intermediate, and those made in mid‐summer were poorest. Placing the seed 1.2 (alfalfa) or 0.6 cm (clover) below the soil surface was found to be the most consistent controllable factor contributing to successful establishment. Stands were equal or superior on the minimumtilled plots i.e., strips 0.6 cm wide and 1.9 cm deep, to those of other treatments. Paraquat banded over the seeded row enhanced legume stands only when grass stands were dense and growth was rapid. Based on success with minimum tillage, a prototype field machine was designed and constructed to till, seed, cultipack, and apply herbicide in one pass over the land.

Comparison of tillage methods on red clover and ryegrass establishment and production under grazing in the establishment year

“…Although these densities were similar to those regarded by Hay et al (1978) to give satisfactory red clover production, it is quite apparent that the red clover plants overdrilled in paraquat bands in this experiment remained too small to make an agronomically significant contribution to yield. The relative improvement of red clover yield brought about by overdrilling compared to oversowing, and the use of paraquat bands (Tables 1 and 2), are similar to findings of Taylor et al (1969) who found that overdrilling with paraquat sprayed in bands resulted in greater plant size and doubled the plant number compared with oversowing. However, the absolute yield response was not of practical significance especially when compared to the levels of red clover yield obtained with full cultivation.…”

“…With limited supply of moisture in spring the development of overdrilled seedlings may be set back and result in poor establishment (Groya & Sheaffer 1981). It is under such adverse moisture conditions that the selection of a suitable directdrilling technique, including the coulter design, may greatly improve seedling survival and development (Taylor et al 1969;Baker 1976;Choudhary & Baker 1977).…”

“…Band spraying of herbicides to reduce competition and to improve seedling development of overdrilled species was introduced in New Zealand by Blackmore (1962). Vegetation is partly controlled by spraying herbicides such as paraquat (Blackmore 1962;Taylor et al 1969;van Keuren & Triplett 1970;Squires 1976) and glyphosate (Squires 1976;Baker et al 1979) in bands. Other herbicides may be used to control ·Overdrilled with paraquat in band, applies throughout tables certain species in pastures to be renovated by overdrilling.…”

Direct seeding of alfalfa in grain stubble and bromegrass sod

“…The level of vegetation suppression needed for successful forage crop establishment is related to seedling vigor, botanical composition, and soil texture (Taylor et al 1969(Taylor et al , 1972 (Kunelius and Campbell 1986). Rayburn et al (1981) found that seeding legumes directly into a grass sod can produce yields comparable to conventional tilling.…”

Sod-Seeding Birdsfoot Trefoil in Established Orchardgrass With Overall or Banded Herbicides

“…The degree of sod suppression required for forage legume establishment depends on the seedling vigor of the seeded legume species, the botanical composition of the sward, and the effects of edaphic and environmental conditions on sward and legume growth (Taylor et al 1969;Taylor et al 1912, Moshier and Penner 1978; Groya and Sheaffer 1981).…”