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Minimum‐tillage establishment of forages offers potential advantages over the conventional method in terms of reducing energy and labor requirements, erosion hazard, and improving flexibility, and timeliness of operation. Our objective was to compare these methods of establishing alfalfa (Medicago sativaL.) with various herbicides, time intervals between herbicide application and seeding, and seeding dates. The seedings were established on a Charlton fine sandy loam (Entic Haplorthod) of high fertility in a sward dominated by quackgrass (Agropyron repensL.). Conventional renovation consisted of plowing, disking, cultipacking, and seeding; minimum‐tillage renovation consisted of mowing and seeding with a J. D. Powrtill seeder. Delaying application of glyphosate IN‐(phosphonomethyl) glycine] from 2 to 16 May had no apparent effect upon quackgrass control, but did lead to a significant reduction (52%) in densities of alfalfa seedlings and, subsequently, of second year alfalfa plants in plots seeded 21 May 1977 by minimum‐tillage. At the first harvest of the seeding year, a delay in glyphosate application resulted in significantly lower forage yield (1.84 vs. 2.82 metric tons/ha) and higher percent crude protein (20.0 vs. 16.8%) for the 21 May and 4 June minimum‐tillage seedings. In subsequent harvests, there were no yield differences due to glyphosate application date for alfalfa established by minimum‐tillage. Date of glyphosate treatment did not affect plant densities, forage yield, or quality of conventionally‐seeded alfalfa. For glyphosate treatments, conventional seeding resulted in an average of 0.6 metric tons/ha more alfalfa than minimum‐tillage during the seeding year. Yields of total forage and alfalfa seeded by the two techniques after glyphosate treatment were similar during the second year, except that yields for conventional seeding continued to be higher than for minimum‐tillage for the 4 June seeding (9.2 vs. 8.5 metric tons/ha of alfalfa). In terms of alfalfa and total forage yields, glyphosate was more important for minimum‐tillage than for conventional seedings. EPTC (S‐ethyldipropylthiocarbamate) produced yields similar to glyphosate with conventional seeding, while with paraquat (l,l'‐dimethyl‐4,4'‐ bipyridinium ion) yields were similar to those with glyphosate only at the earliest minimum‐tillage seeding. Seeding without herbicide led to substantial yield reductions, especially with minimum‐tillage seedings.

Sod‐seeding is the only practical method to introduce improved forage species on many fields. Animal data are needed to adequately evaluate the viability of sod‐seeding. This study determined animal responses to changes in forage composition following several methods of renovation. Two fields with fine, sandy loam soils were used. Bradford Field (Typic Dystrochrepts) was dominated by smooth brome (Bromus inermisL.). Walker Field (Typic Fragiochrepts) was low in fertility and had a diverse sward. Treatments consisted of an N‐fertilized control and sod‐seeding of legumes following either paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) or glyphosate [N‐(phosphonomethyl)glycine] application. Additionally, red clover (Trifolium pratenseL.) and timothy (Phleum pratenseL.) were seeded conventionally at the Walker site. Nutritive value of three harvests from Bradford Field and one harvest from Walker Field was determined in feeding trials with 250‐kg dairy heifers (Bos primigenius). Greater legume content of renovated swards (avg. 720 g kg−1the year following seeding) compared to N‐fertilized controls (avg. 230 g kg−1) resulted in greater forage crude protein (CP) content (all four harvests) and greater dry matter (DM) intake (two of four harvests), greater N intake (NI) (all four harvests), and greater body tissue retention of N (three of four harvests) by dairy heifers. Metabolizable and digestible energy were similar for all harvests and improvement methods. There were no differences in animal response to forages from sod and conventional seedings, except that NI was greater from sod‐seedings. The year following seeding, there was an average 48 and 75% increase in digestible DM and CP yield, respectively, from treatments introducing legumes compared to N‐fertilized controls. These results show that when existing species are not highly responsive to N, improved forage species can be seeded without tillage and without N, and result in improved forage quality and animal performance.

No‐till seeding is the only practical method of improving many pastures and fields, yet direct seeding of perennial forages often results in failure. Japanese millet [Echinochloa frumentacea(Roxb.) Link.], an annual, was evaluated following seedings into herbicide‐treated sod for establishment, yield compared to other annuals and to perennial forages, the enhancement of subsequent perennial establishment, and usefulness in a grazing program. Japanese millet was successfully established by sod seeding, with herbicide, in all four locations years. On a Paxton fine sandy loam (coarse‐loamy, mixed, mesic Typic Fragiochrepts) with low initial fertility, dry matter yields of Japanese millet seeded directly into sod were 8.62 and 9.74 Mg ha−1in 1981 and 1982, respectively. These yields were three to five times greater the seeding year than those of perennial forages seeded into the same herbicide‐treated sod. Birdsfoot trefoil‐timothy (Lotus corniculatusL.‐Phleum pratenseL.) establishment, with tillage, was enhanced by a previous crop of Japanese millet. Japanese millet was no‐till seeded into a permanent pasture with a Sutton loam (coarse‐loamy, mixed, mesic Aquic Dystrochrepts). Lamb (Oris aries) daily gain was less on Japanese millet than on perennial grasses, but total lamb gain per hectare was similar. Forage availability in July and August increased, compared to the unseeded control. The ease of establishment, competitive ability, yield potential, and mid‐ to late‐summer production of forage makes Japanese millet a promising initial crop in a no‐till forage improvement program in which the goal is to establish improved perennials.

Many fields, because of slope and rockiness, are not suited to conventional seeding. However, the no‐tillage methods of establishing perennial forages preclude the incorporation of lime. The objective of this experiment was to evaluate the response of perennial forages seeded without tillage to surface‐applied lime. A long‐term study was conducted on a Penichuk fine sandy loam (loamy‐skeletal, mixed, mesic Dystric Eutrochrept) in which alfalfa (Medicago sativaL.)‐orchardgrass (Dactylis glomerataL.) and birdsfoot trefoil (Lotus corniculatusL.)–timothy (Phleum pratenseL.) mixtures were seeded conventionally and without tillage. Nine months prior to seeding, lime was broadcast at 0, 4.5, and 9.0 Mg ha−1, incorporated for conventional seedings, and left on the surface for no‐till seedings. Soil pH prior to initiating the study was 5.6. In comparison with incorporated lime and conventional establishment, surface liming and establishment without tillage resulted in less vigorous forage seedlings and slower establishment. There was no difference in seedling density with liming or seeding method. Yields of legumes and total forage the seeding year were greater with incorporated than with unincorporated lime. In succeeding years, however, annual yields and 6‐yr total yields from 4.5 Mg ha−1lime rates were not significantly different due to liming method. Over the long term, there was a yield advantage to incorporation of lime at the 9.0 Mg ha−1rate. Rates of 9.0 compared with 4.5 Mg ha−1of surface liming did not speed pH adjustment with depth, and after 6 yr pH had increased to a depth of only 10 cm. Birdsfoot trefoil–timothy was more productive than alfalfa‐orchardgrass without lime, but less responsive to lime. The highest rate (9.0 Mg ha−1) of incorporated lime increased alfalfa‐orchardgrass yields the year of establishment, but similar rates of surface‐applied lime did not produce a yield response until the fourth year.

A heavy dependence on K fertilization in the northeastern U. S. coupled with the luxury accumulation of this element in plants suggest a need for further research. The objective of this greenhouse experiment was to relate CO2uptake, determined by a radioactive carbon method, and yield of maize (Zea maysL., var. Wisconsin 335A') with K concentration and content of tissue. Plants were grown at substrate levels of K from O to 9 mM/liter of K in hydroponic culture. A significant correlation existed between both concentration and content of K and dry weight of plants. There was a curvilinear relationship between both leaf (youngest fully expanded) and plant K percentage and net CO2uptake. Leaf content of K between 0.75 and 1.0% was considered critical (42‐day‐old maize) because CO2fixation was seriously reduced at lower concentrations. There was a close agreement between CO2assimilation and dry weight over the range in substrate K concentrations, .50 to 9.0 mM/liter. An increase in dry weight at the K level of 0.25 mM/liter was not accompanied by an increase in CO2fixation. Uptake of CO2increased nearly 60% between K concentrations of 0.25 and 0.50 mM/liter but at a much slower rate between 0.50 and 9.0 mM/liter.

Yield, water use efficiency, and forage quality of ‘Eski’ sainfoin (Onobrychis viciaefoliaScop.) were examined at the Central Great Plains Field Station, Akron, Colo. to determine its potential as a forage crop under dryland conditions. Despite below‐average rainfall during both years of the experiment, average seasonal forage yields over all treatments were 3,494 and 2,383 kg/ha dry matter for 1969 and 1970, respectively. Most of the forage yield was produced by the first cutting. Water use efficiency was high for the first cutting, but was low for the second cutting due to the slow regrowth. A prolonged late‐season drought stress occurred during both years and plants were dormant during this time. Roots extracted soil moisture from depths of 180 cm. Survival rate over the 2‐year period was slightly lower for plants harvested consistently at the early bloom stage of maturity. Forage quality, in terms of leaf, protein, and mineral percentages, cell wall components, and in vitro dry matter digestibility decreased little from early to late‐bloom maturity. This could be attributed to the high retention of leaves and rapid rate of maturation. Leaves had higher percentages of protein, in vitrodigestibility, Ca, and Mg and had lower percentages of cellulose, hemicellulose, lignin, cellwall constituents, and K than stems.