Crop-livestock integration has demonstrated that cover crops can be terminated using livestock grazing with minimal negative impacts on soil health, however, provides little information on system-level approaches that mutually benefit soil health and both crop and livestock production. Therefore, the objective of this research was to examine the effects of cover crop mixtures on biomass production, quality and the potential for nitrate toxicity on a dryland wheat-cover crop rotation. This research was conducted at the Montana State University-Northern Agricultural Research Center near Havre, MT (48°29′N, −109°48′W) from 2012 to 2019. This experiment was conducted as a randomized-complete-block design, where 29 individual species were utilized in 15 different cover crop mixtures in a wheat-cover crop rotation. Cover crop mixtures were classified into four treatment groups, including (1) cool-season species, (2) warm-season species dominant, (3) cool and warm-season species mixture (mid-season), and (4) a barley (Hordeum vulgare) control. All cover crop mixtures were terminated at anthesis of cool-season cereal species to avoid volunteer cereal grains in the following wheat crop. At the time of cover crop termination, dry matter forage production was estimated and analyzed for crude protein, total digestible nutrients and nitrates as indicators of forage quality. All mixtures containing oats (Avena sativa) had greater (P ⩽ 0.03) biomass production than other mixtures within their respective treatment groups (cool- and mid-season). Forage biomass was influenced by cover crop treatment group, with the barley producing the greatest (P < 0.01) amount of forage biomass when compared to cool-, mid- and warm-season cover crop treatments. Total digestible nutrients were greater (P < 0.01) in the barley control compared to the cool- and mid-season treatment groups. Crude protein was greatest in the warm-season treatment group (P < 0.01) compared to the barley control, cool- and mid-season treatment groups. The barley control produced fewer nitrates (P ⩽ 0.05) than the cool-, mid- and warm-season treatment groups; however, all cover crop mixtures produced nitrates at levels unsafe for livestock consumption at least one year of the study. The relatively high and variable nitrate levels of all cover crop mixtures across years in this study suggest that forage should be tested for nitrates before grazing. In conclusion, our research suggests that in a dryland wheat-cover crop rotation that requires early-July termination, cool-season cover crop mixtures are the most suitable forage source for livestock grazing most years.

Twenty alfalfa cultivars were tested, under rainfed conditions in central Greece, for forage yield, agronomic and nutritive value in order to identify adaptive responses contributing to high resilience and productivity. From 2014 to 2017, five harvests (H1 to H5) per season were conducted. Two cultivars were also grown as irrigated checks. Annual and total dry matter (DMA and DMT) and harvest ratios (RH) were estimated. DMT was reduced by 42.9–48.1% under ambient rainfall compared to irrigated checks, which received 50.2% more water. The seasonal yield distribution demonstrated two contrasting strategies, however, equally effective for high resilience under rainfed conditions. The winter-active imported cultivars were the most resilient in the driest year, potentially due to their ability to exploit autumn rains, whereas the locally adapted genotypes were more productive in summer. The spring harvest ratio (RH1) was more indicative (r = 0.94, P < 0.01) of cultivar productivity, compared to plant survival (r = 0.65, P < 0.01), whereas the autumn harvest ratio (RH5) was representative of productivity under extreme drought (r = 0.53, P < 0.05). RH1 and RH5 were increased by 11.8 and 12.3%, respectively, whereas the summer ratios (RH3, RH4) were reduced by 47.3%, under rainfed v. irrigated conditions. Two Australian cultivars (‘Blue Ace’, ‘Icon’) achieved the highest RH5 suggesting an adaptive response by being more productive in autumn. However, the development of specifically adapted cultivars in terms of higher summer yield and plant survival may be necessary to cope with future climatic changes in the Mediterranean region.

During the 2015, 2016, and 2017 growing seasons, weed and weed-free mixed tall fescue and legume forage samples were harvested from 29 pastures throughout Missouri for investigation of the nutritive value of 20 common pasture weed species throughout the season. At certain times during the growing season, many broadleaf weed species had greater nutritive values for a given quality parameter as compared with the available weed-free, mixed tall fescue and legume forage harvested from the same location. There were no significant differences in crude protein concentration between the weed-free forage and many weeds throughout the growing season. However, crude protein content of common burdock, common cocklebur, common ragweed, dandelion, horsenettle, and lanceleaf ragweed was greater than that of the corresponding forage sample at multiple collection periods. The digestible neutral detergent fiber (dNDF) content of all broadleaf weeds except lanceleaf ragweed was significantly lower than that of the weed-free forage at all collection periods. Conversely, large crabgrass had significantly greater digestible neutral detergent fiber levels than did the mixed tall fescue forage at all sampling dates. Dandelion and spiny amaranth had greater in vitro true digestibility (IVTD) content than did the forage for the entire growing season. Three perennial weeds—horsenettle, vervains, and late boneset—did not differ in IVTD levels as compared with the mixed tall fescue and legume forage at any collection date. For most summer annual weeds, the trend was toward greater digestibility earlier in the season, with a gradual decline and often lower IVTD by the late summer or early fall. The results of this study will enable producers to make more informed management decisions about the potential benefit or detriment a weed may provide to the overall nutritive value of the pasture system.

Pastoralists have traditional ecological knowledge (TEK), which is important for their livelihoods and for policies and interventions. Pastoralism is under pressure, however, which may result in a decline of pastoral lifestyle and its related TEK. We, therefore, addressed the following objectives (i) to inventorise and assess how pastoralists characterise and value soils and forages in their environment, (ii) to analyse how soil, forage and livestock (i.e. cattle) characteristics relate to herding decisions and (iii) to determine whether TEK underlying herding decisions differs across generations. Data were collected through focus groups and individual interviews with 72 pastoralists, belonging to three generations and to three agro-ecological zones. Using a three-point scale (high, medium, low), four grasses and three tree forages were assessed in terms of nutritional quality for milk, meat, health and strength. Using their own visual criteria, pastoralists identified five different soils, which they selected for herding at different times of the year. Pastoralists stated that Pokuri was the best soil because of its low moisture content, whereas Karaal was the worst because forage hardly grows on it. They stated that perennials, such as Andropogon gayanus and Loxoderra ledermannii, were of high nutritional quality, whereas annuals such as Andropogon pseudapricus and Hyparrhenia involucrata were of low nutritional quality. Afzelia africana was perceived of high quality for milk production, whereas Khaya senegalensis had the highest quality for meat, health and strength. Pastoralists first used soil, then forage and finally livestock characteristics in their herding decisions. Pastoralists’ TEK was not associated with their generations, but with their agro-ecological zones. This study suggests that pastoralists had common and detailed TEK about soils, forages and livestock characteristics, underlying their herding decisions. To conclude, pastoralists use a holistic approach, combining soil, vegetation and livestock TEK in herding decisions. Such TEK can guide restoration or improvement of grazing lands, and land use planning.

Established stands of alfalfa (Medicago sativa L.) at two field locations were treated at one date in the fall with pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynil) benzamide] at 0.8 and 1.6 kg ai/ha and at two dates in the spring with sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} at 0.3 and 0.6 kg ai/ha for the control of quackgrass [Agropyron repens (L.) Beauv. # AGRRE]. Herbicide efficacy was compared by measuring botanical and chemical composition and yield of forage. Both chemicals suppressed quackgrass in first-cutting herbage. While sethoxydim at the higher rate was equivalent to pronamide for increasing the proportion of alfalfa in forage, pronamide was superior for increasing seasonal total yield. Late postemergence applications of sethoxydim were more effective for quackgrass regrowth control than earlier spring applications. Controlling quackgrass in late spring resulted in lower crude protein (CP) content in first-cutting forage than did controlling it in fall. Alfalfa competing with untreated quackgrass had a lower CP content than where quackgrass was controlled with herbicides. All herbicide treatments reduced the neutral-detergent fiber (NDF) of the herbage. As measured by the acid-detergent fiber (ADF) concentration of alfalfa, sethoxydim slightly retarded spring growth of the legume.

Spring-applied herbicides were evaluated in the field in 1982 through 1984 in western Nebraska for selective weed control in irrigated seedling alfalfa (Medicago sativa L. ‘Appollo’). Weed densities were least in plots treated preplant with benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine] in combination with postemergence applications of 2,4-DB [4-(2,4-dichlorophenoxy) butyric acid]. Combinations of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} with bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) and fluazifop-butyl {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} with bromoxynil provided less grass control than sethoxydim or fluazifop-butyl applied alone. Annual weeds did not reduce alfalfa stand density.

The herbicides 2,4-D [(2,4-dichlorophenoxy) acetic acid], dalapon (2,2-dichloropropionic acid), glyphosate [(N-phosphonomethyl)glycine], paraquat (1,1’-dimethyl-4,4’-bypiridinium ion), and pronamide [3,5-dichloro-(N-1,1-dimethyl-2-propynyl)benzamide] were applied at selected rates and dates to quackgrass [Agropyron repens (L.) Beauv. ♯ AGRRE]-infested alfalfa (Medicago sativa L.) sod in 1979 and 1980 to suppress vegetation for subsequent establishment of alfalfa without tillage. The influence of herbicides on weed control, alfalfa seedling density and visual stand, and forage yield and quality was assessed for 3 yr. During establishment, all herbicides except 2,4-D effectively controlled quackgrass. Glyphosate applied broadcast increasingly suppressed the existing sod as the rate was increased from 0.6 to 1.6 kg ai/ha. The effectiveness of herbicides as measured by total (old and new) plant density was closely related to the suppression of the sward. While the substitution of new alfalfa plants for old ones was not necessary under dense (40 plants/m2) alfalfa stands, completely controlling the vegetation with glyphosate resulted in sustained productivity throughout the experimental period. After 3 yr, alfalfa percentage and yield were highest when glyphosate was broadcast at 1.6 kg/ha. Improvement in forage quality, as estimated by the concentrations of crude protein and neutral-detergent fiber, was closely related to grass control.

The chemical composition and the utilization by domestic goats (Capra hircus L. ‘Saanen’) of alfalfa (Medicago sativa L.) hay and silage that contained or did not contain hoary alyssum [Berteroa incana (L.) DC. ♯ BEFIN] was studied. Alfalfa was higher in quality than hoary alyssum; crude protein (CP) was 38% higher, and the neutral- and acid-detergent fiber (NDF and ADF) were 18 and 29% lower, respectively. Less CP and more ADF were found in weedy hay than in other forages. Animal utilization, as measured by the dry-matter intake, digestible dry-matter intake, relative intake, and nutritive value index were greater for weed-free than for weedy forages. Hoary alyssum was more deleterious in chopped silage than in long hay, because of selective refusal of the weed by goats that were fed hay. The presence of hoary alyssum in alfalfa decreased its utilization by ruminants.

Spring-applied herbicides were evaluated in field studies conducted in 1985 through 1987 in western Nebraska for selective weed control in irrigated established alfalfa. Imazethapyr, norflurazon, pendimethalin, and prodiamine did not injure alfalfa but varied in their weed control spectrums. Overall weed densities were lowest in plots treated with norflurazon at 2.8 kg ai/ha and diuron at 1.8 kg/ha.

Component yields and forage quality were evaluated in established stands of alfalfa seeded alone and in binary mixtures with smooth bromegrass, orchardgrass, or timothy. Forage yields and quality were determined at three annual harvests in the third and fourth years after seeding. Weed yields in alfalfa seeded alone were significantly greater than those in the alfalfa–orchardgrass mixture. Average weed content was 24, 17, 2, and 15% for the alfalfa seeded alone, alfalfa–bromegrass, alfalfa–orchardgrass, and alfalfa–timothy, respectively. Seeding alfalfa with orchardgrass increased first harvest and annual forage yields while reducing alfalfa yield. Yields of orchardgrass often exceeded those of bromegrass or timothy. In the first harvest each year, crude protein was reduced and acid detergent fiber and neutral detergent fiber increased by including orchardgrass. Neutral detergent fiber was greater in alfalfa–orchardgrass than in the alfalfa seeded alone at most harvests. There were no consistent differences among the alfalfa seeded alone and the other mixtures in yield or quality.

Morphological and chemical characteristics of 11 warm season pasture weed species were defined. Goldenrod (Solidago altissima L.) was significantly taller and common ragweed (Ambrosia artemisiifolia L.) had the largest canopy diameter of the 11 species studied. Species ranged from 14 to 134 cm in height with canopy diameters of 25 to 70 cm. No direct correlation was found between individual leaf size and total leaf area. Macro- and micromineral content varied widely among species but all values obtained were considered high enough to meet the requirements of ruminant animals. Redroot pigweed (Amaranthus retroflexus L.) and horsenettle (Solanum carolinense L.) contained potentially toxic levels of nitrate. Five of the 11 species contained sufficient crude protein for ruminants and six of the 11 species were more than 50% digestible. Digestible energy values averaged 1.9 Mcal/kg for the 11 weeds evaluated.

A field trial was conducted for 3 yr (2005 through 2007) near Scottsbluff, NE, to examine weed control, crop safety, forage production, and economics of glyphosate-tolerant and conventional alfalfa establishment systems. Glyphosate applied to alfalfa at the unifoliate growth stage provided 67% weed control and was similar to imazamox applied at the two-trifoliate leaf stage. Delaying glyphosate application until alfalfa had reached the two-trifoliate growth stage improved weed control to 83%, and weed control was similar to imazamox plus 2,4-DB and imazethapyr plus 2,4-DB. Imazamox and imazethapyr caused minor crop injury, and the addition of bromoxynil or 2,4-DB to both herbicides further decreased crop safety. Weeds were most competitive with the first forage harvest and reduced relative feed value, crude protein, and value (dollars per t) of forage compared to forage that had been treated with herbicides. The total forage yield for the season consisted of three forage harvests and was greatest when no herbicides were applied. The total forage yield of plots treated with glyphosate at the two-trifoliate growth stage was greater than that of plots treated with imazamox or imazethapyr in combination with bromoxynil. When glyphosate was applied at the two-trifoliate growth stage, seasonal forage yield was similar to forage treated with imazamox, imazethapyr, or both herbicides in combination with 2,4-DB. When herbicide was applied to alfalfa at the two-trifoliate growth stage, the net return from using glyphosate with a glyphosate-tolerant alfalfa variety or utilizing imazamox with a conventional alfalfa variety were similar at $742 and $743/ha, respectively.

The objective of this experiment was to determine the effectiveness and crop safety of glyphosate vs. alternative herbicides for weed control in glyphosate-resistant alfalfa. Glyphosate-resistant alfalfa was established at two sites in Pennsylvania in 2004 and in 2005, and herbicides were applied either PRE or POST for weed control. Data were collected on herbicide performance, alfalfa and weed yield, and forage quality. Alfalfa forage response to weed control was variable and depended on weed severity. A single or split application of glyphosate provided similar or better weed control than conventionally based herbicide programs. The most differences from weed control occurred during the first harvest and dissipated in subsequent harvests. Cumulative alfalfa yield for the establishment year of the spring seeding was 26% lower in the untreated check relative to the mean of the herbicide-treated plots in 2004; but no differences were detected in 2005. Forage quality was highest where weed content of the forage was lowest. Effective management of weeds with herbicides during alfalfa establishment can improve forage yield and quality, and weed control is particularly important when summer annual weed populations are severe and emerge with the crop.

Field trials were conducted in 2009 and 2010 to investigate the effects of metsulfuron-containing herbicides on tall fescue growth, seedhead production, yield, and forage nutritive value. Several rates of metsulfuron-containing products and picloram plus 2,4-D were applied to a weed-free tall fescue hay field in the early spring vegetative, late spring boot, and late summer dormancy stages of growth. Compared to the nontreated control, applying metsulfuron-containing herbicides to vegetative tall fescue reduced plant height by 13 to 40% whereas boot-stage applications of these same herbicides reduced height by 28 to 45%. Metsulfuron-containing herbicides reduced seedhead density from 14 to 61% when applied to vegetative tall fescue, and from 53 to 88% when applied at the boot stage. Metsulfuron plus 2,4-D plus dicamba (0.01 + 0.40 + 0.14 kg ai ha−1) was the only metsulfuron-containing treatment applied at the vegetative application timing that did not reduce tall fescue seedheads or yield when compared to the nontreated control. Vegetative-stage applications of metsulfuron-containing herbicides reduced tall fescue yields by 33 to 63%, whereas boot-stage applications reduced yields by 15 to 35%. Picloram plus 2,4-D did not reduce tall fescue height, seedhead density, or yield when applied at either timing. Tall fescue crude protein (CP) concentration was greater in response to the vegetative compared to boot-stage herbicide applications, and vegetative-stage applications of metsulfuron-containing herbicides increased CP concentration of tall fescue by 1.5 to 3.4% compared to the nontreated control. Results from these experiments indicate that spring applications of metsulfuron-containing herbicides can be utilized to reduce tall fescue seedhead production and increase CP content of tall fescue pastures and hay fields, but summer applications of these same herbicide treatments will have only limited effects on yield, nutritive values, or seedhead density of tall fescue harvested in the fall or the spring following treatment.

Field studies were conducted in 2004 and 2005 in Michigan to determine the effect of seeding establishment method and weed control on forage quality of glyphosate-resistant alfalfa in the establishment year. Seeding methods included alfalfa only (clear-seeding) and alfalfa with a companion crop of oat (companion-seeding). Herbicide treatments included an untreated control and glyphosate treatment for both establishment systems, and either imazamox in the clear-seeding system or imazamox + clethodim in the companion-seeding system. The greatest differences among treatments in forage quality were observed at the first harvest in both establishment years. Results suggest high quality, productive alfalfa stands can be established utilizing glyphosate-resistant alfalfa in a clear seeding system.

The introduction of glyphosate-resistant (GR) alfalfa offers a new weed management system for alfalfa establishment; however, alfalfa seeding rates are based on conventional cultivars. Determining optimum seeding rates allows forage producers to maximize yield, quality, and profitability with GR alfalfa. Field experiments were established in 2005 and 2006 to determine the effect of seeding rate and weed control on GR alfalfa yield, forage quality, and persistence up to 3 yr after establishment. Seeding rates of 4.5, 9.0, and 18 kg ha−1 were evaluated. Weed control methods during the seeding year included no herbicide, glyphosate applied once before the first harvest, and glyphosate applied once before the first harvest and then 7 to 10 d following subsequent harvests. Alfalfa yield was greater at higher seeding rates and when weeds were removed with glyphosate. Season forage yields were the greatest with the 18 kg ha−1 seeding rate and where no herbicide was applied. Weed biomass often was lower at the higher seeding rates and was 91 to 98% lower in the glyphosate treatments compared to the nontreated. Forage quality was not affected by seeding rate but varied by herbicide treatment depending on establishment year. Plant density increased with seeding rate and treatment effects persisted for three growing seasons. Herbicide treatment did not affect stand density as greatly as seeding rate and did not influence stand longevity.

Studies were conducted at one location in 1997 (W97) and in two locations in 1998 (E98 and W98) near Garden City, KS, to evaluate the impact of Palmer amaranth at densities of 0, 0.5, 1, 2, 4, and 8 plants/m of row on forage yield and quality of irrigated corn and to determine if harvesting Palmer amaranth–infested corn for forage rather than for grain would reduce losses. Weed-free corn, Palmer amaranth alone, and corn–Palmer amaranth harvested together were evaluated for forage yield and quality. Forage quality was determined by evaluating in vitro dry matter digestibility (IVDMD), acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein (CP). Corn grain and forage yield declined with increasing Palmer amaranth density. However, decline in forage yield ranged from 1 to 44% of the weed-free yield at Palmer amaranth densities of 0.5 and 8 plants/m of row, whereas decline in grain yield ranged from 11 to 74% of the weed-free yield at the same densities. Digestibility of weed-free corn forage, expressed as IVDMD, was significantly higher than that of Palmer amaranth alone at W97 and W98. The CP of weed-free corn forage was similar to that of Palmer amaranth forage at W98, but it was lower at the other two locations. In contrast, CP did not differ between corn–Palmer amaranth harvested together and weed-free corn. The IVDMD of weed-free corn forage was greater than that of corn–Palmer amaranth mixture at W98, but no differences were observed at the other two locations. The relative feeding values of weed-free corn and corn–Palmer amaranth mixture were similar, and greater than that of Palmer amaranth in monoculture. These results indicate that Palmer amaranth interference in corn may not affect forage quality but can cause a decline in yield. This decline in yield is less when harvesting corn and Palmer amaranth together for forage rather than for harvesting corn grain alone.

Glyphosate-resistant (GR) alfalfa offers growers new options for weed control in alfalfa. One potential benefit of using GR alfalfa is increased longevity of an alfalfa stand under frequent harvests. It was hypothesized that GR alfalfa would have a greater longevity because of removal of weed interference with minimal crop injury. To study GR alfalfa yield, weed invasion, alfalfa stand persistence, and relative forage quality (RFQ), a field experiment with three weed control methods (no herbicide, glyphosate, and hexazinone) under two harvest frequencies (high and moderate) was established in August 2003 at the Michigan State University Agronomy Farm in East Lansing, MI. Forage yield of established alfalfa was not adversely affected by herbicide treatments. There were no differences in weed biomass between alfalfa treated with glyphosate and that treated with hexazinone, except in 2007. Average GR alfalfa stand density decreased approximately 90% (from 236 to 27 plant m−2), and yield decreased approximately 30% (from 11.04 to 7.87 Mg ha−1) during the 7-yr period (2004 to 2010) of the experiment. Stand density of GR alfalfa showed natural thinning during the 7-yr period regardless of harvest intensity or herbicide treatment. In most production years (4 out of 5 yr), relative forage quality of GR alfalfa was higher under a high-intensity harvesting system (4 to 5 harvests yr−1) than it was with a moderate intensity harvesting system (3 to 4 harvests yr−1). Relative forage quality was not affected by weed removal with herbicides in most years. Weed removal and harvest intensity in established GR alfalfa had no effect on stand persistence.

Improvement in multi-cut forage sorghum varieties that can perform better than SSG 59-3, a sweet Sudan grass released in 1974, has been a challenge. Efforts were made to create variability in SSG 59-3 through mutagenesis using both physical and chemical mutagens. Fifteen such mutants were evaluated for 2 years in different locations in India. Considerable variability was observed for important fodder yield and quality traits. SSG 237 flowered 10 d early than SSG 59-3. SSG 231, SSG 260, SSG 232 and SSG 237 had high protein percentage and in vitro dry matter digestibility (IVDMD) values compared with SSG 59-3. Hydrocyanic acid (HCN), a major anti-nutritional factor, was low in six mutants, the lowest being in SSG 226. This variability can be used in different breeding programmes aimed at improving multi-cut forage sorghum varieties. The lines with improved fodder quality (low HCN, high protein and IVDMD) can be used in the breeding programme for the improvement in multi-cut forage sorghum varieties.

Man-made grasslands dominated by Imperata cylindrica (L.) Beauv. in forested areas of lowland Nepal are commonly cut and/or burned annually. Changes in grass forage quality following different treatments of cutting and burning and axis deer (Axis axis) response to such habitat manipulations were investigated. Samples of matured grass were collected in December 1990, February and April 1991 from three experimental sites: cut, burned, cut-and-burned. Four locations on cut-and-burned grassland were repeatedly sampled at 12-d intervals from January to April 1992. Numbers of axis deer were recorded during the dry season of 1991/1992 on grassland plots receiving the following treatments: cut, cut-and-burned, and uncut/unburned (controls). Based on grass quality differences between December and February and between December and April, cut-and-burned treatments gave the greater increase in forage quality. N was significantly higher on cut-and-burned plots than on cut plots both in February and in April, while Na, K and P was significantly higher in February. On plots cut-and-burned in January, Ca concentrations were relatively low while the P content fell below required levels for domestic stock towards the end of the dry season in April. Na concentrations were below the minimum required levels for both domestic and wild ruminants during the whole period. When an entire grassland was cut, deer density increased gradually. When the same area was subsequently burned, the daily deer density increased much more rapidly. Axis deer preferred burned plots compared to plots neither cut nor burned and to cut plots. Plots burned in late February had higher densities of axis deer than plots burned 1.5 mo earlier. When nearby recently burned plots were available, deer density was reduced on plots burned earlier.