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.

Habitat specialists are particularly vulnerable to extinction when habitat conditions are altered. Information on the habitat use of such species is thus important because it provides insight into factors that influence distribution and abundance, which is crucial for conservation. Here, we aimed to identify factors that influence the patterns of presence and abundance of the Endangered volcano rabbit Romerolagus diazi, a rare leporid with a patchy distribution. Through exhaustive sampling of its range in the Sierra Chichinautzin and Sierra Nevada volcanic fields, Mexico, and using generalized linear models, we found that the probability of patch occupancy was higher where bunchgrass cover exceeded 75%, rock cover exceeded 5%, no cattle grazing was observed and human settlements were at least 7 km away. Patches with greater relative abundance were those with similar characteristics, but located at elevations > 3,600 m, and with rock cover < 15%. Cattle grazing was identified as a major threat to local populations of the volcano rabbit, particularly in the Sierra Chichinautzin. Because of the significance of bunchgrasses for this species, the protection of the mountain grasslands is required in both volcanic fields.

Few studies document the impacts of conservation management practices such as extensive grazing or mowing on the new ecosystems created by industrial conversions. In southern France, the Rhône channelling led to the construction of dykes to protect the Tricastin industrialized area from floods. Aiming to control plant dynamics for safety reasons and to favour plant biodiversity, mowing or extensive grazing by cattle were recently tested. Monitoring from both permanent plots and aerial photographs shows that three years of extensive grazing and annual mechanical mowing have modified plant composition, significantly increasing plant species richness, evenness and heterogeneity. The increase in evenness and beta-diversity from grazing was significantly higher than from mowing. Only grazing was able to reduce the height and cover of the dominant tussock perennial grass species (Brachypodium phoenicoides), while increasing bare soil cover and thus the contribution of annual species. The Normalized Difference Vegetation Index (NDVI) obtained through aerial photographic analyses confirmed the correlation between NDVI, aboveground biomass and plant species richness for the grazed site alone, allowing the results obtained from quadrats to be generalized to the scale of the grazed site. On the Rhône’s artificial dykes, extensive grazing appears to be a better management tool than mowing to enhance plant biodiversity and meet safety objectives.

Several herbicides were evaluated for control of white locoweed (Oxytropis sericea Nutt. T & G # OXRMA) and changes in botanical composition on two sites on high-elevation rangeland. White locoweed was more abundant and its population more stable on the rocky subalpine wind-swept ridge site than on the subalpine loam site. Picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) at 0.6 and 1.1 kg ae/ha, and 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 2.2 and 4.5 kg ae/ha eliminated white locoweed on the subalpine loam site, although the population on this site declined naturally. Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) was the most effective herbicide on the subalpine wind-swept site. Clopyralid at 0.3 and 0.6 kg ae/ha, dicamba (3,6-dichloro-2-methoxybenzoic acid) at 2.2 kg ae/ha, and 2,4-D at 1.1 kg ae/ha plus clopyralid or picloram at 0.3 kg/ha killed all white locoweed plants. Lower rates of clopyralid (0.1 kg/ha), dicamba (0.6 and 1.1 kg/ha), 2,4-D (2.2 and 4.5 kg/ha), and triclopyr {[(3,5,6-trichloro-2~pyridinyl)oxy] acetic aicid)} (0.6, 1.1, and 2.2 kg ae/ha) killed 45 to 84% of white locoweed plants. Grass cover increased on most treated areas where white locoweed, forbs, and sagebrush declined. Cattle consumption of white locoweed declined following application of 2,4-D.

Broom snakeweed is one of the most widespread range weeds in western North America. Although a native plant, it increases with disturbance such as overgrazing, fire, and drought, and can dominate sites. The objective of this study was to test the hypothesis that defoliation of broom snakeweed alone, and along with associated grasses, would reduce its vigor and increase its mortality in bunchgrass plant communities. The study was conducted at two locations: near Nephi, UT in an invaded crested wheatgrass stand and at Howell, UT in a bluebunch wheatgrass/Wyoming big sagebrush community. Clipping treatments consisted of (1) untreated Control; (2) All Clip—clipping all herbaceous vegetation 2 cm above the soil surface, and current season foliar growth of snakeweed; (3) Grass Clip—clipping all grass and forb plants; (4) Snakeweed Clip—clipping current season foliar growth. Treatments were randomly assigned to 1-m2 plots and clipped in May or late August. Plots were measured and clipped at the respective seasons annually from 2004 to 2007. Defoliation of snakeweed in spring in the Snakeweed Clip treatment caused higher mortality and lower size and vigor of remaining plants than the other treatments at the end of the study. Clipping all vegetation also reduced snakeweed density at Nephi, but not at Howell. There was little regrowth of bluebunch wheatgrass at Howell in the All Clip treatment; thus, it was likely to have not competed with snakeweed regrowth for limited soil moisture. Bluebunch wheatgrass cover declined at Howell in the All and Grass Clip treatments. Crested wheatgrass was not adversely affected by spring defoliation in the All and Grass Clip treatments, and it increased in the Snakeweed Clip treatment. There were few differences in the fall defoliations. Spring defoliation of snakeweed put it at a competitive disadvantage with both intact perennial bunchgrasses and regrowth crested wheatgrass, thus enhancing its mortality.

Soil water content and above-ground biomass accumulation, above 10 cm high, were measured monthly in a flooded savanna ecosystem under grazing pressure and under cattle exclusion, during two growth cycles. Near-to-the-ground and below-ground biomass were measured three times during this period. Besides, composition, species richness and diversity were obtained through a floristic inventory. Despite a relatively high floristic richness and diversity, Panicum laxum is the dominant species throughout the study area, while three other perennial grasses, Paspalum chaffanjonii, Leersia hexandra and Axonopus purpusii, also reach high values of cover and biomass. Each of them reacts specifically to flooding, drought and grazing conditions. This ecosystem shows a strongly seasonal behaviour, with primary production, mortality and decomposition sharply timed by soil relative water content. Both drought and water excess seem to limit plant production, even more during wet years when the savanna might remain flooded for up to 4 mo. Some structural and functional differences between the grazed and the protected systems are demonstrated, but under the actual, relatively low stocking rate, the grazed savanna produces as much forage as the ungrazed one.

Demand-driven agricultural production is unsustainable in Nepal since it is destroying the land base through soil erosion. The forests are also degrading from excessive fodder lopping (excising branches with leaf material) to feed farm animals. This study suggests an alternative for agricultural production, which minimizes environmental problems without impairing the present economic interests of the farmers. The study was conducted in the low-income, food-deficient, environmentally fragile hill district of Dhading in Nepal. A lexicographic goal-programming model was employed to generate an alternative plan that minimizes the environmental impacts relating to soil erosion, cattle grazing, forest fodder lopping, and use of inorganic fertilizers, and pesticides. Food-grain production, milk production, and returns to fixed farm resources are maintained at least at existing levels in the alternative plan. For delineating relationships between farm production and environmental problems, production of these commodities is hypothetically targeted at successively higher levels. The results indicate that the levels of environmental problems, except those from use of inorganic nitrogen fertilizers, are considerably reduced in the alternative farm production system. The alternative crop plan proposes the total exclusion of corn and oilseed crops and a marked decrease in the area under main season paddy rice. Instead, the areas under early paddy, upland paddy, wheat, pulses, and fodder crops would increase. The livestock plan suggests a decrease in the number of bullocks required, due to modification of the crop plan and sharing of bullocks among neighboring farmers. Replacement of cows by buffaloes for milk production is also proposed. Increasing food-grain production is more damaging to the fragile hill ecosystem than an equivalent increase in milk production.