Reduction In Forage Production Research Articles

Water deficit tolerance in genotypes of Urochloa spp.: Water deficit in Urochloa spp.

It is estimated that the world’s population will increase considerably in the coming years. Thus, there is a need to maximize the production of animal protein, of which the pasture production system is the most economical way. However, abiotic factors influence animal production, with water deficit being the factor that most limits the development of forages. In this research, we investigated the tolerance of genotypes Urochloa spp. under periods with water deficit conditions. The experiment was carried out in a randomized block design, under a factorial design. Twelve forage genotypes were evaluated in four periods of stress, with three replications. There was no interaction effect between the genotype factors and time of stress due to water deficit for all variables. There was a reduction in forage production with the increase of time in water restriction, and a decrease of 23% leaf mass and 30% stem. In the case of leaf attributes, there was a decrease of 28% in the area and 21% in the leaf length. For the genotype factor, the G11 material stood out in relation to the others for presenting better agronomic characteristics. However, studies are needed to demonstrate the superiority of this material in production systems.

261 Prescribed burning of endophyte-infected tall fescue pastures: Effects on forage production, ergot alkaloid concentrations, and stand composition

Abstract Prescribed fire may be a non-chemical alternative for seedhead suppression in endophyte-infected tall fescue forage systems. A study was conducted to observe the effects of a single prescribed burn on seed head production, ergot alkaloid concentration, forage production, forage quality, and stand composition in K31 tall fescue plots (endophyte infection=96%). Treatments of an undisturbed control (CON), March mow (MOW), March burn (EARLY), and April burn (LATE) were randomly applied to 56 square meter plots with ten replicates per treatment. Plots were sampled for forage quality and ergot alkaloid concentrations monthly from May to October. Forage production and species composition was recorded in June and October. Fescue seedhead count was conducted in May. After June sampling, plots were clipped to a height of 10 cm and litter was removed to simulate spring grazing. CON had greater (P < 0.01) total forage production in June than other treatments. MOW had greater (P < 0.01) forage production (≤107 kg/ha) than EARLY and LATE in June. There was no effect (P = 0.30) of treatments on forage production in October. LATE burn reduced (month × trt; P = 0.02) ergovaline concentration in June but all treatments were above the established threshold (150 ppb) for fescue toxicosis. Fescue seed head frequency was decreased (P < 0.01) by 50% in LATE plots. There was no treatment effect (P ≥ 0.22) on forb and non-fescue grass frequency in May, but warm season grass frequency was greater (P < 0.01) in LATE plots in October. Crude protein in LATE was greater than other treatments in May and both LATE and CON were greater than other treatments in June (P < 0.01). Neutral detergent fiber for LATE was less than other treatments in May and June (P < 0.01). Under conditions of this experiment, prescribed fire decreased seed head count and ergot alkaloid concentration, with a modest reduction in forage production.

Forage production and quality of tropical forage legumes submitted to shading

ABSTRACT: Find shade-tolerant species is essential to the success of silvopastoral systems, increasingly frequent in recent years. In legumes, which have potential of biological nitrogen fixation, there is a great lack of knowledge when in shaded environments.The cultivation of four tropical forage (Neonotonia wightii, Pueraria phaseoloides, Macrotyloma axilare and Arachis pintoi) was evaluated when submitted to artificial shade levels (30, 50 and 70% shade) and in full sun during water and drought seasons. The design used was in randomized complete blocks in a sub-divided plot scheme with four replications. In the Water-season the Forage Peanuts had higher forage production in full sun (11 ton ha-1 DM), and under shade did not differ from Perennial Soybean, higher than the others in all levels of shade. In Drought-season the forage production was 61% lower than in Water-season. The highest crude protein levels were reported in Forage Peanuts, Tropical Kudzu and Perennial Soybean, 19.0; 18.3 and 18.2% respectively in the Water-season. Forage Peanuts is a good option for use in silvopastoral systems although there is a small reduction in forage production (average of 23.7%). In general, species of fabaceae showed a greater reduction in forage production in the period of water deficit; however, shading at levels of 30% to 50% contribute to mitigation of water shortage. Although, there is a small reduction in forage production, withexception of perennial soybeans in dry season, it is advisable to use tropical forage legumes in silvopastoral systems, since forage quality is not affected by shade.

Increased Intake of Juniperus Phoenicea L. by Supplementation with Barley and Optigen® in Sheep

Dry littoral grasslands and rocky ground pastures throughout the Mediterranean basin are a significant source of forage for small ruminants and as such associated with traditional grazing practices. During the last decade, dissemination of terpene-rich Mediterranean shrubs, Juniperus phoenicea L., onto pastures in Adriatic region of Croatia have caused reduction in forage production and plant diversity. In order to facilitate the intake of this new plant by small ruminants, we investigated the effects of barley and Optigen® (a source of controlled-release non-protein nitrogen) mixture to increase consumption of J. phoenicea by sheep. The preliminary results suggest that barley alone, or in combination with Optigen® enhance the intake of J. phoenicea by sheep. Furthermore, this model can be used as an environmentally safe and economically affordable approach to reduce the abundance of less palatable J. phoenicea in the environment and to increase growth of alternate, better quality forage (grasses and forbs) on Mediterranean pastures.

Forage production and nitrogen nutrition in three grasses under coconut tree shades in the humid-tropics

Reduction in forage production (FP) under trees in the humid tropics is well known, but information on how different levels of nitrogen (N) fertilizer influence FP under trees is meager. The present study reports effects of four N fertilizer levels (0, 60, 80 and 120 kg ha−1 N) on net soil N mineralization rate (NMR) and soil moisture (SM), FP, shoot biomass/root biomass ratio (SB/RB), N concentration in SB, N uptake and nitrogen use efficiency (NUE) of three grasses [guinea (Panicum maximum Jacq.), para (Brachiaria mutica (Forssk) Stapf) and hybrid-napier (Pennisetum purpureum Schumach.)] under three canopy positions [under canopy (UC, representing high shade), between canopy (BC, representing low shade) and open] of coconut trees (Cocos nucifera L.) in a coconut based silvopastoral system in the humid tropical climate of South Andaman Island of India. The study was performed for two annual cycles (2005–2006 and 2006–2007). The hypotheses tested were: (1) FP would decline under tree shades, both in N fertilized as well as no N fertilized conditions, when SM was not growth limiting in the open. However, amount of decline in the FP would depend on grass species and intensity of shades i.e., higher was the shade greater would be the decline; (2) N fertilizer would increase FP under tree shades, but the increase depended on grass species, intensity of shades and amount of N applied. Amount of N applied, however, would not annul the shades effects when SM was not growth limiting in the open. The study revealed that the tree reduced light 59% under UC and 32% under BC positions, but the N fertilizer levels increased NMR by 11–51% under UC and 3–44% under BC positions compared to the open. SM did not differ across the canopy positions. Under all situations, FP of all grasses declined under UC (47–78%) and BC (18–32%) positions compared to the open; the decline was greater in Hybrid-napier than Guinea and Para grasses. Forage production of all grasses increased with N fertilizer increments under all canopy positions reaching 32 t ha−1 dry matters for hybrid-napier at 120 kg ha−1 N in the open. Both guinea and para grasses outyielded hybrid-napier grass under UC but not under BC or in the open. N concentration in the forage (SB) also increased as N fertilizer level increased. These observations support our hypotheses and suggest that forage production under coconut palms can be increased by the application of N fertilizer with both guinea and para grasses being more productive than hybrid-napier grass under the high shade. Where light conditions are better, hybrid-napier would produce more forage than the other species.

Growth Dynamics of Crowns of Eastern Redcedar at 3 Locations in Oklahoma

Eastern redcedar (Juniperus virginiana L.) trees from a location in western, central, and eastern Oklahoma were aged by tree ring analysis to assess the relationship of tree age to tree height and crown area. The relationship of tree age to crown size differed with location. Trees in the oldest age class, 28 to 29 years, ranged in height from 6.2 m on the western Oklahoma location to 8.3 m on the eastern Oklahoma location. The oldest trees at all locations were still actively growing. Height growth rate of the oldest class of trees averaged 0.5 to 0.6 m yr-1 on the western and eastern study locations, respectively. Eastern redcedar reached 2.0 m in height at about 8 years of age on the eastern Oklahoma location. Trees reached 2.0 m in height in 10 to 14 years at the other locations. This suggests that burning intervals should be more frequent on the eastern Oklahoma location than on the central and western Oklahoma locations. Crown area as a function of tree age was not as similar as tree height among the 3 locations. Not only did the relationship differ among locations, but it differed also between 2 central Oklahoma range sites. Crown area of 28-year-old trees ranged from only 15 m(2) on the central Oklahoma Loamy Prairie to 40 m(2) at the eastern Oklahoma location. These data suggest that the smaller crown area of trees at the central Oklahoma location may be a result of an influence other than environment, such as an introduction of plants of a different race with an inherent columnar growth habit. The reduction in forage production associated with eastern redcedar and the efficacy of prescribed burning for controlling eastern redcedar would change more rapidly as trees age on the eastern Oklahoma location than on the other locations.

Effect of Shade and Fertility on NO3‐N Accumulation, Carbohydrate Content, and Dry Matter Production of Tall Fescue1

AbstractNitrate‐N poisoning is a suspected cause of death among cattle grazing in tall fescue (Festuca arundinacea Schreb.) under cloudy or shade conditions. The practice of aerially seeding tall fescue into sprayed brush areas is of special concern since fescue plants grow in shade at times. The purpose of this research was to evaluate the effects of shade and N fertility levels on NO3‐N, carbohydrate content, and tall fescue production. An artificial shade study was designed in which tall fescue and a check forage (wheat, Triticum aestivum L.) were grown in containers at shade levels of 0, 30, 47, 63, 80, and 94%, using Saran shade cloth. Production was measured during three periods of the growing season.Dry matter production of tall fescue increased with some shade. Seedlings did best with 47 and 63% shade. Older plants produced best with 30 and 47% shade! As shade levels increased, there was a reduction in forage production of wheat, and water soluble carbohydrate content of both tall fescue and wheat. More than 63% shade was required to significantly increase NO3‐N content of fescue forage grown with a low level of fertility, whereas only 30% was necessary in high fertility conditions. At 80% shade, fescue forage grown at high fertility showed concentrations of NO3‐N above 9,000 ppm. Levels of NO3‐N in wheat forage were much lower, and no NO3‐N levels above 5,000 ppm were detected.

Response of Switchgrass (Panicum virgatum L.) to Clipping Frequency

Highlight: The native grasses are not widely grown for cultivated pastures in the South but are important forage producers in the United States. Their responses to frequency of clipping are not widely known and appear to be significantly different from that of the introduced cultivars, Bermudagrass (Cynodon dactylon) and Bahiagrass (Paspalum notatum). The introduced species, however, are slow to initiate growth in the spring, and it appears that the forage program in the South could be improved significantly by grazing switchgrass before the summer perennials initiate growth. Haying at flowering and grazing following frost could utilize the switchgrass later in the summer. Pangburn switchgrass (Panicum virgatum L.), a native species, tolerated one clipping during the season with little or no reduction in forage production, clonal survival, tiller number per clone, or tiller height. However, two or more clippings per season reduced all of the above. Over-utilization of switchgrass at the start of the season decreased the number of tillers and clones per plot and resulted in a serious weed problem.

Guidelines for Grazing Sheep on Rangelands Used by Big Game in Winter

A big game winter range in nor-then Utah was grazed with domestic sheep to ascertain what seasons and intensity of use would maximize utilization of herbs and minimize utilization of shrubs which provide the majority of forage for big game in winter, thus minimizing forage competition between big game and sheep. In late spring and early summer sheep ate mostly herbs. The light utilization of shrubs resulted in little or no reduction in forage production by shrubs at the end of the growing season. After midJuly, sheep heavily utilized bitterbrush (Purshiu triamtata), the most desirable and abundant shrub for big game in this area. Grazing after mid-July reduced the volume of bitterbrush forage available for big game proportionately to the percentage utilization observed. There was no evidence that subsequent annual productivity of established plants was impaired by any of the grazing systems imposed.