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1.
Herbage production,nutritive value and animal productivity within hardwood silvopasture,open and mixed pasture systems in Appalachia,United States 
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下载免费PDF全文 Demand for livestock food products is projected to increase dramatically through to 2050. Increased livestock production capacity on marginal lands will be critical to meeting this demand. A 5‐year research effort was undertaken to evaluate lamb and sward productivity within open and hardwood silvopasture (SP) systems in Appalachia, USA. Grazing began in mid to late April each year, with the grazing season averaging 141 d. Grazing system treatments during 2002 and 2003 grazing seasons were as follows: 100% open pasture (OP), 67% OP and 33% SP, and 67% OP and 33% SP with delayed SP grazing initiation (OSD). In 2004, a 100% SP (SP) system was added. Animals were rotationally stocked through either 6 (2002–2004) or 7 (2005–2006) paddocks. Open pasture produced greater (P < 0·001) grazing season herbage yield, while all systems generated similar animal performance. Based on summer solstice, herbage production in spring was greater (P < 0·001) than summer, except in 2003. Total non‐structural carbohydrate (TNC) content was greater (P < 0·05) in spring than in summer, except in 2004. Animal performance was superior in spring versus summer (P < 0·001). Animal plasma urea nitrogen (PUN) was lower (P < 0·05) for OP in 2003. When PUN was correlated with nutritive value indicators, the ratio of TNC to crude protein (CP) had the strongest correlation. The strong correlation indicates the need for synchronized ruminal energy and CP availability. Development of silvopasture from existing woodlots has potential to improve whole farm productivity on marginal lands. 相似文献
2.
Fagner Junior Gomes Bruno Carneiro Pedreira Patrícia Menezes Santos Cristiam Bosi Carlos Guilherme Silveira Pedreira 《Grass and Forage Science》2020,75(3):279-290
In silvopastoral (SP) systems, forage responses depend on the microenvironment in which the plants develop. Our objective was to evaluate canopy and tillering characteristics of shaded 'Marandu' palisadegrass [Brachiaria brizantha (Hochst A Rich) Stapf, syn. Urochloa brizantha] under continuous stocking in a SP system. Treatments were one full sun (FS) and three shaded systems (silvopasture, SP) corresponding to distances from tree groves: 7.5 m north (SP1), and 15 m (SP2) and 7.5 m south (SP3) studied during two rainy seasons (Year 1 and Year 2). The tree in the SP system was Eucalyptus urograndis (hybrid of Eucalyptus grandis W. Hill ex Maiden × Eucalyptus urophylla S. T. Blake). The photosynthetic active radiation was greater in FS (923 μmol m-2 s-1), followed by SP2 (811 μmol m-2 s-1), SP1 (727 μmol m-2 s-1) and SP3 (673 μmol m-2 s-1). Forage accumulation in FS was 15% greater than the mean of SP1, SP2 and SP3 (10,663 kg DM/ha). There was no difference in net accumulation of leaf, stem and dead material, averaging 3,302, 3,420 and 4,063 kg DM/ha respectively. Leaf accumulation and accumulation rate were greater in Year 2, and leaf accumulation rate was similar among treatments (19 kg DM ha−1 day−1). Leaf proportion increased 14% from Year 1 to Year 2. Specific leaf area was greater for treatments SP1 and SP3 (193 cm2/g). Tiller population density was similar across treatments in Year 1. Shaded palisadegrass maintains leaf productivity similar to FS under continuous stocking in an SP system. 相似文献
3.
Alyce Raiana Monteiro dos Santos Lívia Vieira de Barros Matheus Lima Côrrea Abreu Bruno C. Pedreira 《Grass and Forage Science》2020,75(3):339-350
The addition of protein supplementation in a silvopastoral system can contribute to improved forage intake and digestibility. Our objective was to evaluate in vitro ruminal parameters, digestibility and gas production of Marandu palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster] in a silvopastoral system and compare this to parameters obtained from diets with protein supplementation. Forage was sampled during the growing season (November to April) in 2016/17 and 2017/18. In vitro incubation treatments consisted of four levels of protein supplement (20% of crude protein; CP) in the diet (0.1, 0.2, 0.3 and 0.4 g/kg of body weight). The neutral detergent fibre, acid detergent fibre and indigestible neutral detergent fibre concentrations were highest in the first year. In the second year, CP concentration was 21% greater than in the first year. There was a linear increase for digestion rate, a quadratic effect for lag time and a linear decrease for average digestion time as supplementation levels were increased. The least lag time and digestion time occurred in the second year. There was no supplementation effect on ruminal pH, acetate and butyrate concentrations. Second-year in vitro dry matter digestibility (IVDMD) was greater than in the first year. Increases in supplementation levels linearly enhanced IVDMD and reduced methane (CH4) production. The inclusion of a protein supplement contributed to reduced CH4 and increased volatile fatty acids production; therefore, we recommended the supplement inclusion of >0.28 g/kg of BW for animals grazing in well-managed palisadegrass pastures. 相似文献
4.
Kelly M. Mercier Christopher D. Teutsch John H. Fike John F. Munsell Benjamin F. Tracy Brian D. Strahm 《Grass and Forage Science》2020,75(3):291-302
Botanical diversity has been linked to increased biomass production of grasslands, but these relationships have not been explored as extensively in silvopasture systems where shade impacts on forage mass are variable due to the unique structure and environment of each system. The objective of this study was to evaluate the impact of multiple artificial shade levels on the DM yield and botanical composition of three cool-season forage mixtures near Blackstone, Virginia, USA. Mixtures were as follows: simple = tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.] and white clover (Trifulium repens L.); intermediate = simple + orchardgrass (Dactylis glomerate L.) and red clover (Trifolium pretense L.); and complex = intermediate + Kentucky bluegrass (Poa pratensis L.), birdsfoot trefoil (Lotus corniculatus L.) and alfalfa (Medicago sativa L.). Slatted structures created conditions of 30%, 50% and 70% shade relative to a full sun control. Forages were harvested mechanically (no grazers present). Annual yield (DM kg/ha) did not differ among mixtures. As compared to full sun, annual yield was no different at 30% shade, but was reduced by 22 and 36% at 50 and 70% shade respectively. In contrast to other species in the mixtures, orchardgrass increased in proportion when grown beneath all shade levels and is recommended for silvopasture use. Orchardgrass is not particularly well-adapted to the transition zone between the northern temperate and southern subtropical United States; therefore, these results indicate that silvopastures may be an effective way to integrate marginally adapted, shade-tolerant cool-season forages into transition zone grazing systems. 相似文献
5.
Silvopasture is reemerging as a land use in the southern US. Alternate land use treatments based on field trials for timber
and pasture for beef cattle production were financially evaluated. Multiple-use management aspects of these systems were further
illustrated by the addition of fee hunting. Land Expectation Values (LEVs) were lower when silvopasture treatments were compared
to steer grazing only. However, silvopasture treatments compared favorably to some grazing treatments. LEVs were higher when
silvopasture treatments were compared to commercial forest plantation applications on similar sites. Silvopasture systems
promote multiple-use management of the land under an environmentally friendly cropping system whereby certain types of wildlife
can thrive. This is particularly relevant in light of recent increases in fee hunting in the South. LEVs were reduced by $289,
$200, and $151 ha−1 at discount rates of 5%, 7%, and 9% respectively, when fee hunting was excluded in the recommended silvopasture treatment.
The monetary value of a wildlife component in this system can be interpreted as the expected value gained per hectare per
rotation in perpetuity when fee hunting is part of the management plan. On average, it represented an 8.6% gain in LEVs for
this treatment. Results from this study support the potential for silvopasture applications in the South for private landowners.
Cattle grazing of improved forage in commercially productive loblolly pine (Pinus taeda) stands can relieve annual cash flow problems inherent in tree production.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
《Communications in Soil Science and Plant Analysis》2012,43(11):1708-1721
Pine (Pinus spp. L.) stands are often overstocked early in the tree rotation, prior to initial thinning. While pre- and/or post-thinning fertilizer applications are best-management practices to optimize growth of southern pines, there can be poor nitrogen (N) utilization and adverse environmental impacts associated with fertilization. Our objective was to determine short-term (3-year) soil responses of an emulated loblolly pine (P. taeda L.) silvopasture, which received a single application of commercial N–phosphorus (P)–potassium (K) fertilizer (CF) or pelletized poultry litter (PPL) applied at about midrotation (12 years postplanting). Compared to the control, CF decreased soil pH at depths of 0–10 and 10–30 cm, and PPL increased Mehlich 3 available P at 0–10 cm. Fertilizer responses were found for soil extractable ammonium (NH4 +)-N, and nitrate (NO3 ?)-N concentrations, mineral N ha?1, pH, and available P but not for diel carbon dioxide–carbon (CO2-C) flux, total C, and total N. Total soil C, total soil N, pH, and available P decreased with depth, whereas mineral N ha?1 and 1 M potassium chloride (KCl)–extractable aluminum (Al) increased with depth. These results further our understanding of the nutrient dynamics during alley cropping of an upland soil and demonstrate the challenge in detecting short-term responses with fertilization. 相似文献
7.
以立地条件基本相同、林带完好、长势均匀的两行一带锦鸡儿林草带状复合系统(带距分别为4,6,8m)为研究对象,采用壕沟法对锦鸡儿根系进行分层挖掘取样,研究其在不同造林带距条件下的空间分异特征。研究显示:锦鸡儿根系生物量在水平方向上多靠近林带分布,与6m和8m带距系统相比,4m带距系统林地中部锦鸡儿根系生物量密度相对较高。锦鸡儿在林地中部土体的细根根长和表面积密度随带距增大而减小;带距分别为4,6,8m的系统中,锦鸡儿在4m带距系统整个样地土体中细根根长和表面积密度均处于相对较高的水平;而随带距增大,在0～40cm土层中,锦鸡儿平均细根根长密度、细根长度累计百分比、平均细根表面积密度和细根表面积累计百分比均呈减小趋势。因此,与4m和6m带距系统相比,在8m带距系统中,锦鸡儿细根较少地分布于表土层和林地中部土体中,林草主要资源利用层发生隔离,而且林地两侧锦鸡儿根系在林地中部较少发生接触,使得林草种间竞争和锦鸡儿种内竞争较为缓和;同时8m带距系统仍可有效防止林地发生风蚀,所以在我国西北干旱半干旱地区进行锦鸡儿林草带状复合系统建设时,采用8m带距较为适宜。 相似文献
8.
林草复合系统地下部分种间互作关系与化感作用研究进展 总被引：1，自引：0，他引：1
林草复合系统作为一种具有可持续发展特点的土地利用方式,已在全球范围内得到了广泛的应用和研究,其经营的成败通常是由各生物组分之间的相互作用关系所决定。目前,林草复合系统的经营者比较重视对系统地上部分种间互作关系的调控,而忽视地下部分种间互作关系和化感作用对系统经营的潜在影响。笔者对国内外相关研究进行了分析和总结,以完善和加深人们对林草复合系统地下部分种间互作关系和化感作用的认识,可为优化系统物种结构、避免或降低种间不利影响、实现系统经营收益的最大化提供经验借鉴和理论指导。未来应深入研究林草复合系统地下部分与地上部分种间互作关系及化感作用三者之间如何相互影响和协同运行、探索系统对土壤水肥资源利用的耦合效应、揭示林草根系主要分布层发生隔离的机制、筛选具有水力提升作用的树种并尝试性地在人工林草复合系统中进行应用、探求系统地下部分种间互作关系对全球气候变化的响应以及加强林草复合系统中化感作用的研究等。 相似文献
9.
This study mainly compares the economics of one form of agroforestry (involving the simultaneous use of land for pine sawlog, sheep, wool and hay production) with conventional agriculture (sheep and wool production) in the 500 and 700 mm annual rainfall zone of Western Australia. The region is marked by environmental problems, particularly soil and water salinity, owing to past extensive clearly of indigenous deep-rooted vegetation for agriculture. Agroforestry can be a way to control and ameliorate the problems.The major conclusion is that pine agroforestry can be more profitable in the long term than conventional agriculture. It would be a profitable way to control and ameliorate the environmental problems in the region. It would also generate other benefits. A number of measures can be adopted to reduce or avert any problems arising from agroforestry's annual net returns (which fluctuate and are negative for most years before log sales) and annual labour requirements (which vary over time and are generally higher than those for agriculture for about the first half of the agroforestry rotation). These measures include using a low tree density and converting only part of a farm to agroforestry so that the activity is practised in combination with conventional agriculture.The study concerns a region with a Mediterranean climate so that the principles and findings of the study could be of particular relevance to other similar regions of the world. 相似文献
10.
Perivaldo de Carvalho Leandro Ferreira Domiciano Mircia Angele Mombach Hemython Luis Bandeira do Nascimento Luciano da Silva Cabral Lynn E. Sollenberger Dalton Henrique Pereira Bruno Carneiro Pedreira 《Grass and Forage Science》2019,74(4):650-660
To meet the global demand for animal protein, sustainable intensification of existing livestock systems may be possible, especially through integration of livestock with crops or forestry. Thus, our objective was to compare forage production and animal performance in grass monoculture and integrated systems in the Brazilian Amazon biome. The four systems were (a) livestock (L) with Marandu palisadegrass {Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster} as monoculture, (b) palisadegrass pastures integrated with eucalyptus trees (Eucalyptus urograndis; hybrid of Eucalyptus grandis W. Hill ex Maiden and Eucalyptus urophylla S. T. Blake) arranged in three‐row groves with groves spaced 30 m apart (livestock–forestry; LF), (c) palisadegrass after two years of crops (crop–livestock; CL) and (d) palisadegrass after two years of crops with single rows of eucalyptus trees spaced 37 m apart (crop–livestock–forestry; CLF). From July 2016 to July 2017, all experimental units were continuously stocked using a variable stocking rate. Greater herbage accumulation (HA) occurred in CL and CLF in comparison with L and LF (21,310, 24,050, 19,500 and 18,890 kg DM/ha respectively). The gain per hectare of L, LF and CL (average of 932 kg ha–1) was less than CLF (1,190 kg ha–1). Average daily gain was similar among systems (0.69 kg/day). We conclude that integrated systems can support similar (LF or CL) or greater (CLF) levels of animal production than palisadegrass monocultures while increasing diversity of outputs, thereby providing a greater range of viable systems for livestock production in the Brazilian Amazon biome. 相似文献