Sustainable Agriculture and Silvopastoralism
Silvopastoralism:
the complementary relationship between trees and pasture in a forest products and livestock production system. Silvopasture practice takes many forms and is adaptable to a variety of smallholder farms and pastoral systems throughout the world.
Sustainable agricultural practices such as agroforestry will provide the maximum benefits for humans, livestock, and crops, while striving for the least disturbance of wildlife and the natural ecosystems on which they depend. Agroforestry is a relatively low-input integration of trees into crop and pasture systems. Its implementation is of great value in developing countries of the tropics, where people are being driven onto marginal lands by poverty and inequitable land distribution. These marginal lands are critical to wildlife and the preservation of watersheds but are being rapidly deforested to grow crops. This practice leads not only to loss of the forest resource, but to the loss of the soil resource through erosion, damage to watersheds, and to a widening spiral of poverty for the poor people of the world.
One type of agroforestry is silvopastoralism, which focuses on the production of livestock and tree products in one integrated pasture system. Silvopasture is big business in the Southeast of the United States where it is economical to run a single species, cattle, under a pine monoculture in a large silvopastoral operation. However, on small farms, especially in the tropics, diversification through managing a variety of both animal and plant species is the most efficient utilization of the resource, and provides a variety of products, thus providing a hedge against risk.
Photo courtesy Cornell University
In a silvopastoral system,
trees may be planted in pastures
in a variety of spatial patterns...
Photo courtesy Dr. Jim McAdam at The Irish Scientist
...or an existing woodland may be thinned to reduce canopy and encourage growth of forage species in the understory.
Photo courtesy USDA National Agroforestry Center
The many benefits of silvopasture include:
Increased income opportunities through diversification of production
A silvopastoral system, in addition to producing forage for livestock, may produce sawtimber, pulpwood, posts and poles for fences and other structures, and non-timber forest products such as nuts, fruit, honey, maple sugar, mushrooms, fodder, and materials for crafts. Livestock on silvopasture can be domestic mammals such as cattle, bison, sheep, goats, hogs, llamas, or horses, or domestic birds such as chickens, ducks, geese and ostriches. Wildlife such as deer and elk will also benefit from silvopasture and can bring in income from hunting. Animal species provide a wide range of products including wool, feathers, leather, meat, milk, and eggs.
Enhancement of economic performance
Photo courtesy USDA - NRCS
Silvopastoral systems provide a relatively quick return on investments in livestock and a long-term source of income in tree crops. While timber offers higher returns, it is many years before those returns are realized. Livestock provide yearly cash flow between timber harvests.
Because of the differences in preferred forage among species, a mixture of livestock can use the forage resource more efficiently. In addition, livestock grazing is a biological weed control, thus decreasing the need for herbicides. The diversity of both forest and range products help to reduce risk to the agricultural producer.
Reduced climate-induced stress to livestock
Photo courtesy USDA - NAC
Winterkill from exposure to severe weather is a major source of livestock loss, not only in the developing world but in the United States as well. Shelter for livestock is needed in severe weather events, but unfortunately in many locales such shelter is lacking. Stress to livestock can be reduced through moderation of the pasture microclimate that a well-planned silvopastoral system provides. Windbreaks, living snow fences, and outdoor living barns reduce windchill stress and divert snow away from livestock feeding and calving grounds.
Enhanced wildlife habitat
Cover and food for wildlife is provided by structural and species diversity of the tree and shrub overstory. Forest/grassland edges attract a variety of species such as deer and upland game birds. Plant species may be manipulated through carefully managed grazing and timber harvesting to attract desirable wildlife species.
Improved soil conditions
Photo courtesy USDA - NAC
Trees hold nutrients in an efficient, closed cycling system. Their deeper roots tap nutrients from lower soil levels that are inaccessible to forage species, and nitrogen-fixing trees can raise the nutrient levels of pasture soils. Roots combat the compaction of soil and cut soil and organic matter losses to erosion, thereby improving soil structure and soil biological activity. Shade and reduced wind velocity raise the moisture level of soils by reducing evaporation. Trees planted in a living snow fence can raise soil moisture by harvesting and distributing snow. Some species can remedy soil toxicities that limit livestock forage production, such as salinity.
Planning a silvopastoral system
Image courtesy USDA National Agroforestry Center
Well-planned location and spatial pattern of tree plantings can meet many needs in a silvopastoral system. In addition to deciding which species will provide the desired products, the agroforester must consider how the pattern of trees affects wildlife habitat, ease of livestock handling, forage and tree growth and competition, snow distribution, and microclimate.
From the bottom left and moving counter-clockwise, the image shows the following silvopastoral practices:
Continuous even spacing that optimizes light and growing space for both forage and timber. The number and size of trees should be managed for optimum forage production while keeping in mind how the spacing affects tree growth and competion with one another. The thinning treatment is similar to a shelterwood treatment in a timber production system, in which trees are thinned just enough so that regeneration of the tree understory is encouraged while residual trees provide shelter. In a silvopastoral system, thinning allows light in for forage growth for livestock. Trees can be managed for sawtimber with proper spacing of trees. Non-timber forest products such as nuts and fruit may be harvested as well. I have seen pasture on a northern Florida cattle ranch in which oak trees provided acorns for wild pigs, thus bringing in extra income from hunters for the ranching outfit.
Row plantings,when it comes to handling livestock, have a great advantage over evenly-distributed grids of trees. Livestock perceive lines of trees as a solid fence which they will move along with a minimum of herders needed to do the job. All livestock have a point of balance at the shoulder, and will move ahead as long as the herder remains behind this point. In a pasture evenly distributed with trees, the livestock do not perceive a fence, and they will tend to spread out. Trees will then block the line of sight to the herders. At this point the livestock will no longer see the herder behind their point of balance and will tend to bog down and become difficult to herd. In such a pasture, more time and personnel are required to move a herd than in a pasture with trees planted in rows.
Row plantings provide the most edge for species such as deer and upland birds that need both the shelter and the open space provided by the ecotone between woodland and pasture. In addition, row plantings of trees grown for timber or pulp are easiest to harvest.
Living snow fences, when properly designed, will harvest snow and distribute it over a field. Deep drifts are avoided, and water from snowmelt is better distributed over the pasture for forage growth. Snow fences can divert snow away from a road, making access easier for vehicles used for timber harvesting or livestock operations. Snow fences can also provide the same microclimate moderation benefits as windbreaks.
Outdoor living barns provide shelter on winter feedgrounds and calving grounds in severe weather events that are common in winter and spring. Such shelter can greatly cut livestock losses by reducing wind, raising temperatures, and reducing snow depth within the shelter at the time of year when livestock are most vulnerable. The placement of outdoor living barns is critical. Livestock will drift with a storm, so the shelter should be located at the end of the pasture that is farthest away from the direction from which the prevailing winds blow. Livestock must have easy access through an opening that faces away from the wind direction.
Small groupings of trees provide a place in open pastures for livestock to shade up in hot weather.
Windbreaks shelter buildings and working corrals, and protect livestock and pastures from the drying and chilling effects of wind.
เกษตรยั่งยืนและ SilvopastoralismSilvopastoralism: ความสัมพันธ์เสริมระหว่างต้นไม้และพาสเจอร์ในป่าปศุสัตว์และผลิตภัณฑ์ผลิตระบบ Silvopasture ฝึกใช้หลายรูปแบบ และสามารถปรับเปลี่ยนฟาร์มเกษตรกรและระบบ pastoral ปริญญาบัตรทั่วโลก แนวทางเกษตรยั่งยืนเช่น agroforestry จะให้ประโยชน์สูงสุดสำหรับมนุษย์ ปศุสัตว์ และ พืช ในขณะที่กระเสือกกระสนสำหรับรบกวนน้อยที่สุดของสัตว์ป่าและระบบนิเวศธรรมชาติที่ซึ่งขึ้นอยู่ Agroforestry เป็นรวมค่อนข้างต่ำเข้าต้นไม้เป็นพืช และทุ่งหญ้าระบบ นำของมีค่ามากในประเทศกำลังพัฒนาอย่างเต็มที่ ที่คนมีกำลังขับเคลื่อนไปยังดินแดนที่ร่อแร่ โดยความยากจนและการกระจายที่ดิน inequitable ที่ดินส่วนเพิ่มเหล่านี้มีความสำคัญกับสัตว์ป่าและการอนุรักษ์ของรูปธรรม ได้อย่างรวดเร็วเป็น deforested มีการปลูกพืช แบบฝึกหัดนี้ลูกค้าเป้าหมายไม่เพียงสูญเสียทรัพยากรป่าไม้ แต่ การสูญเสียของทรัพยากรดินผ่านกัดเซาะ เสียรูปธรรม และเกลียว widening ความยากจนสำหรับคนยากจนของโลก ชนิดหนึ่งของ agroforestry เป็น silvopastoralism ซึ่งมุ่งเน้นการผลิตผลิตภัณฑ์ปศุสัตว์และต้นไม้ในระบบพาสเจอร์รวมหนึ่ง Silvopasture เป็นธุรกิจขนาดใหญ่ในตะวันออกเฉียงใต้ของสหรัฐอเมริกาที่จะประหยัดในการทำงานชนิดเดียว วัว ภายใต้เรื่องสนใน silvopastoral ขนาดใหญ่ อย่างไรก็ตาม ในฟาร์มขนาดเล็ก โดยเฉพาะอย่างยิ่งในเขตร้อน วิสาหกิจผ่านการจัดการความหลากหลายของพันธุ์สัตว์และพืชเป็นการใช้ประโยชน์ทรัพยากรมีประสิทธิภาพสูงสุด และความหลากหลายของผลิตภัณฑ์ การทำ ให้ป้องกันความเสี่ยง มหาวิทยาลัย Cornell อนุเคราะห์ภาพถ่าย ในระบบ silvopastoral อาจปลูกต้นไม้ใน pastures ในหลากหลายรูปแบบพื้นที่... รูปถ่ายสุภาพดร.จิม McAdam ที่วิทยาศาสตร์เดอะไอริช ... อาจจะ thinned .or ป่าที่มีอยู่เพื่อลดฝาครอบ และส่งเสริมการเจริญเติบโตของอาหารสัตว์สปีชีส์ในการศึกษาได้ ภาพโดยความอนุเคราะห์จากศูนย์แห่งชาติ Agroforestry ประโยชน์มากมายของ silvopasture ประกอบด้วย:โอกาสเพิ่มรายได้ผ่านวิสาหกิจผลิต A silvopastoral system, in addition to producing forage for livestock, may produce sawtimber, pulpwood, posts and poles for fences and other structures, and non-timber forest products such as nuts, fruit, honey, maple sugar, mushrooms, fodder, and materials for crafts. Livestock on silvopasture can be domestic mammals such as cattle, bison, sheep, goats, hogs, llamas, or horses, or domestic birds such as chickens, ducks, geese and ostriches. Wildlife such as deer and elk will also benefit from silvopasture and can bring in income from hunting. Animal species provide a wide range of products including wool, feathers, leather, meat, milk, and eggs. Enhancement of economic performance Photo courtesy USDA - NRCS Silvopastoral systems provide a relatively quick return on investments in livestock and a long-term source of income in tree crops. While timber offers higher returns, it is many years before those returns are realized. Livestock provide yearly cash flow between timber harvests. Because of the differences in preferred forage among species, a mixture of livestock can use the forage resource more efficiently. In addition, livestock grazing is a biological weed control, thus decreasing the need for herbicides. The diversity of both forest and range products help to reduce risk to the agricultural producer. Reduced climate-induced stress to livestock Photo courtesy USDA - NAC Winterkill from exposure to severe weather is a major source of livestock loss, not only in the developing world but in the United States as well. Shelter for livestock is needed in severe weather events, but unfortunately in many locales such shelter is lacking. Stress to livestock can be reduced through moderation of the pasture microclimate that a well-planned silvopastoral system provides. Windbreaks, living snow fences, and outdoor living barns reduce windchill stress and divert snow away from livestock feeding and calving grounds. Enhanced wildlife habitat Cover and food for wildlife is provided by structural and species diversity of the tree and shrub overstory. Forest/grassland edges attract a variety of species such as deer and upland game birds. Plant species may be manipulated through carefully managed grazing and timber harvesting to attract desirable wildlife species. Improved soil conditions Photo courtesy USDA - NAC Trees hold nutrients in an efficient, closed cycling system. Their deeper roots tap nutrients from lower soil levels that are inaccessible to forage species, and nitrogen-fixing trees can raise the nutrient levels of pasture soils. Roots combat the compaction of soil and cut soil and organic matter losses to erosion, thereby improving soil structure and soil biological activity. Shade and reduced wind velocity raise the moisture level of soils by reducing evaporation. Trees planted in a living snow fence can raise soil moisture by harvesting and distributing snow. Some species can remedy soil toxicities that limit livestock forage production, such as salinity.
Planning a silvopastoral system
Image courtesy USDA National Agroforestry Center
Well-planned location and spatial pattern of tree plantings can meet many needs in a silvopastoral system. In addition to deciding which species will provide the desired products, the agroforester must consider how the pattern of trees affects wildlife habitat, ease of livestock handling, forage and tree growth and competition, snow distribution, and microclimate.
From the bottom left and moving counter-clockwise, the image shows the following silvopastoral practices:
Continuous even spacing that optimizes light and growing space for both forage and timber. The number and size of trees should be managed for optimum forage production while keeping in mind how the spacing affects tree growth and competion with one another. The thinning treatment is similar to a shelterwood treatment in a timber production system, in which trees are thinned just enough so that regeneration of the tree understory is encouraged while residual trees provide shelter. In a silvopastoral system, thinning allows light in for forage growth for livestock. Trees can be managed for sawtimber with proper spacing of trees. Non-timber forest products such as nuts and fruit may be harvested as well. I have seen pasture on a northern Florida cattle ranch in which oak trees provided acorns for wild pigs, thus bringing in extra income from hunters for the ranching outfit.
Row plantings,when it comes to handling livestock, have a great advantage over evenly-distributed grids of trees. Livestock perceive lines of trees as a solid fence which they will move along with a minimum of herders needed to do the job. All livestock have a point of balance at the shoulder, and will move ahead as long as the herder remains behind this point. In a pasture evenly distributed with trees, the livestock do not perceive a fence, and they will tend to spread out. Trees will then block the line of sight to the herders. At this point the livestock will no longer see the herder behind their point of balance and will tend to bog down and become difficult to herd. In such a pasture, more time and personnel are required to move a herd than in a pasture with trees planted in rows.
Row plantings provide the most edge for species such as deer and upland birds that need both the shelter and the open space provided by the ecotone between woodland and pasture. In addition, row plantings of trees grown for timber or pulp are easiest to harvest.
Living snow fences, when properly designed, will harvest snow and distribute it over a field. Deep drifts are avoided, and water from snowmelt is better distributed over the pasture for forage growth. Snow fences can divert snow away from a road, making access easier for vehicles used for timber harvesting or livestock operations. Snow fences can also provide the same microclimate moderation benefits as windbreaks.
Outdoor living barns provide shelter on winter feedgrounds and calving grounds in severe weather events that are common in winter and spring. Such shelter can greatly cut livestock losses by reducing wind, raising temperatures, and reducing snow depth within the shelter at the time of year when livestock are most vulnerable. The placement of outdoor living barns is critical. Livestock will drift with a storm, so the shelter should be located at the end of the pasture that is farthest away from the direction from which the prevailing winds blow. Livestock must have easy access through an opening that faces away from the wind direction.
Small groupings of trees provide a place in open pastures for livestock to shade up in hot weather.
Windbreaks shelter buildings and working corrals, and protect livestock and pastures from the drying and chilling effects of wind.
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