Planting Bamboo Helps Slow Deforestation

Scientists may have found a way to slow deforestation. Fast growing bamboo can help quickly replenish a forest stripped of timber.

Forests are shrinking globally as people in developing nations seek wood for fuel and more land for farming. The Worldwatch Institute in Washington says Earth has lost one percent of its woodlands in the past five years, an area about the size of Germany.

Ecologists say the environmental damage is alarming. Overlogging and failure to replant cause widespread soil erosion and loss of wildlife habitat.

Deforestation also affects global climate. Trees absorb carbon dioxide, a greenhouse gas. Burning trees and rotting wood left by loggers are thought to add to global warming by emitting more of the gas into the atmosphere, where it traps the sun's heat.

Experts say the loss of forests will continue unless alternatives to wood are found.

"Most of the forested areas have gone down by 70 to 90 percent, so we need a sustainable form of farming timber," said water specialist, Chin Ong, at the International Center for Research in Agroforestry in Nairobi, Kenya.

He says one promising substitute for wood is bamboo, a grass with a tree-like appearance. Some varieties grow more than 25 meters tall and 20 centimeters thick.

Ong points out that bamboo can be grown all over the world and has advantages over timber. One is its speedy growth.

"You can harvest after three or four years and then every year after that because it is a grass," he explained. "So when you cut a bamboo down, it will produce another shoot and it is ready for harvest in one or two years. Whereas if you grow a eucalyptus tree, you need five to 10 years before you can harvest again. Another reason is that bamboo has a very high water use efficiency, which is double that of any tree species."

Ong says the plants can be an additional cash crop in areas where sugar cane and coffee are already established. He estimates that in the Lake Victoria region of Kenya, Tanzania, and Uganda, as many as 150 million people can benefit economically.

Plant biologist David Midmore of the Central Queensland University in Australia says bamboo also has environmental benefits.

"In Taiwan, bamboo is grown on the hillsides along the edge of the mountains and it is sustainably harvested for its shoots and for its timber, and it is an environmentally friendly species because it is also preventing any erosion," he noted.

Midmore says bamboo shoots are also an important source of nutrition and can withstand harsh climates.

"It is one of the few species that will produce during typhoons, whereas most vegetable species will get blown away or washed away or rot," he added. "Bamboo shoots continue to thrive in hot and wet conditions."

In addition to providing lumber and food, bamboo plants can clean the environment. Chin Ong is studying how bamboo groves could remove toxins from dirty waters.

"We have been analyzing what are the heavy metals that can be removed by bamboo species," he explained. "The bamboo species behave very similarly to papyrus, with natural vegetation to wetlands in this region. So they take up all these heavy metals and they can clean the water."

Ong says there is an unfulfilled potential for bamboo to protect forests and improve agriculture.

Source:
VOA News Service
Author: Frank Ling
First published: August 29, 2006

Switchgrass

Panicum virgatum


Alternate Name

Tall Panic Grass

Description

Panicum virgatum L., switchgrass, is native to all of the United States except California and the Pacific Northwest. It is a perennial sod-forming grass that grows 3 to 5 feet tall and can be distinguished from other warm-season grasses, even when plants are young, by the white patch of hair at the point where the leaf attaches to the stem. The stem is round and usually has a reddish tint. The seed head is an open, spreading panicle.

Uses

Livestock: Switchgrass is noted for its heavy growth during late spring and early summer. It provides good warm-season pasture and high quality hay for livestock.

Erosion Control: Switchgrass is perhaps our most valuable native grass on a wide range of sites. It is a valuable soil stabilization plant on strip-mine spoils, sand dunes, dikes, and other critical areas. It is also suitable for low windbreak plantings in truck crop fields.

Wildlife: Switchgrass provides excellent nesting and fall and winter cover for pheasants, quail, and rabbits. It holds up well in heavy snow (particularly ‘Shelter’ and ‘Kanlow’ cultivars) and is useful on shooting preserves. The seeds provide food for pheasants, quail, turkeys, doves, and songbirds.

Biofuel Source: Interest in switchgrass as a renewable biofuel resource has been increasing in recent years, primarily in the Southern United States. The Booneville, Arkansas, Plant Materials Center (PMC) and the Plant and Soil Science Department of Oklahoma State University (OSU) are cooperating to evaluate several upland types of switchgrass for use as a biomass energy resource. Selections of upland types of switchgrass have been evaluated by OSU for several years. The development of hybrid progeny with substantial heterosis for increased biomass yield will ultimately result in improved hybrid cultivars for the Central and Southern United States. The PMC is in the process of assessing several improved lines along with commercially available cultivars for dry-matter potential and environmental adaptation. Results of this study may contribute to producers cashing in on a growing demand for renewable fuels and a decrease on our dependency on fossil fuels.

Weediness

This plant may become weedy or invasive in some regions or habitats and may displace desirable vegetation if not properly managed. Please consult with your local NRCS Field Office, Cooperative Extension Service office, or state natural resource or agriculture department regarding its status and use.

Adaptation and Distributions

On suitable soils, switchgrass is climatically adapted throughout the most of the United States. Moderately deep to deep, somewhat dry to poorly drained, sandy to clay loam soils are best. It does poorly on heavy soils. In the East, it performs well on shallow and droughty soil.

Switchgrass is distributed throughout the majority of the United States, excluding the far west states.

Establishment

Switchgrass should be seeded in a pure stand when used for pasture or hay because it can be managed better alone than in a mixture. Its slick, free-flowing seed can be planted with most seed drills or with a broadcast spreader. In the Southeast, a planting rate of approximately 10 pounds PLS per acre is recommended. Seedbeds should be firmed with a roller prior to the drilling or broadcasting of seed. If seeds are planted using the broadcast method, the area should be rolled afterward to help cover the seed. When drilled, seeds should be planted 1/4 inch deep. No-tillage seedings in closely grazed or burned sod also have been successful, where control of sod is accomplished with clipping, grazing, or proper herbicides.

Phosphorus and potassium should be applied according to soil tests before or at seeding. Nitrogen, however, should not be used at seeding time because it will stimulate weed growth.

Management

To control weeds during establishment, mow switchgrass to a height of 4 inches in May or 6 inches in June or July. Grazing is generally not recommended the first year, but a vigorous stand can be grazed late in the year if grazing periods are short with at least 30 days of rest provided between grazings. Switchgrass is the earliest maturing of the common native warm-season grasses and it is ready to graze in early summer.

Established stands of switchgrass may be fertilized in accordance with soil tests. Phosphorus and potassium may not be needed if the field is grazed since these elements will be recycled back to the soil by the grazing animal. Apply nitrogen after switchgrass has begun to produce using a single application in mid-to-late May or a split application in both May and early July. Avoid high rates of nitrogen because carry-over could spur cool-season grass growth and harm young plants the following spring.

Switchgrass will benefit from burning of plant residues just prior to initiation of spring growth. Burning fields once every 3 to 5 years decreases weed competition, eliminates excessive residue and stimulates switch grass growth. Switchgrass used for wildlife food and cover should be burned once every 3 to 4 years to reduce mulch accumulations that inhibit movement of hatchlings and attract nest predators.

Under continuous grazing management, begin grazing switchgrass after it has reached a height of 14 to 16 inches, and stop when plants are grazed to within 4 inches of the ground during late spring, 8 inches in early summer, and 12 inches in late summer. A rest before frost is needed to allow plants to store carbohydrates in the stem bases and crown. Plants may be grazed to a height of 6 to 8 inches after frost. The winter stubble is needed to provide insulation.

With management intensive systems, grazing can begin in the first paddocks when plants reach a height of 10 inches and should not be grazed below a stubble height of 6 to 8 inches. Grazed paddocks need to be rested 30-60 days before being grazed again.

Pests and Potential Problems

Grasshoppers and leafhoppers can be major pests in new seedings. Some stands are impacted by damping off and seedling blight. Leaf rust occasionally affects forage quality.

Cultivars, Improved, and Selected Materials (and area of origin)

‘Alamo’ (TX), ‘Blackwell’ (OK), ‘Cave-In-Rock’ (IL), ‘Dacotah’ (ND), ‘Forestburg’ (SD), ‘Kanlow’ (OK), ‘Nebraska 28’ (NE), ‘Shawnee,’ ‘Shelter’ (WV) (cultivars); Grenville (NM) (informal release); Miami (Dade Co, FL), Stuart (Stuart, FL), Wabasso (Wabasso, FL) (source identified releases). Seeds are available from most commercial sources and through large agricultural supply firms.

Control

Please contact your local agricultural extension specialist or county weed specialist to learn what works best in your area and how to use it safely. Always read label and safety instructions for each control method.

Related topic:
Scientists Study Switchgrass for Ethanol and Energy Production

Source:
USDA NRCS Plant Materials Program

Scientists Study Feasibility of Switchgrass for Ethanol and Energy Production

Two switchgrass plants per square foot the first year ensures a successful bioenergy crop harvest in subsequent years. That's the threshold level for success established by an economic study by the Agricultural Research Service (ARS) and cooperators on 10 northern Plains farms in Nebraska, South Dakota and North Dakota.

Soil scientist Mark Liebig, at the ARS Northern Great Plains Research Laboratory in Mandan, N.D., worked on the study led by Ken Vogel, a geneticist at the ARS Grain, Forage and Bioenergy Research Unit at Lincoln, Neb.

As an expert in breeding and management of new, higher-yielding varieties of switchgrasses best suited to ethanol conversion, Vogel collaborates with many ARS labs in various regions of the country.

Liebig's contribution to the study was to quantify another potential switchgrass benefit: soil carbon storage. The study is a cooperative project with University of Nebraska economist Richard Perrin.

Switchgrass is a native prairie grass long used for conservation plantings and cattle feed in the United States. Interest in switchgrass ethanol has intensified recently as the federal government gains confidence in its potential as a bioenergy crop because of its wide adaptability and high yields on marginal lands. The northern Plains region was chosen first because the economics seemed most favorable there. Farmers can expect switchgrass yields to be high enough there to produce 100 to 400 gallons of ethanol per acre with current varieties.

Results from the main part of the study--the economics of growing switchgrass for bioenergy--are promising. Those results will be issued in May.

Switchgrass can be converted to ethanol just as cornstalks can. It also can be burned to produce electricity. Growing switchgrass for ethanol could bring new industries to rural areas.

As a perennial plant, switchgrass has the advantage of not needing annual planting and tillage. Skipping these can save soil and energy. It can also reduce sediment and other pollutant losses to waterways.

The study's seedling threshold results are reported in the January issue of Crop Science magazine.

Related topic:
Switchgrass Fact Sheet

Source:
U.S. Department of Agriculture
Author: Don Comis
First published: March 10, 2006