UNITED STATES GOVERNMENT PRINTING OFFICE DIVISION OF PUBLIC DOCUMENTS WASHINGTON, D. C. 20401 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 POSTAGE AND FEES PAID U. S. GOVERNMENT PRINTING OFFICE A Buffelgrass finds Puerto Rican home strain of buffelgrass native to the low rainfall region of South Africa appears to have won a respected place among conservation plants on the semiarid southwest part of Puerto Rico. In a decade it has proved to be one of the important new forage grasses on the island. Burning, overuse, land clearing, and periods of drought over the years had altered the grass communities on the island's semiarid sites. Less useful grasses took over. The need became urgent for a grass that would thrive and efficiently produce under natural conditions. Buffelgrass T-4464 was introduced to the island by the Soil Conservation Service in 1959 in the SCS program of assembly and evaluation of plants. It is a perennial bunchgrass that attains a height of 6 inches to 4 feet, depending on soil and moisture conditions. Culms develop from buds emerging from a tough knotty crown. The root system extends to an unusual depth. The plant produces abundant, mediumfine leaves of intense green. Seed is abundantly produced all year but especially in late fall. Success of plantings to date indicate that buffelgrass T-4464 is well adapted for pasture and hay uses under the adverse climate conditions prevailing in the Caribe, Sur, and Suroeste soil conservation districts in Puerto Rico. Plantings have been established on more than 3,500 acres of Coamo, Descalabrado, Santa Isabel, Fraternidad, Jácanas, Amelia, Sosa, and Americus soil series. Experiments have shown that buffelgrass produces exceptionally heavy amounts of roots an acre to make the soil more fertile and less susceptible to erosion. To this can be added the role of organic matter in improving the soil's water-holding capacity. Forage value of buffelgrass i high. Recovery from grazing is ex cellent. When adequately fertilized and irrigated, harvest intervals ca be reduced to every 45 days. Hay i of excellent quality and of hig nutritive value when compared t imported hay.-AURELIO SIERRA BRACERO AND EMERITO MARTINEZ RUIZ, plant materials specialis SCS, Mayaguez, and informatio officer SCS, San Juan, Puer Rico. Conservation February 1971, Vol. 36, No. 7 The shape of things An important part of soil and water conservation work involves reshaping bits of the earth's surface to control the flow of water. Without the earthmoving industry -the manufacturers and distributors of equipment and the contractors who use it-modern conservation would be impossible. Without the expertise of engineers and conservationists who help design both equipment and earthen structures, and plan where to use them, our efforts would be misdirected and ineffective. Examples of conservation earthmoving in this issue show something of the ingenuity being used and the variety of problems being met. Professionals and contractors pitched in together to install on-thejob sediment controls during construction of a highway interchange near Pittsburgh (p. 147). In Utah and Wisconsin (pp. 156, 157), engineers met the challenges of problem sites in building dams to control floods and store water for beneficial uses. Irrigation farmers in the Rio Grande Valley (p. 149) shape the entire surface of fields to gain positive control of irrigation water. These examples are matched by countless others across the country as this important work goes forward. COVER: Earth dam being built under Great Plains Conservation Program, Chase County, Nebr., will protect a feed yard, county road, and bridge from flooding. SOIL CONSERVATION is the official magazine of the Soil Conservation Service, pub lished monthly by direction of the Secretary of Agriculture as administrative informa tion required for proper transaction of the public business. Use of funds for printing this publication approved by the Director of the Bureau of the Budget July 17, 1968 Reprint permission: Contents of this magazine may be reprinted without special permission. Credit is not required but is appreciated. Photos available on request. Commercial names: Mention of commercial enterprises or brand names does not constitute endorsement or imply preference by the Department of Agriculture. Subscription: $2.00 per year, $2.50 foreign. Single copy 25 cents. Discount of 25 percent on orders of 100 or more sent to same address. Order direct from Superintendent of Documents, Government Printing Office, Washington, D.C. 20402. Aud and more mud. Highway builders keep sediment on site during construction By John Robb Assistant state conservation engineer, SCS, Harrisburg, Pa. Contractor, engineers, and conservation officials gave sediment control top priority in Campbells Run interchange. Stemming the flow of mud from a major highway construction site during the bad weather of a midAppalachian winter is a problem to make engineers, contractors, and conservationists wonder if there aren't easier ways to make a living. But when the people concerned with a project join their efforts in a common purpose they can greatly reduce erosion and sediment even as work progresses under the most difficult circumstances. They did it on the 70-acre Campbells Run highway interchange near Pittsburgh, Pa. If it could be done there, it can be done elsewhere. The project plan called for moving 6 million cubic yards of earth. Work started in the fall of 1969. When bad weather slowed construc tion, it was obvious that it did not slow erosion. Flood-control structures downstream and the growing public concern for the environment made it imperative that sedimentation be held to a minimum. A meeting was arranged between the contractor, Glasgow Inc., of Glenside, Pa.; the resident engineer of the Pennsylvania Department of Highways, Jim Donovan; a representative of the Pennsylvania Department of Forests and Waters, Vernon T. Houghton, Jr.; and other concerned agencies, including the Soil Conservation Service. Together, they worked out methods of reducing erosion while work proceeded as well as while work was stopped by bad weather. The deep, narrow valley of Camp bells Run makes installing of sediment-control measures unusually difficult. There is no room for conventional debris basins on the main stream, and the side tributaries are too steep for their use there. Since it was winter, seeding of temporary vegetation was impractical. A series of horizontal benches and diversions, which would double for haul roads, were installed. They were laid out in broken patterns so no direct runoff would enter Campbells Run. The runoff water from the site was passed through a series of desilting basins. An abandoned bridge near the lower end of the construction area was used to anchor a dumped-rock dam to trap and hold sediment. The basin will be cleaned when storage capacity is filled. Burning of timber is not permitted in the Pittsburgh airshed area. To dispose of trees cleared from the site without causing air pollution, the contractor used the trunks to construct barriers upstream from the rock dam, thereby slowing the flow of runoff. The limbs and brush were used to make additional barriers, which proved effective in removing sedi ment from the runoff of small storms. Diversions which protect slopes from erosion also protect work areas where culverts are being formed and poured. They are re located as necessary as the work progresses. Damage to control meas ures by unusually heavy storms is promptly repaired. Campbells Run demonstrates that pollution and sedimentation can be controlled during construction ever under difficult conditions. Soil and water conservation is big business In numbers of machines, equipment hours, operator time, supplies, and quantities of earth moved, the magnitude of soil and water conservation action challenges the imagination. Machines in any one year move 1 billion cubic yards of earth in installing the wide range of conservation practices required. This includes 258 million cubic yards for earth dams, 212 million for grassed waterways and channels, 82 million for terracing, and 352 million for land grading, leveling, and smoothing. Other practices in conservation require additional amounts. What does it take to move this mountain of earth each year? A survey completed in 1968 showed that conservation contractors, individual landowners and operators. and soil conservation districts own 457,000 pieces of equipment used primarily to install and maintain conservation work. About 143,000 pieces of equipment are of the heavy construction type: Bulldozers, track-type trac tors, heavy wheel-type tractor drag lines, backhoes, motor graders, and tiling machines. Remaining categories include carryalls, special plows, terracing machines, tree planters, tree planters, special drills, and landplanes. Into the conservation effort each year go 425,000 cubic yards of concrete, 3.9 million feet of corrugated metal pipe, 15 million feet of con crete pipe, 19 million feet of pipe of steel and other materials, 11 million feet of small-diameter water pipe 12 million feet of tile, and 14 million feet of aluminum sprinkler pipe. Getting vegetation on 4.3 million acres of pasture, critical erosion spending of $111 million for seed, areas, and rangeland requires the fertilizer, and lime. For the protection and proper mangement of range, landowners install 14,000 miles of fence.-R C. BARNES, Engineering Division, SCS Washington, D.C. ♦ |