TILLAGE Machinery Laboratory Expected to Yield Valuable Data
The development of farm machinery and tillage methods in the past has been largely through empirical methods. The basic relationship between soil types, machine design and operation, and crop production was not known. The difficulties encountered in handling soils in many areas, such as the Black Belt of Alabama and Mississippi, where the topography is well adapted for cultivation with standard-sized machines, resulted in the abandonment of portions of these areas in favor of the eroded and impoverished hill areas, where soils are more easily tilled. There are few plows which will work satisfactorily in waxy, heavy clay soils, which will shed and scour in "push" soils, or will withstand the abrasion of gravelly soils.
In all studies thus far made of tillage machinery under field conditions there have been variables which could not be controlled by the investigators. For instance, it has been impossible to control the soil moisture or to duplicate exactly any set of conditions. The accuracy of field work has also been handicapped by reason of the fact that the testing equipment used had to be supported by the soil under test, resulting in uncontrollable errors. These handicaps to the proper scientific study of the manifold problems connected with tillage have long been recognized. It was realized that the answer to many tillage-machinery problems could not be found unless the studies were made where soil conditions were within the control of the investigator.
To meet this long-felt need a farm-tillage machinery laboratory has been constructed at Auburn, Ala., with funds furnished by the Public Works Administration. The plant consists of 9 soil bins each 250 feet long, 20 feet wide, and 2 feet deep, 2 of the bins being divided in the center. The bins are separated by concrete walls on which are placed rails which support the testing equipment. The testing equipment includes a power car propelled by a 130-horsepower engine, which will make possible the operation of tillage machinery at speeds of from 0.2 to 10 miles per hour. Supplementary equipment is available for other testing and for fitting the soil.
The soil bins will be filled with 11 distinct types of surface soils of major agricultural importance and which represent progressive steps in variation of the constants of soil classification. These range from sand to tight clay, both new and highly weathered soils. Consequently the results of the tests will have wide application and by proper interpretation will make basic information available to every section of the United States.
The equipment for the laboratory will make it possible to vary the soil conditions in any way desired by the investigators. The soil can be supplied with artificial rainfall or protected from the natural rainfall as desired, thus varying the soil moisture or maintaining a uniform moisture to meet the requirements of the tests.
The work will be conducted cooperatively with the Alabama Agricultural Experiment Station. The first investigation to be undertaken will deal with plows. The tests will be designed to determine accurately the effects of speed, depth of plowing, width of cut, soil type, soil-moisture condition, and soil compaction upon the draft, and the action upon the furrow slice in throw, inversion, pulverization, and coverage, of a plow bottom. Several types of plow bottoms will be used to determine the effects of shape or type and size of bottom upon the above factors. The data thus obtained will be supplemented by other investigations on the action of plow bottoms due to their shape, by studies of the essential characteristics of various metals used for plow bottoms, and by studies of a measure of tilth based on its relationship to plant growth. The combined results of these studies will provide a basis for the design and development of plows which will operate efficiently and satisfactorily under the conditions for which they are intended.
Similar information will be obtained relating to other tillage machinery, and the results will be available for use in the design of improved equipment for cultivation and for the economical control of weeds. Facilities will likewise be available for studies of the rolling resistance of wheels and traction of tractor wheels, covering the complete range of soil conditions that may be encountered. The results obtained should provide a basis for determining the width of tread and size of wheels which will have the lowest rolling resistance for given conditions and for developing traction equipment which will give a tractor maximum efficiency.
The ultimate purpose of the farm-tillage machinery laboratory is to obtain basic data for use in the development of equipment that will meet, the requirements for which it was designed. It is expected that implement manufacturers will take advantage of the facilities which the laboratory will afford to cooperate in investigations of fundamental machinery problems.
It has been estimated recently that 2½ billion horsepower-hours are used annually in plowing and listing alone, and the greater part of all farm power is expended in some form of tillage. If 10 cents be taken as the cost of 1 horsepower-hour the annual plowing and listing bill of the American farmers becomes $250,000,000. Isolated field tests have demonstrated that with proper equipment and methods very considerable savings can be effected in the cost of power. Furthermore, crop field experiments show that better tillage methods increase crop yields. The farm-tillage machinery laboratory therefore offers opportunities to develop equipment which will reduce the cost of power on the farm and at the same time increase the yield per acre.