Patent Application
20120085273
The present invention relates to agricultural fertilizer applicators; and more particularly, it relates to apparatus for subsoil application of livestock waste in the form of a slurry (that is, a freely flowable mixture of liquids and solids).
Historically, livestock waste, particularly in solid form, has been spread on the surface of the soil by a manure spreader using a flail to fling the material to the rear. A more modern side-discharge spreader also deposits the material on the surface of the soil.
The advent of confinement systems for animals which include pits below the confinement area produces a large amount of animal waste in a slurry form which must be handled and disposed of. Typically, the slurry is pumped in a large tank carried by a wagon, but originally it was for the most part, spread or sprayed on the surface of the soil.
This procedure has, as a principal objection, a strong odor which remains after the waste is spread. Moreover, surface spreading of animal waste is not desirable with the potential runoff of nitrates and phosphorus into rivers and streams or seeping of the material into ground water sources. This is objectionable because livestock waste is high in nitrogen, and swine waste is also high in phosphorus and with increasing concern with the quality of drinking water, this procedure is becoming less and less acceptable.
Various methods have been proposed for depositing the slurry underground. One method is to use a fertilizer knife, such as shown in U.S. Pat. No. 4,592,294 and to weld a large pipe to the rear of the knife to deliver the slurry behind the knife and into the slot cut in the soil by the knife. This leaves a very narrow band of fertilizer having a high concentration of nitrogen and other nutrients.
Another method of subsoil delivery of animal waste employs a standard chisel plow shank with an attached wide cultivator sweep, in an attempt to distribute the slurry further laterally and to avoid the concentration which occurs in the case of a simple fertilizer knife, described above.
This method, however, presents still another problem—namely, the cultivator sweep unnecessarily tills the soil and may result in burying surface residue. This may be a separate problem, particularly for farmers whose land may have been designated HEI, because there are federal requirements to maintain a certain percentage of crop residue on the surface of such soil. Both the chisel plow shank (which is a wide shank) and cultivator sweeps are designed to create a plowing action that mixes the soil with the residue, buries a large percentage of the residue, and leaves a furrow of exposed liquid behind the shank.
A more recent improvement is disclosed in U.S. Pat. No. 5,865,131. This device uses a spring-cushioned coulter running ahead of the applicator for cutting an initial slot in the residue and providing a break line in the soil to be parted by a trailing shank. The shank spreads the initial slot and deepens it. The shank includes a shoe provided with a pair of wings extended laterally. The shoe is in the form of a tillage point which fractures and lifts the soil in front of the shank. The wings lift the soil laterally of the shank from the center toward the outward ends of the wings to provide slots for promoting lateral distribution of the slurry.
The applicator of the '131 patent is suitable for delivering higher application rates of slurry, in the range of 9,000 to 10,000 or more gallons per acre. However, the ground speed of the '131 patent is limited to a range of 3-5 miles per hour. At these slower speeds, the soil is lifted sufficient to form lateral fissures in the soil at a depth of approximately 3 to 4 inches which permits the slurry to flow laterally of the applicator shank. Any greater speed would cause too much soil disruption, lifting and redistribution (i.e. tillage) due to the use of a forward portion of the shoe which acts like a plow point, having a surface which is inclined upwardly and rearwardly for fracturing and lifting the soil in front of the shank. Another recent implement is disclosed in U.S. Pat. No. 6,973,884. The current invention is an improvement of the '884 patent.
The present invention is designed for the wide variation of rates for slurry fertilizer, and operation at speeds in the range of 5 to 8 miles per hour. The present invention employs a spring-cushioned coulter running ahead of the applicator for cutting an initial slot in any residue and providing a vertical parting line in the soil to receive the trailing shank which mounts the ground-engaging sweep and to minimize soil disruption.
The mounting shank of the sweep is curved and extends rearwardly and downwardly of the coulter and attaches to a sweep shank at a location slightly above the surface of the soil. This permits the use of a heavier mounting shank and a narrower sweep shank. The sweep includes a shank mounted to the rear of the mounting shank. The sweep shank is thin, preferably less than about 0.5 inches in width. The sweep shank is mounted to the distal end of the mounting shank by two vertically spaced bolts, one of which is a shear bolt. The instant invention permits the sweep shank to be mounted to the main mounting shank at a location slightly above the normal ground level for operating the unit. This has the advantage that the sweep shank need not be as thick as when mounted higher, as shown in the '131 patent.
If an obstruction is encountered, the sweep shank can pivot upwardly and clear the obstruction very quickly. Thus, the sweep shank does not have to be strengthened with increased thickness to the limits required in previous longer units, allowing the sweep shank to be narrow and cause less soil displacement.
The sweep shank of the present invention is in the form of a casting and preferably includes a nose portion which may be an abrasion resistant casting mounted in front of and at the base of the sweep shank. The lower rear portion of the main mounting shank is offset so that the center line of the main mounting shank and the sweep shank may be aligned in the direction of draft. The tip casting has a width substantially the same as the sweep shank which, as indicated, is less than about 0.5 in. The lower forward portion of the sweep shank protrudes forward at a low angle. It is designed to slightly lift the soil while parting it to provide minimal soil disturbance, but rather breaks the soil and parts it at the operating depth. The upper portion of the tip casting may be tapered from a narrow leading edge to the width of the sweep shank at its rear. The lower angle forward protruding tip penetrates hard or frozen soil better than blunt tip as shown in U.S. Pat. No. 6,973,884.
First and second wings are cast to the sides of the sweep shank respectively. The wings are located at the operating depth of the unit; and they lift the soil slightly on the left and right side of the sweep shank, permitting the slurry to flow into the cavity behind the wings, without substantially lifting or turning the soil or burying surface residue.
Behind the sweep shank a slurry delivery tube is mounted to it by means of a horizontal bolt acting as a pivot. The slurry tube delivers the slurry behind the sweep shank and deposits the slurry into the narrow furrow formed by the sweep shank and horizontally as the wings lift the soil. By pivotally connecting the slurry tube to the sweep shank at a location slightly above the soil surface, if the sweep shank shear bolt does break, the slurry tube can rotate out of harm's way quickly without binding or interfering with the sweep shank as it pivots rapidly out of the way. For higher planting rates per acre, the wings of the sweep can be made wider. Also, by changing the inclination angle of the wings, the wings can lift the soil higher providing a larger cavity in the soil to accommodate more liquid fertilizer.
The improved applicator thus extends the lateral distribution of the slurry, thereby reducing high concentrations of slurry, and extends the area in which the fertilizer is available as a nutrient for plants, while permitting operation at higher ground speeds. At the same time, the surface of the soil and any residue thereon is left substantially undisturbed, even at higher ground speeds of 5-8 mph. Operation at these speeds is facilitated, without an undesired amount of soil displacement, as a result of multiple stage furrow formation and widening.
The low angle protruding tip and the lower portion of the abrasion resistant casting gently lift and part the soil. A sharp leading edge of the upper portion of the abrasion resistant casting parts the soil laterally over a narrow width.
The casting has lateral extensions near the soil surface for widening the upper portion of the furrow to receive the lower portion of the slurry discharge tube, insuring that the slurry will be contained by the furrow. Means may be provided for closing the narrow furrow formed by the shank, but the furrow is small and narrow when the furrow shank has a narrow width, as is preferred, so closing of the furrow is not normally necessary.
The invention includes novel features and a combination of elements described and illustrated fully herein. It will be understood that various modifications may be made without departing from the spirit of the invention or sacrificing any of its advantages.
Referring to
The spring cushion mechanism is mounted to a conventional toolbar by shank mount plates 4a and a bracket 5 that pivots on bolt 6. When an upper bolt 7 is inserted, bracket 5 tightly clamps against the tool bar tool (not shown) located in the rectangular opening 7a, between the bracket 5 and mount plates 4a. At the forward portion of the mounting assembly, steel plates are formed inward. At the forward portion of plates 8 is a cross piece 9 of steel. A similar piece of steel is welded behind a coulter mount bar 10. This provides a rectangular sleeve or receptacle so that the coulter mount bar 10 can be telescoped vertically within the sleeve and pinned (see pins 11a) to adjust the coulter blade 18 to the desired operating depth. Additional holes 11 are provided in coulter mount bar 10 to allow for a wide range of different operating depths for the coulter.
On the lower forward portion of coulter mount bar 10 a vertical shaft 13 is welded and the forward portion of the spring-cushioned coulter assembly 14 is provided with a sleeve 15 to telescope over the shaft 13. The coulter assembly 16 including coulter blade 18 is similar to assemblies used on various agricultural tillage tools for forming a slot in the soil and for cutting residue at or near the surface. A spring 32, shown in
Turning again to
Referring to
The sweep shank 54 is preferably approximately ½ in. thick, but the width may vary from about ⅜ inch to about ¾ inch. For higher rates of application involving lower speeds, the sweep shank's width may exceed ¾ inch. However, in many soil conditions this would increase soil disturbance. A lower discharge portion 53 of slurry delivery tube 52 is flattened sideways to facilitate the flow of slurry in the narrow furrow formed by the sweep shank 54 of the applicator sweep assembly 50.
Of significance, mounting shank 3 extends rearwardly and is curved and extends downwardly to a location near, but above, the soil surface S. This permits the sweep shank 54 to be short in its vertical dimension. That is, sweep shank 54 extends from the operating depth to a few inches above the soil, as opposed to a foot or more above the soil. Therefore, bending of the sweep shank 54 is not a significant problem even though it is only approximately ½ inch thick. Also, to allow the applicator sweep assembly 50 with the steep sloping wings 61 shown in
The lift action of the applicator assembly's wings 56a, 56b is slight, not pronounced. This lift action forms an opening near the surface of the soil slightly wider than the width of mounting shank 3, and bulges, or extensions, 68a and 68b cooperate to widen the slot in the soil near the surface. The applicator assembly's wings 56a, 56b sweep outward and rearward providing a slight lift to the soil in forming a horizontal cavity or soil fissure for promoting lateral flow of the slurry. The wings 56a, 56b have sharpened leading edges 61, and are formed sharply rearwardly in a V-shape to more gently lift the soil.
The applicator sweep assembly's wings 56a, 56b are shown in
Turning now to
In the alternative, sweep shank 54 could be preformed in the desired shape as represented by the front and lower surfaces of the disclosed tip casting 74, and its width; and a hard surface such as of welding wire applied to all the forward, soil-engaging surfaces.
Having thus disclosed in detail one embodiment of the invention, persons skilled in the art will be able to modify certain of the structures shown and to substitute equivalent elements for those disclosed while continuing to practice the principle of the invention. It is, therefore, intended that all such modifications and substitutions be covered as they are embraced within the spirit and scope of the claims.
