the present invention is generally directed to a planting unit for us with an agricultural implement . while only one planting unit will be described , it is understood that the agricultural implement may include a plurality of such planting units fig1 shows a planting unit 10 according to one embodiment of the invention . the planting unit 10 generally includes a forward disc 12 that is angled relative to a line of travel . as known in the art , the forward disc 12 rotates about a center hub 14 to cut a furrow into the planting surface , s . a seed boot 16 is mounted rearward of the disc 12 , and as will be described , is designed to cut a seed trench into the furrow formed by the disc 12 . the disc 12 is coupled to a parallel linkage 18 by a disc mount 20 and a mount arm 22 extending upwardly from the disc mount 20 . a trailing arm 24 is also coupled to the parallel linkage 18 and a press or packing wheel 26 is coupled to the trailing arm 24 . the press wheel 26 trails the disc 12 and the seed boot 16 , and as known in the art , applies a packing pressure to the furrow . the downward force is applied by spring 28 , but it is understood that other biasing devices may be used . in addition , the amount of downward force can be varied via lever 30 which has a selector member 32 that can be selectively positioned in one of a series of notches 34 of curved member 36 . the parallel linkage 18 is also coupled to a toolbar mount 38 that is operative to couple the planting unit to a toolbar 40 of an agricultural implement . a hydraulic cylinder 42 is pivotably coupled to the toolbar mount 38 and the mount arm 22 by a bracket 44 . the cylinder 42 is operative to apply a downward pressure on the disc 12 to force the disc 12 into contact with the planting surface . with additional reference to fig9 , the depth at which the disc 12 cuts into the planting surface is variably set by a gauge wheel 46 and a cooperating gauge wheel arm 48 and a control lever 50 . the control lever 50 controls the gauge wheel arm 48 by a crankshaft 52 that extends through the center of the disc 12 . the gauge wheel arm 48 is held in place by teeth 54 that interface with a mating fan shaped member 56 , which includes a series of notches 58 that individually define a different depth the disc 12 can be set via positioning of the control lever 50 . various fasteners 57 , e . g ., nuts , bushing 59 , washers 61 and seal 63 are used to secure the crankshaft 52 to the disc 12 via a hub 65 that is coupled to the disc 12 by fasteners 67 . in addition to setting the depth at which the disc 12 cuts into the planting surface , the depth gauge wheel 46 keeps the outer surface of the disc 12 generally clear of mud and debris . a scraper blade 60 is mounted opposite the depth gauge wheel 46 is designed to remove dirt , mud , and other debris from the inner surface of the disc 12 . the planting unit 10 is designed to separately drop fertilizer and seed into the furrow in a single pass . in this regard , a fertilizer tube 62 is mounted rearward of the center hub of the disc 12 but forward of the seed boot 16 . the seed boot 16 generally includes a seed tube 64 and a cutting member 66 that is forward of the seed tube 64 . in operation , as the disc 12 forms a furrow having a relatively deep fertilizer trench in the planting surface , fertilizer is dropped into the fertilizer trench from a fertilizer source ( not shown ) that communicates with the aforementioned fertilizer tube 62 . the cutting member 66 is offset from the disc 12 and cuts into a sidewall of the furrow to form a ledge or seed bed . seed is then dropped via the seed tube 64 onto the ledge . the seed is fed to the seed tube 64 from a seed source in a known manner . the cutting member 66 cuts into the sidewall of the furrow such that the ledge is offset horizontally and vertically from the fertilizer trench , i . e ., bottom of the furrow . in this regard , the seed is deposited at a position that is spaced horizontally and vertically from the fertilizer that is dropped into the fertilizer trench . as noted above , it is generally preferred to plant seed and drop fertilizer into a furrow with stratification between the fertilizer and the seed . in one preferred embodiment , the cutting member 66 is angled to lift the soil as the cutting member 66 is urged through the sidewall of the furrow . thus , as the disc 12 and the cutting member 66 cut through the planting surface , the soil is temporarily displaced and lifted to form trenches for the deposition of fertilizer and seed . however , when disc 12 and the cutting member 66 pass , the soil will tend to fall back onto itself and effectively fill - in the furrow and thus the fertilizer and seed trenches . the press wheel 26 , which trails the seed boot 16 , then packs the fertilizer and the seed . alternately , the cutting member 66 may be angled downward to force the soil down onto the fertilizer before the seed is deposited onto the seed bed . in one preferred embodiment , a deflector tab 68 extends from the backside of the seed tube 64 . the deflector tab 68 generally provides two separate functions . first , the deflector tab 68 is angled , as shown in fig6 and 7 , as is the lower ends of the seed tube 64 and the cutting member 66 . with this angled orientation , the deflector tab 68 is operative to encourage seed toward the seed trench . second , because of its proximity to the seed tube 64 , the deflector tab 68 reduces the ingress of soil and debris into the seed tube 64 during roll back of the planting unit 10 . referring now to fig2 , the disc 12 is angled relative to the furrow f that is formed by the disc 12 as it is rotated . the furrow f is formed generally in - line with the line of travel for the agricultural implement . the disc 12 is angled such that the angle formed between the leading edge 12 a of the disc 12 and the line of travel , which generally bisects the furrow f , is approximately 7 degrees . while other angles are contemplated , it is generally preferred that the angle fall between 5 and 10 degrees , and more preferably between 6 and 8 degrees . it will be appreciated that while the disc is angled relative to the line of travel , the disc is normal to the plane of the planting surface . turning now to fig3 - 5 , the fertilizer tube 62 is arranged such that the fertilizer falls generally centered in the furrow . the seed tube 64 has an outlet 70 that is angled generally rearward and laterally offset from the outlet ( not numbered ) of the fertilizer tube . as noted above , the seed trench is formed laterally offset from the fertilizer trench . this offset is formed because the seed boot 16 is generally angled away from disc 12 , as particularly shown in fig4 , such that the cutting member 66 forms a side bander . the angle , θ , defined between the leading edge 66 a of the cutting member 66 and an axis transverse to the line of travel is preferably approximately 45 degrees . the angle , γ , defined between the outlet 70 of the seed tube 64 and the plane of the planting surface is preferably approximately 30 degrees . as particularly shown in fig4 , the depth of the seed tube outlet 70 is less than the lower most edge of the disc 12 and the seed tube outlet 70 is laterally offset from the disc 12 clearly illustrating the vertical and horizontal spacing of the fertilizer and seed trenches . as shown in fig6 and 7 , the seed boot 16 includes a header 72 that may be coupled to the disc mount 20 via fasteners 74 . since the header 72 is mounted to the same mount 20 as the disc 12 , the combined assembly is relatively compact when compared to conventional double shoot , single pass planting units . as shown in fig8 , the seed boot 16 is constructed such that seed tube outlet 70 sits behind the cutting member 66 . with this construction , the cutting member 66 cuts a ledge into the sidewall of the furrow and seed is placed onto the ledge as the seed drops through the seed tube outlet 70 . the cutting member 66 generally includes an angled cutting face 76 that in one embodiment includes a wear resistant insert 78 , such as a carbide insert . in one preferred embodiment , the seed tube 64 and the cutting member 66 , and its header 72 are formed as a single assembly . the present invention provides a planting unit of relatively compact design in which a seed boot and a rotatable disc are mounted to the same disc mount . the seed boot has an angled cutting tip that cuts a ledge into the sidewall of a furrow formed by the rotatable disc . a seed tube rearward of the cutting tip deposits seed onto the ledge . a trailing press wheel then packs the fertilizer and seed . the ledge is cut vertically and horizontally spaced from the bottom of the furrow ( fertilizer trench ). in this regard , seed and fertilizer are deposited with vertical and horizontal stratification allowing higher concentrations of fertilizer to be used . in addition to providing a compact design , the present invention avoids the complexities associated with double shoot planting units that have multiple discs to cut fertilizer and seed trenches . in addition , the present invention provides less soil disturbance compared to conventional double shoot , single pass planting units , especially when furrowing at faster speeds , e . g ., greater than 5 m . p . h . many changes and modifications could be made to the invention without departing from the spirit thereof . the scope of these changes will become apparent from the appended claims .
a planting unit for depositing fertilizer and seed in a single pass , double shoot manner includes a rotating disc that cuts a furrow in a planting surface and a trailing seed boot , having a cutting edge , that cuts a vertically and horizontally offset trench in the furrow to form a seed bed in the planting surface . the disc has a mounting frame for mounting the disc to a linkage assembly that is , in turn , coupled to a toolbar mount . the seed boot is also attached to the mounting frame . this common attachment provides a relatively short and compact device without sacrificing fertilizer and seed stratification .