DRII~I~S FOR RANGELAND SOD SEEDING F. B. Dyck G. G. Bowes J. Waddington

In western Canada, there are about 8.9 million hectares of range and marginal cropland that could be improved by establishing tame grass and legume species (Johnston and Smoliak 1977). It is estimated that tame seeded for­age crops will yield three to five times as much as native rangeland. The traditional method of improving pasture productivity is to break up the existing sod, prepare a firm seedbed, and seed tame forage species. This is expensive on marginal land because much of the topography is rocky, rough, and hilly. Further, breaking leaves the soil exposed to wind and water erosion, which is environmentally not desirable. Also, in years of drought, adequate moisture is not available for germination of small forage seeds, which must be placed at a shallow depth in the soil.

Two alternate methods to improve rangeland are: directly sod seed a legume or grass species after suppress­ing or killing the existing vegetation with herbicides; sup­press or kill the existing vegetation by mechanically un­dercutting a strip of sod (36 em wide) at about 3 em depth and removing a ribbon of sod from the center of the strip, and seeding a row oflegume or grass in the center of the slot. Two drills were developed to assess these two methods.

ZERO-TILL RANGELAND DRILL

A zero-till rangeland drill facilitating the first concept was developed by Dyck and Bowes (1982) and has been assessed for renovating pasture and haylands in Saskatchewan by Malik and Waddington (1990), Waddington (1992), and Bowes and Zentner (1991) and in Quebec by Belzile (1988, 1991) and Belzile and Rioux (1983). This machine (fig. 1) originally had a sprayer attachment mounted on the seeder; thus the spraying and the seeding operation could be done at the same time. However, it was soon discov­ered that the optimum time to spray differed from the optimum time to seed and the success rate was enhanced by separating the two operations.

The seed frame was constructed of 100- by 100- by 4.75-mm wall square tubing with a vertical adjustment on the hitch to enable leveling of the frame.

The disc coulters and double-disc openers had 60-cm diameter pans, 4-5 mm thick (fig. 1). The disc coulters were clamped to the tool bar without a trip mechanism or spring cushion , but they can pivot horizontally, which enables the unit to turn when operating in the soil. This simple design has the disadvantage of the whole machine

Poster paper presented at the Symposium on Ecology, Management, and ~storation of Intermountain Annual Rangelands Boise ID May 18-22, 1992. ' ' '

F. B. Dyck is Senior Design Engineer, Agriculture Canada Research Station, Swift Current, SK; G. G. Bowes and J. Waddington ;re Research Scientists at Agriculture Canada, Research Station Saskatoon SK and Swift Current, SK. ' ' '

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lifting should the coulters encounter an obstruction like a rock or a tree stump. On a commercial zero-till drill, it would be advisable to design a trip mechanism for each disc coulter. This was incorporated on the unit used in Quebec (fig. 2). The double-disc openers pivot at the tool bar to enable them to follow the soil contour. Depth bands were mounted on the pans to limit seed placement to 2 em below the soil surface. Cast iron weights were mounted at the rear of the opener to ensure penetration. This in­creased the weight of each opener to 125 kg. The openers were raised and lowered by a rockshaft and chain attached at the rear of the opener.

Figure 1- Zero-till rangeland drill, western prototype.

Figure 2- Zero-till rangeland drill, eastern prototype.

This file was created by scanning the printed publication.Errors identified by the software have been corrected;

however, some errors may remain.

Tabla 1-8eedling alfalfa establishment following zero-till seeding Into a bluegrass sod treated with glyphosate at Parkervlew, SK

Exp. Herbicide No. treatment

Seed alfalfa

Alfalfa Gly-count Control phosate

- - - - - - - - - - - - - - Date - - - - - - - - - - - - - Alfalfa plants mlrow

1 22 Sept. 771 25 Oct. 77 28Aug. 78 12±43 20±5 2 29 May781 29 May78 28Aug. 78 9±2 16±4 3 29 Sept. 7S2 10 Oct. 7S 14Aug. 79 1 ± 1 9±3 4 22 MayS02 22 May SO 12 Aug. so 14±3 24±5 5 22 Sept. SQ2 15 Oct. 80 13 Aug. S1 1±1 6±1

1Giyphosate applied at 2.0 kglha. 'Giyphosate applied at 2.5 kglha. 3Means:t:SE.

The seed box for coarse grass seed has a fluted roll seed cup from a John Deere grain drill. In the seed box, 8-mm round steel bars were welded in the form of a "T" and were attached to a shaft that ran the length of the unit. The T -unit oscillates over the fluted rollers to prevent light, hairy grass seeds from bridging. The seed box for alfalfa had a small fluted roll seed cup from a John Deere forage seed attachment. In both seed boxes, rate adjust­ment was made by sliding the fluted roll in the cup.

The two fertilizer boxes were constructed of galvanized iron and used a C.C.I.L. (Canadian Cooperative Imple­ments Ltd.) fluted roll seed metering cup modified to oper­ate in the overshot mode. This reduced the grinding of the fertilizer. Rate adjustment was done by sliding the fluted roll in the cup. One fertilizer applicator placed the fertilizer with seed and the other one broadcast fertilizer behind the furrow opener.

The seed and fertilizer boxes were driven by chain from the ground wheel and later from one packer wheel. The unit was fitted with tail and signal lights to enable towing by truck to various test plots in the Province.

Performance and seedling establishment was greatly improved by the addition of packer wheels on both units. On the western unit two cast, sharply shaped wheels were mounted together to pinch the furrow shut and pack in the seed zone (fig. 1). On the eastern unit wide V-shaped cast packer wheels were used (fig. 2).

Results for the western unit are given in tables 1 and 2 and figure 3. Results from the eastern unit are described by Belzile (1983, 1988, 1991) and Rioux and Belzile (1983, 1989).

SOD SLOT SEEDER A drill featuring the second approach was also devel­

oped by Dyck and Bowes (1991) (fig. 4). The renovation technique is illustrated in figure 5.

The machine consists of a rugged frame constructed of 100- by 100- by 6-mm tubing supported on two 9.5Lx15 wheels. Overall width is just under 2.6 m to meet high­way transport specifications. Five opener assemblies are individually attached to the frame in a staggered pattern with a flexible link and two pressure springs, which ac­commodates surface irregularities while maintaining op­erating depth. Each opener assembly can move vertically ±7 .5 em from the normal operating position. Adequate ballast is provided with four 225-liter water tanks, thus 900 newtons of force can be exerted at each end of the opener assembly to ensure penetration and contour fol­lowing in uneven terrain. This is accomplished by hy­draulically adjusting the position of the wheels to put most of the weight of the frame plus ballast onto the opener assemblies, thus compressing the pressure springs to about one-half their original length. The wheels also serve to stabilize the machine laterally.

The opener assembly is made up of two or three disc coulters 45 em in diameter (fig. 6) with a depth band in between, or on the outside; a fabricated shank equipped with a sweep; an offset disc opener (Dyck and Tessier 1986; Lawrence and Dyck 1990) with a depth band for precise seed placement; and two narrow V -shaped packer wheels to pinch the furrow shut (fig. 7). The packer

Tabla 2-Estabtishment of fall-seeded forage legumes after sod suppression In the fall1 at Pathlow, SK

Plant countlm of row Percent covar/m of row Alfalfa Mil kvetch Alfalfa Milkvatch

Treatment Rate2 3018/84 24/10/85 30/8/84 24/10/85 15/10/86 15/10/86

kg a.i.lha

Check 32b Be 15 a 6b 20b 4b

Glyphosate + ammonium sulfate 0.05+5% 46a 14a 25ab Ba 36a 9a

Glyphosate + ammonium sulfate 1.1 + 5% 52c 12b 21 ab Sa 29ab Sa

Glyphosate 1.1 46a 11 b 22ab 9a 32ab 7ab

Glyphosate 2.2 50 a 13ab 26a 9a 32ab Sa

tMeans followed by the same letter are not significantly different at P.,. 0.05 according to Duncan's multiple range test. 2a.1 ... active Ingredient.

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Figure 3-Forage establishment using the zero-till rangeland drill.

Figure 4-Rangeland slot seeder.

wheels also act as a gauge wheel for the rear portion of the opener assembly.

The coulters and the sweep shanks are fitted with a hy­draulic trip for protection from obstacles such as rocks. This system was previously reported by Dyck and Tessier (1986) and performs very well. The pressure can be ad­justed to match the conditions encountered and the size of sweep used.

The opener assembly can be modified (fig. 8) to enable seed placement by the sweep shank with the addition of a seed tube and by adjusting the wear rod of the sweep to cut a furrow approximately 2 em deep in the center of the trench created by removing the sod. The disc portion of the opener assembly is replaced by a packer wheel 38 em in diameter and 9 mm thick cut from plate steel. Thus the packer wheel is narrow enough to pack to the bottom of the furrow created by the wear rod which is 12 mm wide. In this mode the double packin~ wheel is banded

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<<>> Ribbon of Socl Renove cl

Figure 5-Schematic of renovative techniques.

Discs 45 em dio . Depth rings .37 em dio.

2.5 -j rs

Figure 6-Schematic of coulters used to define depth and width of the slot (all measurements in centimeters).

II

with a hoop of flat iron 5 mm thick providing a gauge wheel function with minimal packing. This assembly can also be used to meet specification (b) (fig. 5) by replacing the double coulter with a single coulter fitted with a depth band, removing the mold boards from the sweep assem­bly, and adjusting the sweep wear rod to the sweep level. Thus the sod is undercut without removing the center ribbon.

The seed boxes are divided for each row to enable alter­nate row seeding of a legume and a grass species or seed­ing of fewer rows at a wider row spacing. The grass seed box is fitted with an agitator to prevent bridging of seed and to maintain flow through the metering cup. John Deere fluted roll cups are used for both the legume box and a grass seed box. The legume cup is small in size to maintain accurate metering of small seed. The larger cup used for grass seed is a standard grain cup. It features the seed roll close to the bottom of the box to achieve good

Figure 7-Coulter, sweep, and disc opener assembly.

Figure 8-Coulter and sweep assembly with seed place­ment attachment.

~etering roll contact with the seed and to minimize bridg­mg. The seed and fertilizer boxes are ground driven from a separate wheel.

All of the options outlined have not been evaluated to date. Plots using the technique illustrated in figure 5a were seeded with alfalfa at several locations in the Prov­ince. For these tests, three opener assemblies were set up using the disc opener to place the seed and two opener as­semblies were modified to place the seed by the sweep shank with the hoe point. Seeding was done at Neudorf, SK, on May 28, 1991, with two varieties of alfalfa. Plant counts were taken on June 19, 1991. The results are sum­marized in table 3.

Establishment was considered to be adequate. The data indicate that the sweep hoe point combination has given equal (no significant difference) or slightly better establishment than the disc opener. This may be due in part to the different packer wheels used. The former uses a narrow packer wheel that packs to the bottom of the fur­row, while the latter uses a double packer wheel to pinch the furrow shut. This may result in less packing pressure

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Table 3-Results of sod slot seeder tests, removing a ribbon of sod, with two alfalfa varieties

Alfalfa variety Treatment Rangelander Beaver

- - - - - - - - -Plants/meter - - - - - - -

Sweep + disc opener 4c hoe point opener

5.6 7.2

5.5 8.3

in the seed zone and also push a greater amount of soil over the seed. However, the success of the sweep hoe point combination is encouraging because it indicates that perhaps one can simplify the design and construction of the machine, making it shorter and more economical to construct. Continued evaluation in a greater variety of environments will be carried out before conclusions are drawn.

Producer reaction to the prototype has generally been favorable. One suggestion was to reduce the width of the slot to minimize the roughness left in the field by the ribbon of sod. This has been done and is illustrated in figure 6. Field trials with various slot widths were seeded in spring 1992. The desired reduction in roughness is not evident except for the 2.5-cm slot.

CONCLUSIONS

The zero-till rangeland drill has been very successful in the parkland area of the prairies; however, farmers have been reluctant to adopt this technique because of the ap­plication of glyphosate required.

Initial testing of the sod slot seeder has also been very positive and provides a once-over method of renovating range. Further testing will be carried out, and the ben­efits and costs of the two methods will be compared.

REFERENCES

Belzile, L. 1991. Direct seeding on old grassland. Le Cooperateur Agricole. 3: 38-39.

Belzile, L. 1983. Establishment of forage crops by direct seeding. 11. Comparison of three legumes seeded at two times of the year in two types of soil. Notes on Forage Crops. 27: 40-44.

Belzile, L.; Rioux, R. 1983. Establishment offorage crops by direct seeding. Notes on Forage Crops. 27: 32-51.

Bowes, G. G.; Zentner, R. P. 1992. Effect of vegetation suppression on the establishment of sod-seeding alfalfa in the Aspen Parkland. Canadian Journal of Plant Sci­ence. 72: 1349-1358.

Dyck, F. B. ; Bowes, G. G. 1982. A zero-till drill for reseed­ing forage crops. CSAE-AIC Annual Meeting; 1982 July 11-15; Vancouver, BC.

Dyck, F. B. ; Bowes, G. G. 1991. A drill for range renova­tion. Pap. 91-407. CSAE-AIC Annual Meeting; 1991 July 29-31; Fredericton, NB.

Dyck, F. B.; Tessier, S. 1986. Zero-till drill developments at the Swift Current Research Station. Pap. 86-210. Annual Meeting, Canadian Society of Agricultural Engineers; 1986 July 6-10; Saskatoon, SK.

Lawrence, T.; Dyck, F. B. 1990. A comparison of two fur­row opener-depth control assemblies for seeding forage grasses. Journal of Range Management. 43(1): 82-83.

Malik, N.; Waddington, J. 1990. No-till pasture renova­tion after sward suppression by herbicides. Canadian Journal of Plant Science. 70: 261-267.

Rioux, R.; Belzile, L. 1989. Grassland regeneration by di­rect seeding. In: CPVQ, ed. Information day on weed science. Crop weed control and soil conservation. Agdex. 640: 75-101.

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Rioux, R.; Belzile, L. 1985. Establishment of forage crops by direct seeding. 111. Relative value on wet soils. Notes on Forage Crops. 27: 45-51.

Waddington, J. 1992. A comparison of drills for direct seeding alfalfa into established grasslands. Journal of Range Management. 45: 483-487.