Effects of Geometry of Disk Openers on Seed Slot Properties

Offset Double-Disk Opener (DDO) is a popular furrow opener in conservation tillage. It has some limitations such as negative suction to penetrate in the soil, hair pinning and mixing seed and fertilizer in the slot. Because of importance of separation of seed and fertilizer in the slot, by adding two horizontal mini disks to DDO a modified opener was made (MDO) which placed the fertilizer between and under two rows of seed. To consider performance of novel opener an indoor comparison test between DDO and MDO was performed at soil bin. The experiment was conducted with three working speeds (3, 6 and 8 km h-1), two bulk densities of soil (1.1 and 1.4 Mg m-3) and two levels of residues (1 and 2 ton ha-1). The experimental design consisted in a (3×2×2) complete randomized factorial with three replicates for each test. Moisture of seed furrow, separation of seed and fertilizer, hair pinning and resultant forces acting on the openers were used as assessing indexes. There was no significant difference between soil moisture content in slots created by DDO and MDO at 0-4 cm depth, but at 4-8 cm the in the slot created by MDO moisture content was higher about 9%. Horizontal force for both openers increased with increasing speed and soil bulk density. Vertical force for DDO was negative so it needed additional weight for penetrating in the soil, but vertical force for MDO was positive and, which can solve the challenge of penetration in the soil in DDO. In soft soil with heavy residues some trash was pushed by DDO into seed furrow (hair pinning) but at MDO seed were placed at clean groove. Lateral and vertical separation of seed and fertilizer was performed effectively by MDO (4.5 and 5 cm, respectively) while DDO put seed and fertilizer close to each other. Overall, the Modified Offset Double-disks (MDO) had better performance. So by adapting this opener with no-tillage drillers it would possible to have higher yield in conservation tillage where the most appropriate opener is disk type.

Authors:

• E. Seidi

Keywords:

• Seed Slot
• opener's geometry
• physical properties.

References:

[1] C.J. Baker, and C.M. Afzal,. Dry fertilizer placement in conservation
tillage: Seed damage in direct drilling no tillage. Soil Till. Res., 1986 7:
pp 241-250.
[2] D. Chaudhuri,. Performance evaluation of various types of furrow
openers on seed drills-a review. J. Agric. Eng. Res., 2001 Vol. 79, pp
125-137.
[3] M.A. Choudhary, G.P. Yu and C.J. Baker,. Seed placement effects on
seedling establishment in direct drilled fields. Soil Till. Res., 1985 Vol.
6, pp 79-93.
[4] D.P. Damora, and K.P. Pandey,. Evaluation of performance of furrow
openers of combined seed and fertilizer drills. Soil Till. Res., 1995 Vol.
34 pp 127-139.
[5] R.J. Godwin,. A review of the effect of implements geometry on soil
failure and implement forces. Soil Till. Res., 2007, Vol 97, pp 331-340.
[6] A. Hemmat, and A.A. Khashoei,. Emergence of irrigated cotton in flat
land planting in relation to furrow opener type and crust-breaking
treatments for cambisoils in central Iran. Soil Till. Res., 2003, Vol. 70
pp 153-162.
[7] D. Karayel, and A. Özmerzi,. Comparison of vertical and lateral seed
distribution of furrow openers using a new criterion. Soil Till. Res.,
2007, Vol. 95, pp: 69-75.
[8] S. Rahman, and Y. Chen,. Laboratory investigation of cutting forces and
soil disturbance resulting from different manure incorporation tools in a
loamy sand soil. Soil Till. Res., 2001, Vol. 58, pp 19-29.
[9] S. Tessier, G.M. Hyde, R.I. Papendick and K.E. Saxton,. No-till seeders
effects on seed zone properties and heat emergence. Till. ASAE, 1991,
Vol. 34, pp 733-739.
[10] S. Tessier, K.E. Saxton, R.I. Papendick and G.M. Hyde,. Zero-tillage
furrow opener effects on seed environment and wheat emergence. Soil
Till. Res., 1991, Vol. 21, pp 347-360.
[11] T. Vamerali, M. Bertocco and L. Sartori,. Effects of a new wide-sweep
opener for no-till planter on seed zone properties and root establishment
in maize Zea mays L.: A comparison with doubledisk opener. Soil Till.
Res., 2006, vol. 89, pp 196-209.