This study aimed at optimizing tillage depth and hitching length for optimal draft requirement in sandy clay loam soils for animal drawn subsoiler. Field experiments were conducted to collect draft datasets using the MSI 7300 digital dynamometer communicating remotely with MSI-8000 RF data logger connected to a laptop through the serial port. To determine the numeric values of soil parameters pertinent to subsoiling, field experiments, laboratory tests and numerical analysis techniques were employed. For a specified speed, a combination of three hitch lengths of 2.5 m, 3.0 m and 3.5 m and three depths from 0 cm to 30 cm with a range of 10 cm interval was used. Soil bulk density was found to vary between 1.52 to 1.37 g/cm3 and 1.44 to 1.67 g/cm3 for Machakos and Kitui experimental plots respectively. Soil moisture content increased with an increase in depth ranging from 3.53% to 9.94% for Machakos site and from 4.15% to 9.61% for Kitui site. Soil shear strength parameters ranged between 21.71 and 29.6 kPa between depths of 0 - 20 cm and decreased to 28.07 kPa for depths beyond 20 cm at Machakos experimental plot; while for Kitui experimental plot, it ranged between 30.02 and 39.29 kPa between depths of 0 - 30 cm. A second-order quadratic expression of the form y = ax2 + bx + c was obtained for the relationship between specific draft and depth at given hitching length as well as specific draft against hitching length at a given depth. The optimal hitching length and tillage depth for Machakos experimental plot were obtained as 2.9 m (~3 m) and 16.5 cm respectively. In Kitui experimental site, the optimal hitching length was obtained as 2.9 m (~3 m) and the optimal tillage depth was 15.4 cm.
References
[1]
McCarthy, N., Lipper, L. and Branca, G. (2011) Climate-Smart Agriculture: Smallholder Adoption and Implications for Climate Change Adaptation and Mitigation. Mitigation of Climate Change in Agriculture Working Paper, 1-37.
[2]
Kienzle, J. and Sims, B.G. (2014) Agricultural Mechanization Strategies for Sustainable Production Intensification: Concepts and Cases from (and for) Sub-Saharan Africa. FAO, Rome.
[3]
Guthiga, P.M., Karugia, J.T. and Nyikal, R.A. (2007) Does Use of Draft Animal Power Increase Economic Efficiency of Smallholder Farms in Kenya? Renewable Agriculture and Food Systems, 22, 290-296.
https://doi.org/10.1017/S174217050700186X
[4]
Phillips, I.D., Fielke, S.L., Young, I.R. and McMillen, I.C. (1996) The Relative Roles of the Hypothalamus and Cortisol in the Control of Prolactin Gene Expression in the Anterior Pituitary of the Sheep Fetus. Journal of Neuroendocrinology, 8, 929-933. https://doi.org/10.1111/j.1365-2826.1996.tb00823.x
[5]
Anon, (1992) Tools for Agriculture. Intermediate Technology Publications Ltd., London, 238 p.
[6]
Brassington, T.J.M. (1987) Re-Examination of the Plough. Agricultural Engineer, 5, 53-57.
[7]
Gitau, A.N. (1995) Tillage Practices and Draft Power Requirements for Soil Moisture Conservation of a Hard Setting Soil. Masters Dissertation, University of Nairobi, Nairobi.
[8]
Johansen, C., Haque, M.E., Bell, R.W., Thierfelder, C. and Esdaile, R.J. (2012) Conservation Agriculture for Smallholder Rainfed Farming: Opportunities and Constraints of New Mechanized Seeding Systems. Field Crops Research, 132, 18-32.
https://doi.org/10.1016/j.fcr.2011.11.026
[9]
Rusinamhodzi, L., Corbeels, M., Van Wijk, M.T., Rufino, M.C., Nyamangara, J. and Giller, K.E. (2011) A Meta-Analysis of Long-Term Effects of Conservation Agriculture on Maize Grain Yield under Rain-Fed Conditions. Agronomy for Sustainable Development, 31, 657. https://doi.org/10.1007/s13593-011-0040-2
[10]
Giller, K.E., Witter, E., Corbeels, M. and Tittonell, P. (2009) Conservation Agriculture and Smallholder Farming in Africa: The Heretics’ View. Field Crops Research, 114, 23-24. https://doi.org/10.1016/j.fcr.2009.06.017
[11]
Starkey, P. and Kaumbutho, P. (1999) Meeting the Challenges of Animal Traction: A Resource Book of the Animal Traction Network for Eastern and Southern Africa (ATNESA). Intermediate Technology Publications, London, 326 p.
https://doi.org/10.3362/9781780445458
[12]
Chartier, S. and Cousineau, D. (2011) Computing Mixed-Design (Split-Plot) ANOVA. Mathematica Journal, 13, 13-17. https://doi.org/10.3888/tmj.13-17
[13]
Saville, D.J. and Rowarth, J.S. (2008) Statistical Measures, Hypotheses, and Tests in Applied Research. Journal of Natural Resources & Life Sciences Education, 37, 74-82.
[14]
Twum, E.K. and Nii-Annang, S. (2015) Impact of Soil Compaction on Bulk Density and Root Biomass of Quercus Petraea L. at Reclaimed Post-Lignite Mining Site in Lusatia, Germany. Applied and Environmental Soil Science, 2015, Article ID: 504603. https://doi.org/10.1155/2015/504603
[15]
Chaudhari, P.R. Ahire, D.U. Ahire, V.D. Chkravarty, M. and Maity, S. (2013) Soil Bulk Density as Related to Soil Texture, Organic Matter Content and Available Total Nutrients of Coimbatore Soils. International Journal of Scientific and Research Publications, 3, 1-8.
[16]
Boydaş, M.G. and Turgut, N. (2007) Effect of Tillage Implements and Operating Speeds on Soil Physical Properties and Wheat Emergence. Turkish Journal of Agriculture and Forestry, 31, 399-412.
[17]
Mwangi, S.T., Gitau, A.N. and Muchiri, G. (2018) Effect of Chisel Ploughing on Physical and Mechanical Soil Properties on a Maize Cropped Field. International Journal of Emerging Technology and Advanced Engineering, 8, 84-93.
[18]
Bengough, A.G. and Mullins, C.E. (1990) Mechanical Impedance to Root Growth: A Review of Experimental Techniques and Root Growth Responses. Journal of Soil Science, 41, 341-358. https://doi.org/10.1111/j.1365-2389.1990.tb00070.x
[19]
Vepraskas, M.J. (1994) Plant Response Mechanisms to Soil Compaction. In: Wilkerson, R.E., Plant Environment Interactions, M. Dekker, New York, 263-287.
[20]
Gong, Y. Cao, Q. and Sun, Z. (2003) The Effects of Soil Bulk Density, Clay Content and Temperatute on Soil Water Content Measurement Using Time-Domain Reflectometry. Hydrological Processes, 17, 3601-3614.
https://doi.org/10.1002/hyp.1358
[21]
Harrigan. T. and Roosenberg, R. (2002) Estimating Tillage Draft. Tillers International.
