Effect of Tillage Practice on Soil Moisture Retention under Three Selected Cowpea Varieties
R. N. Khaemba *
Department of Plant Science and Crop Protection, University of Nairobi, P.O.Box 30197, 00100 GPO, Nairobi, Kenya.
J. M. Kinama
Department of Plant Science and Crop Protection, University of Nairobi, P.O.Box 30197, 00100 GPO, Nairobi, Kenya.
G. N. Chemining’wa
Department of Plant Science and Crop Protection, University of Nairobi, P.O.Box 30197, 00100 GPO, Nairobi, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Aim: To evaluate the effect of tillage practice on soil moisture retention under three cowpea varieties.
Study Design: The treatments were laid out in a randomized complete block design with a factorial arrangement and replicated three times.
Place and Duration of Study: The experiment was conducted at St. Theresa farm and Nakamane irrigation scheme in Turkana county between November 2014 and January 2015.
Methodology: Treatments comprised three tillage practices: conventional tillage (control), conventional tillage + mulch, and zero tillage and three cowpea varieties: M66, K80, and Kenkunde. Soil samples were collected using an auger (25 mm internal diameter) from near randomly selected 5 plants at the depth of 15 cm in all treatments at an interval of 7 days. The gravimetric moisture was determined using the FAO equation.
Results: Tillage + mulch and zero tillage conserved 37.07% and 31.63% more moisture than conventional tillage at St Theresa demo farm, respectively. At Nakamane irrigation scheme, zero tillage retained more moisture content of 33.02% followed by conventional tillage + mulch at 32.24% as compared to conventional tillage. Significant interaction was realized between tillage practice and variety at Nakamane experimental site only. The main effects of variety had no effect on moisture retention.
Conclusion: Tillage practice has significant effect of moisture retention in Turkana county. Any cowpea variety established has no effect on moisture retention. A broader use of tillage practices and varieties is advisable for further studies.
Keywords: Cowpea, moisture retention, tillage