Effect of Tillage Practice on Soil Moisture Retention under Three Selected Cowpea Varieties

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.