CROP YIELDS ALONG THE TOPOSEQUENCE OF TERRACED ANDOSOLS IN NAROK, KENYA

The principle objective of terracing is to reduce runoff and soil loss but it also contributes to increasing the soil moisture content through improved infiltration. A field experiment was conducted in Suswa, Narok County during the short and long rain seasons of 2013-2015 to assess the effect of terracing on crop yields. A randomized complete block design was used with maize and beans as the test crops. The study examined maize plant height, leaf area index (LAI), above ground biomass yields, number of bean pods and grain yields in the upper (U), upper middle (UM), middle (M), lower middle (LM) and lower (L) terrace, slope positions with farmers’ fields where terraces were not maintained were used as the control. The results showed that yields were significantly (P<0.05) higher in L>LM>UM>M>U, with values ranging from 7.2 t ha-1 to 3.0 t ha-1 for maize and 1374 kg ha-1 to 306 kg ha-1 for beans. Significant differences (P<0.05) were also observed according to cropping patterns with CP2 on average recording the highest (803 kg ha-1) bean yields and CP4 (control) the lowest (576 kg ha-1) in season I. CP3 had the highest (4.97 t ha-1) maize yields compared to CP4 (3.25 t ha-1) in season II. From the results of the study, it was possible to conclude that soil conservation measures and cropping patterns implemented at Suswa increased crop yields and the technology should be promoted for improved livelihoods.