DETERMINATION OF SUITABLE FIELD WORKDAYS FOR TILLAGE OPERATIONS AT SELECTED LOCATIONS OF KADUNA STATE, NIGERIA

Suitable field workdays for agricultural machine operations (ploughing, harrowing and ridging) of some selected areas of Kaduna State in Nigeria were determined using soil moisture level and rainfall criteria. These involved the development of soil moisture budget and establishment of tractability criteria for each soil types assessed. Thirty (30) years meteorological information of these areas were collected from the Institute for Agricultural Research ABU, Zaria and total of 200 soil samples were collected from 20 different farm lands and analyzed. The soil particle sizes, bulk densities, soil moistures level at field capacity and plastic limits were determined and the soil moisture limits were used to set the tractability criteria for each soil types. The information obtained was used to develop a computer based programme to monitor the variation in the moisture level. The estimated soil moisture levels and rainfall amount were compared with the tractability criteria to segregate the tractable and non-tractable soil moisture determining suitable and non-suitable workdays respectively. Out of the annual crop growing season of 214 days (from April to October) considered in this study, the sandy-clay-loam soils had the highest machinery suitable field workdays of 76 (35.51%) days for tillage operations (ploughing, harrowing and ridging). The clay soil had the least available machinery tillage workdays of 49 (23.00%) days. The sandy, sandy-loam, loam and clay-loam soils have 69 (32.24%), 63 (29.44%), 54 (25.23%) and 50 (23.36%) suitable workdays respectively.