LAND DEGRADATION IN THREE LOCATIONS AND SAMPLING PERIODS IN PHYSIOGRAPHIC UNITS UNDER ARABLE CROP PRODUCTION IN SUB- HUMID TROPICS OF NIGERIA

Abstract

Understanding landscape features of cultivable agricultural lands and the influence by topographic settings and degradation has become imperative for sustainable land use planning and management. This study compared land degradation in three locations and sampling periods under arable crop production in Nsukka area. Three locations (Obukpa, Lejja and Ozi-Edem) were selected. Soil auger samples were randomly collected in triplicates fromdepth of 0-30cm in plots of 25 m2 marked on the farmer’s field. Soil core samples were collected at 0-10cm depth. Soil sampling was done at three repeated periods; April-May, July-August and October-November for 1st,2nd and 3rd sampling period, respectively. Soil samples were analyzed for physical and chemical properties and all data statistically analyzed as a 3 x 3 x 3factorial using Genstat statistical software. FAO method was employed in land degradation assessment. Results showed that most physical and chemical properties had significantly (p < 0.05) highest values at low slope relative to others,and also at first sampling period relative to other sampling periods. Degradation in Upper slope increased by 3.4 and 5.9 % over middle and lower slope, respectively. Obukpa had the highest level of degradation relative to other locations. Degradation was highest in 3rdsampling period and increasedby 8.4 and 14.9 %over2ndand 1stsampling period, respectively.Degree of degradation increased with sampling time. Appropriate conservation measures, inclusion of restorative crops in cropping systems, use of locally available materials and bio fertilizer are recommended to reduce effect of land degradation in arable soils.