Abstract

Studying the spatial and temporal variability of soil micronutrients and their effects on plant growth is important for implementing precision-farming and/or economizing fertilizer management. The present investigation was done through soil sampling (0–20 cm depth) from three locations in central Ethiopia. The tools employed include, descriptive and/or classical statistics. The concentrations of available copper ranged from 1.38–3.20 mg/kg with narrower range in season-I, than season-II. Manganese ranged from 5.00 – 65.00 mg/kg, indicating its significant uneven distribution over the years and locations. The concentrations of iron ranged from 1.80 – 8.20 mg/kg. Narrower ranges were observed for zinc, boron and molybdenum. From the influencing factors analysis, soil pH was the major factor negatively influenced the availability of the evaluated micronutrients, except molybdenum. Organic carbon was the major positive contributor to sulfur, nitrogen, manganese, zinc, and boron availability. Considering the widely varied wheat yields due to the variations in soil nutrients, more positive relationship was established for the grain than total biomass yield indicating more partitioning of plant nutrients into grains. Overall, the dynamics of soil nutrients, particularly the micronutrients and their influences on wheat yield were described and the results could provide practical bases for sustaining crop production in precision-agriculture.

Key words: Soil micronutrients, spatial and temporal variability, geostatistics, regression, correlation.