Abstract:
n degraded and leached soils due to intensive cultivation, soil acidity problems and a
decline in fertility comprise major limitations to soil productivity and crop yield. To
overcome this problem, one survey and two experiments were conducted in laboratory,
greenhouse, and field condition. The objective of this study were to assess soil fertility under
different land use types, determine the effects of lime, NPSZnB, and vermicompost on
selected soil chemical properties, and response of maize yield and selected soil properties to
the application of amendments in field experiment. To assess soil fertility, samples were
collected from three representative Kebeles under three land use types. For the incubation
experiment, four levels of lime, four levels of VC, and four rates of NPSZnB fertilizers were
used. For the field experiment, two lime rates, three vermicompost rates, and three blended
fertilizer rates were used. The results indicate that cultivated land has relatively lower soil
pH, organic carbon, total nitrogen, basic cations, CEC, available phosphorus, available
sulfur, extractable Zn, and B, and relatively high bulk density, exchangeable acidity,
extractable Mn and Fe when compared with grazing and forest land. The combination of
different treatments improved soil pH, organic carbon, total nitrogen, available phosphorus
and available sulfur, exchangeable bases, extractable zinc, and boron significantly over the
control treatments. The two years field experiments recorded results indicate that
significantly higher phenology maturity days, plant height, cob length, number of grains per
cob, thousand seed weight, grain Yield, above ground dry biomass yield and harvest index
were recorded in treatments that received integral application 4 tons ha-1 lime, 5 tons ha-1
vermicompost and 200 kg ha-1 NPSZnB inorganic blended fertilizer. The soil analysis after
harvest revealed that amendments improved pH, organic matter, total nitrogen,
exchangeable bases, and cation exchange capacity while exchangeable acidity significantly
decreased. Integrated application of lime, vermicompost, and inorganic fertilizer can be
recommended for ameliorating the acidity of the soils and overcome the current surface soil
acidity and fertility decline problem and increasing maize yield to optimum production
rather than solo application of organic or inorganic fertilizer.
