Oyster shell has a high content of CaCO3 to be used as a acidic soil amendment. To enhance productivity of barley and soil microbe in an upland soil, oyster shell and calcium-magnesium carbonate were selected as a soil amendments in this study. A field experiment was treated no treatment (hereafter, control), oyster shell lime 3.09 Mg ha-1 and 2.38 Mg ha-1, and calcium-magnesium carbonate 2.38 Mg ha-1 as amount of lime requirement in silt loam soil. The yield of barley from the oyster shell lime treatment was the highest. The protein content of barley was the highest of 11.1% in the calcium-magnesium carbonate, followed by 10.7%for the control, 10.6% for the oyster shell lime 3.09 Mg ha-1, and 10.4% for the oyster shell lime 2.38 Mg ha-1.
Soil pH value was higher than that of control in harvesting stage. In addition, the population of soil bacteria was highest in oyster shell lime 2.38 Mg ha-1, actinomycetes was highest in calcium-magnesium 2.38 Mg ha-1.
We concluded that the oyster shell lime can be effective to restore soil nutrient and microbe balance in an upland soil.