pH and pe are very helpful values for understanding soil environmental conditions. Particularly, it has a great influence on the form of nutrients such as nitrogen. When pH+pe is less than 14.32, NO 2 increases and NO 2 (g) produced from NO 2 harms crops. In this study, KOH, KMnO 4 , and sodium percarbonate (sp) were used to raise pH and pe to above the appropriate range (pH 6-7). While the pH was around 5 before the test, the pH was maintained at 6 or higher by all treatments until the end of the test (pH increment (ΔpH) after 5 days 1.0-2.5). pH+pe values were able to be corrected to 14.32 or more by KOH+KMnO 4 treatments and sp treatment in drip irrigation and excessive treatment was good at furrow irrigation with easily reductive condition. Potassium (K), which is one of soil cation exchange capacity (CEC), acts as a strong base to increase the pH, so it is necessary to carry out the CEC measurement and titration test before the KOH+KMnO 4 treatment. Mn 2+ is decreased by the precipitation reaction with phosphate ion (H 2 PO 4 -) in the soil. Phosphate input will be helpful to supply phosphate necessary for crop growth and to prevent Mn excess. In addition, when determining the amount of reagent treated, it is considered that the soil osmotic pressure should be lower than the plant osmotic pressure so as not to cause wilted plant.

Chloroform fumigation and extraction (CFE) has been a widely accepted method for quantifying overall size of soil microbial community, which is a key indicator to assess the quality and health of a given soil. However, the standard procedure of CFE requires careful operations to generate enough CHCl 3 vapors and flush them into soil pores. We suggest a new simple alternative for facilitating gaseous diffusion of CHCl 3 molecules under ambient air pressure conditions. The microbial C values by the new approach, examined for several farmland, forest, and grassland soils, coincided well with those obtained by the standard CFE. The cell lysis and extraction coefficient was also close to that of standard CFE and much higher than that evaluated for a liquid-based CHCl 3 cell lysis.