The fate of fumigants methyl isothiocyanate (MITC) and chloropicrin (CP) is of particular concern to reduce emission loss, increase pest-control efficacy, and minimize their potential to air and groundwater pollution. The emission, distribution, leachability, and persistence of MITC and CP were examined in a sandy soil using repacked soil columns under three surface conditions including the tarping, limited irrigation with tarping, and 5-d non-tarped irrigation. Their volatilization flux rates, gas concentrations at 10-depths in column, and recoveries in leachate were measured for 15 d. The results indicated gas-phase transport strongly influenced MITC and CP volatilization. Volatilization losses of MITC and CP reached up to 62% and 30% of the amount applied under tarping with no water addition. Appling water before tarping enhanced CP volatilization loss to 45% and reduced MITC emission to 36% of the total amount applied over 15 d. Volatilization of two pesticides was significantly suppressed by 5-d irrigation at 4.0 cm per day. Volatilized MITC and CP losses only constituted 0.3% and 5.4% of the amount applied. Downward movement was significantly affected by the amount of water applied. Total recoveries of MITC and CP in the leachates during 15 d were 3.7% and 0.2% of the initial amount, respectively. MITC and CP may have a tendency to reach groundwater under overirrigation or intense precipitation. Both fumigants persisted in the columns for 15 d. MITC retention was relatively low compared to CP. Relatively high concentrations of MITC and CP were detected in soil air in the root zone layer under tarped conditions. The results implied that emission and degradation played a major role. Application and soil management techniques can be developed by optimizing these conditions.