NH3 emissions have significant implications for ecosystems and human health. Pig houses are important sources of NH3 emissions. This study aimed to evaluate the NH3 adsorption capacity of rice husk biochar (RHB), its effectiveness in mitigating NH3 emission from pig house using a RHB column, and the fertilizer potential of the collected RHB for maize growth. In a laboratory assay, NH3 adsorption by RHB was measured using a closed chamber where NH3 was diffused from NH4OH. NH3 adsorption in RHB packed in column was the highest at a flow rate of 2.0 L min−1 (6.52 mg g−1). H2SO4-mixed RHB enhanced NH3 adsorption by 41.7% compared to RHB alone. When compared the efficiency of RHB column in NH3 emission, the emission reduced by 34.5% and 58.2%, respectively, after passing RHB and H2SO4-mixed RHB columns compared to that measured without column (0.59 g d−1). In a pig house setting, NH3 concentration after passing the columns of control, RHB, and H2SO4-mixed RHB was in average 14.8, 8.5, and 3.9 mg m−3, respectively, during experiment period. Cumulative emissions were reduced by 42.6% and 73.3% using RHB and H2SO4-mixed RHB columns, respectively. The application of RHBs collected from the column significantly increased dry matter and crude protein production in maize, with notable enhancement by H2SO4-mixed RHB application. These results demonstrate the integrated effectiveness of RHB application in NH3 management, in which NH3 emissions from the pig house are adsorbed using RHB column, and the NH3-adsorbed RHB collected from column is recycled through the soil to support plant growth.