Ammonia Volatilization from Soils Fertilized with Different Nitrogen Type and Application Method in Germination and Early Seedling Stages from the Radish Field

Ammonia volatilization（AV） from basal fertilizer with different nitrogen（N） types and application methods was investigated by the ventilation method in germination and early seedling stages during radish growth seasons in 2014. Four N fertilizer types, urea（U）, ammonium bicarbonate（AB）, ammonia sulfate（AS）, and controlled urea formaldehyde（CUF） were applied through 5 cm depth placement（I） and 10 cm depth placement（II）. The results showed that the N fertilizer type was the main factor that caused AV loss in germination and early seedling stages from the radish field. The highest and the lowest cumulative AV losses in germination and early seedling stages from the radish fields were 33.23 and 11.21 N kg/hm;for the treatments of AB+I and CUF+II, respectively, accounting for 60.40 and 26.40% of the N application for each treatment. The 10 cm deep placement of N reduced AV rates and lagged the AV process, and CUF significantly reduced ammonia volatilization. The data showed that the suitable N fertilizer type and application method for basal fertilizer were CUF and deep placement, respectively.Therefore, fertilizing with proper N fertilizer types and methods should be the efficient measures to mitigate AV losses from the radish field and will alleviate environment problems.