Studies on Saline Soils in Khon Kaen Region, Northeast Thailand : II. Seasonal Changes of Physical and Chemical Properties

概要

論文の詳細を見る
The direct field measurement of N loss by denitrification in flooded soils has been a long-standing challenge. A field experiments was conducted in puddled, flooded soil without plants to ascertain whether the directly measured evolution of (N_2+N_2O)-^<15> from ^<15>N-labeled nitrate applied to floodwater was an accurate measure of denitrification loss. The evolution of (N_2+N_2O)-^<15>N was determined from the ^<15>N content of air samples collected in a chamber placed over the floodwater. The evolved (N_2+N_2O)-^<15>N correlated (r=0.86) with floodwater (NO_3^-+NO_2^-)-N measured 48 h earlier. The total (N_2+N_2O)-^<15>N evolved over the 10 days following nitrate addition ranged from 20 to 25% of the added N. The added <15>^N not recovered in the soil and floodwater after 10 days ranged from 48 to 64% of the added N. This unrecovered <15>^N after the (N_2+N_2O)^<15 >N evolution decreased to negligible levels (less than 15 g N・ha^<-1>・day^<-1>).
社団法人日本土壌肥料学会の論文