ABSTRACT: Greenhouse gases emission

ABSTRACT: Greenhouse gases emissions have increased during the last century due to human activities such
as agricultural practices, fossil fuel burning and industrial practices. The formation of greenhouse gases, in
particular N2O or CO2
is strongly controlled by both soil temperature and soil humidity. Laboratory experiment
was conducted to assess the response of grassland and arable soils with regard to N2O and CO2
flows and
mineral nitrogen concentration; soils were exposed to various drying rewetting cycles at different gravimetric
water contents (wt
) under controlled conditions. In total,four treatments were conducted:soils under continuously
moist control at 30% wt
soils receiving short drying rewetting cycles (SDWC) between 30% to 21% (wt
), soils
exposed to medium drying rewetting cycles (MDWC) at 30-18% (wt
) and a treatment with long drying rewetting
cycles (LDWC) 30-5% (wt
). The results indicated that both soils reduced N2O-N flow in the long dryingrewetting
treatments. For the CO2
-C flow, soils showed differing patterns, at which the shortly dried-rewetted
cycle treatment of grass soils yielded highest (128 µg/kg) cumulative flow that was 24% higher than LDWC.
There was no effect of drying-rewetting cycles (DWC) on grass soils. The stressed treatments emitted only 18
% higher CO2
-C flow than the control. The treatment with 4% wt
successfully reduced N2O-N flow in grassland
and arable soils. This study shows that the soil net nitrogen mineralization and nitrification rates of arable soil
were significantly higher in arable soil compared to grass soil.

ผลลัพธ์ (อังกฤษ) 3:

ABSTRACT: Greenhouse gases emissions have increased during the last century due to human activities such
as agricultural. Practices fossil fuel, burning and industrial practices. The formation of, greenhouse gases in
particular N2O or CO2
is. Strongly controlled by both soil temperature and soil humidity. Laboratory experiment
.Was conducted to assess the response of grassland and arable soils with regard to N2O and CO2

flows and mineral nitrogen. Concentration; soils were exposed to various drying rewetting cycles at different gravimetric
water contents ( wt
) under. Controlled conditions. In total four treatments, were conducted: soils under continuously
moist control at 30%  wt
.Soils receiving short drying rewetting cycles (SDWC) between 30% to 21% ( wt
), soils
exposed to medium drying rewetting. Cycles (MDWC) at 30-18% ( wt
) and a treatment with long drying rewetting
cycles (LDWC) 30-5% ( wt
). The results indicated. That both soils reduced N2O-N flow in the long dryingrewetting
treatments. For the CO2
- C flow soils showed differing patterns,,At which the shortly dried-rewetted
cycle treatment of grass soils yielded highest (128 could g / kg) cumulative flow that was 24% higher. Than LDWC.
There was no effect of Drying-Rewetting cycles (DWC) on grass soils. The stressed treatments emitted only 18
%. Higher CO2
- C flow than the control. The treatment with 4%  wt
successfully reduced N2O-N flow in grassland
and arable soils.This study shows that the soil net nitrogen mineralization and nitrification rates of arable soil
were significantly higher. In arable soil compared to grass soil.
.