The development of synthetic fertilizers has led to an explosive increase in crop
production, which has resulted in a continuous increase in the world''s population.
Human activities such as indiscriminate fertilizer application and use of fossil fuels
have continuously increased anthropogenic greenhouse gas emissions, and the
concentration is currently at its highest level in the past 800,000 years. As a result,
each country is implementing greenhouse gas reduction policies, and Korea has
presented a goal of reducing emissions by 37% compared to the Business as usual,
and the non-energy sector in agriculture among each industry sector has a reduction
target of about 1.6 million tons, equivalent to 7.9% of the predicted level of cabbage.
Has been set the main greenhouse gases generated in the agricultural sector are CO2,
CH4, and N2O, and CO2 and N2O are mainly generated from open fields and facility
cultivation. Incubation experiment was carried out to investigate greenhouse gas
emissions and soil quality in agricultural soils through varying rates of two biochars
(BC) derived from rice hull biochar and livestock manure biochar. all treatment was
supplemented inorganic fertilizers (by N-P2O5-K2O : 32-7.8-19.8 kg 10a-1
) and
compost (540 kg 10a-1
) with BC derived from rice hull and livestock manure biochars
at varying rates of 5, 10 and 20 t ha-1
(BC5, BC10 and BC20, respectively); the control (BC0) area was untreated only biochar.
Our results reveal that soil quality and
emissions of CO2 and N2O varied significantly with the biochar application rate. Peak
emissions of CO2 and N2O were mainly observed in the early period of incubation
experiment, followed by basal emissions. During the incubation experiment periods,
the overall N2O emission was significantly decreased with BC5, BC10 and BC20
applications as compared to the control, ranging from 11.1 to 13.6%, 8.7 to 15.4%,
23.1 to 26.0%, and 15.0 to 19.6%, respectively. Soil quality results after the incubation
experiment show, T-C, pH, and cation exchange capacity (CEC) were significantly
improved by biochar application, as compared to the control. Inorganic nitrogen
content was evaluated for nitrification potential, and it was confirmed that the
nitrification rate was slowed down as biochar applied. And a field experiment was
carried out to investigate crop productivity, emissions of CO2 and N2O and soil quality
of an upland field treated with compost and varying rates of biochar (BC) derived
from rice hull during crop growing periods in Chinese cabbage cultivation. Compost
was supplemented with BC at varying rates of 1, 3, and 5 t ha-1
(BC1, BC3, and BC5
respectively); the control (BC0) area was untreated. crop productivity was improved
after BC application as compared to the control treatment area, by 28.5% for upland
field and 10.6% for greenhouse field Chinese cabbage cultivation. Greenhouse gases
emissions were calculated and evaluated by greenhouse warming potential and
greenhouse gas intensity. Compared to the control area, emissions during the cropping
period, the overall N2O emission was significantly decreased with by 1.91 - 5.35 times
at maximum BC1, BC3 and BC5 applications as compared to the control, ranging
from 1.91 to 5.35 times at maximum, respectively. Soil quality results after field
experiments Similar to the results of incubation experiments, T-C, pH and cation
exchange capacity (CEC) were significantly improved by biochar fertilization
compared to the control group. Thus, our results indicate that application
supplemented that fertilizer with biochar is for achieving high crop productivity and
improving soil quality in upland and greenhouse field conditions. In conclusion, the
application of biochar has the side benefit of enriching soil quality, reducing the use
of inorganic fertilizers and reducing greenhouse gas emissions.