scholarly journals Effects of soil spatial resolution on quantifying CH4and N2O emissions from rice fields in the Tai Lake region of China by DNDC model

2011 ◽  
Vol 25 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. S. Yu ◽  
H. Yang ◽  
X. Z. Shi ◽  
E. D. Warner ◽  
L. M. Zhang ◽  
...  
2009 ◽  
Vol 43 (17) ◽  
pp. 2737-2746 ◽  
Author(s):  
Liming Zhang ◽  
Dongsheng Yu ◽  
Xuezheng Shi ◽  
David C. Weindorf ◽  
Limin Zhao ◽  
...  

2008 ◽  
Vol 5 (6) ◽  
pp. 4867-4896
Author(s):  
L. Zhang ◽  
D. Yu ◽  
X. Shi ◽  
L. Zhao ◽  
W. Ding ◽  
...  

Abstract. China's paddy rice accounts for about 22% of the world's rice fields, therefore it is crucial to accurately estimate the CH4 emissions at regional scale to gauge their contribution to global greenhouse gas effect. This paper reports an application of a biogeochemical model, DeNitrification and DeComposition or DNDC, for quantifying CH4 emissions from rice fields in Tai-Lake region of China by linking DNDC to a 1:50 000 soil database, which was derived from 1107 paddy soil profiles in the Second National Soil Survey of China in the 1980s–1990s. The modeled results estimate that the 2.34 M ha of paddy rice fields in Tai-Lake region emitted about CH4 of 5.67 Tg C for the period of 1982–2000, with the average CH4 flux ranged from 114 to 138 kg C ha−1y−1. The highest emission rate (659.24 kg C ha−1 y−1) occurred in the subgroup of "gleyed paddy soils", while the lowest (90.72 kg C ha−1y−1) were associated with the subgroup "degleyed paddy soils". The subgroup "hydromorphic paddy soils" accounted for about 52.82% of the total area of paddy soils, the largest of areas of all the soil subgroups, with the CH4 flux rate of 106.47 kg C ha−1y−1. On a sub-regional basis, the annual average CH4 flux in the Tai-Lake plain soil region and alluvial plain soil region was higher than that in low mountainous and hilly soil region and polder soil region. The model simulation was conducted with two databases using polygon or county as the basic unit. The county-based database contained soil information coarser than the polygon system built based on the 1:50 000 soil database. The modeled results with the two databases found similar spatial patterns CH4 emissions in Tai-Lake region. However, discrepancies exist between the results from the two methods, the relative deviation is −42.10% for the entire region, and the relative deviation ranged from −19.53% to 97.30% for most counties, which indicates that the more precise soil database was necessary to better simulate CH4 emissions from rice fields in Tai-Lake region using the DNDC model.


2009 ◽  
Vol 6 (5) ◽  
pp. 739-749 ◽  
Author(s):  
L. Zhang ◽  
D. Yu ◽  
X. Shi ◽  
D. Weindorf ◽  
L. Zhao ◽  
...  

Abstract. As China has approximately 22% of the world's rice paddies, the regional quantification of CH4 emissions from these paddies is important in determining their contribution to the global greenhouse gas effect. This paper reports the use of a biogeochemical model (DeNitrification and DeComposition or DNDC) for quantifying CH4 emissions from rice fields in the Taihu Lake region of China. For this application, the DNDC model was linked to a 1:50 000 soil database derived from 1107 paddy soil profiles compiled during the Second National Soil Survey of China in the 1980s–1990s. The simulated results showed that the 2.3 Mha of paddy rice fields in the Taihu Lake region emitted the equivalent of 5.7 Tg C from 1982–2000, with the average CH4 flux ranging from 114 to 138 kg C ha−1 y−1. As for soil subgroups, the highest emission rate (660 kg C ha−1 y−1) was linked to gleyed paddy soils accounting for about 4.4% of the total area of paddy soils. The lowest emission rate (91 kg C ha−1 y−1) was associated with degleyed paddy soils accounting for about 18% of the total area of paddy soils. The most common soil in the area was hydromorphic paddy soils, which accounted for about 53% of the total area of paddy soils with a CH4 flux of 106 kg C ha−1 y−1. On a regional basis, the annual averaged CH4 flux in the Taihu Lake plain soil region and alluvial plain soil region were higher than that in the low mountainous and hilly soil region and the polder soil region. The model simulation was conducted with two databases using polygons or counties as the basic units. The county-based database contained soil information coarser than the polygon system built based on the 1:50 000 soil database. The modeled results with the two databases found similar spatial patterns of CH4 emissions in the Taihu Lake region. However, discrepancies exist between the results from the two methods. The total CH4 emissions generated from the polygon-based database is 2.6 times the minimum CH4 emissions generated from the county-based database, and is 0.98 times the maximum CH4 emissions generated from the county-based database. The average value of the relative deviation ranged from −20% to 98% for most counties, which indicates that a more precise soil database is necessary to better simulate CH4 emissions from rice fields in the Taihu Lake region using the DNDC model.


2009 ◽  
Vol 9 (5) ◽  
pp. 433-442 ◽  
Author(s):  
Song Li ◽  
Hua Li ◽  
Xingqiang Liang ◽  
Yingxu Chen ◽  
Zhihong Cao ◽  
...  

2008 ◽  
Vol 216 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Josefine Norman ◽  
Per-Erik Jansson ◽  
Neda Farahbakhshazad ◽  
Klaus Butterbach-Bahl ◽  
Changsheng Li ◽  
...  

2000 ◽  
Vol 10 (4) ◽  
pp. 1074-1089 ◽  
Author(s):  
Erle C. Ellis ◽  
Rong Gang Li ◽  
Lin Zhang Yang ◽  
Xu Cheng

2019 ◽  
Vol 11 (21) ◽  
pp. 6158 ◽  
Author(s):  
Wonjae Hwang ◽  
Minseok Park ◽  
Kijong Cho ◽  
Jeong-Gyu Kim ◽  
Seunghun Hyun

In this study, we applied the Denitrification and Decomposition model to predict the greenhouse gas (GHGs; CO2 and N2O) emissions and cabbage yields from 8072 cabbage fields in Korea in the 2020s and 2090s. Model outputs were evaluated as a function of tillage depth (T1, T2, and T3 for 10, 20, and 30 cm) and fertilizer level (F1, F2, and F3 for 100, 200, and 400 kg N ha−1) under the Representative Concentration Pathways 8.5 climate change scenario. For both time periods, CO2 emissions increased with tillage depth, and N2O emissions were predominantly influenced by the level of applied N-fertilizers. Both cabbage yields and GHGs fluxes were highest when the T3F3 farming practice was applied. Under current conventional farming practices (T1F3), cabbage yield was projected at 64.5 t ha−1 in the 2020s, which was close in magnitude to the predicted cabbage demand. In the 2090s, the predicted cabbage supply by the same practice far exceeded the projected demand at 28.9 t ha−1. Cabbage supply and demand were balanced and GHGs emissions reduced by 19.6% in the 2090s when 94% of the total cabbage farms adopted low carbon-farming practices (e.g., reducing fertilizer level). Our results demonstrate the large potential for Korean cabbage farms to significantly contribute towards the mitigation of GHGs emissions through the adoption of low-carbon farming practices. However, in order to incentivize the shift towards sustainable farming, we advise that lower yield and potential economic losses in farmlands from adopting low-carbon practices should be appropriately compensated by institutional policy.


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