for Agricultural Soils and Rice Cultivation in Japan

Transcription

1 The 7th Workshop on GHG Inventories in Asia (WGIA7) 7-10 July 2009, Seoul, Republic of Korea Country-specific Emission i Factors for Agricultural Soils and Rice Cultivation in Japan Kazuyuki Yagi National Institute for Agro-Environmental Sciences, Tsukuba, Japan

2 Country-specific Emission Factors for agricultural soils and rice cultivation in Japan CONTENTS EF for direct and indirect N 2 O from agricultural soils EF for CH 4 from rice cultivation Activity data preparation Recent programs for mitigation

3 National Inventory for Japan Anthropogenic Sources for CH 4 and N 2 O CH 4 :1.08 Mt (22.6 Mt CO 2 eq.) N 2 O:0.049 Mt N (23.8 Mt CO 2 eq.) Fuel combustion Fuel Waste 4% Fugitive Waste water 2% water 6% 5% Wast Industrial incineration processes 10% 1% Other agriculture 0% Waste disposal 20% Rice cultivation 25% Ruminant animals 31% Manure manage 11% Ag. residue burning 0% Agricultural soils 27% Manure manage 20% Fuel combustion 33% Industrial processes 4% Solvent 1% Inventory in 2007 (Colored parts indicate agricultural sources)

4 National Inventory for Japan N 2 O from agricultural soils Methodology Tier 2 methodology for N 2 O from mineral fertilizer and animal manure Country-specific t EFs for 3 crop types, which h are based on seasonal field monitoring at 36 sites Identical EFs for mineral fertilizer and animal manure Tier 1 methodology for other N 2 O sources

5 N/ha) N2O-N (kg tea rice legume other upland crops grassland fallow crop_ upland fallow grassland legume rice tea No clear relationship with N application rate Emissions from tea are remarkably high Emissions from rice are remarkably low Therefore, country specific EFs are set for 3 categories: tea paddy rice other upland crops total N application rate (kg/ha) Relationship between N inputs and N 2 O emissions from different crop types

6 N2O (kgn/ /ha) soil well_drained_soil poor_drained_soil poor drained d soil well drained soil total N application rate (kg/ha) Further analysis for other upland crops Soil drainage classes were categorized from soil types Poorly drained soil > well-drained soil No clear relationship for poorly drained soil Well-drained soil: r 2 = 0.38 Relationship between N inputs and N 2 O emissions from upland fields with different soil drainage type (measurement period more than 90 days)

7 Table Summary of N2O-N emission and fertilizer induced N2O-N emission factor from Japanese upland field (except tea filed) measurement period more than 90 days soil drainage # n mean standard deviation median min max N2O-N emission (kgn ha-1) well drained soil a** poorly drained soil b Fertilizer induced N2O-N emission factor (%) well drained soil a** poorly drained soil b estimated emission factor for 0.62 $ 0.48 $$ all soil poorly drained soil > well-drained soil EF for upland = 062± 0.62 ± 048%(weighted 0.48 by area of soil type) measurement period: more than 90 days assuming that most of the fertilizer-induced N2O emission should be included in this period, because data availability

8 National Inventory for Japan N 2 O from agricultural soils Adopted EFs Direct N 2 O: Mineral fertilizer/animal manure Paddy rice: 0.31 (±0.31) % (IPCC default values) Tea: 2.90 (±1.82) % (from national data analysis) Other crops: 0.62 (±0.48) % (from national data analysis) Direct N 2 O: Crop residues/legumes IPCC default values Direct N 2 O: Organic soils Paddy: 0.30 kg N 2 O-N/ha/year (from national data) Upland: IPCC default values (similar to national data) Indirect N 2 O Atmospheric deposition (IPCC default values) Leaching and run-off: 1.24 % (IPCC default values)

9 National Inventory for Japan CH 4 Emissions from Rice Cultivation Tier 2 methodology Methodology Country-specific EFs for 5 soil types, which are based on seasonal lfield monitoring i at t35 sites over the country during Country-specific scaling factors (SFs) for 3 organic amendment Water management was assumed to be homogeneous intermittent-irrigation for 98% of the rice fields

10 National Inventory for Japan CH 4 Emissions from Rice Cultivation Water Management Categorization Water management was assumed to be homogeneous intermittent-irrigation irrigation for 98% of the rice fields A scaling factor of 1.77 is applied for continuous flooding fields which accounted for 2% of the area No consideration for water regime in the pre-season

11 National Inventory for Japan CH 4 Emissions from Rice Cultivation Emission Factors Type of soil No. of data Straw amendment Various compost Noamendment Proportion of area amendment [gch 4 / m2 /year] % Andosol Yellow soil Lowland soil Gley soil Peat soil Based on field monitoring campaign during at 35 sites over Japan Measured by conventional water management with mid-season drainage followed by intermittent flooding

12 National Inventory for Japan CH 4 Emissions from Rice Cultivation Calculation for Organic Amendment Applied SFo for straw: :1 Andosols Yellow soils Grey lowland soils Gray soils Peat soils SFo for various compost: 1.25 Activity data based on interview with ca. 2,000 farmers by MAFF Straw 60% Compost 20% No 20% CH 4 emission from the plot without rice straw (g m -2 )

13 Estimation of GHG Emissions by a Process-Based Model DNDC model Figure 2 The DNDC Model Ecological Climate Soil Vegetation Anthropogenic activity drivers Plant growth Daily water Daily biomass demand accumulation ( LAI ) Annual average Daily potential Water uptake temperature ET by roots N demand Grain Water stress LAI-regulated Water flow Evaporation Transpiration albedo between layers Stalks Daily N uptake by roots Root respiration Roots CO2 NH4 Labile humads Very labile Labile Resistant litter litter litter Labile microbes Resistant microbes Soil temperature Soil moisture Oxygen Soil Eh Oxygen DOC profile profile diffusion profile consumption Passive humus Soil climate Effect of temperature and moisture on decomposition Decomposition Soil environmental Temperature Moisture ph Eh Substrates (NH4+, NO3- and DOC) variables NO NO2 - N2O N2 Nitrate denitrifier Nitrite denitrifier N2O denitrifier NO3 - DOC Nitrifiers Soil Eh NH4+ Aerenchyma NO3- NH3 Clay-NH4+ DOC DOC N2O NO NH3 Denitrification Nitrification Fermentation Resistent humads CH4 production CH4 CH4 oxidation CH4 transport Emission CH4 Emission Simulation and validation (kg C ha -1 d -1 ) ha -1 d -1 ) CH4 (kg C Simulation Observation DOY 4 3 Straw Control Litter Removed Day of Year No Residue Stubble Straw GIS data for parameters management vegetation soil climate Regional estimation Japan-U.S. High-Level Consultations on Climate Change Effects of agricultural land use on emission and absorption of greenhouse gases NIAES and University of New Hampshire (Prof. Changsheng Li)

14 DNDC-Rice Model Original DNDC introducing rice growth sub-model revising soil redox sub-model Revised DNDC DNDC Rice (kg C ha -1 d -1 ) CH4 Flux -1 ) Flux (kg C ha -1 d - CH4 Comparison of the model simulation with monitoring data: 30 Urea application(300u)and 25 (NH 4 ) 2 SO 4 application (300S) Nanjing 300U (data) 300S (data) 300U (model) 300S (model) Nanjing U (data) Day of Year 300S (data) 2 300U (model) 300S (model) 1 original DNDC DNDC Rice Day of Year メタン発生量 (g m -2 ) わら秋すすき込み わら持持ち出し 刈りり株除去 わら秋すすき込み わら春すすき込み わら秋すすき込み わら持持ち出し わら春すすき込み observation DNDC-Rice 観測 DNDC Rice original DNDC わら秋すすき込み わら持持ち出し 従来の DNDC 尿素施用 つくば比布南京 硫安施用

15 National Inventory for Japan Activity data preparation National statistics MAFF crop statistics MAFF statistics of cultivated and planted area MAFF vegetable production and shipment statistics Yearbook of fertilizer statistics etc. Research and interview MAFF basic survey of ground strength: th soil type distribution, organic matter management Research on nutrient balance of crops in Japan: N content of non-harvest aboveground portion by crop etc. Still some default factors and expert judgments

16 MAFF Basic Survey organic matter management in rice cultivation 100% no organic matter green manure wheat/barley straw 80% rice straw manure with sawdust and tree bark other manure with sawdust swine manure with sawdust 60% cattel manre with sawdust other manure swine manure cattle manure compost 40% 20% 地力保全事 土壌環境影響対策事業報告書 より 0% from interview of 2,300-2,500 farmers in the country

17 Recent Programs for Mitigation included in the Kyoto protocol target plans To reduce application rates of mineral fertilizer N successful by promoting the policies for environmental-friendly agriculture To promote composting rice straw in paddy fields not much progress due to cost and labor To T introduce pro-longed mid-season drainage in paddy fields under experimental stage, but can be extended soon

18 Fukushima, Japan Prolonged Mid-Season Aeration to Reduce CH 4 Emissions (mg m -2 hr -1 ) aeration Continuous flooding 7 days aeration 30 kg N/ha 14 days aeration 21 days aeration 湛水期間 Flooding CH 4 flux kg N/ha MAY JUN JUL AUG SEP

19 Fukushima, Japan Mid season drainage at different period 80 Seasonal CH 4 Emissions メタタン発生量 (gch4m -2 ) Decrease in rice yield 81% 61% 51% 0 Conventional practice 21 days 14 days 7 days Continuous drainage 処理 1 drainage 処理 2 drainage 処理 3 常時湛水 flooding

20 National Inventory for Japan Summary for Soil Emissions Present state: Tier 2/Tier 1 for N 2 O from soils Tier 2 for CH 4 from rice Tier 1 for CH 4 &NOf 2 from residue burning Further improvement: CS-EF for N 2 O from organic amendment and crop residues/legumes Tier 3 for CH 4 from rice by the DNDC model introducing factors for mitigation

21 GHG studies can contribute to For example: sustainable development C sequestration in agricultural soils => can enhance soil fertility and crop production Improved water management for CH 4 mitigation => can increase rice production Various N 2 O mitigation options => can reduce other environmental impact by > can reduce other environmental impact by reactive N losses

22 Roles of Soil Scientists to develop the alternative systems for sustainable agriculture to promote the international agreements on reasonable land use