A Case Study to Estimate the Greenhouse-Gas Mitigation Potential on Rice Production System in Farming without Agricultural Chemicals

2011~2012년 2년간 전북 군산과 익산 지역의 관행농 벼를 재배하는 농가를 대상으로 온실가스 배출량 산정을 위한 인벤토리 목록을 구축하였다. 2년 누적 평균 데이터를 사용하여 전과정평가를 수행하고, 탄소성적 산출 및 온실가스 배출의 주요인을 분석하였다. 분석된 온실가스 배출 주요인자들을 대상으로 민감도 분석을 수행하여 온실가스 잠재량을 산정하고, 대상지역 농가들이 적용할 수 있는 온실가스 저감 영농법을 제안하고자 하였다. 관행농 쌀 생산농가를 대상으로 전과정 목록분석을 수행한 결과 탄소성적은 쌀 1 kg 생산을 기준으로 2.21 kg <TEX>$CO_2.-eq.kg^{-1}$</TEX>가 발생되었다. 온실가스 중 <TEX>$CO_2$</TEX> 배출량이 가장 많았으나, 지구온난화 지수를 곱하여 이산화탄소 등가 (<TEX>$CO_2$</TEX>-eq.)로 환산하면 벼 생산체계의 탄소성적에서 메탄발생 기여도가 가장 컸다. 전체 <TEX>$CO_2$</TEX> 배출량 중 복비생산 공정에서 37%가 발생하였고, 단비생산으로 10%, 벼 재배과정 중 40%가 발생하였다. 벼 재배 중 <TEX>$CO_2$</TEX> 발생원은 농기계의 화석연료 사용에 의한 불완전 연소이다. <TEX>$CH_4$</TEX>는 대부분 벼 재배 중에 발생되었으며, 벼논의 메탄 발생 요인은 혐기조건의 담수논이다. <TEX>$N_2O$</TEX>은 대부분 벼 재배과정에서 배출되었고, 벼 재배 중 <TEX>$N_2O$</TEX>의 발생요인은 복비, 요소 비료, 퇴비 등의 비료시용이었다. 에너지 사용량 변화에 따른 민감도 분석결과 에너지원 중 경유의 민감도가 가장 높았고, 경유사용량을 10% 줄였을 때 약 2.5%의 <TEX>$CO_2$</TEX> 감축 잠재량이 산정되었다. 복비 시용량을 10% 줄였을 때 <TEX>$CO_2$</TEX>는 약 1%, <TEX>$N_2O$</TEX>는 약 1.8%의 감축잠재량이 산정되었다. 퇴비시용을 10% 줄이면 약 1.5%의 메탄발생이 감소하고, 아산화질소는 약 1% 감소효과가 나타났다. 물떼기 일수가 10일 증가하면 메탄발생량이 약 4.5% 감소되었다. 투입량의 변화에 따른 온실가스 감소 효과가 가장 큰 요인은 벼논 물떼기 일수의 증가 및 경운과 수확시 사용하는 농기계용 경유사용량 감소였다. 그에 따라 중간낙수 및 무경운 등이 탄소배출 저감 영농법으로 제시되었다. To estimate greenhouse gas (GHG) emission, we established inventory of conventional rice cultivation from farmers in Gunsan and Iksan, Jeonbuk province in 2011~2012. This study was to calculate carbon footprint and to analyse the major factor of GHGs. We carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we tried to suggest agricultural methods to reduce GHGs that farmers of this case study can apply. Carbon footprint of rice production unit of 1 kg was 2.21 kg <TEX>$CO_2.-eq.kg^{-1}$</TEX>. Although amount of <TEX>$CO_2$</TEX> emissions is largest among GHGs, methane had the highest contribution of carbon footprint on rice production system after methane was converted to carbon dioxide equivalent (<TEX>$CO_2$</TEX>-eq.) multiplied by the global warming potential (GWP). Source of <TEX>$CO_2$</TEX> in the cultivation of rice farming is incomplete combustion of fossil fuels used by agricultural machinery. Most of the <TEX>$CH_4$</TEX> emitted during rice cultivation and major factor of <TEX>$CH_4$</TEX> emission is flooded paddy field in anaerobic condition. Most of the <TEX>$N_2O$</TEX> emitted from rice cultivation process and major sources of <TEX>$N_2O$</TEX> emission is application of fertilizer such as compound fertilizer, urea, orgainc fertilizer, etc. As a result of sensitivity analysis due to the variation in energy consumption, diesel had the highest sensitivity among the energies inputs. If diesel consumption is reduced by 10%, it could be estimated that <TEX>$CO_2$</TEX> potential reduction is about 2.5%. When application rate of compound fertilizer reduces by 10%, the potential reduction is calculated to be approximately 1% for <TEX>$CO_2$</TEX> and approximately 1.8% for <TEX>$N_2O$</TEX>. When drainage duration is decreased until 10 days, methane emissions is reduced by approximately 4.5%. That is to say drainage days, tillage, and reducing diesel consumption were the main sources having the largest effect of GHG reduction due to changing amount of inputs. Accordingly, proposed methods to decrease GHG emissions were no-tillage, midsummer drainage, etc.

2011년 전북 군산과 익산 지역의 관행농, 무농약, 유기농 농가를 대상으로 영농방법별로 쌀 생산 과정 중 투입 배출되는 물질 목록을 면접조사하여 전과정평가를 수행하고 쌀 생산체계에 대한 영농방법별 환경영향을 평가하고 탄소배출량을 비교 분석하였다. 전과정 목록분석 결과 <TEX>$CO_2$</TEX> 배출은 화학비료 생산과 벼 재배단계에서 가장 많았고, <TEX>$CH_4$</TEX>과 <TEX>$N_2O$</TEX> 배출은 대부분 벼 재배 중에 발생되었다. 쌀 (조곡) 1 kg 생산을 기준으로 하는 탄소성적은 관행농이 1.01E+00 <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX>로 가장 높았고, 무농약이 5.37E-01 <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX>, 유기농법이 6.58E-01 <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX>였다. 농자재 투입량이 가장 적었던 무농약 쌀 생산에서 탄소성적이 가장 낮았고, 생산량은 가장 적었지만 복비투입이 없었던 유기농이 관행농보다 탄소성적이 낮았다. 관행농과 무농약 쌀 생산체계에서 온실가스 배출 주요 요인은 복비생산과 벼 재배 중 <TEX>$CH_4$</TEX> 발생이었고, 유기농에서는 벼 재배 중 농기계 연료사용과 논토양 <TEX>$CH_4$</TEX> 발생이었다. 그러므로 온실가스 감축을 위한 영농방법 활용으로 복합비료 적정량 사용을 위한 맞춤형 비료의 권장 및 벼논 물관리에 의한 메탄발생 저감방법 등을 제안하며, 더불어 유기농법에서는 수확량 향상을 위한 생산 효율성 증대와, 벼 재배 단계에서 농기계 연료 효율성 증대 활용에 관한 연구가 요구되었다. This study was performed a comparative life cycle assessment (LCA) among three rice production systems in order to analyze the difference of greenhouse gases (GHGs) emissions and environment impacts. Its life cycle inventory (LCI) database (DB) was established using data obtained from interview with conventional, without agricultural chemical and organic farming at Gunsan and Iksan, Jeonbuk province in 2011. According to the result of LCI analysis, <TEX>$CO_2$</TEX> was mostly emitted from fertilizer production process and rice cropping phase. <TEX>$CH_4$</TEX> and <TEX>$N_2O$</TEX> were almost emitted from rice cultivation phase. The value of carbon footprint to produce 1 kg rice (unhulled) on conventional rice production system was 1.01E+00 kg <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX> and it was the highest value among three rice production systems. The value of carbon footprints on without agricultural chemical and organic rice production systems were 5.37E-01 <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX> and 6.58E-01 <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX>, respectively. Without agricultural chemical rice production system whose input amount was the smallest had the lowest value of carbon footprint. Although the yield of rice from organic farming was the lowest, its value of carbon footprint less than that of conventional farming. Because there is no compound fertilizer inputs in organic farming. Compound fertilizer production and methane emission during rice cultivation were the main factor to GHGs emission in conventional and without agricultural chemical rice production systems. In organic rice production system, the main factors to GHGs emission were using fossil fuel on machine operation and methane emission from rice paddy field.

Abstract. Hidayat RA, Iskandar J, Gunawan B, Partasasmita R. 2020. Impact of green revolution on rice cultivation practices and production system: A case study in Sindang Hamlet, Rancakalong Village, Sumedang District, West Java, Indonesia. Biodiversitas 21: 1258-1265. In the past, farmers of Sindang Hamlet, Rancakalong Village, West Java practiced the wet-rice (sawah) farming system based on the Traditional Ecological Knowledge (TEK) and belief system. They coordinate their planting schedule according to indigenous calendar known as kalender tani or pranata mangsa (Javanese). The various inputs of the sawah farming system, namely rice seeds, organic fertilizers, and pesticides intensively used originate from the village, made little use of farm supplies obtained through purchased from outside (market). In the early 1970s, the Government of the Republic of Indonesia introduced the Green Revolution to increase the rice production of the wet-rice farming system. The five-farming effort (panca usaha tani) programs, namely the use of the High Yielding Rice Varieties (HYVs), the provision for inorganic chemical fertilizers, the use of synthetic pesticides, the development and improvement of irrigation, and the improvement of methods of rice planting methods were intensively implemented. About ten years later, in 1980s, the sawah farmers of Rancakalong Village, Sumedang District, West Java have adopted the Green Revolution program. As a result, the traditional the wet-rice cultivation practices of Rancakalong farmers that was originally based on the low-external inputs has dramatically changed to the high-external-input agriculture, depending more on artificial inputs, such as inorganic fertilizers, pesticides, fossil energy, and modern rice seeds, which originate from outside of the village and generally have to be purchased. The aim of this study is to document and analyze the changing cultivation practices of the wet-rice farming systems, and rice production systems. Study was undertaken in Sindang Hamlet, Rancakalong Village, Sumedang District, West Java. Method applied in this study was a mixed-method, combination of qualitative and quantitative techniques, including observation, semi-structured interviews, and structured interviews applied to 64 respondents. The result of the study showed that the farmers have stopped their traditional cyclical planting schedule based on kalender tani, most local rice varieties have been replaced by the superior or High Yielding Rice Varieties (HYVs), and farmers have become dependent on external inputs, namely inorganic fertilizers, synthetic fertilizers, modern rice seeds, and fossil energy. Consequently, the HYVs have also more vulnerable to diseases and pests, such as brown plant-hopper (Nilarparvata lugens Stal), and also vulnerable to scarcity of water due to drought caused by climate change. This study stresses that a model agriculture system that is ecologically sound, economically viable, and adaptable must be undertaken to develop sustainable agriculture.

본 연구진은 2007년 농진청과 통계청에서 수집한 농축산물소득자료 통계 값으로 국가평균 탄소성적을 산정하는 top-down 방식의 자료수집 방법을 구축하였다. 또한, 본 연구진은 2011년 전북 군산 지역 관행농 쌀 생산 농가 중 벼 평균 재배면적이 3.3 ha인 네 곳의 대규모 생산농가를 섭외하여 면접조사로 사례를 분석하는 bottom-up 방식의 전과정 목록 (LCI, life cycle Inventory)도 구축하였다. 본 연구는 관행농 쌀 생산체계에 대한 전과정 평가를 국립농업과학원에서 구축한 top-down 방식과 사례분석을 통한 bottom-up 방식으로 수행한 결과를 비교하기 위하여 수행되었다. 전과정 목록분석 결과 <TEX>$CO_2$</TEX>은 무기질 비료 생산과 벼 재배과정에서 배출량이 가장 많았고, <TEX>$CH_4$</TEX>와 <TEX>$N_2O$</TEX>은 대부분 벼 재배과정에서 배출되었다. 관행농 쌀 1 kg 생산을 기준으로 하는 탄소성적은 국가평균값이 2.39E+00 kg <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX>, 사례분석이 1.04E+00 kg <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX>으로 국가평균 탄소성적이 사례분석보다 높았다. 쌀 생산 전과정에 투입되는 농자재량은 국가평균과 사례분석이 유사하거나 오히려 사례분석이 더 높게 나타났으나 작기 당 수확량이 높아 사례분석의 탄소성적이 유리한 결과가 나왔다. 관행농 쌀 생산체계에서 각 생산공정별 환경영향을 분석한 결과 화학비료 생산단계가 대부분의 환경영향범주에서 기여도가 가장 높게 나타났으나, GWP 범주는 벼 재배에 의한 환경영향 기여도가 가장 컸다. 관행농 쌀 생산에서 탄소성적을 결정하는 주요 요인은 논토양에서 발생하는 메탄가스와 비료투입량 및 벼 수확량이었다. 본 연구 결과는 향후 '농산물 저탄소인증' 시범사업에서 배출량 산정을 위한 기초자료와 벼논에서 온실가스를 줄이기 위한 영농법 개발에 활용될 것으로 기대된다. '저탄소 농산물 인증제도' 시범사업의 성공을 위해서 쌀을 포함한 농작물에 대한 실제 농가를 대상으로 하는 사례분석 연구가 더욱 늘어나야 할 것이다. 현 단계에서는 자발적인 참여 농가를 대상으로 하여 활동 데이터 수집을 늘리고, 자료의 일관성과 대표성 보완을 위하여 농가의 활동데이터를 수집할 때 모집단 선발과 수집기간 등에 대한 논의가 필요하다. 또한 현재 국립농업과학원에서 구축하고 있는 DB는 2007년 소득자료를 기준으로 하므로 인증사업 시행시 사례분석을 적용할 때 몇 가지 한계와 보완사항이 요구되었다. 첫째, 국가평균 통계와 실제 대상농가 간 품종 및 생산연도에 의한 생산량 차이를 보완하기 위한 가중치 적용 등이 필요할 것으로 판단되었다. 둘째, 현재 국가평균 DB를 기준으로 설정된 시스템 경계에서 육묘 용 상토와 볏짚 및 쌀겨 등 부산물과 수확 후 도정 및 포장 등에 대한 시스템경계 확장 연구 및 이에 관한 LCI DB 구축이 요구되었다. We established a top-down methodology to estimate carbon footprint as national mean value (reference) with the statistical data on agri-livestock incomes in 2007. We also established LCI (life cycle inventory) DB by a bottom-up methodology with the data obtained from interview with farmers from 4 large-scale farms at Gunsan, Jeollabuk-do province to estimate carbon footprint in 2011. This study was carried out to compare top-down methodology and bottom-up methodology in performing LCA (life cycle assessment) to analyze the difference in GHGs (greenhouse gases) emission and carbon footprint under conventional rice cultivation system. Results of LCI analysis showed that most of <TEX>$CO_2$</TEX> was emitted during fertilizer production and rice cultivation, whereas <TEX>$CH_4$</TEX> and <TEX>$N_2O$</TEX> were mostly emitted during rice cultivation. The carbon footprints on conventional rice production system were 2.39E+00 kg <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX> by top-down methodology, whereas 1.04E+00 kg <TEX>$CO_2$</TEX>-eq. <TEX>$kg^{-1}$</TEX> by bottom-up methodology. The amount of agro-materials input during the entire rice cultivation for the two methodologies was similar. The amount of agro-materials input for the bottom-up methodology was sometimes greater than that for top-down methodology. While carbon footprint by the bottom-up methodology was smaller than that by the top-down methodology due to higher yield per cropping season by the bottom-up methodology. Under the conventional rice production system, fertilizer production showed the highest contribution to the environmental impacts on most categories except GWP (global warming potential) category. Rice cultivation was the highest contribution to the environmental impacts on GWP category under the conventional rice production system. The main factors of carbon footprints under the conventional rice production system were <TEX>$CH_4$</TEX> emission from rice paddy field, the amount of fertilizer input and rice yield. Results of this study will be used for establishing baseline data for estimating carbon footprint from 'low carbon certification pilot project' as well as for developing farming methods of reducing <TEX>$CO_2$</TEX> emission from rice paddy fields.

Aim: This study aims to focus on traditional agricultural practices which are gaining momentum around the globe as an energy efficient and sustainable approach in the changing climate condition. In this study, an attempt was under taken to quantify the energy use, green house gas emission and global warming potential of rice cultivated by traditional method in terraced low land. Methodology: The data were collected through Focused Group Discussion (FGD) from farmers of the study area using the questionnaire. The sample size was calculated by Neyman method. Results: Total input and output energy required for traditional rice production were 8513.0 MJ ha-1 and 77356.88 MJ ha-1, respectively. Energy use efficiency was calculated as 9.01. Total global warming potential (GWP) was 610.19 CO2 eq ha-1. In this study, the output and input carbon were found to be 2580.48 and 164.75 kg C ha-1, respectively and the carbon efficiency ratio was 15.66. Energy productivity of this traditional method of rice production system was approximately 1.21 to 3.64 times higher than that of other rice production system. Interpretation: Rice is the staple food of tribal's habited in the highland region of Eastern Ghats Odisha, India, and these tribal people mostly cultivate rice by traditional method. This traditional rice production system can be considered as an environmental friendly and sustainable agricultural system in this changing climatic condition, and this system is also economical than the conventional rice cultivation practices. Key words: Budgeting, Energy, Eastern Ghats, Green house gases, Global warming, Rice

Comparing rice production systems in China: Economic output and carbon footprint

GHG footprint of major cities in India

For the purpose of generating electricity, what leakage rate renders the greenhouse gas (GHG) footprint of natural gas equivalent to that of coal? This paper answers this question using a simple model, which assumes that the comprehensive GHG footprint is the sum of the carbon dioxide-equivalent emissions resulting from (1) electricity generation and (2) natural gas leakage. The emissions resulting from electricity generation are taken from published life-cycle assessments (LCAs), whereas the emissions from natural gas leakage are estimated assuming that natural gas is 80 % methane, whose global warming potential (GWP) is calculated using equations provided by the Intergovernmental Panel on Climate Change (IPCC). Results, presented on a straightforward plot of GHG footprint versus time horizon, show that natural gas leakage of 2.0 % or 4.8 % eliminates half of natural gas’s GHG footprint advantage over coal at 20- or 100-year time horizons, respectively. Leakage of 3.9 % or 9.1 % completely eliminates the GHG footprint advantage at 20- and 100-year time horizons, respectively. A two-parameter power law approximation of the IPCC’s equation for GWP is utilized and gives equivalent results. Results indicate that leakage control is essential for natural gas to deliver a smaller GHG footprint than coal.

Trade-off of greenhouse gas emissions from double-cropped rice due to straw retention and zero tillage practices

Life cycle greenhouse gas emissions from five contrasting rice production systems in the tropics

Life cycle greenhouse gas emissions from rice production systems in Brazil: A comparison between minimal tillage and organic farming

It is of great significance to understand the effects of different rice cultivation methods in southeast China on greenhouse gas emission characteristics and carbon footprint of paddy fields during rice cultivation for rice sustainable production. In this study, the popular conventional rice 'Jiafuzhan' and hybrid rice 'Yongyou 2640' were used as materials to establish four rice cultivation patterns suitable for different ecological types in Fujian Province: 1) double-cropping system, early rice and late rice with Jiafuzhan (D-J); 2) early maturing ratooning system, first season rice and ratooning season rice with Jiafuzhan (R-J); 3) middle-maturing ratooning system, first season rice and ratooning season with Yongyou 2640 (R-Y); and 4) single cropping system with Yongyou 2640 (S-Y), which should be synchronized in heading time with the counterpart (the ratooning season rice). Greenhouse gas emissions from paddy soil were measured by the closed static black box observation method and the gas chromatography method, respectively. The total direct and indirect greenhouse gas emissions (carbon footprints) from different rice farming patterns were evaluated by using the life cycle analysis. The results showed that greenhouse gas emissions in different rice cropping systems were lower in the early growth stage, then decreased after reaching the peak at the booting stage, demonstrating a double peak curve in the whole growth stage, in which the first peak was higher in early season or first season than the second peak in the late season or ratooning season in the cropping patterns. Moreover, the total greenhouse gas emissions were significantly different among cropping systems. The global warming potential (GWP) of different cropping patterns was in order of R-Y>D-J>S-Y>R-J, while the annual greenhouse gas emission intensity (GHGI) was D-J>S-Y>R-Y>R-J. GWP and GHGI of the ratooning system decreased by 26.1% and 14.1%, respectively, compared with those of the double-cropping system. The same pattern was observed in the ratooning rice of Yongyou 2640, which were decreased by 74.3% and 56.7%, respectively, compared with the counterpart, Yongyou 2640 in a single-cropping system synchronized heading. Carbon footprint of rice per unit yield ranged from 0.38-1.08 kg CO2-eq.·kg-1 under the different cropping systems, of which the carbon footprint of rice per unit yield was the highest under the double cropping system compared with that under other cropping systems. The reverse was true in the case of carbon footprint of rice per unit yield under the ratooning system with Yongyou 2640. Additionally, the main source of carbon footprint of different rice cropping patterns was CH4, contributing 44.2%-71.5%, suggesting that rice ratooning system could significantly reduce global warming potential and carbon emission intensity of rice in comparison with other cropping patterns. Therefore, it is key to select rice varieties with high yield and low carbon emission and to establish the supporting scientific cultivation techniques for effective reduction of CH4 emission and carbon footprint of paddy fields and promotion of ratooning rice production.

PDF HTML阅读 XML下载 导出引用 引用提醒 基于生命周期评价的上海市水稻生产的碳足迹 DOI: 10.5846/stxb201304240794 作者: 作者单位: 上海市农业科学院,上海市农业科学院,上海市农业科学院,上海市农业科学院,江西农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家科技部支撑计划后世博专项资助项目（2010BAK69B18）；上海市科委崇明科技攻关专项资助项目（10DZ1960101） Life cycle assessment of carbon footprint for rice production in Shanghai Author: Affiliation: Shanghai Academy of Agricultural Sciences,Seed management station of Shanghai,,,Jiangxi Agricultural University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:碳足迹是指由企业、组织或个人引起的碳排放的集合。参照PAS2050规范并结合生命周期评价方法对上海市水稻生产进行了碳足迹评估。结果表明：（1）目前上海市水稻生产的碳排放为11.8114 t CO2e/hm2，折合每吨水稻生产周期的碳足迹为1.2321 t CO2e；（2）稻田温室气体排放是水稻生产最主要的碳排放源，每吨水稻生产的总排放量为0.9507 t CO2e，占水稻生产全部碳排放的77.1%，其中甲烷（CH4）又是最主要的温室气体，对稻田温室气体碳排放的贡献率高达96.6%；（3）化学肥料的施用是第二大碳排放源，每吨水稻生产的总排放量为0.2044 t CO2e，占水稻生产总碳排放的16.5%，其中N最高，排放量为0.1159 t CO2e。因此，上海低碳水稻生产的关键在降低稻田甲烷的排放，另外可通过提高氮肥利用效率，减少氮肥施用等方法减少种植过程中碳排放。 Abstract:Global climate change has become an urgent issue of concern. Climate change will increasingly threaten our food production, security and even the survival of the human race. It also has a serious impact on natural ecosystems and the socioeconomic system. With the increasing scale and improvement in mechanization levels, the economic linkage between agricultural production and reduction of Greenhouse Gas (GHG) emissions is even closer in the agricultural production system. Therefore, the development of a low-carbon agricultural model is one of the long-term strategies for low-carbon economic growth throughout the country.This research of carbon footprint is introduced to measure the GHG emission over the rice production cycle. The carbon footprint can be defined as the total carbon emissions caused by an organization, event, product or person. At present, carbon footprints are used to measure GHG emissions in products, services, organizations, cities and countries and offer the decision basis for the formulation of GHG emission reduction schemes.Agricultural ecological systems, every year, also produce a lot of GHG emissions. The whole process of prenatal, intrapartum and postpartum agricultural production are closely related to energy consumption and GHG emission. In the process, all the agricultural inputs, such as chemical fertilizers, pesticides, seeds, cultivation, plant protection, agricultural machinery, irrigation and harvest also produce greenhouse gas emissions.The whole cultivation of rice involves methane (CH4) emission. This study shows that rice cultivation is one of the biggest sources of GHG emissions in crop cultivation. Rice paddies emit a large amount of methane in their water logged mode. Different irrigation modes have a great influence on the emission of GHG. Straw return is another factor that promotes GHG emissions. Soil organic content increases with the return of straw, with an increase in the soil methanogen activity, leading to increased methane emissions.The current carbon footprint research is the first time it has been used to measure the carbon emissions involved in rice production. The carbon footprint for rice production in Shanghai was assessed by the PAS2050 paradigm and life cycle assessment. The study area, located in Changjiang Farm, which belongs to the Guangming Group in Chongming County Shanghai City atlatitude 121°32'22' E, longitude31°40'23' N. Chongming County, in the Yangtze River Estuary, is a typical sub tropical monsoon climate with mild climate, abundant rainfall, annual average temperatures of 15.3 ℃, and annual precipitation of 1245 mm. It is the major grain production base for Shanghai city with winter wheat and summer rice forming their main planting patterns, which are typical for the middle and lower reaches of the Yangtze River rice-wheat rotation cropping pattern.The entire carbon emission of rice production in Shanghai was 11.8114 t CO2e (CO2-equivalents)/hm2, corresponding to a 1.2321 t CO2e/t rice grain yield. GHG emissions from paddy fields were the major source, which emitted 0.9507 t CO2e/t rice and accounted for 77.1% of total carbon emissions during rice production. Moreover, CH4 was the largest source for GHG emissions with a contribution rate of 96.6%.Chemical fertilizers were the second largest emission source in rice production. Chemical fertilizers emitted 0.2044 t CO2e for each ton of rice production, contributing 16.5% of total carbon emissions in rice production. N fertilizer was the biggest emission source, which released 0.1159 t CO2e/t rice.This research investigates the GHG emissions over the whole process of the Shanghai rice production cycle and reveals the energy consumption and GHG emissions in rice production. Thus, a rice carbon footprint is calculated by assessing the GHG emissions in Shanghai rice production. The results are beneficial for producing reduction plans of reducing GHG emissions in Shanghai rice production. Furthermore, the results will supply both practicable and theoretical foundations for drafting carbon footprint formulations in other industrial areas. 参考文献 相似文献 引证文献

Rice is the staple food for billions of people in the world. This crop has important cultural, economic, and social impacts on the lives of people. One of the major challenges for food security in the world is ever increasing population growth requiring a significant increase in food supply. This is further threatened by water scarcity. Water shortage is a major threat for sustainable rice production worldwide. It is of utmost importance to explore alternate ways of rice production by using less water for food security. Therefore, the focus is mostly concentrated on water-saving rice production systems in modern agricultural research. Such methods may include reduction of unproductive water outflow, alternate wetting and drying, the system of rice intensification, direct seeding, aerobic rice system, scheduling of irrigation technique using tensiometer, and ground cover rice production system. All these technologies can significantly reduce water demand for rice production and can improve water use efficiency (WUE). These technologies, however, can reduce yield under certain conditions, especially when the existing lowland varieties are used. Efforts are being made to minimize yield losses and improve water economy. For this purpose, new approaches are being explored. Molecular biotechnology is being utilized to develop superior rice varieties with improved drought tolerance, WUE, and transpiration efficiency. These approaches have the potential to provide high and sustainable rice yield in non-flooded conditions. Adoption of these technologies will cause a shift of rice cultivation systems from continuously anaerobic (flooded) to partly or completely aerobic (non-flooded) systems. This change will be associated with some benefits such as conservation of water and a decrease in methane emission. Some potential negative impacts of this shift might be evident in the form of decline in soil organic matter (excluding rice and wheat production systems) and release of nitrous oxide from the soil. An effective integrated natural resource management system needs to be developed to address these issues and to make rice cultivation profitable with increased soil aeration and to maintain the productivity, environmental safety, and sustainable ecosystem. In this chapter, efforts have been made to discuss various approaches for water management in rice production system to increase yield with reduced water demand.

Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use.The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011).