Integrated analysis of techno-economic and environmental efficiencies of Hom Mali Rice cropping systems in Thailand | |
| Author | Kwansirinapa Thanawong |
| Call Number | AIT Diss. no.WM-14-03 |
| Subject(s) | Cropping systems-Thailand Hom Mali Rice--Thailand |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering in Water Engineering and Management, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. WM-14-03 |
| Abstract | Rice is the world’s most important staple food crop with more than half of the world’s population relying on it as the major daily source of calories, especially in Asia. Paddy rice grows throughout Thailand, but the main production areas are in Northeast of Thailand, followed by North region, Central Plains and South region. Among the many varieties of rice grown in paddy areas; Kao Dok Mali 105 variety (Hom Mali rice, or jasmine-scented rice) is a high quality fragrant rice, exported to Europe and the USA. While rice production creates food security, employment and growth, it also generates adverse environmental impacts and resource consumption. Nowadays, consumers’ environmental awareness is rising and rice production systems require more sustainable management practices. It has been hypothesized that both objectives of high economic return and low environmental impacts of rice production systems might not be fully met simultaneously, and that trade-offs are inescapable, towards sustainable yet profitable farming practices. Balanced agricultural systems have to be identified, and the economic viability of environment-friendly practices at the farm level has to be investigated. This research has investigated the environmental impacts and the techno-economic performances of selected rice farms in Nam Mae Lao basin (North region) and Lam Sieo Yai basin (Northeast region). Paddy areas under rain-fed and irrigated conditions, in wet and dry seasons were studied. This research compares the advantages of rice production under irrigation and rain-fed conditions in both environmental and economic terms. Indicators of techno-economic performances were combined with environmental impact indicators based upon life cycle assessment, energy and water use analyses. Data were collected in 2010 at the farm level in 60 households for both study areas, according to three cropping systems, namely wet-season rain-fed (Rw), wet-season irrigated (Iw) and dry-season irrigated (Id) systems. Eco-efficiency indicators were calculated as per impact category. Technical and environmental efficiencies were calculated for both selected basins by using a combination of techno-economic analysis, LCA results and Data Envelopment Analysis (DEA) methodology. DEA approach, particularly allowed to identify the sources of technical and environmental inefficiencies within the systems. The research collected, analyzed and combined indicators of techno-economic performances (rice production, costs, and product value) with environmental impact indicators based upon the life cycle approach. Both approaches applied at the same plot level (cropping system level). Techno-economic analysis typically resulted in monetary values as per factor of production (e.g. labour, land, agro-chemicals). LCA expressed environmental impacts as per selected functional units (mass of product and area of land used). The research reported here is problem-oriented; it focuses on midpoint indicators for different environmental impact categories (e.g., global warming potential, eutrophication, or acidification) and resource use (land, water and energy). LCA methodology can assess such environmental impact categories, but it still does not include methods for assessing the impact of water use at river basin level. Such impacts have been investigated through the application of the water footprint methodology. Blue water and green water were assessed through Crop and Irrigation Water Requirement concepts (CWR, IWR respectively). Both basins show wide-ranging techno-economic performances and environmental impacts, while cropping practices were found to be homogeneous. Differentiation of systems originated mostly from differences in yield, which were mostly impacted by water supply. North region produces higher yields than Northeast region; yields in Nam Mae Lao basin vary from 3,594, 3,258 and 3,438 kg/ha, yield in Lam Sieo Yai basin are 2,625, 2,375 and 2,188 kg/ha in the Iw, Rw and Id systems, respectively. The results highlight the low performances of Id systems in both techno-economic and environmental terms. Id systems require mostly blue water, while the two other systems rely primarily on green water. Id systems also require more energy and labour, due to increased water management needs. Overall, the productivity of most production factors in Nam Mae Lao basin was found to be higher in irrigated systems; these results in return on investment being higher in the Iw systems compared to the Id systems (0.174 kg/THB and 0.162 kg/THB, respectively) and is lowest in the Rw systems (0.154 kg/THB), on the hand, the productivity of most production factors in Lam Sieo Yai basin was found to be higher in Rw and Iw systems which results in return on investment being slightly higher in the Iw systems compared to the Rw systems (0.117 kg/THB and 0.114 kg/THB, respectively) and is lowest in the Id systems (0.095 kg/THB). In northeast region, in Id systems, farmers need to produce twice as much rice (0.411 kg) to obtain 1 THB of net income, compared to 0.228 and 0.248 kg for Iw and Rw respectively. Northern regions to obtain 1 THB of net income, farmers in Rw need to produce 0.20 kg compared to 0.173 and 0.185 kg for Iw and Id. Lam Sieo Yai basin, emissions proved relatively similar across all three systems of selected basins, with the exception of CH4, which was markedly lower in Rw systems due to specific water and organic residue management. Id systems systematically emitted more nitrates, phosphates and pesticides into water sources. Rw systems showed the lowest environmental impacts per ha and per kg of paddy rice produced. GWP100 was higher in Id systems (5.55 kg CO2-eq per kg of rice) compared to Iw (4.87) and Rw (2.97). In Nam Mae Lao basin, emissions proved relatively similar across all 3 systems of selected basins, with the exception of CH4, which is lower in Id systems. Id also showed the lowest environmental impacts per ha and per kg of paddy rice produced due to higher yields. GWP100 was higher in Iw systems (2.90 kg CO2-eq per kg of rice) compared to Rw (2.24) and Id (2.15). This research also addressed the water deprivation potential resulting from water use and the water stress index of each selected basin. The total water use of Nam Mae Lao and Lam Sieo Yai basin are 2,650 and 2,948 Mm3/year, respectively, while the annually available water in basins are 4,301 and 2,483 Mm3/year. WSI were 0.86 in Nam Mae Lao basin, and 1.00 in Lam Sieo Yai , which indicate a higher potential for water deprivation in the northeast region. Lam Sieo Yai basin, Rw systems were found to be more eco-efficient in most impact categories, including Global Warming Potential. The total value product per kg of CO2-eq emitted is 4, 2.5 and 2.2 THB in Rw, Iw, and Id systems respectively. Nam Mae Lao basin, Id systems were found to be more eco-efficient in Global Warming Potential but lowest in other impact categories. Environmental efficiency of Nam Mae Lao basin were found to be higher in Rw system, followed by Id and Iw systems, but Id system has more environmentally efficient in Lam Sieo Yai basin and followed by Rw and Iw systems. Finally, DEA analysis allowed identifying and quantifying the potential increase of technical performances and the potential reduction of environmental impacts of each rice cropping system, based upon the most efficient systems as references. In terms of technical efficiency, both basins converge and show that Id systems have the least efficient. VSR and CSR based efficiency scores are very different, resulting in scale efficiency scores that are low overall. This pinpoints the fact that rice systems operate mostly at increasing return on inputs, which suggests that critical inputs, such as N fertilization, are still not used optimally. In terms of environmental efficiency, both basins also converge to show that Rw systems are the most environmentally efficient, and that Id systems are the worst. Further analyses at DMU level demonstrate the poor overlapping between high-income and low environmental impact sub-groups. Further, high income does not link up with low production costs. These findings highlight the need for trade-off towards sustainability. Rice cropping systems shall optimize inputs and resource use, in order to have lesser environmental impacts. Finally, ranges of potential reductions in input supply are calculated, for systems to achieve full technical efficiency. Final sections of the report discuss the methodological, scientific and societal contributions of the research, and provides some specific recommendations. |
| Year | 2014 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. WM-14-02 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Perret, Sylvain R.;Babel, Mukand S.; |
| Examination Committee(s) | Gabrielle, Benoit;Soni, Peeyush;Clemente, Roberto S.;Rattanawan Mungkung; |
| Scholarship Donor(s) | CIRAD;Royal Thai Government Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2014 |