An integrated sustainability assessment of cotton cropping systems in Punjab, Pakistan : Techno-economic performances, environmental impacts and eco-efficiency analysis | |
| Author | Ullah, Asmat |
| Call Number | AIT Diss. no.NR-14-04 |
| Subject(s) | Cotton--Environmental aspects--Pakistan--Punjab Life cycles (Biology)--Pakistan--Punjab |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Natural Resources Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. NR-14-04 |
| Abstract | Cotton cropping in Pakistan generates rural employment and income, and export revenues. It also utilizes substantial amounts of water and energy resources, and adversely affects the environment with pollutants from inputs, especially pesticides, fertilizers, and emissions from non-renewable energy use. There is a need to assess the sustainability of cotton production systems, which may be achieved through more reasonable use of inputs and resources, hence less environmental impacts, combined with sustained income for farmers. This research investigates the possibility of meeting such challenge by studying existing cropping systems from an integrated, multi-criteria perspective. It analyzes their techno-economic performances and efficiency, along with their environmental impacts. A specific focus is paid to the farm size as a possible factor to performances, impacts and efficiencies. The sources of high environmental impacts and of inefficiencies have also been examined. The research was mostly based upon primary data that was collected from 169 farmers in the southern part of the Punjab province of Pakistan. The environmental impacts have been analysed through Life Cycle Assessment (LCA) methodological approach, and also with an alternative approach to environmental impact analysis using farm-level ad-hoc indicators. LCA based potential environmental impact indicators result from the use of CML characterisation method; they are: abiotic resources depletion (ADP), acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), human toxicity potential (HTP), terrestrial ecotoxicity potential (TETP) fresh water aquatic ecotoxicity potential (FETP) and water use (WU). The farm level ad-hoc indicators are: water use, energy ratio, nitrogen balance, phosphorus balance and pesticides risks. Through these sets of indicators, technical, cost and environmental efficiencies have been estimated by non-parametric Data Envelopment Analysis (DEA) procedure. All these efficiencies estimates have been separately regressed with some specific contextual variables to identify the sources of inefficiencies. Results first highlight the high variability in cropping practices, input and resource utilization patterns, and environmental impacts that exist in cotton cropping systems in Punjab. With regards to factor productivities and farm size, large farms perform better for all production factors, except for pesticide productivity, which is higher in small farms. With regards to environmental impacts, it was observed that field emissions from pesticides and fertilizers are the largest contributors. LCA results as per kg of seed cotton at farm gate are: GWP 3.15 (1.29) kg CO2-eq, AP 0.051(0.018) kg SO2-eq, EP 0.056 (0.027) kg PO4-eq, HTP 2.78 (1.41) kg 1,4-DB-eq, FETP 5.45 (6.86) kg 1,4-DB-eqand WU 2.93 (1.18) m3. No significant difference was observed among farm size groups except for EP where small farms show significantly higher value of EP. Overall, farms show relatively high technical and cost efficiencies. Yet, results contradict the findings on factor productivities since small farms perform slightly better than others: the mean technical efficiency scores are 0.96, 0.92, and 0.91 for small, medium and large farms, respectively; mean cost efficiency scores are 0.84, 0.77 and 0.80 for small, medium and large sized farms, respectively. From environmental perspective, the results reveal that farmers are broadly environmentally inefficient, irrespective of farm size, yet with serious differences according the method used. Based on farm-level ad-hoc indicators, the environmental efficiency scores are 0.93, 0.87 and 0.89 for small, medium, and large farms, respectively. Eco-efficiency estimates through Life Cycle Assessment (LCA) indicators computed on per hectare basis are 0.84, 0.70 and 0.77, respectively, and 0.49, 0.50 and 0.48 respectively when computed on the basis of kilogram of seed cotton. Moreover, differences in technical and environmental efficiencies across different farm sizes were found to be statistically significant at 5%, on per hectare basis. Cost efficiency differences across different farms were found statistically significant at 10%. However, no statistically significant difference of eco-efficiency was found when expressed on per kilogram of seed cotton. Besides efficacy scores, DEA analysis also revealed the potential reduction of input and resource use for non-efficient systems to meet full efficiency as per production frontier curve. Variability in the percentage of potential reduction of pesticides is observed (between 22 to 40%), potential reduction of nitrogen varies between 22 to 31%, and potential reduction of water use varies in the range of 12% to 16%.The variability of input uses lead to variable environmental impacts per kilogram of seed cotton among different farm sizes. The second stage regression analysis with contextual variables identifies that plot size and raised-bed (ridge) sowing methods have significant and negative effects on efficiencies whereas exposure to extension and training affects positively. Paradoxically, formal education level is found to negatively affect efficiencies. The differences in mean efficiencies among farms are mostly explained by varying levels of water use, nitrogen fertilizers and pesticides applications. Towards concrete action and increased sustainability, selection of target inputs for reduction measures should first establish stakeholders‘ preferences (which impacts or cost to reduce? which input or resource to spare?), based on weighting and normalization of environmental impacts, and on thorough assessment of trade-offs between impact and cost reductions, and expectations in terms of yields. A sustainability analysis was carried out, looking for farms that would epitomize sustainable cotton production by showing high economic performance and low environmental impacts. Two approaches have been used at the cropping system level: a comparison of technical, economic and environmental performances, and a comparison of efficiency scores. Both approaches show that such match between high techno-economic and environmental performances proves extremely rare. The findings demonstrate that sustainability in cotton production in Punjab refers to an inescapable trade-offs since it proves almost impossible to combine high economic return with low environmental impacts under current context, technology, patterns, and objectives. However some recommendations could be formulated with regards, to pesticides and fertilizers use by farms, which uses may be significantly reduced with no effect on yield, and with potential positive reduction of environmental impacts. |
| Year | 2014 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. NR-14-04 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Development and Sustainability (DDS) |
| Academic Program/FoS | Natural Resources Management (NRM) |
| Chairperson(s) | Perret, Sylvain Roger; |
| Examination Committee(s) | Werf, Hayo M. G. van der;Shrestha, Rajendra P.;Soni, Peeyush;Gheewala, Shabbir H.; |
| Scholarship Donor(s) | Higher Education Commission (HEC), Pakistan;Asian Institute of Technology Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2014 |