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Causes and Drivers
Published in Ajai, Rimjhim Bhatnagar, Desertification and Land Degradation, 2022
Food shortage in Vietnam during the 1970s and the 1980s had led to significant depletion and degradation of forests in large parts of the highlands of the country. The government of Vietnam has subsequently encouraged the cultivation of cash crops and agroforestry in the upper Ca River basin (Douglas 2006). The population of the Dak Lak province in the central highlands of Vietnam has increased from 0.36 million in 1976 to 1.95 million in 2001 with an average annual growth rate of about 4.87% during the decade 1989–1999 (Douglas 2006). The main reason behind this increase in population was poverty-induced migration from the other parts of the country. Increased population pressure as well as the incentives by the government for coffee cultivation in the central highlands of Vietnam through access to the government land and tax concessions had resulted in the clearing of large areas of marginal land. As expected, the cultivation of low-productivity marginal land had resulted in soil erosion and land degradation problems. Traditional minority swidden cultivators often sell their land and move higher in the hill and occupy newer land for cultivation. The new settlers, being in the immediate need of achieving minimum income to meet their food and other essential requirements have little concern towards long-term soil conservation benefits. In the process, they start degrading the new piece of land as well. Migration, relative poverty, the government's agricultural subsidies and incentives, as well as compulsion to cultivate on erodible soil and marginal lands, all have played their part towards increasing soil erosion and land degradation in the central highlands of Vietnam (Douglas 2006).
Engine Performance
Published in M.R. Riazi, David Chiaramonti, Biofuels Production and Processing Technology, 2017
Roberto Guimarães Pereira, Oscar Edwin Piamba Tulcan, Carlos Eduardo Fellows, M.R. Riazi, David Chiaramonti
The use of vegetable oils as fuel has energetic, environmental, and socioeconomic advantages. These advantages are many, some of them being renewable energy source, positive energy balance, and reduction of the dependence on fossil fuels, among others. The technology involving fuel production from vegetable oils is simple and proven. Their higher flash point allows them to be stored at high temperatures without any fire hazard; the heating values of various vegetable oils are nearly 90% of those of diesel. From the chemical point of view, the additional oxygen molecule in its chemical structure helps in the combustion process, and they have a higher biodegradability and minor influence on the greenhouse effect when used instead of fossil fuels. They present a lower sulfur and aromatic content and at lower percentages of vegetable oil blends with diesel have shown better results than fossil diesel in terms of engine performance and exhaust emissions. Employment and income levels in rural areas are kept and the use of marginal land for energy purposes encourages job creation in various agro-industries, avoiding population migrations, contributing to the creation of new jobs, improving the living conditions of the rural people, and offering greater income opportunities through enhanced rural employment. Straight vegetable oils are available normally in rural areas where their usage is advantageous, especially in smaller engines in the agricultural sector; plant leafs and cakes can be used as organic manure, which can be source of additional income for farmers; selected crops can be grown on arid and semiarid lands, which are presently not cultivable; and they have carbon credit value (Kyoto protocol).
Salt-Tolerant Bioenergy Crops For Improving Productivity of Marginal Lands
Published in Megh R. Goyal, Susmitha S. Nambuthiri, Richard Koech, Technological Interventions in Management of Irrigated Agriculture, 2018
Youping Sun, Genhua Niu, Peiwang Li, Joe Masabni
Marginal lands refer to lands that have low inherent productivity and that have been abandoned or degraded.73 Marginal lands are primarily located in arid and semi-arid regions where soil salinity is too high for most common economic crops and where high salinity groundwater is the primary water source. FAO23 estimated that 397 million ha of land throughout the world are affected by salinity. Most of the salt-affected areas are marginal lands.11
When the virtual water runs out: local and global responses to addressing unsustainable groundwater consumption
Published in Water International, 2022
Iman Haqiqi, Chris J. Perry, Thomas W. Hertel
The findings suggest that restricting groundwater irrigation could have a significant impact on local irrigated production in hotspots of non-renewable groundwater irrigation. This directly causes a substantial reduction in agricultural production and employment for these communities. However, the impact of global groundwater sustainability policies is likely to be overestimated if the dynamic responses to restricted groundwater consumption are ignored. We show that these responses at the local and global levels will lessen the negative impact on food prices and production at the regional and global levels. The changes in relative prices at different scales will motivate changes in decisions and market outcomes. This includes compositional effects at the local level, changes in the location of crop production, changes in surface water irrigation, changes in irrigation extent, changes in irrigation intensity and changes in international trade of food commodities. Of course, these adjustments are costly and can cause environmental issues. Overall, the findings suggest that the land use and deforestation implications are small and the long-run impact on food production is less than 1% at the global level. The long-run change in global cropland is also limited to +0.1% corresponding to +1.2 million ha of cropland. The expansion coming from deforestation and cropping of marginal lands could lead to environmental degradation. In addition, as rainfed zones tended to be richer in carbon and biodiversity (Taheripour et al., 2013), other environmental implications of this policy should be studied more carefully with ecological concerns in mind. This is a critical finding when comparing the likely benefits and costs of such a policy.
Assessment of land degradation through people's perception and knowledge toward management in Oman
Published in Human and Ecological Risk Assessment: An International Journal, 2018
B. S. Choudri, Mahad Baawain, Ahmed Al-Sidairi, Hamed Al-Nadabi, Ahmed Al-Raeesi, Khalifa Al-Zeidi
Perceptions of community and groups at the local level on environmental problems can be viewed from different perspectives. In the first instance, at the local level, most of the people will perceive land degradation depending upon their socioeconomic interests. For example, farmers will be more attentive and concerned about possible environmental changes and damages that affect productivity of their crops. Furthermore, when these farmers understand that their physical environment is deteriorating, they will try to put in efforts to control some of their activities which are leading to degradation (Nsiah-Gyabaah 1994), thereby such farmers are more willing to support any land management program if they are aware that their actions are harmful to the environment (Herberlein 1972). Thus, basing on the local people's perceptions about environmental resources and knowledge, it is possible to develop methods that can allow people themselves to act and provide solutions to their environmental problems (Toulmin and Chambers 1990; Critchley 1991; Nsiah-Gyabaah 1994; Anley et al.2007; Haregeweyn et al.2015). In general, planning and implementation of effective measures of soil and water conservation in a particular area necessitate a detailed understanding of the extent, spatial distribution, and associated risks of the problem including local concerns (Bewket and Teferi 2009; Kangalawe 2009). While sustainable management of resources leads to enduring development, the entrenched poverty leads to more dependence on natural resources for livelihood and in some cases that has weakened the capacity of communities to manage their resources in a sustainable manner. This problem seems to be more critical in developing countries with the rapid growth in population. This factor is leading to the degradation of marginal lands and unsustainable land use practices that in turn encourage successively environmental degradation and continued impoverishment.
Systematic application of a quantitative definition of marginal lands in estimating biomass energy potential in the Missouri/Mississippi River Corridor
Published in Biofuels, 2021
Nasser Ayoub, Christine Costello, Shibu Jose
As noted above, based on the review of the literature and existing national datasets, our proposed marginal land definition, including selected physical properties that made land eligible for classification as marginal, is: ‘Marginal lands are non-croplands and/or lands not suitable for long-term food crop production as a result of high erodibility (K factor > 0.4) and/or being prone to flooding (frequently flooded)’.