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No description available.

Rice (Oryza sativa L.) is an important crop in many countries. According to the IRRI, more than 2 billion people globally depend on rice as a staple food (Dawe, et al. 2003). Studies on micronutrient content in rice and the effect of water in availability of the nutrients may aid in decreasing global nutrient deficiencies. Rice is grown under different water regimes such as AWD and intermittent flooding, sprinkler and furrow irrigation. A greenhouse pot experiment of rice utilizing a split plot design under different water regimes was conducted to assess the affect of water on (1) DTPA extractable soil micronutrients Fe, Mn Cu and Zn; (2) stem micronutrient concentration and uptake of rice (Oryza sativa L.) alone and with ground legume incorporated; and (3) yield of rice. The water regimes included: (1) rice pots watered to field capacity, or well-drained (drain); (2) pots submerged for 3 weeks, dried down for 1 week, then re-submerged for three weeks, or alternate wet and dry (AWD); and (3) continuous flooded (flood) conditions. A preliminary study which examined vegetative yield and micronutrient uptake of rice, faba beans, and sesbania using two different soils (Zaca clay and a loam) under flooded and drained conditions was conducted. Ground sesbania from the exploratory experiment was used for the study to explore the effects of organic matter (OM) on yield and micronutrient content. All DTPA extractable soil micronutrients except Zn were highest in the flood and AWD water treatments and in the lowest pH value. The DTPA extractable Zn values in the drain water treatment were twice as high as the AWD and flood water treatments. Stem Zn concentration was highest in drained, whereas Fe, Mn and Cu stem concentration were highest in AWD and flood treatments. Addition of sesbania incorporated into the soil only affected Mn soil micronutrient concentration, where Mn soil content was observed to be higher in the flood treatment with sesbania incorporated into the soil. Grain weight and grain to stem ratio were significantly increased by AWD and flood water treatments (p<0.05). Organic matter (sesbania) incorporated into the soil did not affect Fe, Mn, Cu or Zn stem to grain ratio. A comparison of stem concentration to grain yield highlighted the effects of Mn and Zn content on yield. Manganese stem content was highest in AWD and flood treatments where grain yield and grain to stem ratio were highest, while Zn content was lowest in AWD and flood treatments. Zinc stem content was highest in the drain treatment.

Cereals represent one of the most important food crops in the world. Rice (Oryza sativa) is one of the most commonly consumed cereal grains, and as a result, has considerable economic and agricultural importance, despite their potential as a source of genetic material. The phylogenetic relationships among rice and its wild species are not well understood. The objectives of this study are to evaluate the rate and type of molecular variation present in the gene that encodes the 10 kDa prolamin polypeptide in Oryza (Poaceae), and use this information in understanding the evolution of the Oryza genus. Our principle hypothesis is that genetic diversity exists at the molecular level in wild species of Oryza, and that this diversity can provide useful information regarding the phylogenetic relationships among rice species and permit a more theoretical examination of the evolutionary processes, such as concerted evolution, within Oryza and its nine genomes. A phylogeny of Oryza is presented, and modes of evolution are discussed. / Master of Science

Risk management has been used regularly in the mining industry over the last few decades. The majority of those instances have focused on health and safety issues. Health and safety has improved in the United States, Australia, and other major mining districts because of the successful use of risk management and mitigation practices. Risk management has been used to a lesser extent to reduce or avoid environmental issues as well. There are a number of factors that make utilization of risk management analysis more applicable to health and safety than to environmental issues. This thesis explores the use of risk management in the context of environmental issues associated with mining. Specifically, two case studies are developed in two self-contained manuscripts: the first focuses on sequestering CO2 while the second focuses on wild rice in Minnesota with regards to the sulfate standard. Through the lens of risk management, an attempt is made to align project goals and efforts with mitigation potential to reduce the likelihood or result of particular risks. The end result is a reduction in risks due to mitigation. The first manuscript shows how risks disappear over time because they have been categorized and addressed. The project goals are keep on track by eliminating or reducing these risks. The second manuscript can be used by stakeholders to review their potential risks and mitigate those risks if possible/necessary. In contrast to the first manuscript that contains risks that are known and measurable, the second manuscript examines different risks based on four potential outcomes. / Master of Science

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No description available.

No description available.

No description available.

Despite concerted efforts at agricultural development over many years, millions of people in developing countries still suffer from poverty and under-nutrition. New crop varieties, such as those released during the green revolution in Asia, increased farmers' income and reduced the level of under-nutrition. In recent years, while the speed of the development of conventional breeding technology has slowed, biotechnology has developed rapidly. In 2005, about 8.5 million farmers in 21 countries grew transgenic crops. Transgenic rice has not been commercially released on a large scale, but progress has been made in developing varieties with potential to increase yield and reduce input costs. In this context, this research aims to provide empirical evidence on the potential effects of introducing transgenic rice on farm households' income and nutritional well-being in Bangladesh, including the impacts on their current nutritional status and nutritional vulnerability over time. To this end, two econometric models are constructed and estimated. A farm household model is employed to project farm households' production and consumption responses to introducing improved rice varieties such as transgenic rice. The model estimates the profit effect of introducing transgenic rice. The influence of the profit effect on farmers' consumption decisions is then considered. Due to the ex ante nature of this research and data limitations, the effects of transgenic rice are assumed to be similar to that of previous high yielding varieties (HYVs), and the impact of transgenic rice on farm household profit is assumed to be similar to the effect of the percentage of rice area in HYVs and the yield effect of transgenic rice is the same as HYVs. On the production side, the supply of three outputs- rice, all other crops and animal products- and demand of labor and fertilizer were estimated. On the consumption side, both poor and non-poor households' demand for rice, wheat/other food, pulse, oil, vegetables/fruits, meat/egg/ milk, fish, and spices were estimated. Based on the parameter estimates, the calorie intake and protein intake elasticities with respect to introducing transgenic rice were computed. The results indicate that the total profit elasticity with respect to the percentage of rice area in HYVs is 0.08. The calorie elasticity with respect to the percentage of rice area in HYVs ranges from 0.062 in non-poor to 0.074 in poor households, and the protein elasticity ranges from 0.075 in non-poor to 0.084 in poor households. The results indicate that transgenic rice is likely to play a positive role in improving farm households' nutritional status in terms of total calorie/protein intake. The magnitude, however, is likely to be moderate, if only the profit effect is considered. A consumption forecasting model is used to examine farmers' nutritional vulnerability a probabilistic concept defined as having a high probability now of suffering a shortfall in the future. It is assumed that when exposed to risk, farmers' consumption decisions have already considered their risk coping strategies. The effect of transgenic rice is reflected by its impact on farm income. Farm households' calorie intake in the future (hunger season) was predicted by a multivariate regression function with the logarithmic daily per resident calorie intake as the dependent variable. The independent variables include variables that represent households' income, flood exposure, assets, and demographic composition. Farm households' nutritional vulnerability profiles, based on the estimation of ex ante mean and variance, indicate that vulnerability exists among surveyed rice farm households. The model also predicts that the income increase induced by introducing transgenic rice will reduce each individual household's probability of suffering a future consumption shortfall and subsequently will reduce its vulnerability. The overall vulnerability profile of farm households improves in Bangladesh. / Ph. D.