Rising Off the Plateau in Learning Arabic

Experiencing plateaus in second language learning is a common experience, especially for language student studying Arabic or one of the other languages considered more difficult. Some of the causes for the plateau experience in Arabic are its complex grammar, its vast amount of vocabulary, and the different roles of Modern Standard Arabic and the spoken dialects of Arabic. Rising off the Plateau in Studying Arabic is a thesis project, which analyzes this second language learner’s attempt to make significant progress in studying Modern Standard Arabic. The project was based on a self-directed, semi-intensive Arabic language program, which prioritized the reading skill because of this learner’s visual learning style. The importance of analyzing one’s own second language acquisition process was emphasized throughout the project. The ACTFL Proficiency Guidelines (American Council on the Teaching of Foreign Languages) were used as an evaluation tool to guide self-assessment of progress being made. This thesis project was the final requirement for a M.A.T. (Masters of Arts in Teaching) degree from the School of International Training. The required classes of this program provided the knowledge, hope, and inspiration that enabled this project to be envisaged, planned, and completed. The Second Language Acquisition course played the most significant role in that process

Agency, pedagogy and e-learning in TAFE educational development

The study is a deconstructive autoethnographic examination of the ways in which various discourses of agency shape the pedagogy of educational developers supporting the use of e-learning in Technical and Further Education (TAFE) institutions

Estimating annual soil carbon loss in agricultural peatland soils using a nitrogen budget approach.

Around the world, peatland degradation and soil subsidence is occurring where these soils have been converted to agriculture. Since initial drainage in the mid-1800s, continuous farming of such soils in the California Sacramento-San Joaquin Delta (the Delta) has led to subsidence of up to 8 meters in places, primarily due to soil organic matter (SOM) oxidation and physical compaction. Rice (Oryza sativa) production has been proposed as an alternative cropping system to limit SOM oxidation. Preliminary research on these soils revealed high N uptake by rice in N fertilizer omission plots, which we hypothesized was the result of SOM oxidation releasing N. Testing this hypothesis, we developed a novel N budgeting approach to assess annual soil C and N loss based on plant N uptake and fallow season N mineralization. Through field experiments examining N dynamics during growing season and winter fallow periods, a complete annual N budget was developed. Soil C loss was calculated from SOM-N mineralization using the soil C:N ratio. Surface water and crop residue were negligible in the total N uptake budget (3 - 4 % combined). Shallow groundwater contributed 24 - 33 %, likely representing subsurface SOM-N mineralization. Assuming 6 and 25 kg N ha-1 from atmospheric deposition and biological N2 fixation, respectively, our results suggest 77 - 81 % of plant N uptake (129 - 149 kg N ha-1) was supplied by SOM mineralization. Considering a range of N uptake efficiency from 50 - 70 %, estimated net C loss ranged from 1149 - 2473 kg C ha-1. These findings suggest that rice systems, as currently managed, reduce the rate of C loss from organic delta soils relative to other agricultural practices

Estimating yield potential in temperate high-yielding, direct-seeded US rice production systems

Accurate estimation of a crop’s yield potential (Yp) is critical to addressing long-term food security via identification of the exploitable yield gap. Due to lack of field data, efforts to quantify crop yield potential typically rely on crop models. Using the ORYZA rice crop model, we sought to estimate Yp of irrigated rice for two widely used rice varieties (M-206 and CXL745) in three major US rice-producing regions that together represent some of the highest yielding rice regions of the world. Three major issues with the crop model had to be addressed to achieve acceptable simulation of Yp; first, the model simulated leaf area index (LAI) and biomass agreed poorly for all direct-seeded systems using default settings;second, cold-induced sterility and associated yield losses were poorly simulated for environments with a large diurnal temperature variation; lastly, simulated Yp was sensitive to the specified definition of physiological maturity. Except for the simulation of cold-induced sterility, all issues could be remedied within the existing model structure. In contrast, simulation of cold-induced sterility posed a continuing challenge to accurate simulation—one that will likely require changes to ORYZA’s formulation. Estimates of Yp from the modified model were validated against large multi-year data sets of experimental yields covering the majority of US rice production areas. Validation showed the adjusted model simulated Yp well, with most top yields falling within 85% of Yp for both varieties (77% and 78% observed yields within15% of Yp for CXL745 and M-206 respectively). Maximum estimated Yp was 14.3 (range of 8.2–14.5) and14.5 (range of 8.7–15.3) t ha−1for the Southern US and CA, respectively