Nitrogen (N) fertilizer applied in the fall has been shown to increase emissions of N2O a GHG (Nyborg et al. 1997). Applying N fertilizer in the spring is a management technique Saskatchewan grain and oilseed producers can use to reduce N2O emissions. The hypothesis of this thesis is that fall application of N fertilizer is more profitable than spring application. Factors to consider in the timing of fertilizer application include, the level of information available, input cost, input efficiency, and application cost. The key objective of this thesis is to determine the financial impact of switching to spring N application from fall N application. Stochastic variables include fall subsoil moisture, winter precipitation, growing season precipitation, input costs, and output prices. Expected utility theory for two representative farms at two locations is used to determine optimal N fertilizer rates and the value of spring subsoil moisture information and the value of spring output price forecasts. The fixed and variable operating costs are calculated for three seeding systems. The results show that it is optimum for producers to purchase N fertilizer in the fall and apply N fertilizer in the spring. Spring subsoil moisture information, and spring output price forecasts have little value to producers committed to continuous cropping. One pass (seed and fertilize in the spring) seeding systems have lower variable and fixed costs than two pass seeding systems for producers applying large amounts of fertilizer.

No description available.

The effect of seeding on the properties of alumina supported MFI membranes was investigated in this study. Membranes were synthesized from clear solutions with a molar batch composition of TPAOH:9.80SiO2:0.025NaOH:0.019Al2O3: 602.27H2O:39.16C2H5OH on bare and seeded alumina supports at 130oC in autoclaves. The amount of seed on the support surface was changed between 0.6 mg/cm2 and 6.9 mg/cm2 by vacuum seeding method, which provided uniform and closely packed seed layers. Membranes were characterized by XRD and SEM, and by measuring single gas permeances of N2, SF6, n-C4H10 and i-C4H10. The quality of membranes was evaluated on the basis of N2/SF6 ideal selectivity. Membranes, which showed N2/SF6 ideal selectivity higher than 40, were considered to be good quality, comprising few defects. Good quality membranes were also used to separate butane isomers. Membranes synthesized on seeded supports had compact and uniform MFI layer if the seed amount is less than 1.0 mg/cm2 on the support surface. Membranes that were synthesized on the supports coated with higher amount of seed crystals showed an asymmetric structure with a dense and uniform MFI layer at the top, the support at the bottom and a seed layer between. Half of the membranes synthesized on seeded supports had N2/SF6 ideal selectivity higher than 40. These membranes exhibited n-C4H10/i-C4H10 separation selectivities between 5 and 27 and 8 and 21 at room temperature and at 200oC, respectively. High ideal and separation selectivities showed that membranes did not include non-zeolitic pores. Membranes synthesized on bare support had non-uniform MFI layer. Those membranes showed N2/SF6 ideal selectivities below Knudsen selectivity, indicating the existence of large non-zeolitic pores in the MFI layer.

Westbred 881 durum wheat commands a premium price due to its superior quality, but produces a lower yield than other commonly grown commercial cultivars. This study was initiated to improve our understanding of how best to manage Westbred 881. Two durum wheat cultivars (Westbred 881 and Aldura) were planted at 5 seeding rates (30, 60, 120, 180, and 240 lbs. seed/A), 5 row spacings (3, 6, 12, 18, and 24 inches), and two planting dates (Dec. 1 and Jan. 16) at the Maricopa Agricultural Center. Both cultivars produced optimum yields at seeding rates of 120 to 180 lbs/A for the Dec. 1 planting date. At the Jan. 16 planting date, however, yields of Westbred 881 increased linearly with seeding rate up to 240 lbs/A, while Aldura produced optimum yields between 120 and 180 lbs. seed/A. At the Dec. 1 planting date, Aldura produced similar yields at row spacings from 3 to 12 inches, while the yield of Westbred 881 decreased linearly with an increase in row spacing. The highest yield achieved in this study was with Westbred 881 at the 3 -inch row spacing. Row spacings of 6 to 12 inches were optimum for both Westbred 881 and Aldura at the Jan. 16 planting date. The seeding rate and row spacing responses attained with Westbred 881 may be related to its tittering characteristics.

Five varieties of durum wheat were evaluated at two different seeding rates, in cooperation with Pacheco Farm Management in Marana. Significant differences between varieties were observed in grain yield, plant height, lodging, bushel weight and protein level. No significant differences in yellow berry were observed between the varieties. The planting rates did not cause significant differences in grain yield nor in any of the other characteristics that were measured. There were no significant variety x planting rate interactions.

Many people around the world live in islands with mountainous lands. These people plant upland rice for their staple food. However, farming in these disadvantageous farms requires high input and gains low yield. One possible solution for improving productivity is by utilizing precision seeding. This study is focused on developing a robot for precision seeding of rice that is suitable for farming in rough terrain. A bioinspired human arm robot for picking seeds and making a hole on the ground was developed in accordance with Aalborg method for bioinspired design. Development of a mobile platform to carry the robot arm was done using hybrid wheel and leg (wheg) wheels and skid steering locomotion. The NugalBot could climb obstacle and perform precision rice seed singulation. However, the performance of the mechanisms for making hole and for covering the hole was dependent on the hardness of the soil.

Due to increasing numbers of non-coding RNA (ncRNA) being discovered recently, there is interest in identifying homologs of a given structured RNA sequence. Exhaustive homology searching for structured RNA molecules using covariance models is infeasible on genome-length sequences. Hence, heuristic methods are employed, but they largely ignore structural information in the query. We present a novel method, which uses secondary structure information, to perform homology searches for a structured RNA molecule. We define the concept of a <em>pair seed</em> and theoretically model alignments of random and related paired regions to compute expected sensitivity and specificity. We show that our method gives theoretical gains in sensitivity and specificity compared to a BLAST-based heuristic approach. We provide experimental verification of this gain. <br /><br /> We also show that pair seeds can be effectively combined with the spaced seeds approach to nucleotide homology search. The hybrid search method has theoretical specificity superior to that of the BLAST seed. We provide experimental evaluation of our hypotheses. Finally, we note that our method is easily modified to process pseudo-knotted regions in the query, something outside the scope of covariance model based methods.

Due to increasing numbers of non-coding RNA (ncRNA) being discovered recently, there is interest in identifying homologs of a given structured RNA sequence. Exhaustive homology searching for structured RNA molecules using covariance models is infeasible on genome-length sequences. Hence, heuristic methods are employed, but they largely ignore structural information in the query. We present a novel method, which uses secondary structure information, to perform homology searches for a structured RNA molecule. We define the concept of a <em>pair seed</em> and theoretically model alignments of random and related paired regions to compute expected sensitivity and specificity. We show that our method gives theoretical gains in sensitivity and specificity compared to a BLAST-based heuristic approach. We provide experimental verification of this gain. <br /><br /> We also show that pair seeds can be effectively combined with the spaced seeds approach to nucleotide homology search. The hybrid search method has theoretical specificity superior to that of the BLAST seed. We provide experimental evaluation of our hypotheses. Finally, we note that our method is easily modified to process pseudo-knotted regions in the query, something outside the scope of covariance model based methods.

Monitoring ecological restoration at the community scale provides insight into how the population dynamics and community interactions are progressing through time in comparison to a restoration’s goals and reference conditions. This study monitored the early post-restoration dynamics of a sand plain located in the Carolinian Canada ecozone called Lake Erie Farms. The restoration consisted of restoring three habitats via sculptured seeding: a mesic forest, oak woodland, and sand barren. The hypothesis of this study is that the restoration efforts have established population dynamics and community interactions consistent with successional patterns expected from comparative literature. Community ecology, directed succession, and alternative stable states are the underlying theories that provided a conceptual and theoretical lens from which to study the objectives and hypothesis. To gain insight into the community dynamics at Lake Erie Farms the vegetation abundance, seed abundance and viability of the seedbank, seed viability of the 6 most dominant species (3 most dominant native species & 3 most dominant weedy species), and soil moisture & pH were monitored. The analysis was conducted using a RMANOVA of a nested design (P > 0.001, 0.01 and 0.05) to compare the variables in relation to the site (i.e. the sum of all the quadrats), the restoration treatment nested within the site, the field nested within the site, the transect nested within the restoration treatment and the quadrat nested within the restoration treatment. The significant findings of this study include: i) the restoration treatments are producing similar results as those expected from the literature, though there is evidence of the sculptured seeding treatment accelerating the successional stage at Lake Erie Farms compared to abandoned agricultural fields in similar ecosystems because of the presence of later-successional species; ii) the control areas are less diverse than each of the restoration units (P>0.05); and iii) the soil moisture among the treatments is beginning to diverge into the desired restoration units.

2 pp. / Describes the proper timing of overseeding, selecting winter grasses, and procedures to prepare for overseeding with the amount of seed to use followed by irrigating, fertilizing, and mowing.