Factors Affecting Crop Response to Liming

Soil acidity levels directly affect the rate, kinds, and degree of chemical reactions which take place in soil. Crops respond to varying degrees to these chemical reactions. For the most part, these reactions affect the solubility of mineral elements in soil and the activity of the soil\u27s biological processes. As a result, the availability of many plant nutrient elements is regulated by soil acidity. The level of availability of plant required nutrients can be adequate, deficient, or toxic to the plant, depending on the nutrient, soil acidity, and the crop. That is why measurement of soil acidity is regarded by many to be the single most important chemical test for use in determining how well plants are likely to grow in soil. Acidity in soil is best controlled by proper applications of agricultural limestone

Fall Fertilization and Liming for Tobacco Production

Proper nutrition of tobacco is a prerequisite for achieving high yields of cured leaf possessing desirable marketing characteristics. Together with the variety grown, soils, climate, and curing conditions, a desirable nutrient environment greatly influences yield, quality, and usability of the leaf produced. Late summer and early fall is a good time to select fields for future tobacco crops or to sample this year\u27s tobacco fields which will be used for tobacco next year, and to assess their needs for lime, phosphorus, and potassium. Planning fertilization strategies this fall that lead to increased profit is much more effective than waiting until next spring

Will Liming Acid Soils Now Be Adequate for Spring Needs?

Each spring many farmers are faced with seeding forages, corn, and soybeans, and transplanting tobacco into acid soils. The choices are either to go ahead with planting and do nothing, don\u27t plant, or to try some liming practice and hope that it works. The results from planting without doing anything may be disastrous or result in limited crop performance. While not planting is a viable option for some producers, most cannot afford this choice. The question most often faced is, Will liming now do any good for this year\u27s crop

Control Measures for Manganese Toxicity of Burley at Transplating Time

Manganese (Mn) toxicity of burley tobacco is viewed by tobacco specialists in Kentucky as the greatest single factor which reduces yields. Estimates are that this problem adds 30 to 50 million dollars to the cost of burley production because of the greater acreage (and all associated costs) required by growers to produce their allotment. And, even though the cause and cure of Mn toxicity has been known for about 50 years, many growers are caught each year at transplanting time with no knowledge as to whether Mn toxicity may be a problem in their fields. The solution to Mn toxicity is to keep soil pH in the rooting zone from dropping below 5.5-5.8 during the growing season. To accomplish this requires starting the season with a soil pH of about 6,4, If soil pH is near this level before fertilizer is applied and the green manure crop decomposes, there is a much better chance that root zone pH will not drop below 5.5-5.8 after transplanting

Experience with Carbon Taxes and Greenhouse Gas Emissions Trading Systems

Carbon taxes and emissions trading systems (ETSs) to limit emissions of greenhouse gases (GHGs) are increasingly common. At the end of 2015, 17 GHG ETSs were operational in 55 jurisdictions, and 18 jurisdictions collected at least one carbon tax. This paper assesses the performance of carbon taxes and ETSs with respect to environmental effectiveness (reduction of emissions regulated by the instrument), cost-effectiveness (marginal abatement cost), economic efficiency, public finance, and administrative issues. Data on emissions subject to carbon taxes are rarely reported. We estimate the taxed emissions for 17 taxes in 12 jurisdictions from 1991 through the end of 2015. All 17 taxes have reduced emissions relative to business-as-usual. Six of the jurisdictions actually reduced emissions, although in at least three of those jurisdictions the reductions appear to be due to other policies. The small sizes of reduction in almost all 17 cases are partially due to the low tax rates; the modest and uncertain changes in tax rates over time; and the limited response of taxed sources, such as fossil fuels, to price changes. Actual emissions declined for at least six of 10 ETSs. Other policies and developments, such as the 2009 recession, contributed to the reductions, but estimates of the share of the reduction attributable to the instrument are rare. All of the ETSs have accumulated banks of surplus allowances and most have implemented measures to reduce these banks. On average, the marginal cost of compliance is substantially lower for ETSs than carbon taxes. ETS experience has been shared bilaterally and via dedicated institutions. As a result, most ETSs have increased the share of allowances auctioned; adopted declining emissions caps; specified future caps and floor prices several years into the future; shifted to benchmarking for free allowance allocations to emissions-intensive, trade-exposed (EITE) sources; reduced accessibility to foreign offset credits; and established market stability reserves. By contrast, there is little evidence of shared learning and virtually no change to the design of carbon taxes. We found no jurisdiction that routinely tracks the taxed emissions. Very few jurisdictions regularly assess the effectiveness of the tax in achieving emission reductions. Additionally, adjustments to the tax rate often are unpredictable after an introductory period of three to five years. Both instruments reduce emissions, but ETSs have performed better than carbon taxes on the principal criteria of environmental effectiveness and cost-effectiveness. Many jurisdictions have implemented both a carbon tax and a GHG ETS, and every jurisdiction that has adopted either instrument has also implemented other policies. More research is needed to improve the design of both instruments and their interaction with non-market-based carbon policies because the use of multiple instruments produces complex interactive and distributional effects. While economically inefficient, market-based policies should be supplemented by non-market-based policies to ensure sustained political support

Periodicity in Rank 2 Graph Algebras

Kumjian and Pask introduced an aperiodicity condition for higher rank graphs. We present a detailed analysis of when this occurs in certain rank 2 graphs. When the algebra is aperiodic, we give another proof of the simplicity of \ca(\Fth). The periodic C*-algebras are characterized, and it is shown that \ca(\Fth) \simeq \rC(\bT) \otimes \fA where \fA is a simple C*-algebra.Comment: 27 page

Connexin43 regulates joint location in zebrafish fins

AbstractJoints are essential for skeletal form and function, yet their development remains poorly understood. In zebrafish fins, joints form between the bony fin ray segments providing essentially unlimited opportunities to evaluate joint morphogenesis. Mutations in cx43 cause the short segment phenotype of short fin (sofb123) mutants, suggesting that direct cell–cell communication may regulate joint location. Interestingly, increased cx43 expression in the another long fin (alfdty86) mutant appears to cause joint failure typical of that mutant. Indeed, knockdown of cx43 in alfdty86 mutant fins rescues joint formation. Together, these data reveal a correlation between the level of Cx43 expression in the fin ray mesenchyme and the location of joints. Cx43 was also observed laterally in cells associated with developing joints. Confocal microscopy revealed that the Cx43 protein initially surrounds the membranes of ZNS5-positive joint cells, but at later stages becomes polarized toward the underlying Cx43-positive mesenchymal cells. One possibility is that communication between the Cx43-positive mesenchyme and the overlying ZNS5-positive cells regulates joint location, and upregulation of Cx43 in joint-forming cells contributes to joint morphogenesis

Effect of Lime and Source of Nitrogen Fertilizer on Yield and Chemical Composition of Burley Tobacco

Current trends in the fertilizer industry indicate a shift to greater production of ammonium forms of nitrogen fertilizer in comparison to nitrate forms. Reasons for these trends are many, but both economic and energy conservation are major factors. Generally, ammonium forms are produced with less, total energy and have higher nitrogen contents that permits lower production and transportation costs per unit of N. Agronomically, ammonium forms are less readily leached from soils, but produce acid as they are converted to nitrates by soil microorganisms. Thus, ammonium sources of nitrogen have both advantages and disadvantages as fertilizers for crops

Factors Affecting Color of Cured Burley Leaf

Much interest has been shown by tobacco growers during recent months in fertilization and or other management practices that can be used to produce darker and redder cured leaf of burley tobacco. The purpose of this newsletter is to summarize what we know about some of the factors which affect color of cured leaf