The effects of liming on the liberation of Potassium in some Iowa soils

The effects of lime on the liberation of potassium in a number of Iowa soils were studied in a series of experiments and the results obtained are summarized as follows: 1. Analyses of 12 high-lime soils showed that all of the soils contained relatively large amounts of total potassium, carbonates and total nitrogen. 2. The available potassium content of 11 of the 12 high-lime soils was insufficient for maximum plant growth according to the Aspergillus niger test. This low content of available potassium was correlated with the high carbonate content. 3. The exchange complex of an acid Tama silt loam was completely saturated by applications of 6 tons of calcium carbonate per acre in greenhouse experiments and 6 months after treatment the amounts of exchangeable and available potassium were decreased. 4. Calcium carbonate, calcium chloride and calcium hydroxide replaced potassium and increased the available potassium in the soil exchange complex in acid Tama silt loam and to a smaller extent in basic Webster silty clay loam, calcium chloride being the most effective. Calcium sulfate had little or no effect on the exchangeable and available potassium. 5. The availability of potassium in high-lime soils was lower in inoculated than in uninoculated soils and the decrease in availability was greater in soils treated with calcium carbonate than in the untreated soils. 6. It is suggested that a decreased hydrolysis of primary potassium-bearing minerals and the formation of insoluble potassium complexes and possibly also a reduction in available potassium by microorganic activity may be responsible, in part at least, for the decreased availability of potassium in these soils

Is a Higher Calling Enough? Incentive Compensation in the Church (CRI 2009-011)

We study the compensation and productivity of more than 2,000 Methodist ministers in a 43-year panel data set. The church appears to use pay-for-performance incentives for its clergy, as their compensation follows a sharing rule by which pastors receive approximately 3% of the incremental revenue from membership increases. Ministers receive the strongest rewards for attracting new parishioners who switch from other congregations within their denomination. Monetary incentives are weaker in settings where ministers have less control over their measured performance

A NEW VISION FOR AN OLD INSTITUTION: ADDRESSING THE CHALLENGES FOR URBAN AND PERI-URBAN AGRICULTURE AT THE WALTHAM EXPERIMENT STATION

Urban and peri-urban agriculture has a new place in (sub)urban landscapes because of the suite of ecosystem services it can provide including, but not limited to; increased local food production, waste recycling, stormwater infiltration, and reconnecting urban dwellers to their food source. The University of Massachusetts Amherst’s Waltham Experiment Station, located in Waltham, Massachusetts, is poised for redevelopment as a model for multi-use urban agriculture production, research, and education as well as a living laboratory to monitor and document the ecosystem services provided to the surrounding community. This project will focus on educational and research categories within the theme of cultural ecosystem services and how this new vision for extension can strengthen urban and peri-urban agriculture activities

Scaling forces to asteroid surfaces: The role of cohesion

The scaling of physical forces to the extremely low ambient gravitational acceleration regimes found on the surfaces of small asteroids is performed. Resulting from this, it is found that van der Waals cohesive forces between regolith grains on asteroid surfaces should be a dominant force and compete with particle weights and be greater, in general, than electrostatic and solar radiation pressure forces. Based on this scaling, we interpret previous experiments performed on cohesive powders in the terrestrial environment as being relevant for the understanding of processes on asteroid surfaces. The implications of these terrestrial experiments for interpreting observations of asteroid surfaces and macro-porosity are considered, and yield interpretations that differ from previously assumed processes for these environments. Based on this understanding, we propose a new model for the end state of small, rapidly rotating asteroids which allows them to be comprised of relatively fine regolith grains held together by van der Waals cohesive forces.Comment: 54 pages, 7 figure

Is There a Deficiency of Available Potassium in So-Called Alkali Soils of Iowa?

A review of the literature reveals conflicting opinions regarding the effects of lime upon the liberation of potassium in soils. The early investigators and most textbooks on soils adhere to the viewpoint that the addition of lime to soils results in the liberation of potassium through chemical reaction. It is believed by some that addition of calcium to soil materially affects the solubility of the potassium from the soil, so much so as to be of considerable practical value under field conditions. According to Jenny, as early as 1847 Liebig pointed out that the addition of lime furnished an invaluable means of liberating from the soil those alkalies that are indispensable to the existence of plants. Hall in 1921 reported that the action of lime upon the potassium compounds in the soil is very marked. The explanation is given that as the water carries down the dissolved calcium bicarbonate, the zeolitic double silicates in the clay are attacked and some of their soluble bases, potassium among them, change place with the lime and go into solution

Why do firms hold so much cash? A tax-based explanation

U.S. corporations hold significant amounts of cash on their balance sheets, and these cash holdings have been justified in the existing empirical literature by transaction costs and precautionary motives. An additional explanation, considered in this study, is that U.S. multinational firms hold cash in their foreign subsidiaries because of the tax costs associated with repatriating foreign income. Consistent with this hypothesis, firms that face higher repatriation tax burdens hold higher levels of cash, hold this cash abroad, and hold this cash in affiliates that trigger high tax costs when repatriating earnings. Estimates indicate that a one standard deviation increase in the tax burden from repatriating foreign income is associated with a 7.9% increase in the ratio of cash to net assets. In addition, certain firms, specifically those that are less financially constrained domestically and those that are more technology intensive, exhibit a higher sensitivity of affiliate cash holdings to repatriation tax burdens.

Optimal Compensation Contracts with Pay-For-Performance and Termination Incentives

This paper studies optimal compensation contracts in the presence of both pay-for-performance and termination incentives. While these incentives have been studied independently, this paper’s model is the first to incorporate both. The primary result is that pay-for-performance and the threat of termination are substitute incentive devices; holding effort constant, optimal pay-for-performance incentives are increasing in the cost of termination. Our test of this result compares compensation contracts of managers of real estate investment trusts and general partners of real estate limited partnerships. REIT managers’ wealth changes by $25.30 per$1,000 change in REIT value. Compensation for general partners, who are more costly to fire than REIT managers, changes by $253.57 per$1,000 change in partnership value

The Effects of Potash and Crop Residues on Available Potassium in Some Alkali Soils of Iowa

Many investigators have found that high-lime soils may often be deficient in available potassium. According to the present theory, the low availability of the potassium in such soils is probably due to the high concentrations of calcium salts. The so-called alkali soils of Iowa have been found to contain high concentrations of both calcium carbonate and calcium bicarbonate. Apparently the concentrations of these salts are so high that they tend to depress the availability of the potassium in the soil

Some Effects of Fertilization on Nitrification in High-Lime Soils

Applications of potassium chloride at the rate of 100, 200 and 500 pounds per acre were made on two soils containing a high calcium content. Oat straw at the rate of 2 tons of dry matter per acre was applied alone and in combination with potassium chloride. Sweet clover at the rate of 2 tons of dry matter per acre was applied alone and in combination with potassium chloride. Samples of the soils were taken 4 weeks after treatment in the greenhouse and again after 5 months for nitrification determinations