Lime and manure application to low-fertility tropical soils enhances phosphorus bioavailability for increased agronomic productivity

Liming and manuring to ameliorate soil acidity and enhance mineralization in acid tropical soils could promote their agronomic productivity. Synthetic lime and poultry-droppings manure’s effects in sandy-loam Ultisols were evaluated on soybean growth, exploring its relationships with soil pH, soil available P and plant P content. Lime was applied at 0, 2.5 and 5 t ha–1 equivalents and manure at 0, 25 and 50 t ha–1 equivalents to 2.5-kg potted soils. Crop growth was monitored and soil-plant analysis done during and after six weeks of growth, respectively. Treatment had more pronounced effects on plant height than leafiness of the soybean plants, being generally highest in the combination of lime at 2.5 t ha–1 and manure at 50 t ha–1 where the plants were about three times taller compared to unamended control. Soybean plants grew better due to 2.5 than 0 and 5 t ha–1 lime and to 50 than 0 and 25 t ha–1 manure. Plant height and leaf area depended on soil pH-influenced soil available P (R2 = 0.69**) and plant P content (R2 = 0.85**), respectively, while above-soil biomass depended on soil pH or plant height (R2 = 0.74**). Moderate synthetic liming (2.5 t ha–1) with ample poultry-droppings manuring (50 t ha–1) could enhance crop early-stage vegetative growth in low-fertility tropical soils, due largely to amelioration of soil acidity to enhance plant uptake of bioavailable P

How We “Fit”: African-American Faculty at a Predominantly White Institution of Higher Education: A Case Study of a Small Liberal Arts College in Virginia

This session will address historical, sociological, and psychological perspectives that should lend insight into fostering the effective performance of culturally diverse individuals within a predominantly Euro-American institutional setting. Research-based implications will be shared through the lens of three African-American female professors within such a context

A quantitative analysis of the antagonism of intravenous noradrenaline by thymoxamine or phentolamine on the blood pressure of the conscious cat

Abstract The blood pressure of the unanaesthetized cat was recorded from a nylon catheter inserted permanently into the aorta via the right carotid artery and intravenous injections were made into a nylon catheter tied permanently into the right external jugular vein. For noradrenaline there was a linear relation between log dose and blood pressure rise. The α-blocking agents thymoxamine and phentolamine lowered the blood pressure and decreased the pressor response to noradrenaline. Quantitative analysis of the results by three different graphical methods revealed that for the first dose of blocking agent the antagonism was complex but had the characteristics associated with mixed non-competitive and uncompetitive antagonism. For further cumulative doses of blocking agent, the antagonism had the characteristics of competitive antagonism. It is concluded that a first dose of α-blocking agent has an effect on the dynamics of a noradrenaline-induced blood pressure rise in the conscious cat which is complex and could in part be due to the initial effect of the blocking agent in lowering the blood pressure and in part to the activity of the vasomotor compensatory reflexes. After α-blockade has been initiated, the characteristics of the antagonism are, like those in the anaesthetized cat, those of competitive antagonism.</jats:p