Ronald S. Swift

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The effect of the solid and dissolved organic matter fractions, mineral composition and ionic strength of the soil solution on the sorption behaviour of pesticides were studied. A number of soils, chosen so as to have different clay mineral and organic carbon content, were used to study the sorption of the pesticides atrazine(More)
The effects of adding lime and/or phosphate to an acid, phosphate-deficient soil on microbial activity, enzyme activities and levels of biomass and extractable N, S and P were studied under laboratory conditions. Following rewetting there was, as expected, an initial flush in microbial growth and activity, as shown by large increases in CO2 evolution, in(More)
The effects of lime and P applications and drying and rewetting cycles, and their interactions, on the extractability and plant-availability of native and applied P were investigated in a glasshouse experiment using an acid (pHwater, 5.3), P-deficient soil. As expected, liming increased soil pH, decreased exchangeable Al to negligible concentrations and(More)
© 2002 University of Minnesota MIS Quarterly Executive Vol. 1 No. 2 / June 2002 95 The perspectives brought forth by Professors Goodhue, Wixon, and Watson in their study of business benefits and appropriate targets of CRM highlights the challenges, opportunities, and expectations of CRM implementations. Their insightful description of the ‘planned(More)
An open incubation technique was used to measure S mineralisation in a range of New Zealand soils. For most of the soils studied, the release of S as sulphate was curvilinear with time, and during a 10-week incubation, the amounts of S mineralised ranged from less than 3 μg S g-1 soil to more than 26 μg S g-1 soil. The best predictor of mineralised S(More)
Prunings of Calliandra calothyrsus, Grevillea robusta, Leucaena diversifolia and farm yard manure were applied each cropping season at 3 and 6 t dry matter ha−1 to an Oxisol in Burundi. The field plots also received basal applications of nitrogen (N), phosphorus (P) and potassium (K). Application of the tree prunings or farm yard manure decreased the(More)
The effects of application of nitrogen as calcium nitrate, urea or ammonium sulphate at two rates through the trickle irrigation system on pH and nutrient status of the wetted volume of soil below the emitters and on growth and nutrition of courgette (zucchini) plants (Cucurbita pepo L.) was investigated. Soil acidification, caused by nitrification,(More)
The effects of soil acidification (pH values from 6.5 to 3.8), and subsequent leaching, on levels of extractable nutrients in a soil were studied in a laboratory experiment. Below pH 5.5, acidification resulted in large increases in the amounts of exchangeable Al in the soil. Simultaneously, exchangeable cations were displayed from exchange sites and Ca,(More)
The effects of soil acidification and micronutrient addition on levels of extractable Fe, Mn, Zn and Cu in a soil, and on the growth and micronutrient uptake of young highbush blueberry plants (Vaccinium corymbosum L. cv. Blueray) was investigated in a greenhouse study. Levels of 0.05M CaCl2-extractable Fe, Mn, Zn and Cu increased as the pH was lowered from(More)
Levels of extractable micronutrients in a peat and the growth and nutrient uptake of young highbush blueberry plants (Vaccinium corymbosum L cv. Blueray) were studied in a greenhouse experiment in response to liming and two rates of addition of Fe, Mn, Zn and Cu. Levels of extractable micronutrients showed different trends with liming depending upon the(More)