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Chad E. Husby, Alexander X. Niemiera, J. Roger Harris and Robert D. Wright

This study was conducted to determine the effects of temperature on nutrient release patterns of three polymer-coated fertilizers (PCFs), each using a different coating technology: Osmocote Plus 15N-3.93P-9.96K, Polyon 18N-2.62P-9.96K, and Nutricote 18N-2.62P-6.64K. Each fertilizer was placed in a sand-filled column and leached with distilled water at ≈100 mL·h-1, while being subjected to a simulated diurnal container temperature change from 20 to 40 °C and back to 20 °C over a period of 20 hours. Column leachate was collected hourly and measured for soluble salts and NO3-N and NH4-N content. For all fertilizers, nutrient release increased and decreased with the respective increase and decrease in temperature. Nutrient release patterns of the three fertilizers differed, with Osmocote Plus showing the greatest overall change in nutrient release between 20 and 40 °C, and Nutricote the least.

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Mark Gaskell and Richard Smith

-farm sources, and purchased organic fertilizers. When discussing organic N fertility programs, it is important to distinguish between short-term and long-term effects. Studies have shown that the total supply of N from SOM on organic farms may be in excess of

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T.K. Hartz, R. Smith and M. Gaskell

potential for water quality degradation from high phosphorus (P) loading ( Sharpley et al., 1994 ). Dry organic fertilizers such as fishery waste, feather meal, and seabird guano are widely used; these products have high N content (>10% of dry weight) and

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Renae E. Moran and James R. Schupp

'Macoun'/B.9 apple (Malus ×domestica Borkh.) trees were planted in May 1998 in ± compost or ± monoammonium phosphate (MAP) for a total of four preplant treatments: 1) 90 g phosphorus (P) per tree, 2) 128 kg compost per tree, 3) 90 g P and 128 kg compost per tree, and 4) and an untreated control. MAP did not increase tree growth or yield in any year of the study. Compost increased canopy width into the sixth year after planting, and increased tree height and trunk cross-sectional area (TCA) into the seventh year. Annual yield was increased by compost in the fifth and seventh years, but not fourth or sixth year after planting. Compost increased cumulative yield in the sixth and seventh years.

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Ka Yeon Jeong, Paul V. Nelson, Carl E. Niedziela Jr. and David A. Dickey

respiratory acidification ( Marschner, 1995 ); acidic, neutral, or alkaline biotic effect of nutrient uptake ( Pertusatti and Prado, 2007 ), which varies among plant species ( Fisher et al., 2014a ; Johnson et al., 2013 ); and the abiotic effect of fertilizer

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M. Lenny Wells

energy costs have led to a dramatic increase in the price of synthetic fertilizer ( Huang, 2009 ). Between 2002 and 2007 the cost of synthetic fertilizer N per acre rose by over 200% for pecan ( Wells, 2009a ). This sharp increase in the cost of a single

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Joseph C. Fetter, Rebecca N. Brown and José A. Amador

acids, and chlorophyll ( Brady and Weil, 2002 ). It is mainly provided to turfgrass in the form of fertilizer, although N from mineralization of soil organic matter (SOM) and precipitation can also enrich the soil N pool. Nitrogen applied to turfgrass is

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Kenneth G. McCabe, Christopher J. Currey, James A. Schrader, David Grewell, Jake Behrens and William R. Graves

flowering plants, foliage plants, and potted herbaceous perennials. Most plants grown in containers are provided water-soluble fertilizers or granular CRF. These fertilizers are typically synthetically derived, and sustainability of their use has been

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E.A. Guertal

A brief review of slow-release fertilizer technology Slow-release nitrogen fertilizers can be separated into three broad categories. The first is “natural” organic fertilizer, with the N contained as a part of crop residue, animal waste, or other

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Touria E. Eaton, Douglas A. Cox and Allen V. Barker

organic media, fertilizers, and pest management methods for greenhouse crops. Organic media are available in the market, and pest management practices using organic pesticides and biological control agents are being established. However, cultural