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Connie N. Johnson, Paul R. Fisher, Jinsheng Huang, Richard P. Vetanovetz, and William R. Argo

uptake of nutrients and the subsequent release of ions and/or root exudates along with other microbially induced processes such as nitrification ( Marschner, 1995 ). Using nitrogen as an example, uptake of NO 3 -N can result in the release of OH – and

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Megan M. Kennelly, Timothy C. Todd, Derek M. Settle, and Jack D. Fry

needed. There are also gaps in knowledge regarding other cultural practices and their impacts on moss. For example, low nitrogen has been linked to increased moss severity ( Hummel, 1994 ; Borst et al., 2009 ), but the impact of nitrogen source, and

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Rebecca L. Turk, Helen T. Kraus, Ted E. Bilderback, William F. Hunt, and William C. Fonteno

. Fig. 1. Nitrogen (NO 3 – + NO 2 – + NH 4 + ) analysis for filter bed substrates blends (v/v). Soil = 50% sandy loam, 50% pine bark; sand = 80% sand, 15% clay and silt fines, 5% pine bark; slate = 80% expanded slate, 20% pine bark by sample date for

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Linda L. Taylor, Alexander X. Niemiera, Robert D. Wright, and J. Roger Harris

investigated. Fertilizer regimes have also been investigated because nitrogen (N) immobilization can decrease plant-available N in uncomposted wood substrates. Research has shown that a higher N application rate for some wood-based substrates is required to

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Bernadine C. Strik and David R. Bryla

Agriculture (USDA), 2015 ]. There were also 495 and 663 acres of organic blackberry and raspberry, respectively, in the United States in 2008 ( USDA, 2010 ). Caneberry plants are perennial with an expected life span of 5 to 15 years for raspberry and 25 to 40

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James E. Altland and Charles Krause

). Treatment design was a 3 × 3 factorial with three substrates and three nitrogen (N) fertilizer rates. The three substrates included coarse switchgrass amended with 0%, 30%, or 50% sphagnum peatmoss (v/v). All substrates were amended with 0.9 kg·m −3

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Lee S. Altier and H. Christian Wien

In a two-year field experiment, sweet corn was intercropped with a perennial cover of white clover. The clover was suppressed after corn emergence by rototilling. The nitrogen exchange between the corn, clover, and soil was closely monitored. Soil sampling indicated the rate and amounts of mineralization of nitrogen from soil organic matter and clover. Fertilizer labelled with 15-N was used to assess contributions of nitrogen from the various sources.

Results from 1989 showed little nitrogen benefit to the corn from the clover. Content of 15-N in the corn indicated that non-fertilizer nitrogen uptake was similar in monocropped and intercropped corn treatments. Corn yields were correlated with the amount of nitrogen fertilizer applied.

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Lee S. Altier and H. Christian Wien

In a two-year field experiment, sweet corn was intercropped with a perennial cover of white clover. The clover was suppressed after corn emergence by rototilling. The nitrogen exchange between the corn, clover, and soil was closely monitored. Soil sampling indicated the rate and amounts of mineralization of nitrogen from soil organic matter and clover. Fertilizer labelled with 15-N was used to assess contributions of nitrogen from the various sources.

Results from 1989 showed little nitrogen benefit to the corn from the clover. Content of 15-N in the corn indicated that non-fertilizer nitrogen uptake was similar in monocropped and intercropped corn treatments. Corn yields were correlated with the amount of nitrogen fertilizer applied.

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Yang Chen, Xianzhi Zhou, Yongsheng Lin, and Lina Ma

locally recommended quantity of fertilizers applied. The quantity of fertilizers applied at levels 0, 1, and 3 were no fertilizer, 0.5-times the amount applied at level 2, and 1.5-times the amount applied at level 2 (as shown in Table 1 ). Fourteen

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Francesco Giuffrida, Marianna Martorana, and Cherubino Leonardi

the Experimental Farm of Catania University in southern Italy (long. 37.3° N, lat. 15.0° E; 20 m a.s.l.). The tomato ( Solanum lycopersicum L.) hybrid Durinta F 1 (Western Seed S.A., Naaldwijk, NL) was selected as one of the most representative