Search Results

You are looking at 1 - 10 of 1,531 items for :

  • "phosphorus" x
Clear All
Restricted access

Michael F. Polozola II, Daniel E. Wells, J. Raymond Kessler, Wheeler G. Foshee, Amy N. Wright and Bryan S. Wilkins

sandy loams and are typical of pecan orchards throughout the southeastern United States. Growers often experience difficulties maintaining recommended foliar phosphorus (P) levels in their orchard trees due to naturally low P in the soils and the nature

Free access

Ricardo González-Ponce, Esther G. López-de-Sá and César Plaza

Phosphorus is one of the primary nutrients essential for plant growth and crop production ( Mengel and Kirkby, 2004 ). At present, most commercial phosphorus (P) fertilizers on the market such as single superphosphate are derived from phosphate rock

Free access

M. Murshidul Hoque, Husein Ajwa, Mona Othman, Richard Smith and Michael Cahn

more than 150 kg nitrogen (N)/ha/crop ( Jackson et al., 1994 ). Similarly, the excessive accumulation of soil phosphorus (P) has raised water quality concerns ( Sims, 1998 ). Salinas Valley soils often contain more than 30 to 40 mg·kg −1 of bicarbonate

Restricted access

Yang Chen, Xianzhi Zhou, Yongsheng Lin and Lina Ma

index of soybean in black soil region of Heilongjiang Province Soybean Sci. 32 512 516 Sun, Y. Guo, Y. Yu, S. Jiang, Q. Cheng, L. Cui, Z. Chen, X. Jiang, R. Zhang, F. 2009 Establishing phosphorus and potassium fertilization recommendation index based on

Free access

Rhoda Burrows, F.L. Pfleger and Luther Waters Jr.

Asparagus offcinalis L. `Mary Washington' seedlings inoculated with Glomus fasciculatum (Thaxter) Gerd. and Trappe emend. Walker and Koske showed increased growth after 9 weeks, compared with noninoculated plants. Phosphorus supplementation (25 g·m-3) increased seedling growth of inoculated and noninoculated plants throughout the 26 weeks of the experiment. However, after 9 weeks, there were no differences in growth of inoculated, non-P-supplemented plants and noninoculated, P-supplemented plants. Fern height, fern and crown weight, and bud numbers correlated positively to the percentage of G. fasciculatum root infection.

Full access

Kristian Borch, Kathleen M. Brown and Jonathan P. Lynch

Bedding plants are frequently exposed to water stress during the postproduction period, resulting in reduced quality. We demonstrated that alumina-buffered P fertilizer (Al-P) provides adequate but much lower P concentrations than conventionally used in soilless mixes. When impatiens (Impatiens wallerana Hook. f. `Impulse Orange') and marigold (Tagetes patula L. `Janie Tangerine') plants were grown with reduced phosphorus using Al-P, P leaching was greatly reduced and plant quality was improved. Diameter of impatiens plants and leaf area of plants of both species were reduced by Al-P. Marigold plants grown with Al-P had more flowers and fewer wilted flowers. Flower wilting was also reduced for impatiens plants grown with Al-P. In marigold plants, roots were confined to a small volume beneath the drip tube in control plants, while roots of Al-P plants were well distributed through the medium. There was no obvious difference in impatiens root distribution. When plants at the marketing stage were exposed to drought, the Al-P plants of both species wilted more slowly than the conventionally fertilized controls. The reduced leaf area in both species and the improved root distribution of marigold may account for the improvement in drought tolerance of the Al-P plants.

Free access

N.E. Christians

161 WORKSHOP 25 (Abstr. 676–680) Phosphorus Management in Horticultural Crops

Free access

Gerry H. Neilsen, Denise Neilsen, Peter Toivonen and Linda Herbert

Phosphorus fertilization of apple orchards has received much less attention than nitrogen (N) and potassium (K) fertilization as a result of limited reports of positive responses to phosphorus (P) fertilization in the historical literature

Free access

Laurence A. Sistrunk

161 WORKSHOP 25 (Abstr. 676–680) Phosphorus Management in Horticultural Crops

Free access

Zhenli He, David. V. Calvert, Peter. J. Stoffella and Mingkui Zhang

To evaluate effects of canopy and micro-irrigation under trees on accumulation and leaching of phosphorus (P) and heavy metals in agricultural sand soils, the horizontal and vertical variations of soil P and metals in a 408-m2 plot within a grove under grapefruit (Citrus paradisi Macf.) production near Fort Pierce, Fla., was examined. A high horizontal variation of labile soil P and metal concentrations was observed. Across the row, the highest values of pH, EC, water-soluble P, and all metals occurred in the soils under the canopies, and the lowest values occurred in the soils near the water furrow or the midway of the inter-row. Along the grapefruit row, the highest values of many measured variables occurred along the northern side of the citrus tree and close to the emitter. The downward movement of P, Cu, and Zn in the soils was more significant in the soils in open areas (near the water furrow and midway of inter-neighboring trees) than those under the canopies. The differences in labile P and metal spatial distributions in the soils were related to the location of emitter fertigation and differences in rainfall-induced leaching in the field. The results suggest that applying fertilizers to sites under the canopy rather than the spaces between the trees can minimize leaching losses of nutrients.