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
T.K. Hartz, R. Smith and M. Gaskell
Touria E. Eaton, Douglas A. Cox and Allen V. Barker
information about using organic fertilizers in a commercial greenhouse operation lags behind that available for other management areas. Specifically, information about the different organic fertilizers available in the market and their effects on plant growth
Zhengli Zhai, David L. Ehret, Tom Forge, Tom Helmer, Wei Lin, Martine Dorais and Athanasios P. Papadopoulos
, the plants would rely on composts as a source of N for as long as possible before it became necessary to supplement with liquid sources of N. Proprietary liquid organic fertilizers are relatively expensive and will potentially plug drippers so it is
John M. Smagula and Ilse Fastook
Acommercial lowbush blueberry field with a history of N and P deficiency was used to study the response to several organic fertilizers. Diammonium phosphate (DAP) is the standard fertilizer for correcting N and P deficiencyin non-organic production. At a rate of 67 kg N/ha Rennaisance (8–2–6), Pro-Holly (4–6–4), Pro Grow (5–3–4), Nutri-Wave (4–1–2), or DAP (18–46–0) was applied preemergent to 1.8 × 15 m treatment plots. An unfertilized plot served as the control. Leaf N and P were deficient in the controls. DAP and Pro-Holly raised leaf N to satisfactory levels (1.6%). Only DAP raised leaf P concentrations (0.144%), compared to controls (0.122%). Leaf K was not deficient but was raised by Pro-Holly. Pro-Holly and DAP were equally effective in increasing stem height, branching, branch length, flower bud formation, and yield. Pro-Holly could effectively substitute for DAP in organic wild blueberry production.
Joji Muramoto, Richard F. Smith, Carol Shennan, Karen M. Klonsky, James Leap, Miriam Silva Ruiz and Stephen R. Gliessman
soil organic matter, compost, recently incorporated crop and cover crop residues, and various organic fertilizers. Cover crops can provide an inexpensive source of N for crop production ( Smith, in press ; Wyland et al., 1996 ). Use of a legume
Carolyn DeMoranville, Anne Averill and Joan Davenport
The two major determinants in sustainable cranberry production are productivity and preservation of water quality. Productivity and water quality were studied using composted chicken manure (CM) and fish hydrolysate fertilizer (FH). In whole bog field trials, soluble granular fertilizer (SG) was replaced with organic fertilizer. At all locations receiving FH, cranberry yields were maintained or improved. The yield results from bogs receiving the CM were mixed, partially due to the quality of the experimental sites. Based on water samples taken from bogs receiving FH, there was no P output and less NH output than from bogs receiving SG. Leaching properties of CM, FH, and SG in cranberry soils were investigated in the laboratory. Concentrations of N03 -, P04 -, and K+ were greatest in the leachate from columns receiving SG, indicating that organic fertilizers are less likely to lead to the leaching of nutrients into cranberry bog water.
Deron Caplan, Mike Dixon and Youbin Zheng
conducted using conventional fertilizers, and there are few on the use of organic fertilizers for container crops. Fertigation rates of 190–400 mg N/L have been reported for container production of organic greenhouse-grown tomatoes ( Solanum lycopersicum L
Yuqi Li and Neil S. Mattson
feedstocks and methods for producing organic fertilizers are extremely variable, which results in different components and physiochemical properties among different organic fertilizers. Many traditional organic fertilizers are produced as composts or other
Deron Caplan, Mike Dixon and Youbin Zheng
of 389 mg N/L was proposed using a liquid organic fertilizer (4.0N–1.3P–1.7K) in two coir-based organic substrates. To our knowledge, there is no research on flowering-stage fertilizer rates for cannabis. Appropriate choice of a growing substrate is
Robert G. Anderson and Robert Hadad
A segment of the greenhouse crop market would like to obtain vegetables and herbs that are certified organic. The technology for the use of biological controls for insects and diseases is well-developed and a significant part of greenhouse vegetable production. Organic fertilizers, however, have not been well-utilized in organic greenhouse vegetable production. Common organic fertilizers were analyzed for the levels of nutrients when mixed with water for use in greenhouse fertigation. Products derived from algae-Algamin (liquid) and Ohrstrom's Garden Maxicrop (powder), Bat Guano, and products derived from fish waste-GreenAll Fish Emulsion (liquid) and Mermaid's Fish Powder, demonstrated nutrient levels comparable to typical water-soluble fertilizers used for greenhouse plant production. Although the organic fertilizers could not be used as a concentrate for injector systems, readings from a conductivity meter were directly related to nitrate nitrogen levels and could be used for fertilizer management in the capillary mat subirrigation system used for plant production.