Productos Organicos

Colorado Master Gardenersm Program Colorado Gardener Certificate Training

Colorado State University Extension

CMG GardenNotes #234

Organic Fertilizers
Outline: Terms, page 1 Plant by-products, page 2 Alfalfa meal or pellets, page 2 Corn gluten meal, page 3 Cottonseed meal, page 3 Soybean mean, page 3 Animal by-products, page 3 Bat guano – high N, page 3 Bat guano – high P, page 4 Bloodmeal, page 4 Bone meal, page 4 Feather meal, page 5 Fish emulsion, page 5 Enzymatically digested hydrolyzed liquid fish, page 5 Fish meal, page 5 Fish powder, page 6 Compost, manure and biosolids based products, page 6 Rock powders, page 6 Colloidal phosphate, page 6 Seaweed, page 7 Kelp meal, page 7 Kelp powder, page 7 Liquid kelp, page 7

Terms
By legal definition, the term fertilizer refersto a soil amendment that guarantees the minimum percentages of nutrients (at least the minimum percentage of nitrogen, phosphate, and potash). An organic fertilizer refers to a soil amendment derived from natural sources that guarantees, at least, the minimum percentages of nitrogen, phosphate, and potash. Examples include plant and animal by-products, rock powders, seaweed, inoculants, andconditioners. These are often available at garden centers and through horticultural supply companies. These should not be confused with substances approved for use with the USDA National Organic Program (NOP). The USDA NOP, with its “USDA Organic” label, allows for the use of only certain substances. The Organic Materials Review Institute (OMRI at www.omri.org) approves brand name products made withingredients from the “national list” for use with the NOP. (For details refer to www.ams.usda.gov/nop and click “NOP Regulations” and then “National List
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Information”). Many of the organic fertilizers listed here will meet NOP standards (based on the National List). Growers participating in the NOP should consult with their certifier to ensure compliance for organic certification. Theterms soil amendment refers to any material mixed into a soil. Mulch refers to a material placed on the soil surface. By legal definition, soil amendments make no legal claims about nutrient content or other helpful (or harmful) effects it will have on the soil and plant growth. In Colorado, the term compost is also unregulated, and could refer to any soil amendment regardless of active microorganismactivity. Many gardeners apply organic soil amendments, such as compost or manure, which most often do not meet the legal requirements as a “fertilizer” but add small amounts of nutrients. Notes: Release Time – Organic products require the activity of soil microorganisms before nutrients are available for plant uptake. Microorganism activity is generally dependant on soil temperatures greater than50ºF in the presence of sufficient soil moisture. Dry and/or cold soil conditions will delay the release of nutrients from these organic sources. This period refers to how long these products are available if applied to the soil. Use this information to time the application of the product. Application – Different products may be applied in various ways. Some may be tilled in (worked into the soilwith a machine or hand tool), others may be applied as a foliar spray (mixed with a surfactant and sprayed in a fine mist on the leaf surface while temperatures are below 80ºF), and some may be injected into a drip or overhead irrigation system (fertigation with a siphon mixer). Application rates in this fact sheet are generalized and based on some manufacturers’ recommendations. Over- orunder-fertilization may occur using these recommendations.

Plant By-)roducts
Alfalfa Meal or Pellets
Alfalfa meal or pellets are often used as animal feed. Primarily they are used to increase organic matter in the soil but do offer nutrients and a high availability of trace minerals. They contain trianconatol, a natural fatty-acid growth stimulant.
Alfalfa Meal or Pellets Typical NPK analysis...