Organic Fertilizers

While the purpose of a fertilizer may be well-known, often many wonder what an organic fertilizer is and how it differs from other fertilizers. Organic fertilizers are green and natural, without using chemicals to concentrate nutrients, byproducts or impurities. Our organic rock phosphate, applied directly or with other needed nutrients, nitrogen, potash, synergistic sulfur or humates and micronutrients, makes for blends that can greatly enhance root zone development and growth for your crops and plants.

Fertoz has a high regard for natural and organic fertilizers which is why we take great care to produce quality products. There are many fertilizer companies, but those looking for certified organic crop fertilizers can rely on our product and process. We create dry organic fertilizers that are phosphorus based and come from only the high quality rock resources, creating a quality, high availability plant and crop fertilizer.

Phosphorus Fertilizers

Plants absorb most of their phosphorus from the soil solution as orthophosphate (H2PO4-), regardless of the original source of phosphorus. Although orthophosphate’s negative charge prevents it from being attracted by the soil’s cation exchange capacity (CEC), it does react strongly, primarily with the large amount of iron and aluminum naturally in the soil, to form products that are very insoluble and thus unavailable to plants. A major factor controlling these reactions is the soil pH. At low or high pH, the solubility of phosphorus and thus its availability), is very low. The maximum availability occurs in the 6.0 to 7.0 pH range. This is also an important reason to lime regularly.

The solubility of phosphorus in fertilizer varies. The legal definition of available phosphorus in fertilizer is the sum of the phosphorus that is soluble in water plus that which is soluble in a citrate solution. Regardless of the actual chemical form of the phosphorus, the analyses of phosphorus fertilizers are given as phosphate (P2O5). The water solubility of this phosphorus can vary from 0 to 100 percent. Generally, the higher the water solubility and acid solubility, the more effective the phosphorus source. This is especially important for short-season, fast-growing crops, for crops with restricted root systems, for starter fertilizers, and for areas where less-than-optimum rates of phosphorus are applied to soils testing low in phosphorus.

– Conventional Chemical Fertilizer –

The most common phosphate fertilizers are triple superphosphate (0–46–0), monoammonium phosphate (11–52–0), diammonium phosphate (18–46–0), and ammonium polyphosphate (10–34–0) liquid. All of these materials are highly water soluble. The ammonium phosphates also are excellent nitrogen sources. Because P is relatively immobile, placement of plant roots will have easy access to the fertilizer is especially important for P fertilizers.

All phosphate fertilizers are obtained by extraction from minerals containing the anion PO43−. In rare cases, fields are treated with the crushed mineral, but most often more soluble salts are produced by chemical treatment of phosphate minerals. The most popular phosphate-containing minerals are referred to collectively as phosphate rock. The main minerals are:

  • fluorapatite Ca5(PO4)3F (CFA)
  • hydroxyapatite Ca5(PO4)3OH.

These minerals are converted to water-soluble phosphate salts by treatment with sulfuric or phosphoric acids. The large production of sulfuric acid as an industrial chemical is primarily due to its use as cheap acid in processing phosphate rock into phosphate fertilizer. The global primary uses for both sulfur and phosphorus compounds relate to this basic process.

In the nitrophosphate process or Odda process (invented in 1927), phosphate rock with up to a 20% phosphorus (P) content is dissolved with nitric acid (HNO3) to produce a mixture of phosphoric acid (H3PO4) and calcium nitrate (Ca(NO3)2). This mixture can be combined with a potassium fertilizer to produce a compound fertilizer with the three macronutrients N, P and K in easily dissolved form.

– Phosphorus sources in organic agriculture –

Phosphorus sources approved for use in organic agriculture have diverse properties that affect P availability and management. Common P sources include rock phosphate, manure, and compost, all of which are frequently used in research studies. Bone meal and guano are among the less commonly cited P sources but can have high P contents (ranging from 7% to 12% and 1% to 9%, respectively).

Phosphate rock application

Direct application of phosphate rock (PR) to soils as a P fertilizer has been practiced for over 100 years. Because direct application of PR continues to be an important P source in developing nations, there is a wealth of research addressing soil, crop, and PR effects on P availability. Phosphate rock is a slowly soluble P source. Although the total P concentration can be relatively high (greater than 15%), the soluble P concentration can be very low (less than 1%). Therefore, a few basic issues must be considered when evaluating the use of PR as a direct P source in agriculture, including PR properties, soil properties, climate, crop species, and soil management practices. Typically, the higher available P, the better source of P to all crops.

Although the phosphate compound found in PR is always some form of the mineral apatite [Ca5(PO4)3X, where X is an anion], the chemical and mineralogical properties, and therefore solubility, vary greatly between PR sources. Soluble P concentration of PR is determined and expressed as water- and citrate-soluble P, similar to the methods used for conventional P fertilizers. Phosphate rocks with greater soluble P concentrations will generally have greater agronomic effectiveness, however, both the total P concentration and the soluble P concentration should be considered when deciding on PR sources. Particle size also affects PR reactivity, in which decreasing particle size down to ≈150 μm increases PR effectiveness.

Phosphate rock sources can be generally classified as either sedimentary or igneous. Sedimentary PR has higher carbonate substitution and up to 20 times greater specific surface area than igneous rocks. Increases in carbonate substitution and specific surface area increase P solubility and make sedimentary PR sources better suited to direct application to soils. Phosphate rock sources known to have consistently high P availability are located throughout the world. Although the PR source mine and mineralogy have a strong influence on PR solubility and P availability, this information can be difficult to obtain for PR sold on the retail market.

Soil pH is one of the primary soil factors affecting PR efficacy. It is difficult to make universally applicable recommendations for PR application because so many factors affect PR dissolution and resultant efficacy as a P source for crops. In general, PR use should be limited to soils with pH less than 5.5 PR has shown limited success on soils with pH as high as 8.0 provided there was adequate irrigation and leaching. Crop response to PR can be equal to that of commercial phosphate fertilizer on low pH soils when the PR is from a highly available source and higher application rates. Crop response to PR at low application rates is often less than that observed with conventional P fertilizers.

Phosphate rock applications to soils with pH greater than 5.5 may require higher rates, greater amounts of incorporation, and more time to react before planting. Phosphate rock may not reach maximum solubility until 4 to 8 weeks after application. Although lime applications can benefit crop growth by reducing Al toxicity, increased pH and Ca concentrations tend to reduce the efficacy of PR. There is considerable evidence that PR availability can be aided by ph reducing compounds like sulfur, composts or hunic acids.

Advantages of Organic Fertilizers

The main “organic fertilizers” are peat, animal wastes, plant wastes from agriculture, and treated sewage sludge (biosolids). Animal sources include the products of the slaughter of animals. Bloodmeal, bone meal, hides, hoofs, and horns are typical components. Organic fertilizer usually contain fewer nutrients, but offer other advantages as well as being appealing to those who are trying to practice “environmentally friendly” or organic farming.

Organic fertilization is a process that allows for healthy plants and crops through the use or organic fertilizers. We produce organic phosphate fertilizer that will contribute to reliable plant growth and good health of the plant and soil alike.

– Where to Buy Our Phosphorus Fertilizer –

We work with a variety of reliable distributors that service many areas around the world. The price of our organic fertilizer, how to easily acquire our organic fertilizer and where it will shop from is all knowledge our representatives and distributors can provide to you. If you’re looking for the best way to buy phosphorus fertilizer, get connected with our agronomist here.

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