Patent Application
20100251790
This invention relates to a granular organic fertilizer.
International Patent Publication No. WO 2007/072161 discloses a process for manufacturing a dry organic fertilizer using peat.
It is an object of this invention to provide an improved dry organic fertilizer product.
According to the invention there is provided a process for producing a granular dry organic fertilizer, the process including the steps of:
In step 3), 5-20%, typically 5-10% of the final volume of the mixture of base is added to the peat and mixed for 2-10, typically ±5 minutes.
In step 4), 2-10 Liters (1-10 kg), typically 5 Liters (kg) organic acid is added per 1000 kg mixture and mixed for 3-5 minutes.
Chemical nutrients such as potassium, phosphates, calcium, magnesium, nitrogen (ammonium sulphate) and chelated micro nutrients may be added to the mixture during the blending step 5), according to a required blend, for example: 8:3:5+Ca+Mg+micro elements.
The granulating step 6) may take place in a pan granulator using a 1-4 mm, typically a 2 mm stainless steel mesh and a binder.
The binder may constitute 0.3%-1%, typically 0.3%-0.5% by weight of the mixture and is preferably a starch, most preferably a maize starch.
Granules produced in the process typically have a size from 2-6 mm, preferably 2-4 mm.
In step 6), the mixture to be granulated typically contains 15-20%, typically 18% by weight moisture.
The invention also relates to a granular dry organic fertilizer containing peat, preferably bituminous peat, which is pH buffered at 6-7, typically 6.5-6.8.
Preferably, the granular dry organic fertilizer contains nutrients which are chelated or clustered by the carbon in the peat.
The chemical nutrients may be one or more of potassium, phosphates, calcium, magnesium, nitrogen (ammonium sulphate) and chelated micro nutrients.
In accordance with a process of the invention, bituminous peat (peat which originates from macro plants (reeds and trees) growing in swamps) having a pH of 6-7, typically 6.8, is sifted through mesh 2-4 mm in order to remove fibers. Fine peat with a moisture content of between 20and 25% is then used as a carrier for the manufacturing of a granular dry organic fertilizer. The average carbon content of the sifted peat is between 45 and 55 percent.
The sifted peat, between 40 and 60 percent of the final mix, is placed into a blender. Ammonium hydroxide, 5-10 percent of the final volume, is added to the peat and mixed for ±5 minutes. 5 Liters or 5 kg per 1000 kg propionic acid (25%) or EDTA is then added and mixed for 3-5 minutes. Nutrients (chemical) such as potassium, phosphates, calcium, magnesium, nitrogen (ammonium sulphate) and chelated micro nutrients are then added to the peat into the blender, according to the required blend, for example: 8:3:5+Ca+Mg+micro elements. The ratio of solubility of each element as the total volume of the added chemical nutrients must be dissolved and absorbed or adsorbed into or onto the peat carrier. Once the chemicals are added, the blending continues until the blend is homogeneous.
The mixture (containing 18% moisture) is then granulated in a pan granulator using 2 mm stainless steel mesh, 0.3%-0.5% maize starch as a binder to provide granules which are 2-4 mm in size.
The granules are dried in an air draft at a temperature of 200° C. to 400° C. Thereafter the granules are allowed to cool down to 40° C. after granulation and are left for +/−8 hours to harden before bagging.
The granulated dry organic fertilizer is a complete slow release fertilizer (all nutrients). Less fertilizer is needed as loss of nutrients through leaching or fixing takes place as all nutrients are released from the peat carrier and is not subject to cation exchange capacity from the clay/soil particles. All nutrients are chelated or clustered by the carbon in the peat carrier. By using the granulated organic product that is pH buffered at 6.5-6.8, the pH of the soil plays a minor role in the availability of the nutrients to the plants as the nutrients required by the specific crop are readily available (open hydroponics).
As the nutrients are released from the carrier, the carbon that remains in the soil serves as a nutrient for microorganisms and earthworms in the soil, thus increasing the organic carbon content of the soil with all the benefits of organic soils.
As the peat is completely anaerobic composted no nitrogen negative periods are experienced as is the case with animal droppings or compost.
A further benefit of the increased carbon content of the soil is that parasitic organisms such as nematodes feed on the carbon in the soil and consequently far less damage to the plant roots. The binding of nitrogen by free-living bacteria in the soil is much enhanced, as the population of the nitrogen binding organisms increase with availability of carbon in the soil, thus far less applied nitrogen is needed reducing the pollution of run off water and ground water.
Further benefits of these organic nutrients are that all nutrients required by the plants can be bound together in the organic carrier, thus making it more user friendly, especially for the subsistence farmers in Africa.
This granular fertilizer is a complete fertilizer and is acceptable for the use in organic farming all over the world.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007/07908 | Sep 2007 | ZA | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB2008/053684 | 9/12/2008 | WO | 00 | 6/16/2010 |
