Description:FIELD OF INVENTION:

The invention relates to processing of sugarcane bagasse, which is a fibrous material obtained after extraction of juice, for making universal grow media used for soilless cultivation.

BACKGROUND OF INVENTION:

World over, fertile soils available for cultivation is diminishing. In many countries due to limited cultivated area and quality soils, cultivation is practiced in marginal lands. This requires some organic materials which can be applied to soil to improve the fertility condition. Alternatively, in smaller countries and countries located in temperate regions of the world, protected cultivation is practiced. This requires quality grow media.

Both the problems can be addressed by using suitable grow media. The popular grow media are cocopeat, sphagnum peat, rice husk, saw dust and compost which are used directly or in combination as a plant growth supporting media. But these media are limited in supply, bulky, cumbersome to prepare, and not cost effective.

Thus, there is an urgent need in the industry to identify an alternative, viable, and economically feasible growth media, having desirable physico-chemical properties to support growth of plants under low water conditions like drought and low rainfall situation, also maintain nutrient balance, timely release of plant nutrients and effective control of weeds.

The fibrous portion of sugarcane after extraction of juice known as bagasse is used as components of growing media. It is available in plenty in the sugarcane growing countries.

It is also used for conditioning soil environment of plants to enhance moisture retention, the rate of plant growth and uniform crop stand. Bagasse is also known as mulching material to minimize weed growth and evaporation of soil moisture.
But with the existing or commercially used sugarcane bagasse grow media, the important physico-chemical properties demanded such as pH, EC, water absorption capacity, nutrient levels, respiration rate are difficult to alter and not cost effective.

OBJECT OF INVENTION:

Accordingly, to the first object of the invention, making of a universal grow media for plants from sugarcane bagasse.

The second object of the invention is to make a universal grow media in a cost-effective process with highly desirable characters for plant growth.

The third object of the invention is to create a universal grow medium which shall be capable of use as an independent growth medium in soilless cultivation.

The fourth object of the invention is to make a grow medium which shall be capable of use as a growth media i.e. a potting mix.

The fifth object of the invention is form of soil and water conservation in the drought prone areas which shall be used as a drought tolerant and to enhance soil properties.
 
DESCRIPTION OF INVENTION:

Grow media is very important for promoting rooting of cuttings, germination of seeds and growth of seedlings. Mixing of grow media with problem soil will improve growth and development of plants. This is because of storing of more water, air and mineral nutrients that ensure easy germination of seed, rooting of cuttings and help further crop growth.

Sugarcane Bagasse is a fibrous organic material obtained from sugarcane after crushing for juice extraction. Chemically it is a Ligno-cellulosic material with particle size of 0.25 to 0.5 mm. Particle size of the sugarcane bagasse has significant impact on physical properties including stability and water holding capacity, and the best results are obtained with fiber size smaller than 0.18 mm. This is very important to use sugarcane bagasse effectively as a substitute for rooting media.

Several research on rooting media suggested that following characteristics are very important for selection of grow media.
• The fibers should be sufficiently firm, stable but porous.
• It should possess sufficiently high moisture retention capacity.
• It should be porous to drain out excess of water and permit aeration.
• It should be dense to hold seeds and cuttings to promote germination and rooting, respectively.
• It should be free from weed seeds and harmful organism.
• It should be cheap, slightly acidic to neutral and lighter than soils.
• Can be composted and used along with other fertilizers to promote crop growth

Therefore, properly processed bagasse having these properties can be the alternate source for rooting media for all kind of crops. But the composition or properties of each batch of sugarcane bagasse will slightly vary depending upon the raw sugarcane used for crushing and the crusher machines used in sugarcane mill. However properly processed sugarcane bagasse has desirable properties such near neutral pH, satisfactory nutrient level, high moisture retention, excellent air porosity, and free from unwanted microorganisms and weed seeds. As the bagasse is used to prepare grow medium, this composition may be supplemented with nutrients based on the selected plant for growth.

Further, the bagasse used herein for grow medium composition may be supplemented additionally with a known filter or organic material to alter the porosity, cation exchange capacity and water retention.

The composition of bagasse described here is observed to exhibit superior results over conventional growth media known in prior art. This medium essentially and entirely replaces the conventional growth materials/media all of which demand natural resources and which is limited. Hence, this composition of this invention prepared from sugarcane bagasse is independent from natural resources availability. Further, sugarcane is grown all over the tropical world and thereby is not restricted by regions.

The use of bagasse causes no damage and no pollution to the environment. The cost of using bagasse is minimal. There is no depletion of any natural resources and there is no destruction of ecological balance in the process of preparation of bagasse growth medium as per the invention. Hence bagasse an economical and environment friendly cultivation substrate of plant grow media.

A method of treating the bagasse for preparing the universal grow medium, comprising the following steps: -

After compacting the seasoned loose bagasse material, a whole some brick type substrate is made using hydrolytic compressor at 100 – 120 bar pressure. The seasoned bagasse fiber is made into 30*30*10 cm grow blocks having 4.8 to 5.1 kg weight with 12 – 15% moisture in it. This can be transported easily from place of preparation to site of use easily due to its lightness and its compactness.

The use of this bagasse-based growth media of the present invention exhibits a high survival rate and also a good growth rate of seeds / seedlings as the compact brick type substrate unfolds and expands into a large substrate when water is added at the site thereby exhibiting saturated water holding capacity. As described above the process of preparation of the bagasse substrate is simple, the operation is convenient and it is extremely cost effective and functionally effective.
Different methods of preparation of grow media as compact brick or block from sugarcane bagasse
Method 1: -
• Shredding Bagasse to remove the pith from Bagasse
• Grading the pith to desirable particle size to less than 0.2 mm to increase the water absorption
• Drying the pith to desirable moisture content
• Compressing through Hydraulic press as Blocks/Bricks.

Method 2:-
• Shredding Bagasse to remove the pith from Bagasse
• Grading the bagasse fibers to desirable particle size to less than 0.2 mm to increase the water absorption
• Drying the pith to desirable moisture content
• Enriching with required amount of slow release water soluble fertilizers
• Compressing through Hydraulic press as Blocks /Bricks

Method 3:-
• Shredding Bagasse to remove the pith from Bagasse
• Grading the bagasse to desirable particle size to less than 0.2 mm to increase the water absorption
• Drying the pith to desirable moisture content
• Fortified with Bio char / growth enhancers
• Compressing through Hydraulic press as Blocks /Bricks

Method 4:-
• Decomposing the Bagasse by using Pleurotus sajarcaju fungus and Nitrogenous fertilizers in layer by layer.
• After 60 days of decomposition period, the decomposed bagasse will be dried to optimum moisture of 15 %.
• Dried & decomposed Bagasse will be passed through Destoning to remove stones and inert material.
• Decomposed bagasse will be compressed through Hydraulic press as Blocks

The methods given above are only suggestive and variations are available. In the present process
• Shredding Bagasse to remove the pith from Bagasse
• Homogenizing and grading the bagasse fibers to desirable particle size to less than 0.2 – 0.4 mm by tandem milling system
• Seasoning / composting to ensure stable and desirable physico-chemical properties
• Drying the pith to desirable moisture content (12 – 15%)
• Enriching with required amount of bio solution for growth promotion
• Compressing through Hydraulic press at 100 – 120 bar pressure to make Blocks /Bricks

By the above methods, the fibrous sugarcane bagasse which is chemically non-uniform and unstable with undesirably high carbon to nitrogen ratio are converted into small compact blocks exhibiting a stable chemical constitution, an improved C-N ratio and near neutral pH by the process of sieving the bagasse in 2 - 4 mm mesh followed by drying, uniformly spraying priming liquid and then finely compacting the bagasse into block. The processed bagasse provides,
• Structural support for the plant roots
• Regulate water flow and aeration
• Serve as reservoir of nutrients and beneficial microbes
• Provide a healthy micro-environment for the plant growth

• Physical aspects include a low bulk density (between 200 to 650 kg/m3), high porosity (between 50% to 80%), particle size between 0.25 to 0.5 mm and water retention between 20% to 60%.
• Chemical aspects represented by the CEC (range between 10 to 40 meq / 100 g), pH easily adjustable (6.0 to 7.0), low salt content (0.75 to 1.9 dSm-1) and a C:N ratio between 1:200 to 1:40 and trace of heavy metals.
• Biological aspects indicate the healthy condition of the growing medium due to the absence of pathogens, weed seeds and pests and absence of toxic compounds. The processed bagasse also consists of organic acids, humic substances and plant growth promoters in desirable amount for plant growth.
The major advantages of the above derived properties are,
• Homogenous fibers and uniform texture that drains well but retains nutrients and water.
• Low bulk density (between 200 and 650 kg/m3) and minimum moisture (12-15%) to be made into bocks that facilitate easy.
• High porosity (between 50% and 80%).
• Particle-size distribution to maintain good balance between air and water retention (between 0.2 - 0.4 mm).
• A pH between 6.0 to 7.0 which can also be adjusted.
• Low content of soluble salts.
• Ability to maintain original physico-chemical properties for long time so that it can be used for many successive cultivation cycles.
• Absence of pathogens, weed seeds and toxic substances affecting plant growth.

As discussed above, the sugarcane bagasse is converted into an improved grow medium for plants with desirable air porosity, water retention properties and necessary nutrients to sustain plant growth. It is also possible to alter and adjust pH, growth substances and salt levels. The process being simple and materials are easy to carry, it can be made commercially available very easily.

Hence, the invention teaches the up-gradation of bagasse so far used only as a filler material into a universal growth media itself.

The bagasse-based grow media can be used in a wide range of applications in combination with other substances.

Further, placing these bagasse blocks on the surface or subsurface of soil is simple and can be done by mechanical or manual methods.

Further, the bagasse is one of the cellolytic materials that is available in abundance all over the tropical world. Further the process of preparing bagasse blocks being simple, there is a much shorter production process time and reduced cost.

In the prepared substrate, bagasse exhibited increased moisture retention, drought tolerance and yield, all of which are highly desired by farmers and stakeholders.

In one aspect, the invention disclosed a bagasse based universal grow medium prepared as previously disclosed, wherein the medium exhibits a plurality of desirable physico-chemical properties,

a. bulk density in the range 200 to 650 kg/m3,
b. high porosity in the range 50% to 80%,
c. particle size in the range 0.2 mm – 0.4 mm, and
d. water retention capacity in the range 20% to 60% and also a plurality of chemical aspects with a
- CEC in the range 10 to 40 meq /100g material
- pH adjustable in the range 6.0 – 7.0
- salt content in the range 0.75 to 1.9 dSm-1
- C:N ratio in the range 1:200 to 1:40.

It can be concluded that composition of the present invention provides an alternative to known conventional growth media and soil and use as a universal plant growth media and/or soil additive. The composition enables the arrangement of plant yield in terms of improved quality and quantity than known method and materials in prior art.

It will be appreciated that the present specification is merely suggestive and includes all equivalents that will be obvious to try and modifications known to the skilled person in the art.
, Claims:1. A process for preparing universal grow medium from sugarcane bagasse comprising the steps:

a. shredding the sugarcane in a tandem milling system to get bagasse fiber of size in the range 0.2 mm – 0.4 mm,
b. sterilization of the fiber at 80 °C for 15-20 minutes to remove infectious microbes, insects and weed seeds,
c. segregating the shredded bagasse fibers by sieving and grading in a sieve-blower,
d. composting and seasoning of the graded bagasse by heaping and tilting method for 60 days,
e. drying and destoning the composed bagasse to 12 - 15% moisture level,
f. spraying growth enhancers having organic acids and growth stimulants uniformly over the bagasse fibers,
g. sieving to remove broken and smaller fibers at 2 – 4 mm size, and
h. compacting the seasoned and homogenized bagasse fiber to block of 30*30*10 cm size at 100 – 120 bar pressure in a hydraulic pressure with the compression ratio of 6:1.

2. A bagasse grow medium prepared as claimed in claim 1, wherein the medium exhibits a plurality of physical aspects with a

a. bulk density in the range 200 to 650 kg/m3,
b. high porosity in the range 50% to 80%,
c. particle size in the range 0.2 mm – 0.4 mm, and
d. water retention capacity in the range 20% to 60% and also a plurality of chemical aspects with a
- CEC in the range 10 to 40 meq /100 g
- pH adjustable in the range 6.0 to 7.0
- salt content in the range 0.75 to 1.9 dSm -1
- C:N ratio in the range 1:200 to 1:40.