GB2249087A

GB2249087A - A fibrous agricultural mulch

Info

Publication number: GB2249087A
Application number: GB9121608A
Authority: GB
Inventors: Allan Michael Bell
Original assignee: GREAT HAGE CO Ltd
Current assignee: GREAT HAGE CO Ltd
Priority date: 1990-10-11
Filing date: 1991-10-11
Publication date: 1992-04-29
Anticipated expiration: 2011-10-11
Also published as: GB9121608D0; GB2249087B; NZ235643A

Abstract

A fibrous agricultural mulch of alfalfa plants is prepared by harvesting alfalfa plants, partially drying the alfalfa. compacting and packaging the dried alfalfa in a container for retail sale that is permeable to carbon dioxide but impermeable to oxygen, sealing the container, and allowing the contents to ferment.

Description

IMPROVEMENTS IN OR RELATING TO A FIBROUS AGRICULTURAL MULCH The invention relates to a fibrous agricultural mulch of alfalfa plants for use in domestic and commercial situations.

Agricultural mulches generally comprise fibrous plant tissue. They are spread upon the ground around plants to reduce evaporation and so maintain moisture in the ground as this assists in controlling weeds. They also enrich the soil and therefore encourage plant growth.

It is known that certain fibrous materials such as moss, hay and alfalfa provide an efficacious form of mulch.

Alfalfa, when used as a mulch, is generally in the form of dried hay, and is known to contain substantial quantities of growth hormones. It is for this reason that alfalfa is highly preferred as a mulch. However the use of alfalfa is restricted, because unless the alfalfa is promptly dried and spread, much of the growth hormones are destroyed. And because of storage difficulties it has hitherto been impossible to successfully market alfalfa mulch through usual retail outlets.

It is an object of the present invention to provide a method of preparing a fibrous agricultural mulch which is an improvement upon known methods or is at least a useful alternative to those methods.

It is another object of the invention to provide a fibrous agricultural mulch that is an improvement over known mulches or is at least a useful alternative to those mulches.

The invention may be said to be a method of preparing a fibrous agricultural mulch of alfalfa plants comprising: harvesting alfalfa plants, partially drying the alfalfa, compacting and packaging the dried alfalfa in a container for retail sale that is permeable to carbon dioxide but impermeable to oxygen, sealing the container, and allowing the contents to ferment.

The invention may also be said to be a fibrous agricultural mulch of alfalfa plants when prepared by the process of harvesting alfalfa plants, partially drying the alfalfa, compacting and packaging the alfalfa in a container for retail sale that is permeable to carbon dioxide but impermeable to oxygen, sealing the container, and allowing the contents to ferment.

Preferably the alfalfa is dried to a moisture content of between 50 to 60% prior to the step compacting the dried alfalfa plants.

Preferably the container is in the form of a plastics bag.

Preferably the compacted alfalfa is vacuum sealed in the container.

Preferably lignocellulosic material, such as bark especially pine or punga bark, cotton seed waste or any organic builder, or any combination thereof is added to the alfalfa before the alfalfa is placed in the container.

In a first preferred form of the invention, a fibrous agricultural alfalfa mulch is prepared as follows: 1. Alfalfa plants that have grown to 10% flower, that is the crown bud emergent stage, are harvested and are sun dried for a period of approximately 12 to 24 hours to reduce the moisture content of the alfalfa plants to between 50 to 60% of their initial weight. This moisture level has been found to be particularly advantageous to allow subsequent fermentation to occur, but the range of moisture level can be greater or lesser than 50 to 60% depending on the conditions required.

2. The alfalfa is compacted by any known means sufficient to reduce contact of the alfalfa with oxygen in the air.

3. The dried compacted alfalfa is then placed in an airtight plastic bag which is evacuated and sealed to prevent any further contact with oxygen. At least a portion and preferably a major portion of the wall of the bag is permeable to carbon dioxide but impermeable to oxygen. After sealing, the alfalfa begins to ferment.

The process of fermentation produces substantial quantities of carbon dioxide. This initially causes the internal pressure and volume of the bag to increase but since the walls of the bag are permeable to carbon dioxide the carbon dioxide can pass through the walls of the bag into the atmosphere so that the pressure within the bag is stabilised.

4. The alfalfa is allowed to ferment over a period of 2 to 5 weeks 5. The product may then be stored for later sale or use.

Since the walls of the container are permeable to carbon dioxide, as the rate of fermentation decreases and less carbon dioxide is generated, the walls of the container gradually collapse onto the contents. And because no oxygen can permeate through the walls of the bag, the hormonal growth properties of the alfalfa are maintained throughout prolonged storage. It is for this reason that the alfalfa mulch so produced not only provides the usual effect of weed suppression and minimisation of evaporation but also contributes significantly to the growth of plants.

In a second preferred form of the invention lignocellulosic material such as bark, especially pine and punga bark, cotton seed waste or any other organic builder is mixed with the alfalfa before the alfalfa is placed in the container. The lignocellulosic material enhances the appearance and texture of the mulch but does not affect the effectiveness of the mulch.

The first and second preferred forms of the invention are described in the following experimental examples however they are not intended to limit the scope of the invention.

Example 1 Alfalfa plants that had grown to 10% flower were harvested and sun dried for 24 hours leaving the alfalfa plants with approximately 60% of their initial moisture content by weight. The dried alfalfa plants were mechanically compacted to two thirds of their original volume and vacuum packed into plastics bags of 100 litres capacity for retail sale which are permeable to carbon dioxide but impermeable to oxygen. The bags were stored for 30 days and then the contents were placed around a plot of garden vegetables. A similar plot of vegetables was not provided with the mulch. Both plots were left for 30 days and then compared. The vegetables that were provided with the mulch were susbtantially larger and noticeably more healthy.

Example 2 Alfalfa plants that had grown to 10% flower were harvested and artificially tumble dried by rotary driers for 12 hours leaving the alfalfa plants with approximately 50% of their initial moisture content by weight. The dried alfalfa plants were mechanically blended with pine bark so that the bark component was about 20% of the blend by weight. Once compacted to about two thirds of its original volume the blend was vacuum packed into plastics bags which are permeable to carbon dioxide but impermeable to oxygen. The bags were stored for 2 weeks and then the contents were placed around a plot of garden vegetables. The vegetables were compared with a control plot of similar vegetables 30 days later and those vegetables which had been provided with the mulch were substantially larger and noticeably more healthy.

The foregoing describes the invention including two preferred forms thereof. Alterations and modifications to the invention as will be obvious to those skilled in the art are intended to be incorporated within the scope of this invention as defined in the accompanying claims.

Claims

WHAT WE CLAIM IS:

1. A method of preparing a fibrous agricultural mulch of alfalfa plants comprising: harvesting alfalfa plants, partially drying the alfalfa, compacting and packaging the dried alfalfa in a container for retail sale that is permeable to carbon dioxide but impermeable to oxygen, sealing the container, and allowing the contents to ferment.

2. A method according to claim 1 wherein the alfalfa is dried to a moisture content of between 50% and 60% prior to the step of compacting the dried alfalfa.

3. A method according to claim 1 or 2, wherein the dried alfalfa is compacted to substantially two thirds of its original volume.

4. A method according to any preceding claim wherein the compacted alfalfa is vacuum packed into the container.

5. A method according to any preceding claim wherein the container is composed of a plastics material.

6. A method according to any preceding claim wherein lignocellulosic material is added to the alfalfa before the alfalfa is placed in the container.

7. A method according to claim 6, wherein the lignocellulosic material is blended with the dried alfalfa prior to the compaction.

8. A method according to claim 6 or 7, wherein the blend of alfalfa and lignocellulosic material contains up to 25% of lignocellulosic material by weight.

9. A method according to any one of claims 6 to 8, wherein the lignocellulosic material is selected from bark, cotton seed waste and any other organic builder, or any combination thereof.

10. A method according to claim 9, wherein the bark is pine bark or punga bark.

11. A fibrous agricultural mulch of alfalfa plants when prepared by the process according to any preceding claim.

12. A method of preparing a fibrous agricultural mulch of alfalfa plants substantially as herein described with reference to the Examples.

13. A fibrous agricultural mulch of alfalfa plants substantially as herein described with reference to the Examples.