[0001] Method of drying chopped forage crops FIELD

[0002] The described method was developed for drying silage. It is now understood that the described method has application to other chopped forage.

BACKGROUND

[0003] When silage is to be transported a substantial distance, such as to an export market, the silage is dried prior to transport. Rotary dryers are currently used to dry silage. Rotary dryers have drums which turn, thereby tumbling the silage crop. This tumbling tends to damages the silage and create fines. Rotary dryers typically operate at temperatures approaching 800 degrees Celsius. This high temperature tends to degrade the quality of the silage. Other drying equipment could be substituted, such as bed dryers. ,

[0004] U.S. Patent 9,301,535 (Bearg et al) titled "Equipment and methods to dry sugar beet pulp and other products" discloses a method of drying which is described as an "alternative to field curing". In accordance with the teachings of Bearg et al, product is positioned in rows or windrows on an asphalt surface. The exposed asphalt radiates heat upon the sides and bottoms of the windrows while sunlight directly cures the exposed product. According to the Bearg et al reference, the use of asphalt or other hard surfaces has produced unexpected and favorable results over the prior art methods in field curing. The disclosed methods and system avoid prior art problems of crusting wherein top layers would dry out while lower layers would remain moist and be in danger of succumbing to mold and rot.

SUMMARY

[0005] There is provided a method of drying chopped forage. In order to practise the method there is required a flat drying area seeded with a ground cover of vegetation. The ground cover is cut to create a uniform drying bed having a height of not less than 1/4 an inch and not more than 4 inches in preparation for receiving chopped forage. The chopped forage is spread evenly onto the drying bed to a depth of between 1/2 inch and four inches, without the use of windrows. The chopped forage this method is intended to apply to is not less than ½ inch and not more than 12 inches in length. The chopped forage is dried by sun curing, without raking or turning the chopped forage, until a selected humidity content is achieved of not less than 5% and not more than 20%. The chopped forage is then collected from the drying bed after the selected humidity content is achieved. The drying area of the drying surface is rotated daily so that after the dried chopped forage is collected the vegetative crop on the drying surface is rested, and can be rehydrated or irrigated if necessary before it is used again for drying. It is anticipated a three to four day rest period is sufficient to sustain growth in the vegetative cover crop. Also, the soil humidity should be checked during the resting stage to determine if enough humidity is present to enhance a dew prior to receiving chopped forage.

[0006] The above described method was tested with silages and green chopped forages having a depth of 1-3 inches. They reached the desired humidity in 5-20 hours of sunlight. It will be appreciated that the speed of drying will vary with the depth of the chopped forage, the intensity of the sun and the desired humidity content. Based upon the experience gained through testing it is anticipated that in most cases the humidity content will be reduced to under 20% within a period of less than 20 hours sunlight. When the depth of the chopped forage is less than 1 inches, it is anticipated that the humidity content will be reduced within a lesser period of less than 10 hours sunlight. It is important to preserve leaf/stem attachment and delicate fibers, and detour the creation of fines during the drying process. For that purpose it is preferred that the drying chopped forage is not disturbed or handled during the drying process, and handled gently during as it's collected.

[0007] The ground cover used for the test was grass. It is believed that Bermuda grass or densely planted rye grass is suitable. However, in considering alternatives to grass, it is believed that a ground cover of legumes, such as clovers would also produce beneficial results. There will be other vegetation ground cover that will work as well. The optimum ground cover is able to be maintained at a short height and provide a breathable barrier between the soil and the drying forage resting above.

[0008] There are ranges specified above within which the method will produce beneficial results. Beyond those ranges the method may not produce the desired results. For example, the ground cover is cut to create a uniform drying bed having a height of not less than 1/4 an inch and not more than 4 inches. A minimum height of ¼ inch is required in order to sustain the vegetative state, protect the drying forage from soil contamination, and allow for air to circulate under the chopped forage. Without this air circulation, there would be problems with uneven drying as described in the Bearg et al reference. In order to avoid this uneven drying it would be necessary to rake or otherwise turn the chopped forage over. It is preferred that handling be minimized to avoid damage to the drying chopped forage. The ground cover has a maximum prescribed height of 4 inches. This height is specified, as beyond that height it becomes increasingly more difficult to recover the chopped forage after drying, as will be further explained. The chopped forage is spread evenly onto the drying bed to a depth of between 1/2 inch and four inches, without the use of windrows. If the depth exceeds four inches, air circulation is limited and mold spots can occur. If over four inches, it is questionable whether the sun will penetrate and dry the underlying chopped forage without need to rake it or flip the drying forage, which is to be avoided in order to not damage leaf stem contact or create unwanted fines. The vegetative cover crop and soil underneath contribute tremendously to the drying process as they absorb moisture into themselves during the heat of the day, but they give a little back during cool nights and early mornings in form of a dew. The interaction between soil, vegetative cover crop and drying chopped forage is moisture migration. The soil and vegetative cover crop take more than they give which aids in drying the chopped forage.

[0009] Most forage crops are prone to leaf loss, fines creation and other damage to plant nutrition as they are handled during the drying process. It is, therefore, preferred that irrigation capability be provided to the drying bed. With irrigation capability, prior to collecting the chopped forage, an artificial dew may be selectively induced to raise the humidity of the chopped forage to range of 10 to 25 percent. This is done indirectly, without directly applying water to the chopped forage on the drying bed. The added humidity ensures that the chopped forage is supple during collection.

[0010] After collection the chopped forage may be piled in loose form under a weather protective cover to allow moisture in the dried and cured forage to homogenize and allow excessive humidity, such as that introduced by the artificial dew, to dissipate prior to shipping or final packaging.

[0011] There are different irrigation systems that can be used. The most basic is flood irrigation in borders adjacent to the drying forage. It will be appreciated that there are numerous other irrigation systems that can raise the humidity to create an artificial dew, including spray systems, subsurface irrigation systems, or flood systems. In order to avoid spraying water directly onto the chopped forage resting on the drying bed, any spray system or flood system would be on land adjacent to the drying forage.

[0012] The existence of a gentle breeze can accelerate the drying process. In some geographic locations, such a breeze naturally occurs. In areas where the air is more stagnant, such a breeze can be induced through the use of large fans.

[0013] When collecting dried chopped forage, it is important To preserve leaf/stem contact and minimize damage to the dried forage. It's also important that all of the dried forage is collected, even the small fragments. In order to gently collect the dried chopped forage a large vacuum suction system is used. Forage having a chop length between 5 inches and 12 inches in length could also be raked and collected with a tine tooth pickup. However, the vacuum suction method of collection is preferred in all cases as it's a more gentle process. When forage is between 1/2 inch and 4 inches collecting the forage becomes much more difficult to collect. A vacuum suction system works well with this material. When drying 1/2 inch to 4 inch chopped forage it is preferred that a lower drying bed be used, with the ground cover having a lesser height of not less than ¼ inch and not more than 1 ½ inches. This is important in order to expose the smaller fragments of shorter chopped forage to the vacuum stream during collection.

[0014] The method, as described above, will be vulnerable to rainfall. In some geographical areas, this is not of importance as there are relatively few days of rainfall. However, in other geographical areas there are more days of rainfall. In such geographical areas, it is preferred that the drying bed be positioned within a greenhouse, which provides weather protection.

[0015] It will be appreciated that once the teachings of the present method are understood, the conditions may be optimised. Depending upon the length of the chopped forage and the desired percentage of moisture content, a drying bed can be prepared that best suits the characteristics of the chopped forage and the depth of the chopped forage may be regulated to ensure thorough drying within a time period of less than 10 hours sunlight.

[0016] After the feed value of the chopped forage is preserved by the drying process, there are a number of delivery methods that can be used. The dried forage may be transported in loose form by truck, trailer or rail car, baled, bagged, pressed into bales, cubed or pelletized, as examples. The feed value is affected by color, aroma, leaf density and minimal fines losses. This drying process favorable impacts those traits.

[0017] It will be understood that chopped forage may be considered to include crops that are intentionally cut "short", so as to be less than 12 inches in length. "Short cut" crops are cut before they reach their full height and often when the plant is in its vegetative state and foliage is abundant and nutrition at its peak. Short cutting enables more cuttings and higher quality product to be obtained from the same land.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

[0019] FIG. 1 is a top plan view of a drying bed.

[0020] FIG. 1A is a top plan view of the drying bed of FIG. 1, with a portion of the drying bed in the process of being irrigated by flood irrigation.

[0021] FIG. 2 is a side elevation view, in section, of a rotating rake or tine pick up.

[0022] FIG. 3 is a side elevation view, in section, of a vacuum pick up.

[0023] FIG. 4 is a side elevation view, in section, of a loose collection pile. [0024] FIG. 5 is an end elevation view, in section, of the drying bed of FIG. 1 positioned in a greenhouse structure.

DETAILED DESCRIPTION

[0025] A method of drying chopped forage will now be described with reference to FIG. 1 through FIG. 5.

[0026] Referring to FIG. 1 there is illustrated a flat drying area, generally identified by reference numeral 12. Referring to FIG. 2, FIG. 3 and FIG. , flat drying area 12 is seeded with a ground cover of vegetation, generally identified by reference numeral 14. Ground cover 14 is cut to create a uniform drying bed 16 having a height of not less than 1/4 an inch and not more than 4 inches, in preparation for receiving chopped forage 18. Chopped forage 18 is spread evenly onto drying bed 16 to a depth of between 1/2 inch and four inches, without the use of windrows. Spreaders capable of spreading chopped forage 18 are commercially available and are currently used as manure spreaders. For example, there is a manure spreader in the form of a trailer sold under the Trademark VERSA manure spreader.

[0027] The chopped forage that this method is intended to apply to is not less than ½ inch and not more than 12 inches in length. The chopped forage is dried by sun curing, without raking or turning the chopped forage, until a selected humidity content is achieved of not less than 5% and not more than 20%. The chopped forage is then collected from the drying bed after the selected humidity content is achieved. A common length for chopped forage used for feed is between 5 inches and 12 inches in length. Referring to FIG. 2, chopped forage 18 of this length may be collected after drying by raking and picking up with a tine tooth pick up 20.

[0028] When collecting dried chopped forage it is important to preserve leaf/stem contact and minimize damage to the dried forage. It is also important that all of the dried forage is collected, even the small fragments. In order to gently collect the dried chopped forage it is preferred that a large vacuum suction system be used, as will hereinafter be further described. While forage having a chop length between 5 inches and 12 inches in length may be raked and collected after drying with tine tooth pick up 20, the vacuum suction method of collection is preferred in all cases, as it is a more gentle process.

[0029] The drying area of the drying surface is rotated daily so that after the dried chopped forage is collected the vegetative crop on the drying surface is rested, and can be rehydrated or irrigated if necessary before it is used again for drying. It is anticipated a three to four day rest period is sufficient to sustain growth in the vegetative cover crop. Also, the soil humidity should be checked during the resting stage to determine if enough humidity is present to enhance a dew prior to receiving chopped forage.

[0030] The above described method was tested with silages and green chopped forages having a depth of 1 to 3 inches. They reached the desired humidity after 5-20 hours of sunlight exposure. It will be appreciated that the speed of drying will vary with the depth of the chopped forage, the intensity of the sun and the desired humidity content. Based upon the experience gained through testing it is anticipated that in most cases the humidity content will be reduced to under 20% within a period of less than 20 hours of sunlight. When the depth of the chopped forage is less than 2 inches, it is anticipated that the humidity content will be reduced within a lesser period of less than 10 hours. It is important to preserve leaf/stem attachment and delicate fibers, and detour the creation of fines during the drying process. For that purpose it is preferred that the drying chopped forage is not disturbed or handled during the drying process, and handled gently during as it's collected.

[0031] Referring to FIG. 2, FIG. 3, and FIG. 5, ground cover 14 used for the test was grass. It is believed that Bermuda grass or densely planted rye grass is suitable. However, in considering alternatives to grass, it is believed that ground cover 14 could be legumes, such as clovers. There will be other vegetation ground cover that will work as well. The optimum ground cover is able to be maintained at a short height and provide a breathable barrier between the soil and the drying forage resting above.

[0032] There are ranges specified above within which the method will produce beneficial results. Beyond those ranges the method may not produce the desired results. For example, the ground cover 14 is cut to create a uniform drying bed having a height of not less than 1/4 an inch and not more than 4 inches. A minimum height of ¼ inch is required in order to sustain the vegetative state, protect the drying forage from soil contamination, and allow for air to circulate under the chopped forage. Without this air circulation, there would be problems with uneven drying as described in the Bearg et al reference. In order to avoid this uneven drying it would be necessary to rake or otherwise turn the chopped forage over. It is preferred that handling be minimized to avoid damage to the drying chopped forage. The ground cover has a maximum prescribed height of 4 inches. This height is specified, as beyond that height it becomes increasingly more difficult to recover the chopped forage after drying, as will be further explained. The chopped forage is spread evenly onto the drying bed to a depth of between 1/2 inch and four inches, without the use of windrows. If the depth exceeds four inches, air circulation is limited and mold spots can occur. If over four inches, it is questionable whether the sun will penetrate and dry the underlying chopped forage, without needing to rake it or flip the drying forage, which is to be avoided in order to not damage leaf stem contact or create unwanted fines.

[0033] Most chopped forage crops are prone to leaf loss, fines creation and other damage that adversely effects plant nutrition as they are handled during the drying process. It is, therefore, preferred that irrigation 22 be provided to the drying bed. With irrigation capability, prior to collecting the chopped forage, an artificial dew may be selectively induced to raise the humidity of the chopped forage to a range of 10 to 25 percent. This is done indirectly, without directly applying water to the chopped forage on the drying bed. The added humidity ensures that the chopped forage is supple during collection. There are different irrigation systems that can be used. Referring to FIG. 1, the most basic form of irrigation 22 is to simply have flood irrigation in borders adjacent to the drying forage. For the drying bed illustrated in FIG. 1, three ditches have been provided that divide drying bed 16 into four sections. As described above, these four sections are used in rotation with three or four rest days in between uses in order to promote the health of the vegetative ground cover. Referring to FIG. 1 A, one of the four sections can be flooded to provide indirect irrigation to adjacent sections. This is accomplished by opening flood gate 23 and allowing water, identified by reference numeral 25 to flood the selected section. It will be appreciated that there are numerous other irrigation systems that can raise the humidity to create an artificial dew, including spray systems, subsurface irrigation systems, or flood systems. As shown in FIG. 1 A, in order to avoid spraying water directly onto the chopped forage resting on the drying bed, any spray system or flood system would be on land adjacent to the drying bed on which the drying chopped forage rests.

[0034] Referring to FIG. 4, after collection the chopped forage 18 may be placed in a pile 24 in loose form under a weather protective cover 26 to allow moisture in the dried and cured forage to homogenize and allow excessive humidity, such as that introduced by the artificial dew, to dissipate prior to shipping or final packaging.

[0035] The existence of a gentle breeze can accelerate the drying process. In some geographic locations, such a breeze naturally occurs. Referring to FIG. 1, in areas where the air is more stagnant, such a breeze, as indicated by arrows 27, can be induced through the use of large fans 28. Large fans 28 of this nature are commercially available and are currently used to circulate air in orchards to prevent freezing.

[0036] When the chopped forage is between 1/2 inch and 4 inches in length, collecting the chopped forage becomes more difficult. In such cases, it is preferred that a lower drying bed be used, with the ground cover having a lesser height of not less than ¼ inch and not more than 1 ½ inches . This is important to expose the smaller fragments of shorter chopped forage to the vacuum stream during collection. Referring to FIG. 3, there is illustrated short chopped forage 18 that is between ½ inch and 4 inches in length being collected after drying is completed using vacuum suction harvesters 30. Vacuum suction harvesters 30 are commercially available and are currently used in the harvesting of peat moss. For example, there is a self-propelled peat moss vacuum suction harvester sold under the Trademark PREMIER TECH CHRONOS self-propelled peat moss vacuum.

[0037] The method, as described above, will be vulnerable to rainfall. In some geographical areas, this is not of importance as there are relatively few days of rainfall. However, in other geographical areas there are more days of rainfall. Referring to FIG. 5, in such geographical areas with relatively frequent rainfall, it is preferred that drying bed 16 be positioned within a greenhouse structure 32, which provides weather protection. Greenhouse structure 32 enables rays of the sun, as indicated by arrows 33, to pass through glass partitions to drying bed 16 below.

[0038] It will be appreciated that once the teachings of the present method are understood, the conditions may be optimized. Depending upon the length of the chopped forage and the desired percentage of moisture content, a drying bed can be prepared that best suits the characteristics of the chopped forage and the depth of the chopped forage may be regulated to ensure thorough drying within a time period of less than 10 hours.

[0039] It is preferred that the chopped forage 18 be spread evenly without the formation of windrows in order to create an even depth across the entire drying bed 16. It is also preferred that the chopped forage 18 not be turned or otherwise handled, until it is dried and ready of collection. Every instance of turning and handling tends to result in leaf loss and degrades the produce. The less handling the better.

[0040] There is a further advantage the above described method provides over rotary dryers and bed dryers. Both rotary dryers and bed dryers involve significant capital cost. Both rotary drum and bed dryers are costly to operate due to the requirement of a fuel source. The fuel costs of drying forage in these type of dryers often exceed $30 a ton. Rotary Drum and bed dryers also are more increasingly difficult to obtain permits for installations due to the emissions they generate. In contrast, the method described utilizes solar energy in a low temperature drying environment that preserves feed quality throughout the drying process. The feed value is affected by color, aroma, leaf density and minimal fines losses.

[0041] The new drying method described herein provides multiple benefits unachievable in conventional methods of drying forages. Low temperatures are utilized in the drying process in an environmentally friendly and sustainable way. Drying time and weather risks are greatly reduced in comparison to conventional sun curing in a field. Chopped forages are never subjected to extremely high temperatures as found in conventional dehydration processes. Nutrient content and plant quality are preserved from time of cut or chop throughout drying and collection to delivery to a final packaging facility. When freshly chopped forage or silage is received and spread to dry, it remains untouched or undisturbed until ready for collection. A light breeze is generated to accelerate drying when the air is still. A dew is stimulated when necessary to enable the gentle collection of a supple dried chopped forage in manner which minimizes damage to leaf/stem contact or damage to finer fibers found in chopped forage. This enhances the overall nutrition and palatability of the product. The shortened drying time and low heat preserves color in the dried chopped forage which is recognizable as a character trait of products dried in this drying method. The new drying process enables, for the first time, an opportunity for an exporter or final packaging facility to receive a sun cured freshly chopped or short cut forage in loose form which has never been subjected to damages of dry raking or pounding in a multi-stroke baler. This new drying process concentrates the critical steps of controlling quality during the drying process away from the field, where unskilled labor is often encountered and climate conditions aren't always conducive to drying, to a specialized drying facility where the process and atmosphere are managed by experts in methods eliminating abusive steps which harm plant quality and nutrients. The new drying process greatly reduces drying costs in comparison to conventional drying methods. The new drying process enables the development of new products. An example of this is sun cured green chopped forages or silages. They have only been able to be dried heretofore with conventional dehydration methods. Another example of a new product is "Short Cut" sun cured forages. This is where a forage is intentionally cut short (5"-12") while early in the regrowth process when nutrition and palatability is highest. In conventional field sun drying methods, the costs to produce a "Short Cut" sun cured forage are exorbitant, due to low tonnage yields, frequency of harvest requirements, and impact of increased heavy equipment traffic on the field. However, the new drying method offers fewer processing steps and lower costs to produce sun cured "Short Cut" forage. The new drying method benefits farmers by reducing weather risks by shortening drying time, and by allowing them to increase yields as drying no longer takes place in the field and the crop can be irrigated back the same day it's cut as opposed to five or six days later as required for field drying. [0042] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[0043] The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.