Cardboard Chips as a Farm Input

Progress report for FNE21-994

Project Type: Farmer
Funds awarded in 2021: $14,484.00
Projected End Date: 12/31/2022
Grant Recipient: Coonamessett Farm
Region: Northeast
State: Massachusetts
Project Leader:
Ronald Smolowitz
Coonamessett Farm
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Project Information

Project Objectives:

This project seeks to document the economics of using cardboard chips as a replacement for wood shavings as an animal bedding. We will quantify the quantity and type of cardboard used, the time it takes to remove tape and staples, and the time it takes to produce a certain volume of product. We will utilize the cardboard bedding, alongside of our traditional bedding, in stalls with poultry, goats, sheep, donkeys, and alpacas. We will evaluate the bedding regarding odor control, wetness, ease in stall cleaning, handling, and storage. We will evaluate the time it takes to breakdown in our composting operation. The question to be answered is it better and more cost effective than wood shavings.

This project also seeks to demonstrate cardboard chips as a mulch; either used alone or blended with wood chips. We will evaluate the productions costs, as stated above, and its effectiveness as a mulch. We will evaluate weed and pest control; does it control slugs, does it blow away,  and what weeds are controlled. 

Introduction:

Our farm conducts a diversity of agricultural operations that require expensive inputs. Virtually every farm conducts one or more of these type of operations. We start seeds and plugs in containers for field transplanting and direct sales. This requires buying potting mixes that are usually peat or coconut coir based. These ingredients raise environmental issues. We grow a wide variety of field crops without the use herbicides; we use cultivation and mulches. Our mulches are partially composted organic materials that do not contain weed seeds such as wood chips and cardboard. We also buy plastic mulch. We buy a lot of wood shavings for animal bedding for our livestock. 

We have noticed a large increase in cardboard boxes coming to the farm as now many items are ordered on line and are delivered in these boxes. These include items used by our restaurant, items for resale in the store, and general operating supplies. We have a six cubic foot dumpster that is emptied once a week at a cost of about $100. I estimate 40-50% of the trash is clean cardboard. That is in the range given for typical solid waste streams. Virtually every farmer I know has thought it would be a great idea to use this cardboard to replace costly inputs and not have to pay for disposal. However, it has to be cut up into small pieces for use as animal bedding, mulch, and a potting mix ingredient. This has been problematic. We have tried shredded/perforated cardboard for mulch, that is used as a packing material by some shippers, but the pieces don't pack easy. They won't work as animal bedding as the absorbency per unit volume is low. The pieces are too big as a potting mix ingredient. 

While on a trip to Scotland last year, we visited a cattle farm and noticed they were using cardboard chips as animal bedding. Their source was a large commercial operation and was not applicable to our size operation. However, we were intrigued and researched the issue and found that there are small cardboard chipping machines produced in China, Germany, and Italy. After discussion with knowledgeable Europeans we found that the Chinese machines are junk, the German machine is expensive and requires technicians to maintain, and that the Italian machine is well built, reliable, and easy to maintain. We have the Italian machine on order through a cardboard processing company in England. The machine plus shipping will cost us $8000. We feel this is well worth the cost when we take into account the potential reduction in just the cost of animal bedding.

We see this as an opportunity to make our farm more economically viable, while also addressing a solid waste disposal issue. However, there are lots of questions that have to be investigated to demonstrate that using cardboard chips is beneficial to the environment and to crop production. We are proposing to accurately document our production and use of the cardboard chips. We will document the amount of cardboard used and the amount of chips produced. We will document how the chips are used and any issues associated with their use.  We will document the cost savings with the reduction of purchased inputs.

 

 

Description of farm operation:

Coonamessett Farm is a 20-acre vegetable and berry farm that also raises livestock. The farm has five greenhouses, two high tunnels, six barns, a farm store and restaurant, and an on-farm composting operation. Basically, the farm conducts a wide range of farming activities and requires a large number of inputs for production. Some of these typical farm inputs include mulch for weed control, potting mixes for planting, bedding for animal housing, and feed stock for composting operation.

Project staff researched the machine options available to small farms that can convert cardboard to usable products; wood chippers, cardboard shredders, and perforating machines. This research located an Italian-made cardboard chipping machine utilized in England for making animal bedding. The machine is a MIKEA Hypershredder 400 modified to produce cardboard chips. The machine uses a single-phase 3 Hp motor and the manufacturer claims it can produce 6 cubic meters of cardboard chips per hour (loose; not compacted). The noise level is 55 dbs. The dimensions are 95x50x50cm and the wheel-mounted machine weighs 140 kg. Coonamessett Farm purchased one of these machines in 2021. https://www.hypershredder.net/

Coonamessett Farm also has a rotational "Ecodrum" composter (25 feet long by 5 feet diameter, solar powered). We use the machine to make compost using barn bedding and crop waste. We blend this compost with commercial potting mix for transplant production and container plants for sale. We will be trying to make a better potting mix by blending cardboard chips with other inputs and processing through the composter.

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Allison Maikath (Researcher)
  • Kari Parcell
  • Karen Schwalbe
  • Dr. Liese Siemann - Technical Advisor

Research

Materials and methods:

The first part of the project focused on materials handling. We only used clean, dry, corrugated cardboard; no paperboard or waxed boxes. We tracked the manhours it took to flatten the boxes and remove the non-cardboard material (labels, staples, tape). The cardboard was bundled and   stored undercover to keep dry.

We tried a number of cutting tools to prepare the cardboard boxes for the chipping machine. We settled on using a Canary corrugated cardboard cutter; a 7.48" Japanese corrugated cardboard cutter featuring a 2.95" double Stainless Steel serrated blade with nonstick coating that prevents adhesive tape from sticking on the blade surface. https://www.canary-usa.com/

The Hyper Shredder machine was used to make the chips (Figure1 ); it has a lateral opening thus the cardboard does not have to be cut to a certain width to be fed into the machine (Figure2). The machine’s manufacturer claims this model is capable of producing six cubic meters per hour when continuously fed cardboard. We designed the most efficient operation for the chipping and documented that process and the manhours used to produce a known volume of product.

The cardboard chips were packed and stored in standardized polyethylene tote 61x41x18.4cm (24” x 16.13” x 7.25”; 1.62 cubic feet) (Figure3 ). We developed a packing procedure to standardize the content weight for a tote. On two occasions, totes were filled and weighed. Then the contents of the totes were compressed by standing on the contents; continuously filling and compressing until level with the top and then weighed again. The time to fill a tote with the machine’s uncompressed output was measured.        The total compressed tote output per hour by one person was also measured.

Animal Bedding: The cardboard chips that were used for animal bedding were stored in plastic totes and placed in a dry unheated barn until use. The absorbency of the cardboard chips was determined several times during the project's duration using the procedures described in Johnson and Ott (1982) using either a weighed or volumetric subsample (Figure4). This will be compared to similar samples of wood pellets (Top Bedding Granules;35 lb. bags @$6.40 each), wood shavings (compressed 8 cubic foot bags @$5.90 each), and straw (compressed bales 36”x18”x14” @$10.50 each).

Poultry Test: We have five hen houses used for egg production that have nesting boxes that are normally filled with straw. In two of the hen-houses we used the cardboard chips in place of straw in half the nests selected by a random process; the nesting boxes were numbered (Figure5 and Figure6 ) We kept track of the overall amounts of straw and cardboard chips used as well as track the number of eggs from each nesting box. We also used cardboard chips as bedding on the hen-house floor; sometimes mixed with wood shavings (Figure7 ). We have one turkey barn where wood chips are used as litter (Figure8 ). We alternated using cardboard chips; wood shavings, and a combination of both. The goal is to design a blend of wood and cardboard chips that will be optimum. The results are qualitative; documenting odor, wetness, flies, and compostability.

Alpacas: Alpacas housed together is a paddock choose a small “latrine” area that they all consistently use for relief; sometimes one area inside the stall and one area outside. We use large amounts of wood pellets in these areas twice a day. Our experimental design will be to shift between wood pellets and cardboard chips every other week ( Figure9 ). Amounts and costs will be tracked. The comparisons will again be qualitative; are cardboard chips as good as wood pellets for ease of clean-up.

Donkeys: Wood shavings and straw are used as litter in the donkey stalls. Similar to the alpacas, we will alternate between wood shavings/straw and cardboard chips every other week. The qualitative criteria will be the same as the alpacas; sanitation and ease of clean-up.

Goats and Sheep: Wood shavings are used as litter in the stalls. We will do the same testing as with the donkeys but also pay attention to whether the goats will be consuming the cardboard.

All the used bedding will be placed into our compost pile and used as feed stock in our rotational composter (Figure10 ). The various components of the feed stock are measured and recorded volumetrically before being blended and added to the composter. Compost time, and other operating parameters, are recorded and the composter output is characterized by visual observations and documented. We expect to use the output of the rotational composter operation as a potting mix component and this use will also be documented.

Mulch: The cardboard chips used as a mulch was measured in compressed tote units. We tested three mulch types;100% cardboard, a 50/50 blend of cardboard and wood chips, and 100% wood chips (Figure11 ). Our wood chips come from local tree companies and we selected from piles that were only pure wood chips; no twigs, leaves, or brush. We have lots of experience using wood chip mulch on our berry crops; strawberries, blueberries, raspberries, and blackberries. We will experiment with cardboard chips in these areas (Figure12 and Figure13).  Only about half a dozen weed varieties make up 95% of our weed problem when we use mulch; mug wort, black swallow wart, nutsedge, bindweed, crabgrass, and purslane. Our method of weed control is to go through the rows at least once a week and hand weed. The amounts of weed vary by season and rainfall. The criteria we will use for this experiment based on our experience is weeding time. We will not be commenting on plant growth unless a very obvious difference occurs.

Our experimental design will be on a row-by-row basis. For example, we currently have three-foot-wide rows of perennial flowers that are mulched with wood chips. These rows are about 100 feet long. We will use an alternate square approach; 10 feet of wood chip mulch, 10 feet of cardboard mulch, and 10 feet of the 50/50blend for every 100 feet of row. Our cardboard mulch will also be applied on the footpaths of both annual and perennial crops. Observations will be made on annual weed growth. Our snap pea crop has a three-foot pathway between each row so that access is easy for customers to pick. Each row will be mulched to a 3–4-inch thickness. The same application will be used in our strawberry field. Observations on ease of access will be recorded.

Research results and discussion:

The Hypershredder 400 was used to make the cardboard chips. The carboard came from a number of sources with different degrees of preparation (removal of staples and plastic; pre-cut into pieces). Though the machine manufacturer claims the machine can process staples and plastic, we choose not to do so to avoid issues with animals and fields. However, we estimate it takes about an hour to pre-process boxes that yield a cubic yard of loose cardboard.

The calculations shown in Table 1 are based on many hours of timing the production using a single individual. The tasks included feeding cardboard into the machine where the output was collected in individual totes (1.62 cubic feet). This required moving the totes when filled, and then compressing the contents.

Our results indicate that we can produce about one cubic yard of loose cardboard chips per hour. We set up an experiment, using three people, to feed cardboard sheets into the machine without interruption, and found the best output we could achieve was about 3 cubic yards per hour (2.9 cubic meters); about half of what the manufacturer claims. We chose $25/hour as a labor cost (which includes overhead) to get our approximate cost of cardboard chips.

Table 1: Standard chip unit calculation

Bins               per hour

cu ft/hr

cost/hr

Cost    (cu ft)

20

32.4

$25.00

$0.77

13

21.06

$25.00

$1.19

 

On three occasions during the project, we tested three samples of each material for absorbency (nine samples total of each material). The weighed dry sample was covered with water and let sit for one (one test) or two hours (two tests). Excess water was drained off and the material samples then again weighed. The results shown in Table 2 indicate no major difference in absorbency over the time periods tested. However, while it would seem that wood pellets were then a very costly alternative, our in-stall tests show they are very fast-acting in soaking up liquid, which may be important at times.

We also noted that there was more variance in the cardboard samples then in the other three materials when it came to calculating the absorbency. This may be due to the wide range of cardboard types processed at different times.

 

 

 

 

Table 2: Weight and cost per cubic foot of tested materials. The Absorption Coefficient is the ratio of wet weight divided by dry weight.

 

Dry weight per cubic ft (lbs.)

Cost per cubic foot

Absorption Coefficient

wood shavings Loose

3.42

$0.62

4.03

wood shavings compressed

10.28

$1.85

 

wood pellets

35

$7.00

3.87

cardboard chips Loose

2.25

$0.77

3.62

cardboard chips compressed

3.40

$1.19

 

straw loose

1.05

$0.32

3.68

straw compressed

6.47

$2.00

 

Poultry data analysis: At first chickens favored the control bedding of hay and shavings over the cardboard bedding during testing (Table 3, Poultry data tables), but over time they were becoming acclimated to the cardboard bedding at the end of the trial (Table 4, Poultry data tables). After moving the birds to the larger barn, we started not only treating the nest boxes with cardboard but also the floors. The birds responded even better to the cardboard after the material was also used on the floor (Table 5, Poultry data tables). No stronger odor was noted nor was there any more difficulty in the cleaning process.

Goats: Cardboard chips were attempted under supervision in the goat barns as bedding. The goats immediately tried to consume the cardboard and for safety of the animals had to be removed.

Alpacas: The alpacas were hesitant at first to use the cardboard, mainly using the area around it. By the end of the week, they had acclimated to the change and were using the cardboard chips. The cardboard is more easily spread around by the animal’s movements than the bedding pellets, making a less cohesive pile for the liquid to be soaked up. No stronger odor was noted nor was there any more difficulty in the cleaning process.

Donkeys: The donkeys were the most receptive to using the cardboard initially. No stronger odor was noted nor was there any more difficulty in the cleaning process.

Mulching: A row of daffodils was the first to be mulched using the alternate square approach. Materials held in place equally, even after high winds and a leaf blower had been used down the pathways. Every other week the rows were inspected for weeds. All materials were equally beneficial for weed suppression, however none of the three were successful at keeping down rhizome-based weeds like mug wort or bindweed.

Snap pea and strawberry foot paths were mulched. Initially the material was harder to walk on then the woodchips we would normally use but after light compression they were comparable. It was also noted that the cardboard chips were just as visually pleasing to the customers than the wood mulch.  

At the end of the season small areas of the carboard mulch were pulled back in the strawberries to observe the soil. More worm casings were observed then in a normal season.

Compost: Carboard chips were used in the bottoms of our food scrap collection bins in replacement of leaves. Layering the bottom of the container soaks up excess moisture from the food scraps preventing odors, flies, and aiding in cleaning of the bucket after use. It is also an important feedstock ingredient. The buckets of food scraps with cardboard chips and the used animal bedding were put into our Ecodrum rotational composter. When observing the compost discharge recognizable pieces of wood chips and straw have been documented, along with identifiable food scrap.  We have never noted anything resembling card board come out. The cardboard is more efficiently broken down in this type of machine. Our next trial will be to compare its breakdown in a static compost pile.

Participation Summary
5 Farmers participating in research

Education & Outreach Activities and Participation Summary

1 Published press articles, newsletters
50 Tours

Participation Summary:

2 Farmers
2 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

Coonamessett Farm is a pick your own farm opened to the public. We are open 7 days a week from April thru December. We have around 50+ visitors a day coming to the farm during high season. Interested parties have access throughout the study to observe the cardboard chipping process, its use as animal bedding, and its use as mulch. Our project was outlined in one of our newsletters which are sent out to our 1500+ members. Each spring and fall we hold school tours which average at around 25+ per season. Our cardboard experiment is one of the projects that is discussed with the students. At the end of the project we expect to produce a scientific publication as well as informational brochures. These will be physically distributed as well as being posted on our various web sites which reach a minimum of 3000 potentially interested parties.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.