Mulch layer + Cardboard roll + fertilizer

I have a crazy idea, so this is how it goes:
Step 1: collect used cardboard

Step 2: make cardboard slurry
Step 3: add fertilizer to slurry (ex. Blood meal, bone meal, ashes, etc..)
Step 4: make cardboard sheet rolls (1 meter in width).
Step 5: use a mulch layer (tractor attachment) to lay the cardboard sheets.
Step 6: use a hand held transplanter (small scale) or a similar tractor attachment for larger scale.
Step 7: harvest crop.
Step 8: till the bed to mix cardboard with soil.
Step 9: lay a new cardboard sheet for the next season crop.
Step 10: win?

Please tell me your ideas, things I’ve missed, or improvements to the system.

The biggest flaw as it stands is I think the lack of airflow through the cardboard. Oxygen is as critical for roots as anything, i'd imagine you want to puncture the cardboard sheets at the very least.

Benefits from the system:
1- weed control
2- moisture retention
3- provide fertilizer to next season crop.
Cuts the cost of applying the fertilizer separately.
4- better for the environment because of using cardboard instead of plastic.
5- cuts the cost of removing the plastic.
6- raw materials can be collected for a low cost.

Lucas Green wrote:The biggest flaw as it stands is I think the lack of airflow through the cardboard. Oxygen is as critical for roots as anything, i'd imagine you want to puncture the cardboard sheets at the very least.

There will be holes made by the transplanter for the plants to poke through, I believe this will provide enough airflow, don’t you think?

Yea I think so, thinking about it again, since this will be used in tilled applications it will prob work well.

I just had another idea; the cardboard sheets can be made with different npk values depending on your needs, say for example you want to grow cauliflower as a cool season crop then corn for the warm season. Then you get a cardboard sheet that has the npk requirements for corn, and plant in it the cauliflower, so after the cauliflower is harvested, you till the cardboard sheet which helps in its decomposition and add the nutrients to the soil for your corn crop, then when planting your corn you lay a sheet that has the npk of the cool season crop etc...

Nifty idea Hisham!  I'm not sure how healthy the ingredients in cardboard are.  I use it myself for mulch but just one application.  If it's being reapplied each year and tilled in, I wonder if the repeated application of those components would be a concern?  I'm thinking of the inks and glues and things that aren't cellulose...

Mike Jay wrote:Nifty idea Hisham!  I'm not sure how healthy the ingredients in cardboard are.  I use it myself for mulch but just one application.  If it's being reapplied each year and tilled in, I wonder if the repeated application of those components would be a concern?  I'm thinking of the inks and glues and things that aren't cellulose...

Hi Mike, I agree with your concern, maybe a filtering process can minimize the glue content, and in regards to ink, I believe the ink used on cardboards is soy based.

The important thing about gardening is to have a mix of ingredients, not just one that overwhelms all the others.   Cardboard is carbon and commercial glues.

However anyone wants to spend time breaking down cardboard is up to them.  But applying it to the garden, the soil needs to be mixed in or the cardboard  buried.  It's the soil critters that break it down, and if it's dry, or not under thick leaf mulch or several inches of soil, they just can't be in that environment.

And what nutrients are being added to the soil by cardboard?   3" deep leaf mulch, maintained at that depth, checked weekly, will suppress weeds, keep moisture in the soil for worms, not just soil microbes, and add nutrients, create the soil food web that we are all looking for.

These days I have no idea what kind of glues they are using to make cardboard, but odds are it's not non-toxic.  A lot of cardboard is required to stay in a sterile state for X amount of time, depending on regulations.  

Where it doesn't rain in the summer it's a real struggle to keep it wet enough, in any form.  The corners curl up, even under a few inches of soil (unless the soil is saturated regularly, which means by hand, which means another chore in the summer) and wind/air gets underneath it, dries it out.  I've found it to be very ineffective if I have to provide the moisture.

And here's a question:

If something is recyclable, into the same or other usable products that can also be recycled, and we take it out of the recycle loop by sticking it in the garden, isn't the demand for the original ingredients going to go up?  In the case of cardboard, more trees need to be cut down, which requires diesel-belching sawing machinery, and diesel-belching trucks to haul cut trees to sawmills.  

It's an interesting thought, though not without its' issues.

I see the use in making a cardboard slurry paper mat for this application, but I don't think it's the best material for the application. I prefer the idea of using woven reed or other biomass mats as a mulch layer, but in an urban environment, especially if we're talking about cardboard contaminated with relatively clean food waste, like pizza boxes and the like, it might be the thing to do.

My concern wouldn't be the adhesives as much as the inks. To combat the ickiness of either, I would include mushroom spore in the slurry specific to the soil needs. I would also consider seed for a range of low-growing living mulches that could likewise be added to the slurry in the sheet-making process, to dry out and be stored dry until application on the soil, when regular watering and weathering would cause the mulch layer seeds and fungal spore to germinate.

The living component of such a mat would first anchor it to the soil with thousands of tiny roots, it would also accelerate its breakdown into soil.

-CK

Chris Kott wrote:It's an interesting thought, though not without its' issues.

I see the use in making a cardboard slurry paper mat for this application, but I don't think it's the best material for the application. I prefer the idea of using woven reed or other biomass mats as a mulch layer, but in an urban environment, especially if we're talking about cardboard contaminated with relatively clean food waste, like pizza boxes and the like, it might be the thing to do.

My concern wouldn't be the adhesives as much as the inks. To combat the ickiness of either, I would include mushroom spore in the slurry specific to the soil needs. I would also consider seed for a range of low-growing living mulches that could likewise be added to the slurry in the sheet-making process, to dry out and be stored dry until application on the soil, when regular watering and weathering would cause the mulch layer seeds and fungal spore to germinate.

The living component of such a mat would first anchor it to the soil with thousands of tiny roots, it would also accelerate its breakdown into soil.

-CK

Hi Chris, I’m interested in your idea about the biomass mat, can you please elaborate on how it would be done? What would be the best materials to use? Would it provide weed suppression like the cardboard?