Posts Tagged ‘compost’

Q&A: Tofu left-overs feed the soil

Question from Shlomy Goldman in Cranston, Rhode Island:

I’m inspired by what you guys are doing. I’m growing my first garden ever this season (I’m on the east coast) and I’m doing it veganic! I brought in some leaf mold compost which I put on top of turned sod to start my garden. I think the compost is a bit carbon rich. I’ve already got a mixture of vegetables beginning to grow. Can you make a recommendation on amendments I should add? I am about to start making my own tofu. would the okara, the left over pulp from making soymilk be nitrogen rich? Is okara different from soybean meal? how would I use it for the crops? Any other suggestions?

Answer by Greg Litus, Animal Place horticulturist:

I had assumed that the leftovers from tofu manufacturing would be depleted of proteins and most other minerals.  However, that isn’t the case. In a study about the various uses of okara published by the Journal of Agricultural and Food Chemistry, Characteristics and Use of Okara, the Soybean Residue from Soy Milk Production, the okara was found to be high in crude fibers but also contains 25% protein and other minerals as described in the article.  The one thing missing from the article is okara’s potential as fertilizer.

Okara would be useful as a fertilizer in the same way that your leaf mold compost is a good soil amendment.   All organic rich soil amendments depend on healthy soil microbial activity to break down the carbon.  That process takes time and can initially cause a reduction in available nutrients to plants as the soil microbes sequester those nutrients.  For that reason it is usually best to apply amendments like okara a few weeks to months before it is time to plant.   That time period allows microbial action to take organic forms of nitrogen and phosphorous and make those nutrients available to the plant in an inorganic or mineralized form.

In the case of nitrogen, microbial activity will eventually cause slow denitrification while excess water will leach some nitrogen out of the root zone.  Therefore, more nitrogen needs to added depending on the rate of loss.  That can be achieved by growing green manures such as legumes (beans and peas) that have a symbiosis with bacteria that actually fix nitrogen into the soil from the atmosphere.  When those crops are turned into the soil, the process of mineralization and denitrification starts all over again.  In lieu of the green manures many of us just add compost or other plant-based amendments such as leaf mold compost, alfalfa or okara.  These plant-based amendments will also add other nutrients like phosphorous that will not be lost to the atmosphere but have their own specific cycles in the soil/plant environment.  The best gardens are ones that develop good fertility over time such that new additions of compost and other amendments replace the elements lost through harvest.

Even when focusing on long-term soil development, there are times when we get it wrong and the plants starve because we intercepted the soil nutrient cycles at the wrong time.  In those cases, readily available nutrients must be added to the soil to assure good plant growth.  At our micro-farm we keep alfalfa tea brewing for that purpose.  We also use very small amounts of synthetic fertilizers occasionally.   One teaspoon of 10-10-10 goes a long way on young seedlings.  When small amounts of synthetic fertilizer are applied to soils rich in organic matter and healthy microbial activity the whole system is enhanced.  The negative side of synthetic fertilizer is obvious but when directly compared to blood and bone meals and fish emulsions the synthetic fertilizers have less environmental impact.

Like you, we have a strategy for long-term soil fertility that will eventually eliminate need for any emergency inputs.  FYI we add soybean meal directly to the soil and take all other plant waste from the field and kitchen directly to the compost heap.

For those able to travel to Grass Valley, Greg will be giving a free introductory course on veganic farming at Animal Place on Tuesday, June 5, 6:30-8:30pm.

And on this farm he had a goat.


Gilbert, the goat.

This week, in my new world of vegetable farming, I’ve had three experiences with or about goats.


“I dig a trench [in the compost pile] and fill it will hooves, stomachs, offal.  Cover it up, and in one week’s time you’d never know it was there”.

I have recently gotten involved with a network of local farmers that provide training and mentorship to apprentices and interns like me.  While grateful for the opportunity to learn, for free, from folks who are donating their time and energy to train the next generation of vegetable farmers, it comes at the price of heartbreak in this cult of omnivores.  In what would seem like an innocent “Intro to Compost” class, the instructing farmer spoke offhandedly about his mass grave of animals as if he was recycling old newspapers.

This grave of stomachs sunk my own belly down into a pit of sadness.  Why kill innocent, sentient beings when plant-based composting is just as effective, and a whole lot less cruel?  Read about how to create your cruelty-free compost heap on the Vegan Organic Network.

Weed Control

Carmen is not a goat, but she, too, was kept as a weed eater.

I’ve also been interning 1-2 days per week at the aptly named Sweet Roots Farm, where two sweet young farmers named Deena and Robbie are in their second year of organic vegetable farming.  It’s not a veganic farm, i.e. there is animal manure in their compost, and while those conditions are not ideal for me, they are tolerable for me in this work-learn relationship.  This week, as we propagated veggie and flower seeds in the greenhouse, we chatted about weed control.  I’ve been conflicted with our use of plastic weed barrier at Animal Place, and looking for other manageable ways to suppress these crop killers on a larger scale.  For vegetable beds, we spoke of the importance of soil cultivation and timely tilling, cover crops, and other carefully planned techniques that could minimize the manual labor (or use of plastic) over time.

And then, the goats.  I wondered, inwardly, about their cheerful idea to keep pet goats on the property to eat up the thistle weeds and invasive blackberries along their babbling brook.  Was this just another form of animal slavery and would I be able to continue my internship in that setting?  I did some research…

According to the Puget Sound Goat Rescue, goats not only like these weeds, but need them in their diet to be healthy.  Animal Care Manager Jamie London at Animal Place backed this up with, “Goats LOVE blackberries, they’ll take them right out of your hand!”  It’s a relief to me to think that my new teachers at Sweet Roots could cultivate a caring, symbiotic relationship with their companion animals.  Over at Animal Place, I’ve fallen in love with Carmen, a tri-pod lamb who was rescued from neglect in a pasture where she, like so many goats, was kept merely to mow down unwanted vegetation.


8pm, Wednesday, March 14, 2012.  I was putting the finishing touches on our late meal of baked potatoes and lentils when my boyfriend Greg radioed me to put on all my rain gear, bring the headlamps, and meet him at the Animal Care Room to help with an emergency.  One of the old-timer goats, Gilbert, had been acting strangely; he would not follow his herd into the barn at bedtime, and was standing obstinately in the pasture, drenched and grinding his teeth in distress.  It took three of us to urge Gilbert into his bed of straw in the trailer, pushing and pulling and coaxing.  With empty bellies and pounding hearts, Greg and I jumped into the truck’s cab and zoomed off to the vet hospital at UC Davis for emergency care.

Temporarily blinded by what turned out to be a urinary blockage that is common in castrated male goats, Gilbert lay shaking on a cold metal examination table while a fourth year student shaved his abdomen for an ultrasound.  A people-shy goat by nature, I imagine that the touch of multiple human hands on his body, in addition to the loss of eyesight and physical pain he must have been feeling, was hugely traumatic for Gilbert.  The tickle of the ultrasound device sent him thrashing into Greg’s arms on the floor.  We stayed for a little while longer – not really much help to the skilled vets, but unable to tear ourselves away from this critter, so clearly experiencing physical pain and strong emotions.

We’re not sure that Gilbert will survive, but at least he was able to live a peaceful life at Animal Place.  Read more about Gilbert’s life as a peacemaking and curious goat on Animal Place’s website.

photos by Marji Beach, Animal Place

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