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Grow your soil first, your food second. This is a piece of advice many ecological growers are familiar with.

So how exactly does one grow a mass of brownish black dirt? Soil is a living and thriving thing. It is a substrate hosting microbes, bacteria, and a multitude of nutrients, the most important for plant growth being Calcium, Potassium, Nitrogen, Magnesium, and Phosphorus.  The soil feeds living microbes. Healthy soil is teeming with living matter from microscopic material to slimy earthworms. The things we put into or take out of the soil in agriculture can either improve the health of this living system or severely deplete it of nutrients.

For example, chemical based agriculture pumps alien sources of synthetic chemicals into soil to feed crops rather than relying on the natural occurring substances to do so. Intensive farming of one crop, monocropping, sucks too much out of the soil substrate. Soon farmers are left with a dead brown mass that once was home to millions of thriving microbes. In order to continue growing crops, farmers must pump more external, synthetic substances into the depleted soil, essentially just using the dirt as a place to put plants who then eat these synthetic fertilizers.

The alternative to this model is feeding the soil so it grows and in turn provides nutrients to support the growth of healthy crops in a more natural way. This can only be done by harnessing the power of nature and working with, not controlling or depleting, ecological nutrient cycles. AASD and many other ecological growers grow the soil through natural fertility building techniques such as compost and bocashi. These materials restore the nutrients we took out of the soil with the previous crops. And most importantly, we rotate crops.

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Different types of crops take different nutrients out of the soil and put other ones back in during their growing cycle. In order to ensure the balance of nutrients is restored, we can rotate crops based on the ratio of nutrients they give and take. For example, lettuce feeds heavily on nitrogen.  So we don’t want to plant kale after  lettuce which because both are what we call heavy feeders. Instead, we want to balance this nutrient load out. We use the above chart to help plan this rotation. This is a simplified version to help one remember which plants usually give, take, or lightly feed on nitrogen. Of course, other nutrients are restored through this balance too. Normally we rotate our crops by fruiting varieties (tomatoes) to leafing varieties (lettuce) to rooting varieties (onions) to leguminous varieties ( beans). With this rotation, we can help restore the nutrient balance, growing our soil, and in turn growing healthy plants. ~Kat

Growing Soil Fertility

Oftentimes at the farm we say we’re growing soil fertility first and vegetables second. Why’s that? Because without fertile soil you can only cultivate crops for so long before yields decline and external inputs are no longer sufficient to feed the needs of healthy crops. The soil is a substrate for growing. It is a living, thriving world full of microorganisms and nutrients necessary for healthy plant growth. The agroindustrial model looks at the soil as this dry, dark matter that must be pumped full of chemically constructed nutrients and additives. The soil in such a model is dead, dry, and just a substrate for placing roots of plants into. When we recognize that the soil is really a complex and very alive system, we begin to think about how to nurture this system so that there is a symbiosis with plants. The cylce of a growing plant and growing soil quality thus go hand in hand. At the farm we practice this in various ways, a few being:

  • Crop Rotation: Crops take and give different nutrients. We balance this through carefully planned rotation so as to increase, not deplete, soil fertility.
  • Association of plants: Certain plants complement each other and the soil.
  • Soil Fertility: composting, vermiculture, local soil fertility methods such as biol and bocashi (explained in future posts!)

What is Biol?

Over time we’ll adress our different methods for building soil fertility. Last week we made Biol. Along with the photos in this post, I’ll explain the process. Biol is a compost tea-like substance made from a mix of  crushed egg shells (calcium), ash (potassium, phosphorus, magnesium), yeast or chicha with sugar (quick break down), alfalfa (nitrogen), guano de corral (sheep/lama/guinea pig droppings), and milk all mixed with water. This can be done anaerobically (without oxygen) or aerobically (with oxygen) and stirred daily for a few weeks. Kind of like making a “potion” in your mom’s basement – one of my favorite childhood pastimes. When ready, we dilute it with water and spray this natural fertilizer on and at the base of our veggies for healthier plants and healthier soil! We learned this neat technique from a local expert here in Peru. It is so applicable for the highland communities we work with because Bocahsi utilizes only resources that the farmers here have at hand making it easy to make, low to no cost, and more likely to be put in practice. Plus it looks so nice (below), huh? Pretty neat! ~ Kat