I’m not an agronomist, and I have a feeling you’d really need to be one to properly assess this book. But I’m totally on board with the notion that you need to feed the soil and all its critters before it can feed the plants that grow in it. That’s the premise of the just-published Building Soils Naturally: Innovative Methods for Organic Gardeners by Phil Natua (Acres USA, 2012, $19.95). Nauta, who taught organic horticulture at Gaia College and was a director of the Society for Organic Urban Land Care, asserts that feeding the soil well not only helps maintain the health of our planet, it grows vegetables and fruits that are so nutritionally dense that they don’t rot for weeks. I find that last claim a bit suspect, though it does make sense to me that the more nutrition available for fruit and vegetable uptake from the soil, the more nutritionally dense they will be. Twinkie-effect aside, the book is well organized, is written in a breezy style and has lots of great info.
There are three sections: The Soil and Its Inhabitants, Six Steps to Creating Healthy Soil, and Garden Action Strategies. Within those sections are short chapters on such things as Soil Nutrient Testing (and choosing the best testing facility), Calcium and Phosphorous, Other Major Nutrients, and Garden Health Management Plan. Each chapter has a short review list so you can quickly check to see what chapter might be most helpful to your particular question if, like me, you have trouble keeping every single bit of chemistry, Cation Exchange Capacity (CEC) and the chart of Reams-Based Ideal Nutrient Levels in Soil in your head.
Natua restates – but enlarges upon — much of the currently accepted wisdom in the spiral-bound Master Gardener tome that’s laughingly called the ‘handbook,’ though Building Soils Naturally is a much more detailed look at soil ecology and chemistry and includes soil nutrients’ effect on Brix (a measure of the dissolved solids in plant juice, including sucrose and fructose, vitamins and minerals, protein and amino acids and more), which has got to affect the density of vitamins and minerals in their fruits.
Nauta also takes issue with some current conventional wisdom. For example, he says that soaker or drip hoses that target individual plants deprive the organisms in the un-watered soil and affects nutrient uptake; he prefers to overhead water since research at University of Nebraska shows it loses only about 4% to evaporation. (I would think the real percentage loss would fluctuate depending on ambient temperature, wind velocity and sun exposure, but never mind.). Regardless, overhead watering, which is what Nature does, makes sense, provided you’re strategic and not profligate with it. For example, in our garden during drought, the dust from the surrounding fields coats the leaves of everything. A good overhead soaking very early in the morning every ten days or so washes off the leaves, clearing stomata, while giving the plants and the critters in the surrounding (mulched) soil critical hydration. It produces visible benefits – even though the sprinkler water is chlorinated town water and does more to keep things alive than to grow stuff. The water I haul from the rain barrels every five days or so and pour only on the plant roots actually helps things grow. There’s a visible difference.
I question some of Nauta’s assertions, but as I said, I’d need to be an agronomist to do a proper job of it, in which case I might agree with them. And I find that taking issue with assertions usually means we do further research and pay closer attention, good things in gardening and in life. I highly recommend Building Soils Naturally. The bibliography runs to 43 books, some of which look like they’d be really good additions to a serious gardener’s (and a serious planet-dweller’s) library.