Book Review, The Bio-integrated Farm by Shawn Jadrnicek

Publisher: Chelsea Green. ISBN: 9781603585880

This book, by Shawn and Stephanie Jadrnicek, was hidden in my “to read” pile for too long! The title doesn’t make it clear enough that this is an authoritative text on all kinds of water management on the farm: integrating ponds, swales, ditches, water catchment, heat storage in water, irrigation, water for light reflection in winter, fish and shrimp-farming. Chickens and black soldier flies, compost-making and vegetable production in hoophouses and outdoors are all part of the bigger picture.

This book speaks from Shawn Jadrnicek’s experience at the Clemson University Student Organic Farm in South Carolina, and at his own homestead. The author tells us honestly when things he tried didn’t work out, and why. It is a permaculture book written for non-believers as well as the converted. It does not mystify with strange jargon. It does not make unsubstantiated claims about how things ought to be. Full disclosure: I suffer from having read too much permaculture writing that was obscure, convoluted, not backed with direct experience and written for people with a lot of time and only a small piece of land. This book is a breath of fresh air! The ideas have been tested on a farm scale, with a close eye on efficiency. It’s written for market farmers, homesteaders and serious gardeners, showing how to make best use of natural resources to help feed the world. Each technique has to have at least seven functions to qualify for inclusion in the author’s farming practices and the book.

You may not want to follow all of the author’s methods. I, for one, am not going to grow hydroponically. (I doubt that fully nutritious food can be grown without soil, with just the nutrients we know to feed in.) You may not want a hoophouse that is almost all pond. But you may be very happy to find a book that describes how to build a hoophouse on sloping land; very happy to learn how to grade your land to move rainwater away from where you don’t want it to sit, to where you do want it to improve growth of your pastures. You may be very happy to learn how to use a pond to grow minnows (tadpoles in the non-minnow season) to feed chickens. You may like the idea of filling your hoophouse with sweet potatoes or cowpeas in summer to act as a “smother crop,” dealing with weeds while keeping the soil alive. Perhaps you’d like to try freshwater prawn (large shrimp) farming? The regulations are easier than for fish-farming. Giant river prawns can weigh as much as a pound, they are easy to process and cook, and they sell at a good price.

Water management fills over half of the book, complemented by 30 pages on chickens, 33 on compost, 13 on fly farming, 28 on field layout and drainage, and 56 pages of case studies. Most of the vegetable production mentioned takes place in hoophouses (high tunnels). The book includes various ideas for heating the indoor crops, using hydronics (indirect heating with water in pipes warmed in outdoor ponds or compost piles), indoor ponds with solar pool covers, and compost piles leaning on the sidewall of the hoophouse. The information on rainwater harvesting includes checking your roofing material for toxicity (there is a special coating you can put on if necessary), how to avoid leaves clogging gutters (cleverly designed downspout filters), regulations about harvested rainwater, how to make gravity flow toilets and gravity drip irrigation systems that really work, and how to find the data and do the calculations. The level of detail in this book inspires confidence!

The chicken-farming system in this book uses a permanent coop and alley (mulched corridor) along with temporary pens made with electric netting. This makes better use of resources than free-ranging, unless you have only mature trees and grass. The birds get 30% of their dietary needs from the landscape, if rotated every 6-12 days onto perennial clover and grass pasture that has regrown to 4-8″ in height. This system ensures the chickens can always reach shade, and you can reseed bare spots in the resting pens with rye, wheat, millet, sunflowers and buckwheat, and reduce their feed costs by 30%. I liked the careful thinking and observation behind this scheme.

And then we come to the black soldier flies. The mesh flooring of the chicken pen lets the manure fall through into a fly digester below. The fly larvae digest the manure and grow, later becoming chicken food themselves. I wasn’t initially attracted to the idea of deliberately breeding flies, but the system has a lot going for it. Black soldier flies (Hermetia illucens) are not a pest. In fact they out-compete houseflies and thus reduce their numbers 95%! The adult soldier flies live only 5-15 days – they have no functioning mouthparts, and they don’t vector diseases. They are native in zone 7 and warmer, especially in the Southeast, so consult your Extension Service to find out if you’ll need to mail order them or just set out a nice digester once it’s warm enough. This sounds better than worm-bin farming! The flies tolerate a wider range of conditions and consume waste faster than earthworms. The large segmented larvae will “self-harvest” into buckets, if you have a well-designed digester. Two commercial models are available, the larger ProtaPod (4 ft diameter) and the smaller BioPod. They have internal ramps that the pre-pupae will climb, and a curled rim that prevents escape. The creatures launch themselves down a tube into a lidded bucket. All the details are in the book! Add fresh waste daily, and empty the bucket at least weekly (to prevent adult flies hatching out and setting up residence where you don’t want them).

The section on compost-making includes how to extract heat from your compost pile to warm your hoophouse, and how not to extract so much heat that the compost stops working. My beef with some other books about methods of heating greenhouses is that they fail to address the unintended side-effects, such as having very humid air go into your living space, or having little space left to grow plants because the greenhouse is full of heat-storing devices. Make good compost, and warm your hoophouse a bit.

The section on field application of these ideas is not about growing vegetables, but about field layout and drainage. It includes useful calculations on using drip irrigation. It also discusses keyline plowing, which had previously been just a bit of permaculture theory to me. Shawn says, “keyline pattern cultivating intrigued me for years, but I first had to implement the technique before becoming a convert.” There is no need to buy the special equipment some advocates suggest, if you have a box scraper with ripping tines. Keyline plowing (ripping 4″ deep in lines through pasture or grassways to direct water from a valley to a bit of a ridge) helps build soil and increase grass growth. Reading Shawn’s results, I now understand why others said it was a good idea.

I recommend this book to any small-scale farmers who are interested in learning efficient techniques to increase productivity while reducing use of resources.

Stephanie and Shawn Jadrnicek
Photo Chelsea Green

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