Okay I finished the book. Probably the most important thing I learned is that when you plow (or till), you break the capillarity of the soil. Recall back to junior high science: capillary action is what makes water climb up the sides of a glass. When the glass is very narrow like a soda straw only like 0.010 inches in diameter, the water will climb up all the way to the top of short lengths of it. When soil stabilizes with a structure, there is established in that structure a bunch of capillary "tubes" made from the soil minerals and organic materials. These capillary tubes keep the surface irrigated from the bottom when there has been no irrigation topside. By tilling or plowing the soil, you break all these capillary tubes and the surface soil can remain dry for weeks until the capillary structure is restored.
Faulkner recommends using a disk harrow to scratch the surface of the soil previously planted with a cover crop like oats. The harrow knocks the cover crop down and breaks it into the top 2 inches of soil. Yes it does break the capillary tubes but only at the 2 inch level. As a replacement for the broken tubes the harrow leaves the green cover crop. The cover has an even greater capillarity than the soil when they are not folded 10 inches below ground (like a regular moldboard plow). The cover crop needs to be somewhat intact right near the surface to get all the benefits.
The benefits include (1) the soil's ability to absorb moisture into the organic matter right near the surface where the new plant roots will be, and (2) the ability of the soil microbes to absorb nitrogen from the air and deposit it into the soil. On this second point, Faulkner acknowledges the idea that inoculated legumes are known to absorb nitrogen but Faulkner claims that other microbes will do the same thing under these no-till circumstances. His evidence is that he has use nonleguminous cover crops for years and harvested record crops from the same fields without any nitrogen added.
_________________ David Hall Moderator Dirt Doctor Lawns Forum
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