Elliott, E. T. and Coleman, D. C. 1988. Let the soil work for us - Ecol. Bull. 39: 23-32. Reprinted with Ecological Bulletin permission Abstract: Appropriate management of microbial populations in soil can reduce leakage of excess nutrients from the rooting zone and enhance the fertilizer use efficiency and agroecosystem production. Manipulation of the microbial habitat by varying residue and tillage management is an effective and practicable way to manage soil microorganisms. Aggregation, pore space and preferential flow are strongly influenced by cultivation. The architecture of the soil structure can determine the habitability for soil microorganisms and nutrient fluxes through agroecosystems. Soil organic matter availability to microorganisms is related to its position within the soil matrix. A simple hierarchical model for soil aggregation can explain many aspects of changes in soil organic matter aggradation and degradation. Likewise, four hierarchical pore categories are presented which relate to the aggregate structure of the soil and provide a basis for predicting how soil pore networks influence ecological relationships among organisms in soil detrital food webs. Macroporosity is sensitive to variations in cultivation practices and can increase under no-till management. Less leaching of nitrate was observed in no-till experimental plots. This was related to increased infiltration rates and preferential flow of incoming nitrate-free rain water down large pores; this effectively bypasses or short circuits the nitrate in the surface soil layers. Where soils were tilled, the water moved down the profile more slowly and subsequently transported more nitrate deeper. Greater macroporosity and a responsive microbial community can be used to provide more efficient management of agroecosystems. Establishment of a new steady state for soils put under no-till cultivation may take as long as a decade in temperate climates.
E. T. Elliott, Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, U.S.A. D. C. Coleman, Dept of Entomology and Institute of Ecology, Univ. of Georgia, Athens, GA 30602, U.S.A. Read on: Let The Soil Work For Us Soil Quality, Soil Health
Q. Are feedlot manures okay to use on organic farms?
The Canadian Organic Standards requires producers to use manure from their own farm first, manure from other organic operations second, followed by manures from mainstream operations as a last option - but those are limited to all but veal crate or hog barns where farrowing crates are in full use. Additionally, producers must also be able to substantiate that manure or compost made from off-farm non-organic operations does not contain any materials prohibited in the standard (Read “When do I need to hot compost?” for further insights on this topic). Growers should also consider that manures are not the be-all and end-all, and that complete success can be had with green manure crops, application of compost (from compliant sources) and organic meals and minerals. As an example of nutrients available in local plants, please note that while cow manure averages at 11-3-9, Canada thistle measures in at 54-13-82. (from The Fertile Soil, by Robert Parnes
Q. Is one sterilized soil mix advised over the other if I want to conform to Canadian organic standards for my seedlings? Although sterilized, store-bought soil blends are widely advertised as absolutely necessary to robust seed starting, we certainly have healthy alternatives outside our own doors. As a matter of fact, the high content of vermiculite, perlite and peatmoss in most purchased blends displaces nutrient rich soil. And obviously, helpful microorganisms cannot live through the sterilization process, so these purchased soils, while initially free of pathogens, insects and weed seeds, could also be considered “inert”. And natural soil contains its own fungicides, which sterilized soils do not. Starts growing in natural soil are far less likely to develop damping off disease because of this. Weed seeds are a problem and hot composting can help this. Make sure all visible insects are removed before planting. Save some money, save a trip to the store, and reduce your carbon footprint!
The opening paragraph from Chris Wells's Managing Cover Crops on a Small Scale No-till Farm article:
"I tend to talk a lot about no-till soil management in a casual way. But it seems that I often get less than casual reactions from people when I do. One question I often get is in dealing with cover crops and turning them in. Discussing no-till farming in relation to cover crops is a great way to communicate the principles of no-till farming, as cover crops likely post the biggest challenge to the no-till concept. I would like to take you through the process I use to deal with cover crops and carry that on to give you a look at the life-cycle of a no-till farming system. But first, a short introduction to no-till farming." Click here to read the rest of the article.
Yeomans Keyline Plow: a view rarely seen of this implement in operation.