Andrew McGuire

Ecosystems are Not Smart, We Are – Applications on the Farm

Posted by Andrew McGuire | March 5, 2014
17 species cover crop seed blend

Cover crop seed blend of 17 species

In a recent post, I argued that we should cast aside the ideas of “balance of nature” and “nature knows best” in designing farming systems. If nature has not been optimized by any process that we know of, and therefore consists of mostly random mixes of species dictated primarily by natural disturbances, then there is no reason to “follow nature’s lead.”  But if we don’t, what are we left with? Read more »

Don’t Mimic Nature on the Farm, Improve it

Posted by Andrew McGuire | March 3, 2014

Garden of Eden. Thomas Cole [Public domain], via Wikimedia Commons

Behind many efforts to make agriculture more sustainable is the idea that our farming systems need to be more like nature. According to agroecologist Miguel Alteri, “By designing farming systems that mimic nature, optimal use can be made of sunlight, soil nutrients, and rainfall.” This strategy arises from a long history of thinking that there exists a “balance of nature.” This idea has greatly influenced how we look at nature1 and agriculture. In the latter case, it drives much of what is done in organic farming and agroecology, but also finds its way into no-till farming. Nonetheless, it is false, and because it is false we can abandon the restrictive “nature knows best” argument in designing agricultural systems. Instead, we can improve on nature.

Read more »

How about GMO cover crops?

Posted by Andrew McGuire | January 28, 2014

This post follows Chad Kruger’s introduction to the discussion of GMOs and sustainability.

In a past post, I argued that killing a cover crop with an herbicide was better for building soil than killing it with tillage. Here is another option. Why not develop genetically engineered (GE) cover crops that die easily when sprayed with an innocuous substance? Read more »

Cover the Soil for Quick Benefits

Posted by Andrew McGuire | October 16, 2013

As noted in colleague Chad Kruger’s informative posts about soil carbon sequestration (1, 2), it takes a long time to reap the benefits of building up soil organic matter. There is, however, a quick way to improve the function of your soil; keep it covered with crop residues. Read more »

Forego a Hamburger, Feed a Person

Posted by Andrew McGuire | September 5, 2013

I eat meat. More specifically, I eat feedlot beef from major supermarket chains and generally enjoy it. Nonetheless, the implications of a recent study have me questioning whether I will eat meat in the future. Read more »

Change your crop, change your soil

Posted by Andrew McGuire | August 9, 2013

When I was a college student, almost every ag-related class I took mentioned the benefits of the “rotation effect” (better yields, fewer pests, etc.). However, aside from insect pests, how the “rotation effect” actually worked was always taught in only general terms, especially when it came to rotation effects in the soil. Recently, however, genetic methods are allowing soil scientists to begin to see what happens in the soil when a crop is grown. In their paper, Comparative metatranscriptomics reveals kingdom level changes in the rhizosphere microbiome of plants, Turner et al. describe the genetic tool they used, metatranscriptomics, and how they used it to get an “initial comprehensive picture of the [soil] community structure” in the plant rhizosphere. Read more »

Study Shows Soil-Building Benefits of Manure and Crop Rotation, so why didn’t they say so?

Posted by Andrew McGuire | June 27, 2013

Here is the secret to building soils – manure and diverse crop rotation. Underwhelmed? Researchers in Iowa (Delate et al, 2013) came to this conclusion after conducting ten years of field research. Only this wasn’t their conclusion.

“Iowa State study shows soil-building benefits of organic practices,” reads the headline of the Leopold Center press release on this research. This is misleading for two reasons. Read more »

Are You Micromanaging Your Soil?

Posted by Andrew McGuire | May 21, 2013

mi·cro·man·age: to manage or control with excessive attention to minor details.

As a means to improve soil management, I commend the high interest in soil biology among farmers and gardeners. However, I have noticed the tendency for this interest to be combined with the thought that we should be able to fine-tune our soil biology for the good of our crops, health, sustainability, democracy, justice, and peace.. OK, mostly just crops and soil health, but exaggeration does seem to be rampant when it comes to expectations. The problem is that the idea that we can accurately fine-tune our soils is wrong. Unfortunately, this has not stopped a swarm of salesmen from swooping upon budding soil micromanagers hawking their bio-products. And this is not just at organic farming conferences where biological products are commonplace. I collected this list of products at last year’s Pacific Northwest Vegetable Association conference in Kennewick: Bio Secure, Bio Safe, Bio Innovator, Bio Flora, Bio Generator, Byo Soil, Byo Gon, Bio Forge, Bio Works, Bio Terra Plus, and BioBurst. Read more »

Mixing the Perfect Cover Crop Cocktail

Posted by Andrew McGuire | April 17, 2013

Last November, at the WSU Building Soils for Better Crops conference, farmers from Kansas, North Dakota, and Colorado all spoke on the benefits they were seeing from using multi-species cover crops. These cover crop “cocktails” consist of 8 or more species chosen to maximize diversity. Cocktail mixers aim for at least one entry from each of the following categories: warm season broadleaf species, cool season broadleaf species, warm season grasses and cool season grasses. In addition to the benefits regularly associated with cover crops, farmers using these cocktails often point to increased crop yields and reduced inputs as the reasons they are using them. These cocktails also seem to give rise to a passion not seen in farmers using single-species cover crops.

So, what is going on here? Read more »

No-till Does Not Reverse Soil Degradation?

Posted by Andrew McGuire | March 14, 2013

A recent paper (Olson, 2013) finds a number of long-term studies were wrong about no-till practices building soil organic matter and thus sequestering carbon.  The problem, says Kenneth Olson, soil scientist at the University of Illinois, is how the studies in question measured the gains or losses in soil organic carbon (SOC; organic carbon is about 50% of soil organic matter by weight). According to Olson, these long-term studies made soil carbon measurements during or at the end of the experiments which compared the results of no-till (NT1 in figure 1) to moldboard plowing (MP). They then concluded that carbon was sequestered in the soil under no-till but not in tillage systems. The figure below represents what Olson says these studies measured. Read more »

Filed under Climate Change, Sustainability

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