The toxic algae and No-Till-The environmental Darling industrial agriculture and genetic engineering is less attractive :
Read attempts to defend the sustainability of industrial agriculture and genetic engineering, and you soon find yourself without tillage, or more generally, conservation tillage. It now appears that tillage can contribute to serious environmental problems.
Massive algal bloom, green, spreading across Lake Erie. NASA photo.
Tillage or tillage, is the ancient practice of turning the soil to kill weeds or incorporating plant material or manure. Tillage but often leads to increased soil erosion and loss of fertility. Erosion also contributes to the settling of phosphorus flows carrying the ground, a major cause of contamination of fresh water. So conservation tillage and direct seeding, in particular, have some real benefits, especially for industrial agriculture, which depletes soil fertility.
And soil fertility, in turn, is vital to ensure the productivity and resilience of crops.
We know that, while providing some real benefits, conservation tillage also has important limitations compared with agroecological approaches that reduce erosion, such as the growth of cover crops. Cover crops are grown to protect the soil in crops like maize are not present in the fall, winter and spring. They not only greatly reduce erosion and improve soil fertility, but also substantially reduce nitrogen loss caused by water pollution, such as dead zones in coastal areas. They can also suppress weeds and other pests, and reduce the need for synthetic fertilizers and pesticides. Conservation tillage provides none of these other benefits.
Another possible benefit of conservation tillage, the largest carbon capture is unproven. There may be providing some additional carbon capture some types of soils and climates compared to conventional tillage, but that remains to be seen. Furthermore, organic and related methods may not reliably increase soil carbon sequestration.
Toxic Slime
And now, new research reveals a darker side of the till, which can actually aggravate phosphorus pollution of waterways.
I grew up in Michigan, the heart of the Great Lakes region. These lakes, the largest in the world, are a wonder of nature that are more like freshwater seas. The lakes are an excellent resource for recreation, from swimming to fishing to boating. The Great Lakes have also had important commercial fisheries whitefish and other species. There has even been the Great Lakes cruises. The presence of lakes, including the smaller lakes in the region that extends from the Canadian prairies of the Midwest through upstate New York, greatly improves the quality of life and supports tourism.
He learns that the green slime cyanobacteria (sometimes called blue-green algae) was back with a vengeance was a shock. Efforts to reduce phosphorus plant wastewater treatment and laundry detergents in the 60s and 70s led to one of the real successes of the environmental movement. Lake Erie is particularly susceptible because they are relatively shallow. But in general are vulnerable lakes, smaller lakes and reservoirs, possibly even more. So although detected in Lake Erie, also happening elsewhere. For example, Lake Winnipeg, a large lake in Canada, is also seeing increasing eutrophication.
And the problems go beyond an eyesore cause odors or missing or fish kills. Two major species of cyanobacterial neurotoxins liver or products, found in the lake to alarming levels.
Lake Erie algal bloom of 2011 set records, reaching nearly 5,000 square miles, or about 3 times that of the next largest flowering. However, records show that algal blooms have increased since the mid-1990s, after several decades of progress.
What happened? Why the drive towards cleaner water reversed?
Direct seeding and climate change: a bad combination
The increase in harmful algal blooms coincides with the increasing use of direct seeding in the corn belt. It turns out that no-till, apply phosphorus fertilizer and phosphorus in manure is concentrated in the topsoil. Although direct seeding reduces runoff and soil erosion, which leads phosphorus bound to soil particles into waterways, resulting high concentration of phosphorus in the soil surface leads to runoff dissolved reactive phosphorus. Algal blooms resulting from this are compounded by heavy rains, which wash more phosphorus in the lake, which is expected to be more frequent in the region as global warming progresses.
Besides that, the phosphorus may become scarce in the future. Large deposits are found in only a few locations worldwide. Therefore, the loss of phosphorus from agricultural soils is also a waste of a valuable resource.
Tillage may occasionally help alleviate this problem, by burying the match. But it is clear that many forms of farming, such as the use of chisel plows cultivators or not invert the soil, or methods such as tillage or ridge rotation until, and so on, will address the problem effectively. And the data are scarce on whether the other benefits of direct seeding also be reduced in the process. Furthermore, most of the maize area still do not use direct seeding or conservation tillage, so it is possible that greater adoption could make things worse.
One lesson from this is that reductionist approaches to environmental problems that almost focus on solving a problem, such as soil erosion, without understanding the agricultural ecosystem are vulnerable to lack of harmful unintended consequences. Direct seeding is a valuable practice in some aspects, but as used in industrial agriculture, which relies on heavy use of herbicides, which causes its damage to agroecosystems, such as loss of habitat of the monarch butterfly, bees and other beneficial organisms.
It is also important to remember that other agro-based practices such as cover crops can achieve the benefits of direct seeding and more. Not only that, but no-till organic can also be practiced without the use of herbicides.
But it is no coincidence that the industry no-till has been a popular practice as a rhetorical tool ag community and industry. Fits the highly simplified and unsustainable system that big ag industry wants to keep. It is one of the few large ag practices that can promote that has some environmental benefits. And unlike agroecology, which depends on the products purchased expensive. That's good for the profitability of the industry, but not so good for the rest of us.
Posted in: Agriculture & Food Tags: agriculture, climate change, cover crops, genetic engineering, GMO, industrial agriculture, Lake Erie, phosphorus, sustainable agriculture, toxic algae, water pollution
About the author: Doug Gurian-Sherman is a widely cited expert on biotechnology and sustainable agriculture. He holds a Ph.D. in plant pathology. Subscribe to entries Doug
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