Category Archives: Soil Quality

Cover Crops and Carbon Sequestration

The recent Climate conference in Paris included talk about cover crops and carbon sequestration. With a buildup of carbon dioxide in the atmosphere, scientists are looking at ways to improve the soil’s capacity to regain some of what it has lost to cultivation and oxidation. Here’s a section of an article from an agronomist at Yale University, speaking about work that Ohio State’s Rattan Lal has done.

According to Rattan Lal, director of Ohio State University’s Carbon Management and Sequestration Center, the world’s cultivated soils have lost between 50 and 70 percent of their original carbon stock, much of which has oxidized upon exposure to air to become CO2. Now, armed with rapidly expanding knowledge about carbon sequestration in soils, researchers are studying how land restoration programs in places like the former North American prairie, the North China Plain, and even the parched interior of Australia might help put carbon back into the soil. 

Dan Towery said that cover crops have lots of promise, bringing carbon back into and storing it in the soil. But, he added that no-till and cover cropping are still new, and gains by one farmer who steadfastly improves the carbon base can quickly be lost again. “All it takes is one tillage trip to lose about 90 percent of what you’ve gained in a decade of cover crops and no-till,” he said. The carbon, even after a decade, isn’t much deeper than two inches. And, there’s no guarantee that, with the sale or rental of that farm, successive farmers will continue to abide with that practice.

So, the idea of paying people to sequester carbon will have to wait some time, he said, until the management practices have settled firmly on the side of conservation tillage.

 

NRCS Funds Expanded Use of Cover Crops

From No-Till Magazine’s managing editor this week, an article about expanded use of federal taxpayer funds for establishing agricultural conservation measures. Click here for the whole article. Below, a portion of that article.

It’s becoming ever more clear that the NRCS believes no-tilling, cover crops and more precise grazing methods will be crucial to shoring up the declining Ogallala aquifer.

And it’s also clear farmers in the southern Plains will continue to feel pressure to reduce or eliminate their dependence on irrigation, or adopt more efficient technology.

The NRCS announced this month that it will invest $8 million in the ongoing Ogallala Aquifer Initiative (OEI) in 2016 to help farmers and ranchers conserve water in the Ogallala’s footprint. This is up from $6.5 million that was spent for 2015.

The NRCS is also adding two new management areas for the OEI:

  • Middle Republican Natural Resource District: The project in southwestern Nebraska addresses groundwater quantity and quality concerns, and will enable participants to voluntarily implement practices to conserve irrigation water and improve groundwater quality.
  • Oklahoma Ogallala Aquifer Initiative: Among other things, this project will help landowners implement conservation practices — including crop residue and tillage management — that decrease water use. One goal is helping farmers convert from irrigated to dryland farming.

The NRCS already has focus areas in Nebraska, New Mexico, Texas, Kansas and Colorado, which you can read more about by clicking here.

The NRCS says it’s continuing to address problems with the aquifer by working with farmers to build soil health through seeding cover crops and implementing no-till practices, which will improve water-holding capacity and buffer roots from higher temperatures.

Good News and More News about Cover Crops

Climate Change photoIn next week’s UN Climate Change Conference, cover crops won’t be center stage but certainly will be part of the mix of popular go-to strategies for long-term global health.

Cover crops, including the ever-popular annual ryegrass, continue to gain credibility as a low cost boost for soil, water and air quality. Reducing runoff from agricultural fields, cover crops can help to improve Earth’s water quality. In the US, cover crops are already showing their value in reducing the problems in Chesapeake Bay, the Great Lakes and the Gulf of Mexico.

In addition, cover crops including annual ryegrass and crimson clover are seen as crucial allies in reducing the need for extra nitrogen in mono-crop systems like corn and soybeans. By sequestering (annual ryegrass) or fixing (clover) nitrogen in the soil, cover crops save money while not sacrificing production.

Whatever comes out of the Conference in Paris will be good news for those adopting new conservation strategies including cover crops. Whether good practices like cover crops are further incentivized or regulated, their use will be good for agriculture and good for the health of the planet.

Farmers increasing cover-crop use

The annual report from the CTIC (Conservation Technology Info Center) published recently is more good news for the soil, the planet and the farmers who employ the cover crop technique. (Click here for the full report, including graphs). The news was reported by www.Agriview.com.

Here’s a paragraph outlining the gains being seen in the Midwest.

“Cover crops are growing in popularity by leaps and bounds among farmers. A recent survey of more than 1,200 growers throughout the United States showed cover crops boosted corn yields in 2014 by an average of 3.66 bushels per acre, or 2.1 percent, and soybean yields by 2.19 bushels or 4.2 percent. Last year was the third-consecutive year that yield boosts from cover crops were recorded by the Conservation Technology Information Center, a public-private partnership in West Lafayette, Indiana.”

“The 2015 survey also recorded a fifth year of steady increase in the average number of acres planted to cover crops by survey respondents, at almost 374,000 acres this year. The average number of cover-crop acres per farm in the annual surveys has nearly tripled over the past five years. The average cover-crop acreage per respondent planting a cover crop was 300 acres in 2015.”

From 1200 respondents, the survey determined that cereal rye and annual ryegrass are still the top cover crop seeds used. Here’s the breakout of use reported by farmers:

“Among cover-crop species, cereal grains and grasses are most popular, planted by 84 percent of cover-crop users. Cereal rye accounted for 44 percent of the total cover-crop acres in 2015. Annual ryegrass was a distant second with about half cereal rye’s acreage. Oats was third, covering 17 percent of respondents’ land in 2015. Triticale and winter barley rounded out the top-five cereal grains and grasses.”

It also appears that brassicas, including radish, turnips, rapeseed and canola, continue to gain in use, especially as the practice of seeding four or more cover crop species together in a mix continues to increase.

Interestingly, the top reason farmers cited use of cover crops was because it aids the improvement of soil health. The CTIC had assumed previously that the main reason was because it improved the chances of better production and, thus, profit.

Field Day for Cover Crops in Illinois

MO-Matt-Volkman-NRCS-ARG-field-shot.jpgA cover crop field day has been scheduled at two locations in Illinois’ Coe Township, convened by the Rock Island Soil & Water Conservation District.(See below for specifics)

According to an article in the Dispatch-Argus paper in Moline, IL, cover crops continue to prove their value, both in building soil health and improving profits for growers. Here’s a segment of the article (if you want to read the whole thing, click here)

“Cover crops lengthen the growing season of live plant material with many winter annual species like winter wheat, cereal rye and annual ryegrass maintaining live root systems under the soil surface during the winter months providing food for soil microbes to stay active.  Currently, idle crop fields become biological deserts in which soil microbes reduce in population with limited food resources.  Some covers like cereal rye and annual ryegrass also provide biological weed control in crop fields during the early portion of the growing season.  This helps reduce the amount of pesticides that need to be used.”

“Those benefits include reduced soil erosion, enhancement of soil biology through increased microbial activity and the development of higher organic levels, improved water quality from reduced run-off along with the capture of un-used phosphorus and nitrogen making those nutrients available for the next cropping season.”

Location of the field days:

Wed. Nov 5th – DePauw farm, located at 122nd Ave N, in Port Byron, IL.

Thurs. Nov. 6th. – the Anderson Farm located ½ mile east of Sherrard High School or west of the junction of 176th Ave W and 63rd St. W.

For more information and reservations call the Rock Island SWCD office at (309) 764-1486 ext. 3.

Annual Ryegrass Roots – What’s Going on There?

Pioneering cover crop use in the 1990s, University of Illinois Extension educator Mike Plumer discovered something that surprised everybody. Annual ryegrass has a root structure that grows to depths of more than five feet over winter, while the top growth is pretty much dormant.

One of annual ryegrass’ most compelling features is that deep rooting system, because it breaks up compaction of all kinds, and in doing so, it also helps bring nutrients deeper in the soil profile up to the surface. This not only helps crops thrive, it also reduces the amount of nutrient inputs needed.

So, it’s unclear why Cornell and Michigan State universities still have printed information about annual ryegrass stating that annual ryegrass has “a shallow” rooting system.

In fact, the plant DOES have a shallow root mass, which makes  it valuable for preventing erosion. But what they don’t say is that annual ryegrass roots also grow to depths of five feet. And this is equally important, for reasons stated above.

In sum, the combined root mass of annual ryegrass also provide another benefit: helping to build organic matter in depleted soils. Once the plant is terminated, in springtime just before planting corn or soybeans, all that root matter decays and becomes the basis for a healthy population of microorganisms and a more friable soil.

 

soil pit2

 

(In the photo above, growers are inspecting deep channels created by annual ryegrass roots, which allow corn roots more penetration into the soil following those same channels. Thus, corn plants can better tolerate dry weather because they can reach deeper into soil for needed moisture.)

Plumer said that because of long-term tillage practices, plus tiling fields for drainage and not planting cover crops, Midwest soils have lost half or more of their organic matter. The good news is that for every additional percentage point of organic matter you can add back into the soil, you’re adding back about 1000 pounds of nitrogen per acre!

Annual ryegrass and other cover crops help to raise the organic level back up, though it takes years of consistent cover crop use to make up for the decades of less productive management methods including heavy tillage.

Cover Crops and Grazing in Your Future?

A Pennsylvania Extension educator has shown that intensive grazing on cropland low in organic matter can rebuild the soil quickly – in a matter of a few years in some cases. The cover crop and grazing practice also led to a “drastic increase in cation exchange capacity and water holding capacity of the soil,” according to the author, Sjoerd Duiker. (Read the article by clicking here).

Cation exchange capacity (CEC) refers to the soil’s capability to store and then provide certain nutrients, like calcium and magnesium, to crops grown on the soil. While soil types tend to dictate a CEC range, building soil organic matter greatly increases the capacity for cation exchange. That, in turn, determines the productivity of the soil and how much fertilizer you need to add.

Duiker said he sees potential for increased profitably by bringing grazing animals back on the croplands in the US. Crop and livestock experts he talked to advised combining nighttime-grazing and daytime stall feeding to allow for continued high milk production (75 lbs/day).

In terms of cover crop varieties used, Duiker mentioned annual ryegrass mixed with triticale for fall and spring forage and other crops like tillering corn, sudangrass, sorghum-sudangrass hybrids and forage soybeans, cowpeas, brassicas and sunnhemp for the rest of the year. He said that perennials are “tremendous soil builders and the annuals add benefits such as meeting forage needs during the summer slump when the weather is hot and dry as well as in late fall, and are a break crop between an old and new perennial pasture stands.”

Annual Ryegrass – Part of a “Sustainable” Soil Future

SARE: Sustainable Agriculture Research and EducationIf you want to build soil without investing much in a cover crop, consider annual ryegrass. A quick-growing, non-spreading bunch grass, annual ryegrass is a reliable, versatile performer almost anywhere, assuming adequate moisture and fertility. It does a fine job of holding soil, taking up excess N and outcompeting weeds.

Ryegrass is an excellent choice for building soil structure in orchards, vineyards and other cropland to enhance water infiltration, water-holding capacity or irrigation efficiency. It can reduce soil splash on solanaceous crops and small fruit crops, decreasing disease and increasing forage quality. You also can overseed ryegrass readily into corn, soybeans and many high-value crops.

Cover Crops in a Semi-Desert? Seems so!

Midvale, Nevada receives less than 5 inches of rain annually. The Klein’s have started a no-till and cover crop experiment that they hope will ultimately do three things:

  • increase organic matter
  • reduce the need for irrigation
  • add substance and permeability to light, compacted soil

Click here for the full article, in No-Till Farmer.

KLEIN3.jpeg

In their first year of cover crop trials, 2013, the first-generation family operation (sugar beets,alfalfa, malt barley, beet seed, sheep and bees) planted a blend of cover crops, in June, to an acre parcel  on the edge of a center-pivot irrigation system.

The mix contained forage corn, sunflowers, sorghum, buckwheat, radishes, turnips, kale and some additional plant species. He seeded it at about 40 pounds per acre and then incorporated it with a harrow.

One thing that surprised them: the cover crop plants dominated other annual weeds and thrived, well into the fall, even after the first frosts. The second surprise: even after that one year, the soil in the acre of cover crop was “much more mellow.” And their sheep found the new crop tasty, which gave the Klein’s another possible source for supplemental forage value.

While tillage seems advantageous in the first year of cover crop planting, the type of equipment can be less aggressive. Eventually, the benefits to the soil will preclude the need for tillage, and far less water, they believe.

“The carrot at the end of that stick is better water infiltration and water-holding capacity. We have a gut feeling we’ll need less irrigation as soil quality improves, although it’s too early to confirm that,” said Richard Klein.

In 2014, the Klein’s planted five fields in cover crops, the largest of which was about 18 acres. By staggering the planting dates and using a GPS, they were better able to determine the best time to plant. This spring, they saw another benefit: the cover crop residue has reduced the impact of frequent seasonal wind storms on soil loss.