Tag Archives: sequester nitrogen

Iowa Study Trumpets Ag Practices to Build Yield, Sustain Profit & Decrease Chemical Use

An Iowa University ag study determined that long rotations is as profitable and more productive for soil and the environment. Yet, the move away from conventional tillage is slow. Here’s part of the article, which you can see entirely by clicking here:

The study was done on land owned by Iowa State University called the Marsden Farm. On 22 acres of it, beginning in 2003, researchers set up three plots: one replicated the typical Midwestern cycle of planting corn one year and then soybeans the next, along with its routine mix of chemicals. On another, they planted a three-year cycle that included oats; the third plot added a four-year cycle and alfalfa. The longer rotations also integrated the raising of livestock, whose manure was used as fertilizer.

The results were stunning: The longer rotations produced better yields of both corn and soy, reduced the need for nitrogen fertilizer and herbicides by up to 88 percent, reduced the amounts of toxins in groundwater 200-fold and didn’t reduce profits by a single cent.

In short, there was only upside — and no downside at all — associated with the longer rotations.

With conventional tillage being the old way and organic representing another way, the author points to this study as “a third path”.

The Marsden Farm study points to a third path. And though critics of this path can be predictably counted on to say it’s moving backward, the increased yields, markedly decreased input of chemicals, reduced energy costs and stable profits tell another story, one of serious progress.

Perhaps most difficult to quantify is that this kind of farming — more thoughtful and less reflexive — requires more walking of the fields, more observations, more applications of fertilizer and chemicals if, when and where they’re needed, rather than on an all-inclusive schedule. “You substitute producer knowledge for blindly using inputs,” Davis says.

So: combine crop rotation, the re-integration of animals into crop production and intelligent farming, and you can use chemicals (to paraphrase the report’s abstract) to fine-tune rather than drive the system, with no loss in performance and in fact the gain of animal products.

Soil and Water Improvements with No-Till and Cover Crops

From No-Till Farmer online, an article about the reduction of nutrients in Chesapeake Bay with conservation ag practices. Note, at the bottom, the finding about cover crop adoption being able to make significant additional contributions.

USDA-NRCS released an assessment of the effects of conservation practices on cultivated cropland in the Chesapeake Bay Region.

The findings of the report were encouraging – with cash incentives, farmers volunteered to protect nearly half of cropland acres with buffers or terraces, while no-tillage was used on 48% and reduced tillage on 40% of cropland.

The adoption of conservation practices resulted in 55% reduction in edge-of field sediment loss, 42% reduction in surface nitrogen losses, 31% reduction of subsurface losses of nitrogen, and 41% reduction in phosphorus losses (both sediment-bound and soluble).

Implementation of the BMPs reduced total loads from all sources (including urban, hay and pasture, urban land) delivered to the Chesapeake Bay by 10% for sediment, 14% for phosphorus and 14% for nitrogen.

The report also recognized there was potential for further improvement, especially on 19% of cropland which was in need of further conservation treatment. The report recommended targeting these areas of highest need, and to help land users implement comprehensive conservation plans which cover soil erosion control and comprehensive nutrient management (including rate, form, timing and method of nutrient application).

The report estimated that only 4% of cropped acres used cover crops in the period of assessment (2003-06). It was estimated that adoption of cover crops on all cropped acres could reduce sediment loss further by 59%, nitrogen loss by 19% (subsurface loss by 31%), and phosphorus loss by 32%.

Mike Plumer Address Oregon Seed Growers about Annual Ryegrass Cover Crop Project

In 1996, Oregon sold perhaps a total of 100,000 pounds of annual ryegrass seed into the Midwest. By that time, the annual ryegrass cover cropping project had been active for almost a decade.But cover crops had not caught on in a big way, even though those early adopters were enthusiastic about the results they were seeing in their soil and their yields.

By the end of 2010, the annual amount had risen to about 5,000,000 pounds. Two years later, that figure has tripled (15 million pounds/year) and by some estimates, that amount could nearly double again next year.

What happened to propel sale of annual ryegrass in the Midwest? Four things, according to Mike Plumer, a pioneering cover crop educator and crop consultant:

  • The government’s heavy subsidy of ethanol fuel production. Beginning in 2008 farmers in the Midwest began to get ahead a few dollars and so they invested in cover crops to boost soil health and yields.
  • Because annual ryegrass had  become a familiar product (because of a decade or more of education, field days, conference presentations, etc.), farmers turned to annual ryegrass for a cover crop alternative.
  • Government promotion of cover crops as an effective conservation measure
  • The drought of 2012 further encouraged cover cropping simply because so many farmers had excess nitrogen in the field and wanted something that would keep it there.

Annual ryegrass was among the most popular cover crops because those who had planted it last fall may have had less crop losses because of the deep rooting.

Mike Plumer 2012 Report on Annual Ryegrass and Other Cover Crops

“Why has there been such an increase in cover crops in recent years?” asked Mike Plumer at the Oregon Seed League meeting yesterday.

  • First, it’s about capturing the nutrients in the field, keeping nutrients from running off during winter and spring months. In a normal year, there can be 90 lb/ac of nitrate available for annual ryegrass or another cover crop to take up. In 2012, because of the drought, there was probably well over 100 lb/ac in many places. With the cost of nitrogen going to $1500 – $2000/ton, it’s easy math to see why cover crops make sense.
  • “Cover crops can double your yields,” Plumer said. Though rare, in a terrible weather year like 2012, there were lots of instances where farmers more than doubled their yields with annual ryegrass and other cover crops. The secret is rooting depth. Without cover crops, corn roots starve out quickly as they hit compacted layers. With annual ryegrass roots penetrating to beyond 6 feet, they allow channels for corn roots to follow.

Plumer’s caution to the group was in terms of cover crop seed quality. “There are about 7 varieties of annual ryegrass that are hardy enough to weather a Midwest winter,” he said. Because of the popularity of annual ryegrass, however, seed provided to unwary Midwest farmers may not be among those seven varieties. Plumer said it would be a tragedy to flood the Midwest with seed that won’t grow well. His advice to buyer’s;  beware…and ask lots of questions about the source and variety of seed. His advice to seed growers: make sure you’re sending us varieties that will withstand Midwest winter conditions.

 

Pioneer of Cover Crops and Annual Ryegrass Talks Dry Year Benefits

Ralph “Junior” Upton (Springerton, IL) began using cover crops (buckwheat and hairy vetch) in the 1980s, mainly to reduce erosion on his hilly acres. In the 90s, he began looking for a cover crop to break up the hardpan soil just below plow depth. “I haven’t got the best soil, so I’ve always been tinkering with how to improve my yield, especially in dry years,” he said.

Working closely with Mike Plumer (a farmer and Univ. IL Extension educator at the time), Upton was among a half dozen Midwest producers who tried annual ryegrass on small plots, planted in the fall after harvest. “I rely on Mike for knowing what to look for in the soil. When I called him out that next April, we were all surprised to find ryegrass roots to 72 inches, with a top growth of only 4 inches,” Upton said. “I had always thought that you only get an inch of roots for every inch of top growth.”

Later that summer, after having killed the ryegrass and then planted corn, he went back to the same field location to see whether the deep ryegrass roots might have impacted the growth of corn roots. “The annual ryegrass opened up small channels that corn roots used to access deeper soil and moisture,” Upton said. Deep rooting has allowed his corn and bean crops to do better in dry years, because the cover crop also took care of the hardpan soil. “There was no longer any restriction to growth,” he added.

This year, having gotten only one rainfall when the corn was knee high, his crop was not as productive as in normal years. Still, with some farmers in his area mowing down their entire acreage, Upton was happy getting an average of 70 bu/ac. and a high of about 130 bu/ac. With temperatures above 100 degrees for weeks, many saw their corn fail to pollinate. Upton wonders whether pollination, in addition to deeper rooting (soil was bone dry to 3 feet), could be impacted by the presence of annual ryegrass.

Dan Towery Recalls the Early Days of Cover Crops

Back in the mid to late 1980s, Dan Towery got enthusiastic about cover crops. “Mainly, we were interested in reducing erosion but we were also looking at nitrogen fixation properties that could benefit corn planted into the residue,” he said.

But then, in the summer of 1988, the drought was much like it was this past summer (2012), and as Towery recalls, the results of “not knowing enough about cover crops” created a multiplier effect in the drought’s impact.”In order to give the hairy vetch the maximum time in the ground, to maximize the nitrogen fixation, farmers left the cover crop in the field until the 3rd week of May, when normal corn planting is the 3rd week of April.

“The vetch sucked too much moisture from the ground and the drought was made worse because of that decision,” Towery said. I said then: ‘I’m not promoting cover crops anymore!'”

But times and attitudes changed with the addition of annual ryegrass as a cover crop alternative in the early 90s.By the late 90s, Towery was working at the Conservation Tillage Information Center, promoting no-till mostly. Early results from Mike Plumer’s work with farmers in Illinois were producing promising results with annual ryegrass.

It wasn’t long before Towery was a believer again. In fact, he was an advisor working with the Nature Conservancy on a watershed enhancement project in Tippecanoe County, Indiana, where farmers were paid to use annual ryegrass to prevent field runoff.

“Look at the change in acceptance since then,” Towery said. “From a time where we paid farmers $500 to plant 10 acres of cover crops  (1998) to now, when we’re experiencing a shortage of annual ryegrass and other cover crop seed, because of the demand.”

Towery said that education has bee a key element in the popularity of cover crops. “And, an important element continues to be the caution about use of cover crops….you have to be willing to be a good manager of the cover crop, no matter which one you choose.”

Annual Ryegrass, Cover Crops in General are the Wave of Ag’s Future

Progressive Farmer magazine published an article by its Ag Policy Editor last week advocating the use of cover crops, especially this year, due to the potential for winter crops to sequester nitrates left in the field from the foreshortened corn crop season.

You can read the whole document here: Advocating for the Soil

Statistics indicate that less than 1% of farmers in the “Upper Mississippi River, Great Lakes and Missouri River basin” were planting cover crops in 2007. My belief, having seen firsthand the growth over the past decade, suggests that the increase in cover crop use since 2007 has absolutely gone off the charts.

I’ve been told that cover crop seed sales (and with annual ryegrass near the top of popular choices) doubled last year (2011) and tripled in the year before that.

Part of the increase has been publicity and the cost-sharing programs rolled out by various governmental agencies. In addition to cover crops being great for soil building, a lot of folks are looking at cover crops as the antidote to hypoxia in various bodies of waters: Chesapeake Bay, the Gulf of Mexico, the Great Lakes and all the rivers feeding those massive bodies of water.

 

Annual Ryegrass IS NOT THE SAME as Cereal Rye

The name “rye” in both cover crops is confusing.  Annual ryegrass is a grass; Cereal rye is a grain, more like wheat.

Both are used for cover crops and forage.

Here are some basic differences, with the most distinctive in bold:

1.                   Annual Ryegrass                                                                         2.      Cereal Rye

Seed size/weight –     very small (26 lb/bu)                                                          larger (56 lb/bu)

Plant date –         varies, but late Aug/early Sept. best                                    can be planted later Sept.

Seeding rate –     drill: 12 – 17 lb/ac; aerial: 25 lb/ac                                               drill: 45 lb/ac.

Winterkill –        med. risk, less with 40 days fall growth and snow cover                          no

Deep rooting –     yes, to 60 inches over a few years                                   not as deep, 24 – 36 inches

Top growth –      10 ” to 12″ in spring, before burndown                    20″ at burndown, can get to 72″

Nitrogen –       sequesters N; releases N after burndown                     sequesters N; too much in stalks

Management –    care in burndown; no volunteers!                         easy kill; careful w/ over growth

Allelopathic –                              no                                                          yes, with certain crop seeds

Cost –              less $/ac. because of low cost/# and fewer #/ac.                higher cost/# and more #/ac

 

Cover Crops, including Annual Ryegrass, Important This Year to Soak Up Residual Nitrates

The University of Wisconsin (UW) published today an invitation for Midwest farmers to use cover crops this year, especially in light of the severe drought. You can see the whole article by clicking here:

An excerpt of the article, by UW staffers Matt Ruark, Kevin Shelley and Francisco Arriaga, as well as Rock County Extension staffer Jim Stute, follows:

With a growing season like we are having in 2012, it is likely that residual nitrate concentrations in the soil will be high, especially if corn was harvested early as silage or if yields are well below expected. One benefit of planting cover crops after corn silage, small grain, or a processing vegetable crop, or after a manure application is that the cover crop can take up residual nitrate and reduce the risk of nitrate leaching between harvest and planting.

Cover crops trap nitrate. The ideal cover crops for a nitrate trap crop are grass crops that establish quickly, such as cereal rye (aka winter rye), oat, barley, annual ryegrass (aka Italian ryegrass), and sorghum-sudangrass. These cover crops also have a fibrous root system. Brassicas (e.g. radish, turnip, mustard) and legumes (clover, hairy vetch) will also take up residual nitrate, but do not establish as quickly. Radish has been popular cover crop in no-till systems and, if planted early enough, radish can take up as much or more N compared to grass cover crops during the winter, but grass cover crops can scavenge N deeper into the soil profile.

The USDA-NRCS has announced additional funding through Environmental Quality Incentive Program (EQIP) to provide financial assistance to establish cover crops. The sign up for this program runs to August 24.

Some Rain, Too Late. Cover Crops May Help Protect Soil, Save Nutrients

The half-inch or so of rain in the Midwest this week has sprouted spirits, although with more warm weather forecast, the prospect for a reversal of fortunes on most corn crops is slim. The worst drought in more than 50 years has farmers mowing starved and stunted corn for sileage and bracing for similar hits with soybeans. (Make sure to check the nitrate levels in the corn stalks before saving it…too high a nitrate level can be fatal to livestock.) Even those able to salvage a corn crop this year will see vastly reduced yields.

Purdue’s Extension forage specialist Keith Johnson today recommended planting annual ryegrass, or another forage crop such as spring oat or forage turnip. Seeded early enough (August), farmers could get a grazing off the grass this fall, as well as next spring. Ryegrass would normally have a better chance of wintering over than oats or turnips.

Perhaps the only “silver lining” in the drought news is that there’s probably a lot of residual fertility in the soil that can be saved by planting a late summer cover crop, according to Nick Bowers, a seed grower in Oregon’s Willamette Valley. The good news with annual ryegrass: it’s inexpensive, it’s a scavenger of excess N in the soil and, even if it doesn’t germinate this fall, it will sprout next spring. If normal rainfall picks up, aerial seeding will be adequate, but drilling is otherwise advised. For more on seeding, check out this page.

Looking for another silver lining? Iowa State University climatologist Owen Taylor said it appears that this weather pattern – similar to 1956 and 1988 – comes in 20 year cycles. It appears, Taylor said, that we’re headed back to a “normal” pattern with an El Nino forming. Keep your fingers crossed.