Even though annual corn and soybean rotations could be diversified without losing an annual cash crop by adding cover crops, few farmers include winter annuals in their rotations.  Singer and Nusser (2007) surveyed farmers in the Corn Belt and found only 18 percent of them had ever used cover crops and that in 2005, those who did planted them on just 6 percent of their farmland.  Fear of yield loss and the extra time constraints were cited as reasons not to use covers.  Research is doing much to reduce and clarify the risks associated with cover crop management in corn and soybean systems (e.g., Miguez and Bollero, 2005.  This, and improvements in planters are making cover cropping a real option for mainstream agriculture.  Over half the farmers Singer and Nusser surveyed indicated they would cover crop if cost-sharing was available. They identified a mean minimum payment price needed to promote adoption of $56.81/ha or $23/ac.  If one multiplies that value by the acres planted to corn and soybean in Illinois and Iowa last year, they’d find it would have cost us a billion dollars to protect the soil.  Hind sight is probably going to tell me and other tax payers this is worth the cost. 

The cost of flood damage in Iowa had topped $1.5 billion last month when the White House asked Congress for nearly 2 billion dollars in emergency disaster aid to address the historic floods.  This was well before water levels peaked.  A financial argument for cover cropping can be strengthened if we accept National Weather Service findings that flood damage estimates typically underestimate costs by an average of 40 percent (Pielke et al. 2002).  Planting cover crops would not have stopped the rains but countless studies indicate their presence would have reduced flooding, leaching and erosion and with this, done much to keep needed nutrients and organic matter where they belonged (eg: Jiang et al. 2008; Kladivko et al. 2004; Gowda et al. 2008). 

The influence that current agricultural practices had on flooding made national news (Achenbach, 2008).  Changes in drainage and hydrology were cited in addition to cropping patterns.  By removing perennials or actively growing plants from the landscape, we have reduced evapotranspiration and increased spring runoff to streams (Zhang and Schilling, 2006).  The argument that crop diversification is needed to help cope with climate change has been met with counter arguments offering up continuous GM corn grown with no-tillage practices as a superior alternative.  The data on organic matter has yet to come in; certainly no one disputes that reduced tillage can reduce erosion. In that scenario, bare or plant-free soil would remain a spring problem. 

It is good we had at least some perennials in place this spring thanks to the CRP program.  Growing plants help cope with water onslaughts by removing and slowing water movement.   CRP lands can also supply emergency feed to livestock.  Release of CRP lands for feed has been approved in the 48 flood-damaged counties in Illinois but, rather than pay them more for this emergency relief, the Farm Service Agency will reduce payments by 25 percent for acreage opened for grazing.  Apparently appreciation for the conservation value of perennials has not gone up as a result of recent floods. As usual, our minds are on our stomachs.  Rising food and energy prices have caused many to look for solutions.  Large scale agriculture seems to be considering more monoculture corn while small scale producers are diversifying markets and crops.

If we can resist over simplifying the challenge of land management to one that pits diverse, tillage and management-intensive farming against simple, input and technology- intensive farming we are likely to make more progress.  As currently practiced, common organic and conventional rotations have different strengths and weaknesses.  It is difficult to compare the two approaches because organic systems use crop rotation and cultural practices to do much more than protect the soil.  Cropping pattern and cultural techniques must also supply and retain nutrients, control weeds, disease, and reduce insect pressure in organic systems.  Imagine the subsidy organic farming systems will provide to mainstream agriculture if we figure this out.  In my experience, maintaining adequate weed control in medium- to fine- textured soils is a bigger challenge for organic growers than building soil quality.

We are always thinking about improving the rotation on our farm where husband Jon Cherniss grows organic vegetables. Soil tests indicate our rotation is maintaining or building organic matter.  I am emphasizing rotation here because we don’t have animals and use very little compost or manure.  We were both impressed by how well our soil stood up to the rains this year as we watched the neighbor’s soil and residue pile up on the road.  We do have tile drainage and offset our environmental guilt with the knowledge that improved tile and carefully managed surface drainage have spared spring crops during three of the past four years.  

Our field of spring brassicas after intense rains.	A neighbor’s field on the same day.  This is (was?) not a waterway.

Our spring crops were planted into fallow ground that followed fall crops.  Getting covers incorporated in time for summer crops was a challenge, but we were lucky with the rains and confess a bit aggressive with the spader.  By adding all the organic matter with tillage, soils resist or quickly recover from any damage.  While we are pleased that spading covers in during spring to prepare beds doesn’t seem to be compromising soil quality, we are concerned that it is exposing us to certain kinds of weed pressure.  Legume covers like hairy vetch or field peas are mowed before incorporation with a spader.

Field peas. Click image for larger photo.	Hairy vetch. Click image for larger photo.

We can use in-row cultivation for some crops but not others and can follow the spring crop with a summer fallow or smothering summer cover.  The presence of a crop or a cover crop prevents us from tilling as much one would want to control thistle.  Time constraints and rain prevent us from tilling frequently enough to control things like purslane so we need to find a way to mulch.  This is why rollers are once again piquing Jon’s interest.  So, even though we are trying to achieve more with rotation than our conventional neighbors, we share an interest in incorporating reduced tillage into our system.  Getting from the mulched phase of a rotation to a clean seed bed ready for spring greens will be another challenge.  So what about a cost share program for organic growers?

The Agricultural Management Assistance Program, authorized by the Federal Crop Insurance Act in 2002 has allocated funds to reimburse producers for organic certification costs.  The new Farm Bill includes $22 million with five years of guaranteed funding to cover up to 75 percent of the cost of certification with maximum annual cost-share eligibility of $750 per farm.  This cost share defrays certification expenses – not organic production costs.  It currently costs growers over $70 an acre to plant hairy vetch. This is what it would cost to apply nitrogen fertilizer at 150 lbs per acre.  So, the diverse rotation turns out to be a deal for the downstream public while organic farmers are substituting effort, land area, and time for purchased inputs. We devote 50% of our land area to soil building crops instead of cash cropping it each year.  Even with this, we are probably too small to make it worthwhile to fill out and apply for a $23 per acre cost share for covers if it were available.  Now paying us back for the price of certified cover crop seed might fit the bill. 

References
Achenbach, J. Iowa Flooding Could Be and Act of Man, Experts Say. June 19, 2008. Washington Post: http://www.washingtonpost.com/wpdyn/content/story/2008/06/19/ST2008061901432.html; and http://blogs.dmregister.com/?author=1894 accessed July 19, 2008.

Gowda P.H., Mulla D.J., Jaynes D.B. 2008. Simulated long-term nitrogen losses for a midwestern agricultural watershed in the United States AGRICULTURAL WATER MANAGEMENT    95 616-624.   

Jiang X.B., Huang C.H., Ruan F.S.  Impacts of land cover changes on runoff and sediment in the Cedar Creek Watershed, St. Joseph River, Indiana, United States 2008. JOURNAL OF MOUNTAIN SCIENCE   5:113-121.   

Kladivko EJ, Frankenberger JR, Jaynes DB, Meek DW, Jenkinson BJ, Fausey NR 2004. Nitrate leaching to subsurface drains as affected by drain spacing and changes in crop production system JOURNAL OF ENVIRONMENTAL QUALITY  33:1803-1813.    

Miguez F.E., Bollero G.A. 2006. Winter cover crops in Illinois: Evaluation of ecophysiological characteristics of corn CROP SCIENCE   Volume: 46:1536-1545.National Agricultural Statistics Service (NASS); http://www.nass.usda.gov/index.asp

Pielke, R.A. Jr. Downton MW., Barnard Miller J.Z.  2002. Flood Damage in the United States, 1926–2000; A Reanalysis of National Weather Service Estimates; NOAA. http://www.flooddamagedata.org/use_interpretation.html; accessed July 2008).

Singer J.W., Nusser, S.M. 2007 Are cover crops being used in the US corn belt?
JOURNAL OF SOIL AND WATER CONSERVATION 62: 353-358.

Zhang YK, Schilling KE 2006. Increasing streamflow and baseflow in Mississippi River since the 1940 s: Effect of land use change JOURNAL OF HYDROLOGY 324:412-422.    

• Western bean cutworm moths are flying in many areas, although numbers are still relatively low in Michigan.
• In corn, milk jug traps help time scouting activities.
• In dry beans, milk jug traps help time insecticide application.

Western bean cutworm trapping with milk jug pheromone traps began several weeks ago, and catches are just starting to pick up in Michigan. So far, moths have been caught (from south to north) in Ingham, Kent, Montcalm, Mecosta, Oceana, Mason and Grand Traverse counties. In general, the number of moths per trap is 1 to 2, but one hot spot in Oceana County caught 28 moths in several days. Based on trapping in 2006 and 2007, expect peak flight to occur the last week of July into early August in Michigan. In comparison—so you don’t freak out—in western states during western bean cutworms outbreaks, hundreds of moths may be captured each night during peak flights. The numbers in Michigan so far are nowhere near that level, but the catches do confirm we now have a resident, overwintering population of western bean cutworms throughout western and central Michigan.

What does the trap catch mean for corn? 

• Managing WBC in corn depends on using the milk jug traps to detect the intensity and timing of peak flight, because most eggs are laid during this time frame. A heavy flight (so far we haven’t seen that) may require checking the traps several times per week or even daily.
• Scouting for eggs and larvae should begin when moths are detected, concentrating particularly on the weeks of peak catch. Moths prefer to lay eggs in fields close to tasselling. The recommendation is to scout several locations per field. With the unevenness of stands this season, that becomes even more important.
• Eggs are laid on the upper leaf surface, higher up in the canopy. They will be round (not flat and shingle-like, like corn borer egg masses) in groups of a few to 200, pearly white at first, then turning purple prior to hatch.
• Tiny larvae first feed in the whorl and on the tassel. As second and third instars they move down to the silks, and then as larger larvae into the ear. Insecticide applications must be timed close to egg hatch and when small larvae are exposed on the tassel and leaf surface.
• The threshold for treatment is 5 percent of plants with egg masses or small larvae. Many bulletins and my MSU Insect Guide (E-1582) give a threshold of 8 percent. However, in discussions this winter with my colleague Tom Hunt from the University of Nebraska, I decided to reduce the threshold this summer to 5 percent (5 of 100 plants with eggs or larvae).
• A special alert to people managing sweet corn—growers tend to have consecutive planting dates of sweet corn, which makes it likely that one or more of the plantings will be attractive to western bean cutworm females. I will let Beth Bishop in MSU’s Vegetable Program develop a recommendation for sweet corn. Check the Vegetable CAT alert for her thoughts.

What does the trap catch mean for dry beans?

• Less information is available for managing western bean cutworms on dry beans, and it is harder to scout for eggs and caterpillars on the plants. Eggs are laid on the underside of dry bean leaves.
• On the plus side, the milk jug trap itself is used to time spray treatments on dry bean. Moth number in a trap is accumulated over time until peak moth flight. This requires checking traps regularly to detect the peak.
• Threshold: If the accumulated catch is between 700 and 1,000 moths, damage risk to beans is moderate and beans must be scouted. Check fields for larvae and larval feeding 10 to 20 days after the peak, and spray if pod feeding is found. If the catch exceeds 1,000 moths by the peak, risk for damage in dry bean is high and an insecticide application is most likely needed 10 to 20 days after peak flight. Obviously so far, we are not near the 700 to 1,000 per trap required to scout dry beans.  

Midwest Organic & Sustainable Education Service (MOSES) is seeking nominations for our 2009 'Organic Farmer of the Year' award. Don't miss this opportunity to acknowledge the outstanding efforts of an organic farmer. As in past years, the award will be presented at the Organic Farming Conference to be held next February 26-28, 2009 in La Crosse, Wisconsin.

Please visit our website for a nomination form and to view a press release with more information. MOSES 2009 Farmer of the Year  (http://www.mosesorganic.org/foy/)

The nomination deadline is September 15, 2008. 

New publication helps understand weed seedbank dynamics

Although there is an old saying that "one year's seeding makes seven years' weeding," farmers don't always pay much attention to the importance of managing weed seedbanks.

The weed seedbank is the reserve of viable weed seeds on and in the soil. The study of seedbanks is a relatively new but promising area of weed science, and a new publication from Montana State University Extension describes the dynamics of seedbanks in a way that can help agricultural producers deal with them.

The seedbank consists of both weed seeds recently shed and older seeds that have persisted in the soil for several years. 

"Not only do these seeds represent a history of past successes and failures in weed management decisions," says Fabian Menalled, Montana State University Extension cropland weeds specialist, "they have the potential to create future weed problems."

MSU will host this year’s soil building workshop in Sears, Michigan. The workshop will be held August 20-21 and  include a tour of Morgan Composting facility, demonstrations of equipment useful to expand operations, educational sessions and trade booths.

Sessions will include understanding organic matter’s roles in production, increasing nitrogen and its availability to crops, balancing the soil for better soil and crops, co-ops that pay off, and market success stories from farmers. Registration by August 15 will be $30/ one day or $50 both days. Later registration will be $40/ one day and $60 both days. Trade booth tables are available for $60.

The online registration system for this year's soil-building workshop is up and running. This is a secure, easy way to register for either or both days of the workshop by check, credit card or MSU account. Visit http://web2.canr.msu.edu/mottgroup/  to access the online registration form.

This event will be held at Morgan Composting in Sears, Michigan, on August 20 and 21 from 9 a.m. to 4:30 p.m. each day. For more information, visit www.MichiganOrganic.msu.edu, or contact Vicki Morrone at sorrone@msu.edu or 517-353-3542.