Stay the course: Corn-soybean rotation still the best option

Too often the soil will dry to the depth of tillage. An average silt loam soil holds about 2 inches of plant available soil moisture per foot of soil. Tilling 6 inches deep and allowing the soil to dry to the depth of tillage could result in a loss of up to 1 inch of soil moisture with each trip. Shallower tillage, even row crop cultivation, can still result in moisture losses of about ˝ inch. By not tilling or cultivating, you can minimize these moisture losses.

Water issues This week's Market Journal, Cooperative Extension's Television for Ag Business Decisions, focuses on Nebraska water issues. Watch or listen using RealPlayer as host and Agricultural Economics Specialist Doug Jose visits with water use and policy experts. Ag Policy: Irrigation Water (Length 3:36) Dave Aiken, NU Extension Water and Ag Law Specialist, discusses progress made with laws regarding groundwater and surface water irrigation. watch | listen Maximum Profits and Efficient Water Use (Length 8:23) Ray Supalla, Professor of Agricultural Economics, and Scott Nedved, Agricultural Economics Research Associate, discuss a new computer model that would allow producers to generate maximum profits while being efficient with the available water. watch | listen

Soil water conservation

Greater yet are the soil moisture losses from evaporation once tillage destroys residue cover. The residue mulch reduces evaporation in several ways: by reducing solar heating of the soil, by keeping drying winds off the soil surface, by insulating the soil to keep it cooler, and by intercepting some of the water as it evaporates. Research has shown that the residue mulch can reduce water losses from evaporation by as much as 3 to 5 inches during the season. This can mean as much as 25 to 50 extra bushels of corn per acre in dryland production or greatly reduced watering costs in irrigated production, about $14 to $23 less per acre.

Erosion control

While flattened residue makes a better mulch, leaving standing residue until planting is preferred for crop production. Standing residue that is anchored to the soil is more effective in blocking wind from the soil surface, reducing wind blown soil losses and the dust storms common in the spring. In addition, anchored standing residue doesn’t have to be cut or handled during fertilizing or planting and is far less likely to move with the wind, surface water runoff, or during furrow irrigation. Unlike a flattened mat of residue which may keep the soil surface too cold and wet for planting, the air movement among the standing residue allows more timely field operations while maintaining the benefits of the residue.

Mythbusters

While some say “the soil needs to be tilled to open it up to let water in,” unfortunately the soil often dries to the depth of tillage so the initial water let into the soil just replaces what was lost with tillage rather than adding to the soil moisture reserve. Tillage breaks up and pulverizes the soil surface, destroying residue cover and making the soil prone to crusting from raindrop impact. Tillage actually creates a condition that seals the soil, resulting in more runoff and less effective rainfall or irrigation. With residue, the raindrop impact is absorbed and erosion is reduced. The residue also slows the runoff allowing more time for infiltration.

Another reason sometimes given for tillage is that “the field has to be tilled to dry out wet soil or a wet spot.” Driving on or tilling a wet soil is the major source of compaction. The wet soil particles are lubricated such that they slide below the weight of tillage implement, causing compaction. While the surface may dry out, the tillage itself compacts the soil below the tilled layer, slowing infiltration and making the soil surface stay wetter next time. With less water infiltrating into the soil and some compaction restricting root growth, those tilled wet spots are often the first areas in the field to show moisture stress during hot dry weather.

Reduced input costs

Higher fuel costs — about 30% more this year — also are a factor when considering reducing tillage. The diesel fuel requirements for the typical disk-disk-field cultivate tillage system is about 3.77 gallons per acre including knifing in fertilizer, planting, and one row crop cultivation. By switching to a no-till system, the fuel use decreases to about 1.43 gallons per acre including knifing in fertilizer, planting, and two sprayings. Decreasing the tillage results in a corresponding decrease in labor and improves the timeliness of other field operations.

However, the fuel cost is a small percentage of the total tillage cost when fixed costs, depreciation, repairs, maintenance, and labor are included. For instance, the typical custom rate for disking is about $8 an acre and requires about 3/4 gallon of diesel fuel. Even if farm fuel prices doubled from $1 per gallon to $2 per gallon, the custom rate for disking would only go up $0.75 an acre, less than a 10% increase.

While switching from a disk-disk-field cultivate system to no-till would save 2.34 gallons of fuel, the reduction of tillage costs would be much greater -- more than $22 an acre, based on custom rates. This added to the savings of 3 to 5 inches of soil moisture makes switching to no-till a wise management decision. The improved soil structure, reduction in erosion, and opportunity for more timely field operations add even more benefits when no-till is properly managed.

Paul Jasa
Extension Engineer

This week the Panhandle and southwest Nebraska continue in a severe drought with much of the rest of the state sustaining moderate drought to abnormally dry conditions. See the U.S. Drought Monitor map for more details (Map provided by the National Drought Mitigation Center at the University of Nebraska-Lincoln, in cooperation with USDA.)

As with past Bt corn hybrids, insect resistance management (IRM) will be required of farmers who grow YieldGard Rootworm corn. Although the IRM program is similar to those for earlier Bt corns that targeted European corn borer, there are some significant differences. This only makes sense since the biology of the corn rootworm is very different from that of the European corn borer.

Resistance management:
YieldGard rootworm corn

The resistance management requirements for YieldGard Rootworm corn are:

1. Growers must plant a structured refuge of at least 20% non-YieldGard Rootworm corn that may be treated with insecticides as needed to control corn rootworm larvae. Growers will not be permitted to apply insecticides labeled for corn rootworm to the refuge for control of insect pests while adult corn rootworm are present unless the YieldGard Rootworm field is treated similarly. Refuge acres should be planted as blocks in or adjacent to YieldGard Rootworm cornfields or as in-field strips.
2. External refuges must be planted adjacent to YieldGard Rootworm fields.
3. When planting the refuge in strips across a field, refuges must be at least six rows wide, preferably 12 consecutive rows wide.
4. In addition, the refuge must be planted in similar ground as the YieldGard Rootworm corn. If the YieldGard is planted in ground that was in corn the previous year, the refuge must be planted in ground previously planted to corn. General management of the YieldGard Rootworm corn and the refuge should be similar.

Figure 1 shows that the southeastern third of the state has received more than 4 inches of moisture from October 1, 2004 to February 27, 2005. Most of this moisture came in the last 30 days. The northwestern two-thirds of the state had 2-4 inches of precipitation during that five-month period, with most of it in October-November 2004.

Since Nebraska generally receives only 7% of its annual precipitation from December to February, it’s helpful to look at moisture in terms of percent of normal (Figure 2). First, the Panhandle, southwest, south central, central, and east central portions of Nebraska had above normal moisture during the five-month period. Drier than normal conditions occurred in the Sandhills, northeast, and southeast. Even with the heavy moisture across southeastern Nebraska during the last 30 days, this area remains in a moisture deficit due to the extremely dry fall.

Why am I keying in on the period from October 1 to this week? Fall and spring soil moisture recharge gives us an idea of the potential risk producers face as they enter the production season. Dryland corn producers in eastern Nebraska should be able to expect 11.5-12.0 inches of moisture from October 1 to April 30. Studies have found that if this occurs along with normal growing season moisture, average corn yields can be expected. For each inch shy of 12 inches, coupled with normal growing season moisture, dryland corn yields can be expected to drop 2.5%-3.0%.

Because water supplies are tight or non-existent for gravity fed irrigation across western Nebraska, above normal fall and spring moisture can help offset the loss of growing season irrigation. It also can provide a valuable moisture base for seed germination and early root development. For center pivot operators, above normal off-season moisture can help reduce summer applications and lower fuel costs as long as normal growing weather is observed.

Research was conducted in the early 1990s at Mead on the effective rate of off-season soil moisture recharge on fields not receiving fall tillage. An average of 70% of the precipitation was effective; 30% was lost to evaporation or runoff. The variance of moisture recharge ranged from 60%-80%, with the lower values observed when soils froze up before December 1.

Applying the 70% effective precipitation rate to the moisture received from October 1, 2004 through Feb. 27, 2005, Figure 3 was created. The western Sandhills have the smallest estimated soil moisture recharge with an average of 1.5-2.0 inches, while the remaining western two-thirds of the state has 2-3 inches of soil moisture recharge. Most of the southeastern third of the state has an estimated 3.0-4.5 inches of soil moisture recharge, except for the I-80 corridor between Lincoln and Omaha which shows 4.5-5.0 inches of recharge.

How do these estimates stack up against normal expectations? Figure 4 shows the difference between recharge based on normal precipitation and the current recharge season. Positive values indicate recharge is ahead of normal, while negative values indicate recharge is lagging. Soil moisture deficits approaching 1.5 inches are evident across the central Sandhills, while most of northeast and southeast Nebraska have deficits under an inch. Surplus moisture is present across the remainder of the state, with amounts between 0.5-1.0 inches indicated across the northern Panhandle, south central, central, and western parts of east central Nebraska.

With two months left in the off-season recharge period, what is the likelihood of normal recharge by May 1? The last 100 years of March-April precipitation data were added to moisture received during the previous five-month period to see what the odds are that there will be normal recharge by May 1. The lowest odds for normal recharge were found to occur across the Sandhills, with a 25-40% likelihood of achieving full recharge. For northeast and southeast Nebraska, there is a 40-55% chance, while the remainder of the state falls in the 55-70% range.

Soil moisture levels were much better at this point last spring across northeast and southeast Nebraska; however, if northeast and southeast Nebraska see 120% of normal precipitation in the next 60 days, the recharge season deficits will be eliminated. Although soil moisture recharge looks more promising across western Nebraska in comparison to the last few years, long-term hydrological drought issues have not been resolved.

Critical snowpack data and streamflow projections will be released in early March and should tell us more about how severe water restrictions are likely to be for Platte River irrigators. A summary of these reports will appear in an upcoming issue of CropWatch.

Al Dutcher
Extension State Climatologist

Producers have several new options to consider when buying crop insurance before the March 15 deadline for spring planted 2005 crops.

Revenue Assurance or Crop Revenue Coverage

Revenue Assurance (RA) was available for the first time in Nebraska in 2004. There are three differences between Revenue Assurance and Crop Revenue Coverage (CRC). The basic revenue assurance contract has only one price: the price established in February. The harvest price is not part of the basic contract; however, the “harvest price option” is available for RA insurance, making it almost the same as CRC.

The “almost” qualifier is that the harvest price for RA is determined from the December Chicago Board of Trade (CBOT) contract during November rather than in October as with the CRC. The “whole farm” option is available for RA but not CRC and coverage levels below 65% are not available for RA. A key consideration in choosing CRC or RA is the premium rates.

Prices for 2005 The prices established by the Risk Management Agency (RMA) to calculate the premiums and indemnities for the standard APH/MPCI program for 2005 are: Corn $2.20 per bu. Grain Sorghum $2.15 per bu. Soybeans $5.00 per bu. The spring base prices for Crop Revenue Coverage (CRC) and Revenue Assurance (RA) are the averages of the closing prices during February for the December and November CBOT contracts for corn and soybeans, respectively. The unofficial prices for this year are: Corn $2.31 per bu Soybeans $5.58 per bu

Recommendations

1. Only consider RA with the harvest price option.
2. Buy the cheapest policy for your county.
3. Chart the December contract for corn and November contract for soybeans during February and begin planning forward pricing strategies if you plan to buy either revenue policy.

The GRIP program is being offered for the first time in 2005 in Nebraska. GRIP is an area-based revenue insurance product that pays the insured in the event a county average per acre revenue falls below the insured’s county “trigger revenue.” GRIP is similar to GRP in that participation is driven by the relationship of individual yield to the county expected yield, except that price is added into the equation.

Coverage levels are the same as for GRP, 70% to 90% in 5% increments.

GRIP Prices for Corn

Expected: Average of the final closing prices for the last five trading days in February for the CBOT December corn futures contract for the current crop year.

Harvest: Average of the final closing prices in November for the CBOT December corn futures contract.

GRIP Prices for Soybeans

Expected: Average of the final closing prices for the last five trading days in February for the CBOT November soybean futures contract for the current crop year.

Harvest: Average of the final closing prices in October for the CBOT November soybean futures contract.

GRIP Prices for Grain Sorghum

Expected: Average of the final closing prices for the month of February for the CBOT December corn futures contract for the current crop year multiplied by the price percentage relationship between grain sorghum and corn as determined by RMA based on the January estimate of corn and sorghum prices.

Harvest: Average of the final closing prices in October of the CBOT December corn futures contract multiplied by the price relationship between grain sorghum and corn as determined by RMA based on the January estimate of corn and sorghum prices. The harvest price cannot be less than the expected price minus $1.50, or greater than the expected price plus $1.50.

Dollar amount of protection per acre is selected from amounts specified in the actuarial tables. The payment calculation factor and the loss payment or indemnity are calculated using formulas similar to those used for the Grassland Reserve Program.

Payment Calculation Factor = (Trigger Revenue - County Revenue) / Trigger Revenue
Indemnity = Payment Calculation Factor x Policy Protection
Expected County Revenue = Expected County Yield x Expected Price
Trigger Revenue = Expected County Revenue x Coverage Level Selected
County Revenue = Final County Yield x Harvest Price

GRIP is available in 74 counties for corn, 20 counties for grain sorghum and 35 counties for soybeans.

Recommendation

Check with your agent to determine what the GRIP history would have been for your county for the past five years.

H. Doug Jose
Extension Agricultural Economist

Waiting until the air is warmer to aerate the bin invites problems. Ice dams can form in the bin when the grain temperature is below the dew point temperature of the air and the grain temperature is below freezing.

Any evidence of winter injury or crown and root rot usually doesn’t become evident until late March or early April when the wheat resumes growth. Additional surveys will be conducted in April as the crop comes out of dormancy.

Reports to the south indicate that leaf rust survived the winter in much of Texas and Oklahoma. Also, abundant leaf and stripe rust was found on wheat plots in south-central Texas. Active powdery mildew was found on plants in Oklahoma and, as with leaf rust, appears to have survived the winter. These diseases will become more prevalent as temperatures increase.

As the growing season gets underway, I will continue to monitor the development of both rusts and powdery mildew in states south of Nebraska.

John Watkins
Extension Plant Pathologist

Jagalene first appeared in the state in 2003 and quickly rose in popularity. Pronghorn, introduced in 1997, increased to become the second most popular variety, with Millennium slipping to third. For the 2005 crop, Jagalene accounted for 16.8% of the acreage while Pronghorn was planted on 11.4%. Millennium was planted on 10.7% with Alliance dropping to fourth place at 10.1%. Wesley improved to finish fifth with 5.5%.

Jagalene was the most popular wheat variety in the south, southwest, east and southeast districts. Pronghorn came in first in the northwest, helping it become the second most popular variety planted in the state. Arapahoe was the most popular in the Northern District. Wesley was ranked first in the Central District, helping it improve to fifth overall.

USDA Nebraska Agricultural Statistics Service

A late March planting date for biodiesel crops means producers should be signing contracts and getting their seed purchased now.

According to David Baltensperger, dryland crop specialist at the University of Nebraska Panhandle Research and Extension Center at Scottsbluff, production acres are available by investing in Progressive Producers Coop in Sidney, which is working with Blue Sun Biodiesel in Colorado. Investors receive the right to deliver their crop, receiving a return on investment when that occurs.

Baltensperger said the University of Nebraska and land-grant universities in the High Plains have worked cooperatively to identify some of the better adapted brown mustard and canola for this area. They have also worked to develop management strategies. Good agronomic systems have been worked out, but work is ongoing to improve weed control, especially for brown mustard, he said.

The last 10 days of March is the targeted planting date, so those who want to participate in 2005 should not delay in getting contracts signed and seed ordered, Baltensperger said.

A value-added grant will make it possible to assist with delivery of the crop this year. For more information call Bob Kelly at Crossroads Cooperative in Sidney, 800-833-2951 or Dan Laursen, President of Progressive Producers, at 308-487-5541.

The 2005 brown mustard or canola price will be $12 per hundredweight, or 12 cents per pound. This is based on a 35% oil content. Arid brown mustard is the variety with the most production records in the Panhandle, but Pioneer, Interstate Seed and Mycogen all have materials that have performed well in Panhandle trials, Baltensperger said.

Haven’t we all seen or heard such tempting product claims. You know the pitch. Maybe it’s a ber-mudagrass that yields 20 tons per acre or a foliar fertilizer that doubles alfalfa yield. It could be a soil enhancer that makes water wetter or releases more soil nutrients.

These claims sound good and often have a reasonable explanation about why they would work. But will they work? I can’t summarily discount every “miraculous” product. But let’s face it. You know the old adage -- if it sounds too good to be true, it probably is. Still, what if it is true? Why not take the gamble?

Maybe the big question should be -- how much should you gamble.? I have no problem with trying something new -- that’s how we improve -- but start slow. Spray a couple test strips or plant just a couple acres. Make the product prove itself before you bet the farm. If it really is good, it will be available next year. If the salesperson won’t let you try just a little, just say no.

We all want something that will make us richer, but be careful not to jeopardize what you already have for a “miracle product” that can’t deliver.

Bruce Anderson
Extension Forage Specialist

Cotton glove liners can increase the comfort of wearing chemical-resistant gloves for ag pesticide applications, especially on hot days.

While there are some restrictions to using the liners, there also are many benefits. Restrictions outlined in the EPA Worker Protection Standard include: 1) liners may not be longer than or extend beyond the glove, and 2) they must be disposed of after 10 hours of use or whenever they become contaminated. Benefits include: 1) increased comfort to applicators’ hands, especially during periods of extreme heat (and profuse sweating) and cold; 2) reduced risk of allergic reaction to glove materials; 3) reduced risk of pesticide exposure; 4) potentially reduced risk of dermatitis on the hands.

Herbicides can easily kill these weeds in pastures dominated by warm-season grasses. One option is to spray one pint of glyphosate per acre early in the spring after weedy bromes green up but before warm-season grasses start growing. You also can use four to six ounces of Plateau herbicide and get similar results. With Plateau, residual herbicide activity will control some later emerging weeds as well.

If your pasture is cool-season grass, the job is tougher. Both glyphosate and Plateau harm cool-season grasses, so they aren’t a good option. Gramoxone is a better choice but don’t spray until the weedy bromes are about to form seed heads. Then Gramoxone will kill all the green top growth it contacts, even your good grass. Although you will lose some early grazing, your good grass will start to regrow after two or three weeks.

Herbicides can control winter annual bromes if you use them right.

Bruce Anderson
Extension Forage Specialist

Field update

The cool season grasses are actually showing a green color and some early growth. Seed delivery has begun and there has been a lot of interest in soybean rust at the pesticide training sessions. Farmers are wary of the rust situation and have the most questions about whether drilled soybeans will be more susceptible to rust than 30-inch row soybeans.

The indepth training will cover growth staging, identifying fertilizer deficiencies and major pests, understanding insect economic thresholds, handling soybean cyst nematode, and weed and disease identification and management. Certified Crop Advisor credits are available: 4 in pest management, 1 in crop management and 0.5 in fertility/nutrient management.

Cost is $20 for the first person from an operation and $10 for another from the same operation. All workshops begin at 10 a.m. and end at 3 p.m.

Remaining dates and locations:

• March 8, Minden, Fairgrounds, Kearney County Community Building
• March 16, Clay Center, Fairgrounds, 4-H Building
• March 18, Columbus, Ag Park, The Starter Cafe
• March 23, Stanton, VFW, 126 E. Main St.

The course provides indepth information on soil nutrition for crop production as well as hands-on, money-saving recommendations for applying the information in your operation. The course covers 1) how soil fertility affects crop production; 2) how to take more accurate soil samples; 3) how to save money by applying nutrients when it's the most cost effective and they are least apt to be lost; 4) why recommendations from different soil testing labs vary; and 5) how to select the best fertilizer for your needs and your farm management plan, and more.

Conference registration is $200 until March 25 and $275 thereafter. Students can attend the conference free. A banquet registration of $30 is required by March 25, since seating for that event is limited.

Participants will use young and established vines to do hands-on practical applications that will teach them about balanced pruning, trellis development, vine management and fertilizer practices.