Agronomy Notes

February 17, 2000

Contents

COTTON

Dr. Will McCarty

In times of high input costs and low cotton prices, growers must look at each part of their operation carefully. Growers should consider the basic economic principalówhen the prices of output goods decline, there is an indication inputs need to be scaled back; however, you must make decisions carefully. The following are some points to consider. If one of these points catches your interest, please get additional information through your local county Extension office.

* Diversify: Match crops to soil capability and productivity. Plant fields with low-yield with such alternative crops as grain sorghum, corn, soybeans, or perhaps wheat. Proper consideration to on-farm rotations will enhance profitability by hedging markets and other risks. Optimization of a number of commodities and not just one stream of revenue from a single commodity will provide more resiliency in overall farm operations. Research indicates that rotating cotton land to corn can result in yield responses of more than 100 pounds of lint per acre when the field is returned to cotton.

* Plant the bulk of your acreage in varieties that are proven performers, and experiment with ones on a limited acreage basis. A suggestion might be to plant in the range of perhaps 75 to 80 percent in proven performers, 10 to 15 percent in expanded acreage of varieties previously grown and showing promise, and maybe 5 to 10 percent of the acreage in varieties unknown to them or are totally new.

* Drainage and water management are critical; you must address these areas to allow proper benefits from crop rotation.

* Do not overapply nitrogen fertilizer. Research shows that about 50 pounds per acre of supplemental nitrogen are required per bale of realistic yield potential on loams to sandy loam soils and 70 pounds per acre per bale on clay to clay loam soils. Nitrogen rated higher than this can delay maturity and reduce yields.

* Incorporate crop rotation as it spreads risk, improves soil tilth and other factors, and optimizes yield for the two crops being rotated. It is a sound agronomic principle that is often overlooked because of its apparent absence of short-term benefits.

* Explore all available means of risk management to include crop insurance, CRP programs, WRP programs, or other programs available for crops you might grow.

* Shop carefully for inputs. Current situations and levels of competition in the supply channel indicate that price competitiveness may be in the grower's favor. Small savings add up óa 5 percent reduction in input cost can mean saving from $15 to $30 per acre.

* Extend the season: Successful farm operations will need to consider multiyear approaches to farming. Average yearly returns for 3- to 5-year periods need to be considered instead of annual returns on a year-to-year basis.

* Build a sound marketing plan. Marketing should be at least as big a priority as production.

* The entire farm operation must be considered in building a budget, after which it should be adhered to.

* Avoid any new capital expenditures, and farm with what you have, even if it means cooperating with a neighbor in harvesting, planting, and other operations.

* Pull detailed soil samples representative of soil types and differences in cropping history to avoid overapplying fertilizers and lime. No not overapply nitrogen to your crop.

* Where possible, convert to reduced tillage as a way of trimming labor, equipment, maintenance, and fuel expenses. In some cases, this will also allow reduction of expenses for disease, weed, and insect controls.

* Base pest management decisions on a proven threshold rather than continuing the "when in doubt, spray" philosophy used by many growers.

* Do not cut corners on scouting. Accurate, timely scouting can save money by your avoiding unnecessary applications and by minimizing yield loss. Scouting reports should give well-defined numbers that state the number of plants or fruiting structures examined and number of pests found.

* Do optimize use of Bt-cotton, which is a useful tool for managing yield losses and control costs because of tobacco budworm outbreaks. Growers in areas involved in the early years of boll weevil eradication may wish to plant a relatively high percentage to Bt varieties. Growers in areas where eradication efforts are more advanced may wish to cut back on Bt-cotton use.

* Do use increased treatment thresholds after the crop enters "cut out," and learn how to use the "node above white bloom - 5 + 350 DD60s rule" to avoid making costly late-season treatments that are not likely to improve yields (See the Mississippi Cotton Insect Control Guide).

* Practice insecticide resistance management. Resistance results increased yield losses, because of treatment failures and in increased costs because of the need to use more costly alternative treatments. Resistance also contributes to higher prices for new alternative products.

* Don't underbudget for insect control. Yearly insect control costs can range from less than $60 to more than $120 per acre. During severe outbreaks, it is important to do what is necessary to minimize yield losses.

RICE

Dr. Joe Street

Variety selection has not been a difficult decision with two-thirds to three-fourths of the Mississippi acreage planted with Lemont for the past several years. New variety introductions will provide more options. Cocodrie form Louisiana, Priscilla from Mississippi, and Wells from Arkansas are all high-yielding varieties. No variety is perfect, and these varieties are no exception. Get a copy of the 1999 Rice Variety Trial Bulletin from your county Extension agent and evaluate the varieties for agronomic characteristics. With any new variety, plant it on a small portion of the farm, and plant the remainder of the acreage with a proven variety.

Priscilla was grown on 18 percent of the Mississippi acreage in 1999. In general, yields ranged from the same as Lemont to 36 bushels more than Lemont. The average yield increase over Lemont was about 20 bushels per acre. In research plots, Priscilla has always milled just under Lemont, which was offset by the higher yields. In several cases in 1999, on-farm milling was much lower than expected for Priscilla and Lemont. Rice dried quickly after draining, and moisture at harvest was low in many cases. The high heat took its toll on the large seed of Priscilla and Lemont. You will recall that most growers were not happy with Lemont during its introductory year. Many growers vowed never to plant it again, and you know the rest of the story. I hope that is the case with Priscilla and growers learn to grow it. In research plots, Priscilla continues to mill similar to Lemont. With some adjustment in harvesting techniques, I trust that on-farm-milling yields will be satisfactory.

I know it is early to be thinking about rice water weevils, but it is time to think about treating seed with Icon for water weevil control. If you have a history of water weevil damage on your farm, you can expect to have them in 2000. You can apply Icon only by an authorized seed dealer, so it is a good idea to order seed early for treatment. Icon has done an excellent job of controlling rice water weevils, and it reduces the need for scouting for adults. Other options include Dimilin and Karate Z for controlling the adult water weevils just after permanent flood establishment. Both insecticides provide excellent control of water weevils. Whether Icon is used or not, you need to apply a good fungicide seed treatment, especially if you intend to plant early during cooler weather.

With the excellent dry weather during the fall of 1999, much precision land leveling was accomplished. Soil fertility is generally one of the limiting factors in good rice production on the recently leveled fields. Some nutrient deficiency is almost always present in the cut areas of the leveled fields. The most common deficiency I observed last year was phosphorus, which can definitely limit yields. Only soil analysis reveals the true nutrient needs of the field. You can use grid sampling and variable rate application technology to get the needed nutrient on the correct portion of the field. It is much better to correct the nutrient problem before planting than after symptoms occur on the crop.

SOIL TESTING

Dr. Keith Crouse

Maintaining soil levels for crops and pastures requires a regular soil testing program. An acceptable soil pH level promotes better overall availability of essential nutrient for healthy crop growth; good pH levels increase the efficiency of fertilizers applied. The availability of various plant nutrients is affected somewhat differently by changes in the soil pH. Macronutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur will increase in soil pH. Micronutrients such as iron, manganese, boron, copper, and zinc, with the exception of molybdenum, will decrease in availability as soil pH increases.

A fertility recommendation is only as good as the soil sample submitted. A representative soil sample, therefore, is important in any soil testing program.

Sustainable Agriculture Management Principles

Dr. Malcolm Broome

Sustainable production practices involve several general principles that can help growers select appropriate management practices. Specific strategies must take into account topography, soil characteristics, climate, pests, input availability, and the individual grower's goals. Sustainable agriculture is site-specific and individual in nature to the grower's farm; however, five general principles can be applied across all farms. 1. Select species and varieties that are best suited to the site and conditions on the farm. 2. Diversify crops and cultural practices. 3. Manage the soil to enhance and protect soil quality. 4. Use inputs efficiently. 5. Consider grower's goals and quality of life.

Selection of site, species, and variety. Preventive methods adopted early can reduce inputs and help establish a sustainable production system. A systems perspective is essential to understanding sustainability. The system allows a larger and more thorough view of the consequences of farming practices on human communities and the environment. When possible, select pest-resistant crops that tolerate existing soil or site conditions. When site selection is an option, factors such as soil type and depth, previous crop history, and topography should be taken into account before planting.

Diversification. Diversified farms are usually more economically and ecologically resilient. Monoculture farming has advantages in terms of efficiency and ease of management, but the loss of that crop in any one year could put the grower out of business or seriously disruptt he stability of the farm. By growing more than one crop, growers spread the risk and are less susceptible to radical price fluctuations associated with supply and demand changes. Diversity can also buffer a farm in a biological sense, for example, crop rotation to help suppress weeds, diseases, and insect pests.

Soil Management. A "healthy" soil is a key component of sustainability because it will produce a healthy plant that has optimum vigor and can better withstand pests. This does not mean a healthy plant will not be attacked by certain insects, but proper soil, water, and nutrient management can help to prevent some pest problems associated with crop stress or fertility imbalances. The soil is a fragile living medium that must be protected and nurtured to maintain its long-term sustainability. Some ways to enhance soil productivity are to reduce tillage, use compost or manures, if available, avoid traffic on wet soils, and maintain soil cover by crop residue or cover crops.

Efficient use of inputs. Conventional and sustainable farmers use many of the same practices and inputs; however a sustainable farmer will try to maximize renewable and on-farm inputs first. Converting to sustainable practices does not mean simple input substitution but more likely enhanced management and scientific knowledge for conventional inputs. Growers often think synthetic chemicals are not used in sustainable systems, when in reality such a system would use the least toxic and least energy intensive chemical and still maintain profitability. There will be cases where chemicals would be more sustainable than an organic or nonchemical approach; for example, switching from an intensive tillage program to a few applications of a broad spectrum contact herbicide may use less energy and may compact the soil less than several trips with a cultivator.

Grower goals and quality of life. Individual goals and life style also result in management decisions that reflect more than environmental or social impacts. New technologies or input practices that could enhance profitability sometimes require more intensive management that causes quality of life to diminish. Decisions that promote economic viability, environmental awareness, and community acceptance are influenced by a single factoróthe human element.

Soil and Nutrient Management

Dr. Larry Oldham

Do producers get value when buying fertilizer in Mississippi? A consumer protection mechanism exists in the 1970 Mississippi Fertilizer Law. In July 1996, the Bureau of Plant Industry was given the responsibility within the Mississippi Department of Agriculture and Commerce of enforcing the Mississippi Fertilizer Law. All fertilizers sold in the state should be registered with a guaranteed content of plant nutrients. Currently 318 companies have 2,291 fertilizers registered.

Bureau inspectors pull samples at commercial outlets and manufacturing centers on a regular basis. Custom blends are normally produced about two months a year, and movement of the finished product to the field occurs soon after blending; however, inspectors are instructed to concentrate on these blends during the rush season.

According to the latest Department report, 2,041 official samples (submitted by inspectors) were analyzed at the Mississippi State Chemistry Lab in 1999. Less than 13 percent of these samples were deficient, but this continued a general decline in deficiencies seen over the last 5 years. These deficiencies occur most often during blending through several physical processes, or while the blend is allowed to "cone" as it is transferred to the spreader. Particle-size segregation does not occur during travel from the bulk plant to fields.

Each dealer is required to have at least one staff member attend periodic bulk-blending workshops organized by The Fertilizer Institute and the Bureau of Plant Industries. The topics at these training sessions include raw material selection, good manufacturing practices, formulation, in-house quality control, and environmental compliance.

No state in the United States regulates screen or particle size of fertilizer materials. It is a complicated situation that depends on the chemical properties of the fertilizer material. Some interest exists to adopt a Canadian process called Size Guide Numbers (SGN); this process can be used to more evenly match particle sizes of different materials.

SOYBEANS

Dr. Alan Blaine

"BMPs" in Crop ProductionóOftentimes soybean growers hear about using "BMPs" in crop production. As the growing season approaches, growers need to give consideration to BMPs but even more, they need to concentrate on "blocking and tackling." This is not the year to use unproven practices or unproven varieties. This season, it is imperative producers concentrate on the basics of crop production.

This past fall many producers had the opportunity to conduct a lot of fall land preparation. Given this scenario, the stage is set for an early planted crop. Give some thought to final land preparation. If fields are in good condition, do not make unnecessary trips across the field. If fields are smooth, all you might need to apply is a burn-down material. Remember. When you use chemical weed control instead of tillage, you might be trading dollars but the time-savings factor may be hard to measure.

Many options are available, but the most cost effective approach to burn downs will be to start early to minimize rates and costs. Base your needs on specific weed's presence and size.

If at all possible, avoid waiting too late to start. Every year I see some producers get into a "Catch 22" situation. They want to run some type of tillage tool but that early window never opens up. Even in the situation where tillage is desired, an early burn down can help fields dry faster, possibly opening up that window sooner.

Think early. From now until planting, every decision you make should focus on earliness, whether it is minimum tillage, burn downs, or whatever. Two approaches exist in the burn-down arena. First, spray approximately 2 to 3 weeks before planting. The second approach is to use a two-step approach to burn down. At this time of year, winter vegetation is emerged. Starting early accomplishes two objectives: 1) For less money, it allows you to eliminate winter vegetation while it is small, and 2) It will bear up the soils, allowing soils to warm and dry faster. If you do not destroy winter vegetation in a timely fashion (whether with tillage or a burn-down herbicide), two things can happen: 1) In a wet spring, the green cover will let a field remain wetter and colder longer, or 2) In a dry spring, the green cover may pump all the moisture out of the ground.

If you spray early, fields have the potential to allow your first flush of summer annuals to emerge. This flush can then be controlled with a preemerge/burn-down combination if needed. The two-step approach to burn downs gives you an additional option that might prove valuable.

Variety trial information is available in your county Extension office. Information includes copies of the Mississippi Soybean Variety Trial and a short list of high-yield-potential soybeans. The variety trials are at the printers, and bound copies should be available soon; also, the trials are being posted on the Internet at www.mafes.msstate.edu/pubs/info bulletins/ib363.pdf.

CORN

Dr. Erick Larson

Early planting - Timely planting is an essential part of producing maximum corn grain yields. Early planting results in better yields than late planting for numerous reasons related to crop development. Early planted corn's sensitive silking period, when grain yield is most susceptible, generally occurs before drought stress reaches its normal late summer peak. Early planted corn generally also has greater opportunity to develop a deeper and more extensive root system before droughty conditions arise. Early planted corn will undergo reproductive development during a time with more available solar energy due to longer day lengths, but with lower air temperatures. Early planting often helps reduce yield loss associated with late season leaf diseases and insect pressure. Early planted corn will also mature during August, meaning increased likelihood of favorable conditions for field drying and greater harvest efficiency due to a quicker dry down period.

Burndown herbicide application: Moist soil conditions typically severely restrict planting time during the optimum corn planting period. Utilizing a late winter burndown herbicide to control winter vegetation encourages earlier planting. Killing winter weeds several weeks before planting allows the soil to absorb much more solar energy compared to soils covered by a blanket of green vegetation. This warms and dries the soil, which widens planting time windows and promotes corn seedling vigor. Burndown herbicides should be applied three to six weeks before planting to gain these advantages.

WHEAT

Dr. Erick Larson

Wheat nitrogen fertilization: Timing of nitrogen application plays a large role in N use efficiency. Recommended spring nitrogen rates vary from 90 - 140 lbs./a. with higher rates recommended on clay soils and high yield potential wheat. Nitrogen should be applied in the late winter beginning during tillering and ending before the second node (joint) forms in the early spring. This generally occurs from early-February through early-March. Thin wheat stands can be fertilized earlier to promote compensation by growing more tillers. Split nitrogen applications in the spring often produce better results due to high likelihood of denitrification and possibly volatization during wet conditions. Split applications may also reduce yellow streaks through a field resulting from a single nonuniform application.

A black line that separates the body text from footer information