Northcentral

Variability in crop health throughout the Northcentral region has been dramatic this season. Some areas have been subjected to overwhelming drought and heat while others have seen good conditions. All of this means that this fall it will be important to look back and see what yields were planned at the beginning and what yields actually were harvested. How much phosphorus (P) and potassium (K) did crops remove this year? How much have they removed during the past few years? Sustained low crop prices have led many to skimp on their P and K applications for several seasons. It is time to look back and see if nutrient applications have been keeping up with the nutrient removal by crops, or if they have been falling behind…not just this year, but for the past several years. Mining soil supplies requires a watchful eye to ensure soil test levels do not fall to yield-limiting levels. Decisions to apply P or K must be based on more than this season's crop performance. Looking farther than just one season puts this year's crop performance in perspective and helps better evaluate fertilization decisions.

For information on how much P and K is removed by various crops, visit the Crop Nutrient Utilization Chart on the Back-to-Basics homepage.

Autumn approaches. Soon forage plants will enter the critical fall growth period, during which they store the carbohydrates they need to survive the winter. Adequate potassium (K) is essential for this carbohydrate storage, and August is an excellent time to apply fertilizers as needed. Potassium is particularly likely to run short if previous harvests have been heavy. The amount to apply is an important decision. Make sure it's based on a recent soil test, and supported by forage analysis as well. Calculating a nutrient balance - nutrients removed by previous harvests minus the amounts supplied in manures and fertilizers - can also help determine the right amount to replace. For harvested cereals underseeded to forage, K should have been supplied at planting. But if it wasn't, applying as soon as possible after cereal harvest will ensure the seedlings develop into winter-hardy plants.

Winter wheat has performed well in many parts of the region, with good yields and very little mold and mycotoxin. For next year, assure yourself a good start by planning for the fertility needs of the crop to be seeded this fall. Nitrogen (N) and phosphorus (P) are important components of a starter to ensure a healthy stand. Wheat can be profitable, as well as an excellent soil builder in the rotation.

Manure applications following harvests of cereals and silage corn should be guided by soil tests and manure nutrient analysis. Rates should be appropriate to supply the soil's needs for P, K and organic matter. Avoid wasting N by ensuring a cover crop grows to absorb what is released from the manure.

When sampling for P and potassium (K), you need to have a good understanding of the field history. A clear understanding of where not to collect soil cores for a composite sample in a field can be as important as selecting representative locations. Old farmyard sites, pastures, or manured portions of fields can all lead to a high soil test reading which may in fact not be representative of the majority of the field. This requires that the farmer travel with the soil sampling truck to help the operator steer clear of these potentially problem areas. All the technology in the lab cannot compensate for a sample collected from an inappropriate location.

Given the important role soil testing plays in nutrient management planning, collection of a representative sample is critical. This means ensuring that the landowner clearly describes the representative areas of each field to be sampled, and identifies where manure was applied and how fertilizer P and K have been placed in the past. Remember, representative soil tests can help take the 'guess work' out of crop nutrient management.

Planning for cool season forage establishment and production is well underway. Growers and ag professionals should remember that fertility is an input that significantly affects not only yield, but also forage quality. Profitability from a forage production system is largely determined by the amount of animal product (beef, milk, wool, etc.) generated in that system. The amount of product generated in a forage system is a function of the number of animals carried per acre (stocking rate), and the production per individual animal. Forage quantity (yield) is the primary determinate of the number of animals an acre will bear, while forage quality is a major determinate of product generated per animal. Therefore, within a forage production system, yield and quality combine to determine how much animal product will be generated per acre… the ultimate measure of success. Following this logic and using these facts, it becomes clear that in cool or warm season forage production systems complete and balanced fertility is critical to generating optimal levels of the desired animal product and to maximizing profits.

What does this mean for 2003? That is the question we need to think about. Where soil tests were marginal in 2002, drought stress had more severe effect on crop yields. Potassium (K) is essential to water use efficiency. This is not a new idea, but it was brought home in fields across the region this summer. The 2001 PPI Summary of Soil Tests in North America showed a growing need for K. The 2002 season reflected it in reduced yields and profits for producers who have been too conservative in their nutrient applications. That condition will not go away; it must be fixed with improved K applications. We will continue working with dealers and farmers this winter to help them assess how much they are losing with low testing fields or areas within fields. It is a major economic problem that is easily corrected with proper K management.

Peanuts in Alabama, Georgia, and Florida are maturing. In spite of some recent showers in localized areas, drought earlier made prospects for a fair to good crop unlikely. More recent widespread rain in the Southeast has improved the yield potential, but increased farmers' expenses as they apply fungicides and insecticides to protect the crop.

Recent rains in portions of the region have helped soybean crop development. Early-maturity fields are nearing harvest. Insecticides are being applied to control stinkbugs, but the stinkbug numbers have declined since early July in many areas in the middle South. Some fields with leaf and pod-feeding worms were also being treated. Yield potential looks pretty good in irrigated fields, and the dryland fields that received moisture during bloom to pod-filling.

The cotton crop is maturing and some of the April-planted fields will be terminated soon in preparation for picking. Bolls were opening in the southern portion of the Southeast cotton belt. Insect pressures seem to be increasing in some areas: bollworm, budworm, tarnished plantbugs, and spider mites. The weather the next ten days to two weeks will be critical for many farmers. Farmers who are striving for high yields, with the assistance of irrigation, must be sure that plants receive optimum moisture over the next several weeks, to fill out bolls, and to allow the crop termination (defoliants and boll openers) to work effectively.

Rice harvest continues in south Louisiana, with about 20 percent harvested to date. Yields are fair to good, but bin-busting yields are not expected. Fields in other parts of the southern rice growing region are mostly headed and many are approaching the dough stage. Fields will be drained in the next several weeks in preparation for harvest in Arkansas, Mississippi, and the bootheel of Missouri. Sheath blight is a concern in some fields and farmers and consultants are scouting and treating for sporadic stinkbug outbreaks. Many farmers in the region will be under a lot of pressure to harvest mature rice fields and early-maturity soybean fields in a week to two-week harvest window, to achieve optimum crop quality.

Sorghum harvesting has begun in some states, with other states reporting rapidly maturing conditions. Yields were reported as fair.

Sweet potatoes were in mostly fair to good condition. Tobacco harvesting is moving along at its normal rate. Peach harvest is nearing completion and apples are rated in good condition.

Many cattlemen are feeding hay because of continued drought. Yet in parts of the Southeast, farmers were rapidly baling summer hay where moisture was more plentiful. Where moisture was adequate, farmers were fertilizing pastures and hay meadows.

In citrus, some fertilizer and pest management applications had to be supplemented because of recent showers and thunderstorms in Florida.

Sugarcane was rated as good to excellent in Florida and Louisiana.

In several states, land was being prepared for fall vegetable planting.

This fall would be a great time to sample fields, especially where fertility needs have been neglected in recent years. If lime is needed, based on soil test results, applications this fall would help ensure that soil acidity is reduced and that the soil pH is in the optimum range at planting.

Fall applications of potassium should work just as well as spring applications, except on the sandier soils with a low cation exchange capacity (below 5 to 7 milliequivalents /100 grams). Fall applications of phosphorus are also appropriate where soil pH levels have been properly maintained.