Northcentral

Fertilization that is agronomically sound, environmentally responsible, and economically viable is paramount in the Northcentral region. Low crop prices have hit farmers hard for the past few seasons, causing most to re-examine their operations and find ways to cut costs. As some farmers are learning, fertility is a variable that cannot be taken for granted. Potassium deficiencies are being observed more frequently in areas of South Dakota and western Iowa. Farmers in these areas have not needed to apply much potassium in the past, due to naturally high soil levels.

However, some have now mined their soils to the point of being deficient. In Wisconsin, potassium deficiencies have commonly been observed in corn following alfalfa, particularly under reduced tillage practices where only low rates of potassium are applied with starter fertilizer. In these and similar cases, too little concern about fertility has cut into yields and much needed profits. The universities in the Northcentral region provide good guidance on how to rectify and prevent such problems. Farmers and those who support farmers are encouraged to familiarize themselves with the best practices defined locally. For instance, Wisconsin has shown that soil testing should be performed prior to the corn crop following alfalfa. Alfalfa can remove large amounts of potassium, leaving little available for the corn. In Iowa and Minnesota, research has shown that banded potassium can boost yields in soils under no-till or ridge-till systems. In South Dakota, research is trying to discover the critical soil test level for potassium, to help producers keep the nutrient in good supply in the soil.

The key is to become informed of the research, discoveries, and recommended practices in each area to ensure that fertility is managed to gain profit, adhere to agronomic principles, and protect the environment.

In New York State, crop yields were fair, but poor quality of harvested forages may hamper milk production. Soybean yields in the region were not reduced as much. In Pennsylvania, soybeans yielded as high as ever (42 bu/A).

Diseases prevailed in both corn and soybeans, but hopefully the early onset of a cold and snowy winter will minimize the carryover of inoculum. Growers will want to pay attention to the roles of potassium and chloride in disease suppression. The heavy rains may have leached much chloride, and in light textured soils even potassium may have been lost by leaching.
Nutrient management planning programs in the region continue to demand the attention of all crop advisers and input suppliers. New York State's Agricultural Environmental Management (AEM) program is moving forward. Three individuals have so far been certified to prepare comprehensive nutrient management plans (CNMP's), and many more expect to be soon. While AEM is voluntary and incentive-based for most farms, concentrated animal feeding operations (CAFO's) will find it mandatory.

The introduction of the Ontario Agricultural Standards Act has been delayed. This legislation, which will likely require nutrient management plans of all nutrient users, is now expected to be released in the spring of 2001. The water contamination catastrophe in Walkerton was rated as the top media story of the year 2000 for all of Canada. For this reason, the provincial government is developing this legislation with comprehensive scrutiny. Increasingly tough rules on manure use will also spill over to affect application of fertilizer nutrients. Growers will need to pay increasing attention to best management practices that optimize utilization of applied nutrients and minimize losses that impact the environment.

In response to this rapid expansion of pulse crop acres, the Potash and Phosphate Institute and the Foundation for Agronomic Research are providing financial support to a number of new field projects in western Canada. Given the nitrogen-fixing potential of these grain legume crops, input management needs to focus on proper inoculation and balancing P and K to optimize crop yield and quality. The value of lentils and chickpeas relative to other cereal and oilseed crop options is heightening farmers interest in management practices that will optimize yield and returns. It is anticipated that the research projects being funded will improve our understanding of how to manage pulse crops in the western Canadian cropping system.

One of the factors that can affect wheat production in the Great Plains region is chloride (Cl) nutrition. Research has shown that where conditions favor response to Cl fertilizer wheat yields are increased by an average of about 5 bu/A, although yield increases as high as 23 bu/A have been observed. Chloride response is likely where soil Cl levels are low or where fungal disease pressure is high. Where soil Cl is less than about 30 lb/A (2 ft sample) wheat response to Cl fertilizer is likely. Also, where leaf rust, septoria, tan spot, and other fungal disease pressure is high Cl topdress may be beneficial. Chloride fertilization has been shown to significantly reduce infection of these diseases. In fact, one Texas study demonstrated that a spring Cl topdress application reduced leaf rust infection of flag leaves by over 40 percent and increased grain yield by over 6 bu/A. Wheat variety is another factor affecting probability of response to Cl. If a responsive situation is suspected or has been identified there are several sources of fertilizer Cl available for use. The most common and cost effective source is muriate of potash (0-0-60, 47% Cl). Research has shown that there is no difference in the efficacy of different Cl fertilizers. Since Cl is mobile in soils, topdressing prior to jointing is an effective way of addressing needs. Although application rates should be based on soil tests (target soil level is at least 60 lb Cl/A 2 feet), most research has shown that topdress application of between 20 and 40 lb Cl/A is usually sufficient to meet winter wheat crop needs.

Peripheral areas had excellent yields and contributed to record or near-record yields for many farmers. Farmers followed the advice of university and industry specialists and held back on N application until the soil temperatures cooled to levels where losses are minimized. Unfortunately, rainfall came along with the cooler conditions and ended the season before all of the N could be applied. P and K applications were delayed somewhat by harvest problems, but movement was generally good. If adjustments are needed for 2001, consider strip or starter placement as alternatives to help increase nutrient efficiency, especially in reduced tillage systems. If soil tests are high, placement is less of a concern and any method of application is acceptable.

What does this all mean for 2001 plans? We cannot predict what the coming growing season will be for any specific area, so the best approach is to plan for a good year. Moisture shortages have been relieved in many areas. Where yields were higher than normal, adjustments may be needed to replace higher levels of P and K removed in the harvested crops. Where disease and lodging were a problem in 2000, pay special attention to soil test levels. Low soil P and K can contribute to late-season stress, premature dying of plants and reduced yields and grain quality.

Re-check N plans. Even with the higher prices, it is dangerous to reduce rates. Split application and side-dressing can help improve efficiency of N use and reduce losses. It also provides an opportunity to make late adjustments for expected changes in potential yield. But remember, if the crop runs out of N before maturity, potential yields and profits suffer. Tight profit margins make fine-tuning of management details especially important for 2001. Review records, soil test, and yield goals. Remember, cutting back on basic inputs like fertility is not likely to improve yields and profits. Maintain best management practices to hedge against growing season stresses.

Certain basic truths hold year in and year out. For example, a plant's nutrient needs and other growth requirements for high yield and quality are not regulated by a market value placed on the grain, forage or fiber. Also, a healthy, well nourished plant can best withstand the in-season growth stress due to diseases, insect attacks, high or low temperature, or extremes in available soil moisture. A third truth deserves our attention in that a high crop yield of grain, forage or fiber is the best approach to lowering the unit cost of production and coping with low crop market value.

Research continues to document that proper fertilizer use can help farmers to achieve basic farming objectives such as higher crop yield, improved crop stress resistance and sustained profitability. Let's get back to the basics of how fertilizer nutrients such as nitrogen (N), phosphorus (P), potassium (K), sulfur (S) and magnesium (Mg) work to achieve such goals.

• Individually, each nutrient is essential for plant growth by getting a critical job done. These jobs involve photosynthesis, growth of new root and shoot cells, protein formation, enzyme activity, energy storage and transfer, fiber length and strength, seed formation, resistance to specific diseases, and the list goes on and on.

• Collectively, the nutrients interact to elevate crop yield and quality to a higher plateau. This happens when P, K and Mg improve photosynthesis, or when N, K and S enhance protein synthesis. In a Florida study, this type of internal influence resulted in a 15 bushel per acre yield increase for NPK fertilization vs the yield when each nutrient was applied separately. Some express this concept in terms of nutrient balance or a balanced fertilization program.

• Positive interactions also exist between nutrients and other best management practices (BMPs). For example, liming an acidic soil can improve the availability and plant use of nutrients such as P for better root growth or molybdenum (Mo) for efficient nitrogen fixation by legumes. Also, the effectiveness of certain insecticides and nematocides has improved in the presence of fertilizer boron (B) or K.

• Drought tolerance and plant use efficiency of available water are nutrition and crop health related. Specific nutrient functions allow this to happen. For example, P is known to stimulate root growth which can allow improved access to deeper soil moisture. Also, during periods of extremely high temperature, K closes leaf pores (stomates) to reduce water loss by plant transpiration. Farmers in Israel are experts in managing plant nutrition, fertilizer use and other BMPs to secure the maximum production from each inch of water available for plant growth. The value of fertilizer in achieving a healthy, well nourished, high yielding crop is without question. Many believe this input alone accounts for at least a third of crop yield.

In the Southeast, the challenge relating to proper fertilizer use is elevated by the vast number of crops grown, the complexity of growing two or more crops in a year, and the influence of quantity/intensity/distribution of natural rainfall on nutrient retention by sandy soils. A return to the basic functions of fertilizer nutrients is fundamental to harvesting higher crop yields, improving profitability, and remaining a good steward of the environment.

Some are pondering the possibility of reserving their fertilization budget for nitrogen only. Except on soils testing medium to high in phosphorus (P) and potassium (K), use of nitrogen only may lead to reductions in nitrogen use-efficiency. One way to improve nitrogen use-efficiency (recovery) by corn, cotton, rice, forage grasses and other non-legume crops is to fertilize with P and K to provide crop needs, and to raise soil test levels to the optimum range over a period of about four to eight years. Soil fertility research with corn in Kansas and Ohio has shown that optimum P and K fertilization increases yields, increases nitrogen use-efficiency by the standing crop, and reduces the amount of carry-over or residual soil nitrate-nitrogen. A reduction in the amount of residual nitrate-nitrogen in the soil profile will reduce the risk of nitrate leaching to groundwater and lateral movement to surface waters.

Drought the last three years in much of the Midsouth has taken a toll on crop yields and farmer profits. In 2000, many farmers and consultants observed what they thought was crop wilting due to moisture deficits. Close inspection of plants and soils in many fields indicated that some of the worst wilting symptoms were in fields with low soil test K levels. Potassium performs many key functions in plant growth, reproduction, and maturation. One of the most important K functions is maintenance of a desirable plant water status. Without adequate K, the stomates (pores) in plant leaves will close and plants will not be able to transpire and cool themselves properly. Aggressive K fertilization will not prevent drought, but K deficiency will aggravate the damage from drought.

Fertilization with K is especially important on soils testing medium and lower in K to ensure that the moisture that is present in the soil, and that provided by irrigation, is used efficiently by crops. If K is needed, based on a good soil test and knowledge of crop uptake and harvest removal, potash fertilization can be one of the least expensive and most rewarding crop production inputs a farmer can purchase. In 2001, farmers should be sure to consider their K needs, to increase yields and to reduce the potential for K deficiency and to hedge against damages from periods of drought.

Farmer surveys by universities in a number of states have shown that the most profitable farmers are usually those producing the highest yields. The most profitable production is that which results in the lowest cost per unit of commodity produced (i.e. per bushel of grain, per pound of lint, per ton of forage/hay). In 2001, many Midsouth farmers need to be wary of "cutting back and losing out". Careful attention to recent soil test results, and knowledge of the yield potential in individual fields, and sub-field areas, can enhance the ability to make wise, economic fertilization decisions.

Trying to farm without a sound soil fertility program is like running an engine after filling the gas tank (purchasing seed, performing tillage, planting, controlling weeds and other pests)… and neglecting to put oil in the engine's crankcase.