Spring 2008

Northcentral

Higher fertilizer prices and short supplies have many farmers and advisers concerned about getting enough fertilizer and being able to afford what is available. There are no silver bullets to solve this problem. A sound strategy is to remember the basics of fertilization: soil test, concern yourself with macronutrients and soil pH first, then micronutrients, and band nutrients to maximize effectiveness if they are applied at lower rates. Don't forget that there are many under-utilized tools out there: the PSNT test, the soil nitrate test, the stalk nitrate test, and the chlorophyll meter. Familiarize yourself with these tools and give them a try if you have never used them. Who knows? They may be a fit for your situation.

The heat is on! Both the markets and the issues that impact the fertilizer industry have heated up for 2008. High prices for both crops and inputs mean greater profit possibilities from applying the right fertilizer at the right rate, time, and place. At the same time, international action on global ecological issues including greenhouses gases has deep implications for fertilizer management.

The International Plant Nutrition Institute offers several new information sources that sort through the issues and help you improve the use efficiency of plant nutrients. Check out the following:

• Managing Nutrients to Mitigate Greenhouse Gases
• A Global Framework for Best Management Practices for Fertilizer Use
• BMPs to Minimize Greenhouse Gas Emissions Associated with Fertilizer Use
• Greenhouse Gas Emissions from Cropping Systems: Influence of Fertilizer Management
• Will Biotechnology Replace Nitrogen Fertilizer?
• Effective Nutrient Use Efficiency Improvement
• Ecologically Intensify Your Corn Nutrition
• Limiting Nutrient Leaks

Research results:
The more we work on improving N recommendations, the more we see the strong role played by the weather. A recent symposium focused on the sciences that could be applied to account for weather variability. The proceedings, Managing Crop Nitrogen for Weather, are available for purchase from IPNI. A recent article in Better Crops with Plant Food also summarizes the findings: A Research Agenda for Managing Crop Nitrogen for Weather.

Using Nitrogen Fertilizers Efficiently not only Increases Net-Farm Incomes, but Is Environmentally Beneficial

The use of N-based fertilizers is a common practice in much of agricultural production because N is usually less available from soils than needed to achieve optimum or desired crop yields. Use of N fertilizers allows growers to increase both the yield and quality of crops that rely on N originating from soil and fertilizer sources. Such crops include small grain cereals, corn, and oilseed crops such as canola and flax. Legume crops including forage legumes such as alfalfa, and pulse crops such as field peas or soybeans do not rely as much on soil and fertilizer N because the Rhizobia species of bacteria that live in nodules on legume roots are capable of supplying much of these crops N needs by transforming atmospheric N gas (N2) to plant available ammonium (NH4+).

The dramatic increase in energy costs over the past couple of decades has resulted in agricultural producers spending more to purchase fertilizers, as well as spending more on fuel to power equipment used to plant crops and apply fertilizer. These increased costs have encouraged agricultural producers to try and use their purchased fertilizer products as effectively as possible while achieving the yields of crops wanted.

The fertilizer industry encourages the efficient use of all fertilizers including N fertilizers by following the so-called “Four Rs of Fertilizer Use”. This includes the following:

1. Apply the Right Rate of fertilizer to adequately meet crop needs while avoiding over application.
2. Apply fertilizer at the Right Time so crop uptake is maximized.
3. Apply fertilizer using the Right Placement method to allow effective crop root interception and uptake, and
4. Apply the Right Form of fertilizer so it is available to the crop.

By following these principles the use of fertilizer by crops is maximized and unwanted losses to the environment are minimized.

N losses to the environment can happen in three different ways, one is when nitrate (NO3) is leached down through the soil below the rooting depth of crops and can contribute to excessive NO3 concentration in ground and surface waters. Another is ammonia (NH 3) volatilization losses to the air from soil and plant residue surfaces when the urea molecules in urea containing N fertilizers are hydrolyzed to release NH3 and carbon dioxide (CO2). The third way is when nitrous oxide (N2O) is released to the atmosphere resulting from the reduction of NO3 and to a lesser extent nitrite (NO2) in soils under wet or near saturated conditions. Emissions as N2O are of specific concern because it is considered one of the greenhouse gases (GHG) contributing to global warming. The other GHG compounds involved are CO2 and methane (CH4).

The following are some examples of management practices used in the Northern Great Plains that can help increase crop utilization and minimize unwanted N fertilizer losses.

• Apply N fertilizer close to the time of planting in the spring if possible. If fall application is used the application is delayed until later in the fall when soil temperatures are below 50 °F (10°C). (Right Timing)
• Band place N fertilizer below the soil surface. This can be done in the fall or early spring prior to planting or in a precision band away from the seed row during the planting operation. (Right Placement)
• Take soil samples from fields prior to fertilizer applications and have the samples analyzed for plant available nutrients. The soil test results along with estimates of soil N-mineralization, crop needs, and likely moisture conditions can help determine the rate of N fertilizer required to achieve target crop yields. (Right Rate)
• Apply surface applications of urea containing fertilizers early in the spring as opposed to late spring or early summer. The normally cooler early spring air temperatures result in less potential for ammonia volatilization losses, and a greater chance of early spring moisture moving the dissolved urea into the soil away from the soil surface. (Right Timing)
• If surface applications of urea are done when air temperatures are warmer in the spring or early summer and moisture from rain or irrigation is not consider treating the urea with an urease inhibitor additive to reduce the potential losses from NH 3 volatilization. (Right Form)

Reduced losses of N fertilizer also means increased net farm incomes as crop yields are increased because of reduced losses from the amount of N applied. Economic and environmental benefits are both realized when N fertilizers are used efficiently.

Conditions across the 6-state Southern and Central Great Plains Region are relatively good at this writing. The latest Palmer Drought Severity Index (March 8) shows the entire region in the near normal and above range in terms of moisture. However, some areas, especially in the west and southwest, are in need of more rain. Wheat conditions are somewhat variable across the region, but overall most states report the majority of wheat in fair or better condition. With wheat prices as high as they are, this was not a year to short the crop on N. While the window for topdressing in many instances is already past, in some cases it may still be appropriate. Remember, topdressed N needs to be in the root zone by the time winter wheat hits jointing, otherwise it will have limited yield benefit.

We are all aware that the crop production environment has changed dramatically over the past year or so. Grain prices are much higher, but so are input prices. The price of fertilizer is certainly no exception. Now is a good time to remind growers of the importance of basic agronomy in decision making. For instance, some manufacturers and vendors claim that their fertilizer products can be used at greatly reduced rates compared to conventional sources with the same or better results. These claims are often associated with nontraditional materials of unusual chemistry and/or high purity. While the nontraditional, low-rate programs might look good on the surface, one should always evaluate such evidence and claims through the lens of sound agronomic principles. Reduced rate schemes that don’t even meet crop removal levels for major nutrients are not sustainable and will ultimately result in depletion of soil P and K reserves. So, beware of fertilizer products and fertility schemes that seem too good to be true… if it sounds too good to be true, it probably is.

Finally, remember that yield is the most important determinant of profitability, even in the current market conditions. As we go into the spring make sure that the crop is provided complete and balanced nutrition to produce top yields.

Spring is a great time to appreciate the diversity of agriculture in the Southeast region. Vegetable and citrus harvests are in full swing in Florida, potato planting is underway in North Carolina, and land is ready to plant 2 million acres of rice in AR, LA, MS, and MO. Over 5 million acres of winter wheat has been, or is being topdressed with N fertilizer, with sugarcane not far behind. Corn acreage is not expected to fall much from the approximately 10 million acres planted last year. However, cotton acreage may be lower than we’ve seen in the southeast since 1983. Strong wheat and soybean futures are pushing many growers out of cotton for another year. The greatest declines are expected in MS (31%), AR (30%), and TN (29). In the eastern part of the region, NC and SC are expected to reduce their cotton planting by 22 and 20%, respectively.

Many growers are still looking at nutrient inputs as a way to save money in 2008. Dr. Larry Oldham, Nutrient Management Specialist at Mississippi State, is responding by saying : I’m hearing people say they cannot afford fertilizer this year. The question is…can you afford not to fertilize?” His data show that while it is possible that the percentage yield decrease due to not applying soil test-recommended P and K may be minimal (8%), if fertilizer is not used when soil tests are in the low range yields can be as much as 25% lower. “At a 50 bushel per acre potential soybean yield, taking 12.5 bushels out of the picture, at $12 per bushel for soybeans, the cost of not applying is $150. Management needs to assess whether this is acceptable given their production system and variables in addition to fertilizer costs: soil-specific yield potential, irrigation, pest management, weather, variety yield potential, etc. Soils testing in the very low range require even more detailed decision processes.” Jason Kelley, Extension Wheat Agronomist in AR, echoes these sentiments saying, “I believe cutting back on fertilizer would be the wrong thing to do. With grain prices at these levels, it does not take much of a yield response to get your fertilizer money back”.

Even considering the economics, it is critical that growers continue to think about maximizing nutrient use efficiency to maintain profitability and minimize nutrient losses. Applying nutrients at the correct rates at the right time of the growing season are sure ways to improve efficiency.

Despite the declining acreage, grower interest in K fertility of cotton is very high heading into the 2008 growing season. This interest was evident at the recent Beltwide Cotton Conference, when a special session on K fertility was standing-room-only. The increased concern is likely because growers are reporting K deficiency showing up in fields where it had never been a problem before. For more information on K fertility in cotton, see article Number 5 in the Spring 2008 series of Plant Nutrition TODAY. A more detailed look at K nutrition, including the complexity of the K cycle, K in soil, uptake mechanisms, K role in plants, and plant response to K fertilizer is available in the slide set "Advanced Topics in K Nutrition".

As farming operations get in high gear, there is considerable pressure to juggle expenses to keep financially solvent. The outlook for a good productive year is bright, but crop prices for some commodities are not keeping pace with the rising costs of many inputs. Many people are looking for short cuts that will boost the bottom line by improving yields or shaving costs. Will things ever get “back to normal” again? Old-timers in agriculture will affirm that there is never a “normal” year! So take a close look at your entire operation and see what fine-tuning is needed to make 2008 the best yet.

It makes sense to cut back on any inputs that are not a good financial investment. Look carefully at how field operations can be combined and minimized. Crop health chemicals should only be used after careful scouting and considering economic thresholds. Fertilizers additions that are in excess of that needed for optimal crop health are probably unnecessary.

The water outlook for 2008 looks mostly promising throughout the West. Average rainfall and snowpack may bring a relief to some areas of persistent drought in the Southwest. However, the forecast for the West Coast and the Pacific Northwest is for adequate water for agriculture this summer.

It’s not too late to take soil samples and plan for tissue analysis during the season to track the crop nutritional status. It may be more important than ever to closely monitor your crops to get the most out of your fertilizer. You’ll keep hearing the word “efficiency” in regards to farm inputs. This involves getting the most return from every decision you make on the farm. Visit our website to get help in making fertilizer use as efficient as possible: www.ipni.net.

As the growing season gets underway, let’s make the most of our opportunities in 2008 and put the pieces together to grow a productive and profitable crop!