A bi-monthly news publication of The Ohio State University Extension, Editors: Clif Little and Mark Sulc
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Contents:

• Is It To Late For Nitrogen?
• How Valuable Is Your Forage?
• Fall Nutrient Applications

[top] Is It To Late For Nitrogen? - Clif Litte, Extension Educator, Guernsey County

Each of us must decide how long the growing will last. The economic response to a nitrogen application is forage production. Will we have some moisture to move the nitrogen into the ground and produce enough forage growth to pay for the cost of fertilizer and spreading? The end of the growing season occurs with a killing freeze or frost. That date varies around the state but for most of us 50% of the time that will occur sometime in mid-October. Ideally we would have six weeks from the last application of nitrogen to the killing frost. However, we don't always need that length of time to pay for the application. Generally speaking an application much past the second week in September can greatly reduce our rate of return from the nitrogen application. Another factor to consider is how much nitrogen to apply and in what form? The later we get into the growing season the less actual nitrogen we should apply to grazing forages and we will want to use water-soluble forms. For example Urea 46-0-0 is a water-soluble form of nitrogen and 100 pounds of urea per acre gives us 46 pounds of actual nitrogen per acre. This is one of the types of application that would be appropriate for stockpiled Fescue, Orchardgrass or cool-season annual grasses the first or second week of September.

[top] How Valuable Is Your Forage? - Clif Little, Extension Educator, Guernsey County

As the winter feeding period approaches thoughts of my feeding program come to mind. For me, each forage has a value. I usually value forage with primary emphasis on its nutrient content. With all of the rain this year some forages may have reached maturity or it may have been damaged by the wet conditions. To place a value on two different grass hay sources I am considering I need to know the nutrient content of each. A forage analysis can provide me with the information I need to make a good decision on my purchase and feeding of this hay.

Consider these two sources of hay for example:

Which hay source is worth more? The three major nutrients provided allow us to put a price on these hay samples. Hay number one is worth approximately $126.80 per ton and hay number two is worth $71.20/ton, based on our local prices for these nutrients. I would also consider some other factors, such as neutral detergent fiber and micro-mineral content before making my final decision on these hay sources.

As you can see, hay can vary considerably in nutrient content, digestibility, and value. To properly sample your forage, pick up a copy of OSU Extension Fact Sheet ANR-2-98 and Fact Sheet AS-1-99 at your local Extension Office.

[top] Fall Nutrient Applications- Mark Landefeld, Extension Educator, Monroe County

Fall is an excellent time to correct soil nutrient deficiencies for grass and legume forage crops. Maintaining high-yielding, profitable hay production over a period of years requires careful attention to fertilizer management. Few crops deplete the soil of available phosphorus (P), potassium (K) and other nutrients faster than high yielding forage crops that are removed from the fields. Generally 13-15 pounds of P2O5 and approximately 50 pounds of K2O are removed for each ton of forage removed. Therefore fall fertilization is an important part of nutrient management, particularly with alfalfa.

Soil testing is the only way to accurately assess nutrients that remain in the soil for crops to utilize. Fall is an ideal time to test soils and make amendments if needed. Soil tests provide information about nutrient levels, pH of the soil and the cation exchange capacity (CEC) of your soil. Testing fields every 3 to 4 years allows the farm manager to make wise use of purchased nutrients to maximize yield of forage crops.

Phosphorus, potassium and soil pH can be managed from a long-term prospective. Building and maintaining appropriate pH, P and K levels should be the farm manager’s goal if consistently high yields are expected. When applications to correct pH are necessary, aglime may be applied, but it requires time (4 to 6 months) to react with the soil and neutralize acidity. Different forms of liming material are available so selection should be made depending on the amount of magnesium in your soils. Dolomitic lime is generally12 to15 percent higher in magnesium than calcitic lime. Liming materials can also vary considerably in price, so consider the cost vs. benefit based on neutralizing power of the product.

Soil test results are only as good as the sample taken. It is extremely important to provide representative samples of the area to be tested so reliable recommendations may be made. A good sample consists of a minimum 15-20 cores or slices. Each core or slice should be the same depth (approximately 6 inches) and include the same volume of soil at each site. Samples should be taken using a random zigzag pattern over the entire area, putting samples into a clean plastic container to make one composite sample. After air drying the composite sample at room temperature, thoroughly mix the cores or slices and take about two cups of this soil to a reputable testing lab. Most University Extension offices can send soil samples to a laboratory for testing or supply information where testing may be done.

During sampling, remove top debris or residue from the soil surface before taking the sample. In row crop fields take samples between rows to avoid fertilizer bands. Make separate samples from fields that have received different fertility programs or those where distinguishable differences are noted (i.e. light vs. dark soil or predominant legume vs. grass area). Sampling the same time of year provides the most consistent results for a producer when looking at a long-term soil fertility program.

So, why doesn’t everyone apply fertilizers in the fall? There are some situations where fall applications are not the best practice. Sandy soils have higher potential for leaching loss of nutrients. Complete fertilizers with nitrogen included may not be as efficiently used in fall applications as they are in the spring. Areas with steep or sloping soils, if adequate ground cover is not available, may experience erosion causing loss of nutrients and possibly adding contaminates to water supplies.

Are you planning to add any nutrients to your fields this fall? Do you have up-to-date soil tests to determine the amount of nutrients needed? Now is the time to make preparations. Making fall applications of needed nutrients should result in higher crop yields the following year because fertility will not be limiting and soil acidity will not reduce the crop’s ability to use all available nutrients within the soil.