A bi-monthly news publication of The Ohio State University Extension, Editors: Clif Little and Mark Sulc
This newsletter is made possible with support from the Bob & Jewell Evans Foundation
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Contents:

• Fertilizer Value of Organic Nutrient Sources
• Summer Annuals for Grazing
• Forage Shortage? Make Plans Now!
• Electric Fence Review
• Grazing Management in Dry Times

[top] Fertilizer Value of Organic Nutrient Sources - Clif Little, Extension Educator, Guernsey County

What is the value of organic fertilizers, such as manure? While it can be difficult to quantify the true value of an organic nutrient source, we can put a value on the nitrogen (N), phosphorus (P₂O₅) and potassium (K₂O) relatively easy. When utilizing an organic nutrient source insist on having the product analyzed. This analysis provides us with the best means of determining the product’s true value.

Consider for example, this poultry analysis (analysis is on an as is basis): The analysis reads:

The actual analysis of manure will vary based on storage, digestion method, diet of the animals, etc. This is why it is a good idea to have the analysis.

Step 1: (Establish price of nutrients in manure based on commercial fertilizer values.) Checking with our local fertilizer dealer, we found the following prices for Nitrogen (N), Phosphate (P₂O₅), and Potash (K₂O).

Prices for fertilizers based on local dealers revealed that the following fertilizers can be purchased for:

Calculating nitrogen values first, determine plant available nitrogen (PAN) in this manure sample. The amount of plant available nitrogen (PAN) in a manure sample varies with temperature, method of application, soil pH, and method of treatment or processing. Manure may contain up to three types of nitrogen each varying in their plant availability. Microorganisms (mineralization) break down organic nitrogen. Mineralization rates are adjusted according to digestion process and the time of year. Typically, 30 to 33 percent of the organic nitrogen applied is available to the plant in the year of application.

The value of the nitrogen in this source depends on when we apply and how we apply this manure. For instance, we can lose up to 75% of the ammonia nitrogen if we surface apply this product in July or August.

Therefore: The plant available nitrogen = The organic nitrogen x (efficiency factor) + ammonium N x (efficiency factor) + nitrate nitrogen

If we select a surface application in March, we should use the following efficiency factors (from OSU Bulletin 879). Organic nitrogen = (TKN) 52.91 - (ammonia N) 3.36 = 49.55 lbs/ton Organic nitrogen = 49.55 x (efficiency factor .30) x ammonia nitrogen 3.36 x (efficiency factor .50) + (nitrate nitrogen 0) = 16.55 lbs/ton of Plant Available Nitrogen.

We only have 16.55 lbs/ton of nitrogen available for growing plants in the initial year of applica-tion. The remaining organic nitrogen will be broken down and some N will be available next year. Ammonium nitrogen if not incorporated can be lost to the atmosphere very quickly in dry, hot weather.

From this total value, we can subtract our trucking and spreading costs. Trucking cost may be significant and spreading costs vary from $4-$6/ton. As we see, manure has significant fertilizer value. It is important to note fertilizer value will vary with species. Use the above formulas to see what kind of deal you are getting.

[top]Summer Annuals for Grazing- Jeff McCutcheon, Extension Educator, Knox County

It is the first of June and grass growth has slowed or stopped. You are grazing through your fields and considering your options. One option to con-sider is planting summer annuals for grazing in mid to late July.

If there is any land not planted in corn, we could still plant something that could be grazed in 45-60 days. Of course corn is a grass and could be grazed but that is a whole different subject. What options are there?

According to the Ohio Agronomy Guide we have the options of Sudangrass, Sorghum–Sudangrass and Millet.

Sudangrass is a fine-stemmed, leafy summer annual grass that can grow between three to eight-feet tall. It will regrow after grazing until a killing frost. Sudangrass usually contains lower levels of prussic acid and is usually lower yielding than the other sorghum family grasses. Do not feed to horses.

Sorghum-Sudangrass is a hybrid cross, although there are multiple varieties available. They re-semble Sudangrass, but are generally taller, have larger stems and leaves, and are higher yielding. Sorghum-Sudangrass hybrids regrow after each grazing with proper environmental conditions. These can contain prussic acid. Brown mid-rib varieties have shown higher animal preference and performance. Do not feed to horses.

Pearl Millet does not produce prussic acid. It tends to have smaller stems and more leaf than the Sorghum grasses. Pearl Millet regrows after each harvest, but not as rapidly as Sudangrass or Sorghum-Sudangrass hybrids.

Fertilize all three according to soil test results similar to corn with a target of 100-150 bu. They can be no-tilled or broadcast into a prepared seed bed. Plant each at a rate between 25-30 lbs. to the acre. All of these summer annual grasses can be grazed or even cut for silage. These summer an-nuals should be grazed after they are 18-inches tall. Grazing earlier has concerns with prussic acid or nitrates and will weaken the plants. Trampling and wastage will increase when graz-ing is delayed past the boot stage. Plants reach the grazable height of 18 to 30 inches about six to eight weeks after planting. Rotational grazing or strip grazing management should be practiced. A high stocking density should be used to graze the grass down in less than 10 days. Clipping leftover stems down to 8 inches will improve forage quality for the next grazing period.

Another summer annual not mentioned in the Agronomy Guide is Teff. Teff is a summer an-nual grass from Ethiopia. It can grow well in low moisture conditions. It is a fine stem grass that can be grazed in about 50 days and re-grazed about 45 days after the first grazing. Plant it at a rate of 4-5 lbs. to the acre. Use 50 lbs. nitrogen as a starter. Check out the factsheet from Cornell University for more information. http://nmsp.css.cornell.edu/publications/factsheets/factsheet24.pdf

[top]Forage Shortage? Make Plans Now!- Alan Gahler, Extension Educator, Fairfield County

By now, hopefully most of you have made your first cutting hay, have rotated through each pasture a couple of times, and have clipped all of your pastures to ensure vegetative growth into summer. And I’m sure plenty of you have realized by now that your forage production may not have met your expectations, and may have come significantly short, in both hay and pasture settings. Probably due in part to the Easter freeze, and the abnormally dry month of May, or a com-bination of the two - our spring growth has just not provided us with the tonnage we desire in most areas of Ohio. And as we continue through a hot, dry spell in most of the state into the first weekend of June, livestock graziers and hay producers alike are beginning to worry about their forage supply.

With rumors of some cattlemen already beginning to feed hay before first cutting has even been finished, combined with the less than optimal regrowth that will occur in the dry soils, hay demand is likely to be high and supply low by summer’s end and definitely into winter. So what strategies can we begin to explore at this point in the year to ease the mind and the budget, while keeping the bellies of our stock full?

One thing that should come to mind is thinking long term. If you cannot graze in the summer time, can you graze in the fall, or even the winter? And if your hay production is going to be sub-par throughout the season, are there ways to utilize any other ground or forages in order to put up the tonnage you need?

It is probably an everyday occurrence for most of us to drive down the road anytime from Novem-ber through March and see beef cows eating hay from a round bale feeder or from a bale unrolled down the hillside. And it is not all that uncom-mon to drive down a rural road in Ohio during that same time period and see cows grazing in an open pasture of stockpiled fescue or a harvested corn field. However, how often do we regularly drive down the road in Ohio, or anywhere in the Midwest, in the fall or winter and see cows grazing oats, rye, and turnips along a single strand of electric fence in a small section of field that we distinctly remember soybeans, corn, or wheat being harvested from just a few weeks or months back? Similarly, how often do we see lush, dark green, what appears to be grass hay fields being baled in late summer? Or how often do we experience any hay field producing much more than one large round bale per acre in late summer or early fall?

The answer to almost all of the above questions is “not nearly often enough.” But we do have the power to be able to answer that question differently for ourselves, as long as we plan ahead, and get at least a slight amount of cooperation from mother nature.

If you are also a row crop producer, the solutions may certainly be easier to implement, but with a little legwork, most anyone can adapt some of the practices with at least some benefits. The main component of my strategies is looking to other forages that can be seeded yet this season. From my experiences with local operations in Fairfield County, oats would be the forage of choice to provide the lowest input, most readily available forage, with the best chance for significant tonnage. All you need is some ground to grow them on, and summer planted oats can accomplish one of 3 things for us yet this year. 1 – additional for-age to be grazed late summer through early winter. 2 – additional forage that can be baled or wet-wrapped late summer into fall. 3 – temporary pasture renovation.

The ideal situation is planting oats into a harvested wheat field in mid-summer. With just a little moisture and a small amount of nitrogen, you might be surprised at the growth you can get out of oats planted in July or August. If you have a wheat field that can be fenced with water nearby, or can rent such a field from a neighbor who does not plan to double crop beans, this oat field could be grazed as early as September, and depending on management and size, could provide feed well into winter while pastures are rested and/or dormant during the hot, dry summer we are already experiencing. And if you have a wheat field that cannot be grazed, or you are simply a hay producer, why not use that wheat field to grow summer oats for hay? With a rather quick dry down even under less than ideal conditions, it is certainly possible to make dry hay from oats well into September and possibly October, and the tonnage will often exceed production of any other hayfield this time of year while still providing adequate nutritional quality for any species. If you do not get that window to cut them for dry hay, it may cost a little more, but having the oats wet-wrapped beats the alternative of having no hay or forage available into winter!

But what if you do not have a wheat field to plant summer oats into? Are you growing corn or beans, or have a neighbor who is? Consider aerial seeding oats into a standing corn field in August, or a standing bean field in September, and graze the field immediately after harvest.

No row crops around at all, but still looking for options? Consider drilling oats into a pasture that has gone dormant or that needs renovation. Although they are an annual, this may give some needed forage to help you through the year on an otherwise unproductive piece of ground.

As I mentioned, the key to any of these scenarios will be at least a little cooperation with a timely shower from mother nature to foster oat growth. But even in extremely dry years, we have seen yields from ½ ton to 3 tons per acre, giving us not only enough forage to recoup our costs of seed, nitrogen, and fuel, but also enough to ease our minds and fill the bellies of our stock. For more information, or questions with how you can make oats as a forage work for your operation, feel free to contact the Fairfield County Extension office at 740-653-5419 for our recommendations on seed-ing rates, nitrogen rates, planting methods and timing, and harvest management.

[top]Electric Fence Review- Rory Lewandowski, Extension Educator, Athens County

For many graziers using rotational grazing, the electric fence is a critical component of the total system. I know of examples where just 1 or 2 strands of electrified high tensile wire are serving as a perimeter fence along a road. The grazier is trusting in the electrical system and the prior ex-perience/training livestock have received to insure the fence is not crossed. In wet years, there are a lot of electrical fence systems that can do an adequate job. Soils with good moisture insure that the animal is well grounded, and when wet nose meets a wire, even if the voltage is not high, a good circuit is made and the resulting shock can convince an animal that the grass is not really greener on the other side. In dry years, like we are currently experiencing, marginal electrical fence systems may not maintain the desired voltage. Dry soils don’t provide the same grounding between animal and fence. Fences that might not be challenged in a year with plentiful forage may be tested in dry years with limited forage growth. During dry years we talk about slowing rotations down and even holding animals in one paddock as a sacrifice area until grass growth allows the rota-tion to be resumed. Can your fence keep your livestock from moving to where the grass really is greener?

Although many graziers have learned the basics of electric fencing, most of us can benefit from a review every now and then. The basic components of your electric fence system that should be evaluated include: the fence energizer/charger, ground rods, and the fence wire. In grazing schools you will hear that the fence energizer/charger is the “heart” of the electric fence system. The beginning grazier will avoid some frustrations by spending the necessary money for high quality energizer/charger. When the time comes to replace the current energizer/charger this is not the place to cut budget corners.

Size the energizer/charger to handle your current fencing system, plus some room for growth. I know graziers that have significantly increased the amount of electric fence they are running over the years. Sometimes the fence has increased as a result of expanded pasture acreage; sometimes the fence has increased as a result of more internal divisions as paddock numbers increase. Some-times, it is both. As the amount of fence grows, graziers should check to make sure that the energizer they have is adequate for the amount of fence they are asking it to charge.

Graziers should be checking the voltage on the fence to make sure it carries a voltage adequate to deter livestock from crossing. Figures that I have heard thrown around regarding voltage levels and various livestock species include 1600 to 2000 volts for cattle, 3000 volts minimum on electric netting for sheep and goats and 4000+ volts on high tensile fence for sheep/goats. I also know of sheep/goat producers who maintain 7000+ volts on their fence. The point here is to evaluate the charger/energizer as fencing needs grow/change and either fence to include another charger/energizer in the system, or add a larger charger/energizer to handle the increased fence. There are many ways to evaluate chargers/ energizers, but one method is to look at output in joules. Also remember that when a product is ad-vertised by the miles of fence it can energize, this includes one wire. If multiple wires are energized, these must be added together. Four strands of high tensile wire around a mile perimeter with 2 hot strands accounts for 2 miles of energized wire.

One component of the electric fence system that is sometimes overlooked is the ground rods. The full capacity of the charger/energizer will not be utilized unless there is a good ground system in place. In a dry year, it is critical to have the correct number of ground rods, properly spaced in-stalled to help keep enough voltage on fences. What is the correct ground rod system? A general rule of thumb says to install a minimum of 3 feet of ground rod per joule of energizer output capacity. For example, if I have a 15-joule energizer, this requires 45 feet of ground rods. Generally either galvanized or copper rods in 6 to 8 foot lengths are used. This energizer would require 6 to 8 ground rods depending upon if a 6 or 8-foot ground rod was used. If copper rods are used make sure to use a copper wire from the energizer ground terminal to the ground rod. If different metals are mixed, electrolysis can occur and the effectiveness of the grounding system is reduced, so stick with either galvanized or copper. Ground rods should be driven in their full length, or if rocky soils don’t permit this, driven in at an angle so that essentially the rods are lying in a trench. Ground rods should be at least 10 feet apart and 40 to 50 feet away from any other existing grounds. Ground rods should be tied together in a system, connected with wire between rods. Try to locate ground rods in an area that is likely to stay moist. Northern exposures under building drip lines often work well. In drought situations, it may be a good idea to water your ground rod areas to increase the effectiveness of your electric fence.

Finally evaluate the fence itself. Remember that as the diameter of the fence wire decreases, there is more resistance to push electric current around the fence. Polywire is very handy stuff but it should not be used to carry the charge long distances. Use high tensile wire to carry the charge and for perimeter fencing and polywire to hook on to the high tensile wire for internal paddock divi-sions. Graziers should also be aware that if barbed wire is used in an electric fence system, each of those barbs is siphoning off some of the electricity. Efficiency is reduced. Voltage will be dropping in the fence as distance and amount of fence increases. Check to make sure the galva-nized coating on the fence wire is intact. Rust is an enemy of electric fences.

Electric fence technology has allowed many graziers to more effectively utilize pastures and their management ability. Graziers need to periodically evaluate the energizer, ground rods and fence wire components of their electric fence sys-tem to insure fences are operating efficiently and serving as effective barriers for livestock.

References: Beef Cattle Handbook, BCH-6201: Fence Systems for Grazing Management and Kencove Farm Fence Supplies Catalog

[top]Grazing Management in Dry Times- Jeff McCutcheon, Extension Educator, Knox County

Graziers with whom I have the privilege to work are reporting 0.4” total rain for the month of May and the average temperature 10 degrees hotter than normal. This translates into grass growth slowing and even stopping, right in the peak production period for our cool season pastures. What is a grazier to do? Relax. Remember, we have been here before; dry periods are expected, but not enjoyed. Check out drought information published in 2002, http://corn.osu.edu/drought02/ if you don’t believe me. Of course, if you just started managing grazing in the last two wet years, consider this a crucial part of your education. Many experienced graziers refer to it as the school of hard knocks.

Rotations need to slow down. Grass is growing slower, it takes longer to start regrowth after being grazed and it takes longer to reach optimum grazing mass (height) for the next grazing. The number of days grazing a paddock can be increased, as long as you do not over graze. The rest period needs to increase. For most graziers this means pulling more acreage into the rotation. Many use fields where they made first cutting hay. Another consideration is unused fields in your area. Every year I get calls from landowners looking for producers to mow their fields and take all the hay. They just want it mowed. Check around, many of these could easily be grazed.

Every grazier works to protect their perennial forage resource. Do not overgraze! Overgrazing is something we try to avoid in normal years, but is especially critical in dry ones. Overgrazing during a drought can cause slower recovery when we do get rain, reduced productivity even longer after recovery and can cause stand loss.

The amount of residual affects root growth. Many of you have seen the study from 1955 on leaf area removal and root growth. This data showed that at 50% leaf removal, only 2% of the roots stopped growing. At 60% leaf removal 50% of the roots stopped growing. All of the roots stopped growing at 80% leaf removal. A healthy root system helps the plants survive the dry times. If more than 50% of the leaf area is removed then root growth stops. Root growth is used to capture more water and nutrients. At the very least this slows re-growth.

The amount of residual affects re-growth. Green leaves are needed to capture sunlight for photosynthesis. This creates the non-structural carbohydrates needed to fuel re-growth. Without enough leaf area the forages must fuel re-growth from their stored reserves. Growth fueled by the root reserves is slower than growth fueled from active photosynthesis.

The amount of residual affects water absorption by the soil. Grazing below 1200-1500 lbs./DM per acre or 2-3” will allow most of the rain that does come to run off and not be absorbed by the soil. A classic forage study from the 1930's shows the runoff results from a 10% slope where three inches of rain was applied through a sprinkler system over 90 minutes. Pasture grazed to 95% cover experienced a little over 10% runoff. Overgrazed pasture, 50% ground cover, lost 75% of the rain that was applied.

More leaf area means less water runoff. The more vegetative material you have will shade the soil and slow the movement of rain allowing the water to be absorbed by the soil.

When we consider grazing management during dry times remember that without rain pastures grow slower, and close grazing will compound the problem. Slow growth means the rest between grazing needs to be longer. Do not take more re-sidual to allow for this rest. It may get to the point where you need to consider other options, like annual forages, supplemental feeding, and even penning the animals up and feeding them. If growth stops, the worst option would be to open up all of the gates letting animals overgraze the whole farm. Putting them in a dry-lot may be the best option.