Nitrogen Confusion Correction

A few weeks back I authored an article about nitrogen stabilizers available to our producers. In this article I made mention of Twin N as a products that mitigates volatilization and nitrate leaching. Please note that this information is not correct. Twin N is actually a microbial mix of nitrogen fixing bacteria. Sorry for this confusion, however this does bring us back to the fact as stated in the article to make sure you know what type of inhibitor you want, a urease or nitrification inhibitor. Similar to our herbicide and insecticide counterparts if we know the active ingredients and/or pathways we won't have to worry about specific brand names. Again I apologize for any confusion this has caused.

Nitrogen Confusion

As the spring season starts off and you are planning your fertility programs a question may arise as to what is the best way to handle nitrogen? When we used to talk about nitrogen management it was largely based on your method of application, were you going to put the nitrogen in the ground or apply it on top. After that we would recommend different fertilizers due to their properties to minimize loss. These approaches still work, however the focus has now been turned to nitrogen stabilization products to help keep nitrogen in the field and crop available.

Before we get too deep into these products we first need a basic understanding nitrogen and the major ways we can lose it. For plants there are two forms of nitrogen they can utilize, ammonium and nitrate. Each of these have their own losses associated with them. It is also important to note that these forms are not static in the soil, for instance ammonium can change forms to nitrate.

The most common form of loss is volatilization. This occurs when ammonium (NH₄⁺) looses a hydrogen ion to form ammonia (NH₃). The ammonia ion is what we associate with some of the manure smell on broadcast applications. This ammonia is a gas and it is lost to the atmosphere. This only happens in our soils with products containing urea such as UAN and manures. The 'old' way to control this loss was to incorporate these products into the soil by either injection or tillage.

The other loss mechanism is leaching. If we think back to basic soils we may remember that our soil has a negative charge. This allows it to hold positively charged ions such as ammonium, potassium, calcium and others. However the negative to this is that our other plant available form of nitrogen, nitrate, is negatively charged. As we all know like charges repel. This means that the nitrate molecules are not held to the soil and can be washed out of the root zone during wet conditions.

Now how do you choose between the products on the market such as Agrotain, Agrotain Plus, N-Serve, Twin N, Instinct; just to name a few. Although there are a many products the answer still lies in what you are applying and how you will be applying it. It is very important to ask your sales representative what form(s) of nitrogen loss their product inhibits. For instance, if you are applying UAN (an ammonium product) with a sprayer or broadcasting dry urea your largest worry is volatilization. This means you want a product that inhibits volatilization. These products are broadly known as urease inhibitors. This actually stops the reaction that changes ammonium to ammonia. So if you are broadcasting nitrogen that is subject to volatilization (UAN, Urea, etc.) you want to use a urease inhibitor. Agrotain is an example of a urease inhibitor.

If you are injecting your nitrogen you are already limiting the losses due to volatilization so you are more likely to be worried about losing nitrate nitrogen. For this situation you will need to use the product broadly called a nitrification inhibitor. It is important to note that these products to not stop the leaching of nitrate already in the soil they simply do not allow the ammonium ion to convert to nitrate. Products such as N-Serve , Instinct, and Guardian are nitrification inhibitors. Nitrification inhibitors have the most value when N is applied long before expected crop uptake and especially on soils at the extreme of soil drainage ie. excessively well drained or very poorly drained soils. For example, a lot of N is fall applied in the midwest and a nitrification inhibitor is essential but that is not a common practice in our area. The last class of nitrogen stabilization products are nothing new but actually a mix of the two previous. Products such as Agrotain Plus and Twin N are actually a mixture that will mitigate volatilization and nitrate leaching.

The important point on all of this is pay for what you need, not what you don't need. For instance, if you are injecting it makes little sense to use a urease inhibitor, but a nitrification inhibitor may be a good option depending on your soil conditions and timing of N application. For those who are broadcasting you have the choice of using just a urease inhibitor to stop volatilization or both urease and nitrification inhibitors. This will largely depend on your rate of application and how long you are depending on that nitrogen. If you are putting everything on up front well before crop uptake you may want to use both inhibitors, if not maybe only a urease inhibitor.

A final note is that the products mentioned are only a few of the total products out there. For products not listed, simply ask what the specific mode of action is for the product. If you have any other questions please contact me or your local extension agent.

Additives	Mode of Action	Example Products
Urease Inhibitors	Inhibit volatilization from surface applied urea containing fertilizers	Agrotain
Nitrification Inhibitors	Inhibits conversion of ammonium N (NH4+) to nitrate N (NO3-). Can reduce loss of N by leaching in well drained soils or denitrification in poorly drained soils	N Serve Instinct Guardian
Combination Products	Both urease inhibitor and nitrification inhibitor	Agrotain Plus

Spring pastures can bring bloat

Spring time is here and pastures are growing quickly. With this new lush growth also comes an increased concern for bloat. Bloat typically occurs on young fast growing pastures that have more than 50 percent legumes (clover, alfalfa, etc.). Bloat is simply a condition brought on due to excess protein in the rumen which creates foam that will not allow gasses to escape the rumen. This condition leads to excess pressure in the cattle's rumen and in worst cases can lead to death. Bloat can be a major problem on lush spring pastures, however it can be managed.

The first step in managing bloat is to identify your pastures containing more than 50 percent legumes. These pastures will contain high protein levels especially in the spring when all of the growth is new and lush. Identify your pastures that are most likely to be a problem and use extra caution when animals are on those pastures. If all of your pastures contain high portions of legumes you want to take special care to give animals time to get used to the pastures early in the spring.

Management strategies such as feeding grass hay prior to the grazing period and not allowing access to pastures when excess moisture is present due to rain or heavy dew will help minimize the occurrence of bloat. Over eating frequently occurs when hungry cattle are turned onto fresh pastures with high percentage of legumes. Bloat is probable if these animals have not been accustomed to the legume mixture. Feeding grass hay prior to grazing allows the cattle to fill the rumen with a lower protein feed and will decrease the occurrence of over eating and thus minimizes the risk of bloat. Continue to feed hay prior to grazing for 5-6 days. During this time decrease the amount of hay fed until they are dependent totally on the pasture.

Poloxalene is another management option for those dealing with high percentage legume pastures. This chemical reacts in the rumen and decreases the instance of foam and allows excess gasses to escape naturally. This chemical is most easily fed in a molasses, salt, and poloxalene block mix. Allow one block for every 5-6 cattle and keep them in places where cattle typically gather. You may also be able to add poloxalene into any grain mixes you may be feeding. You should feed half a pound of poloxalene per animal.

Finally, the best management strategy will be to check your cattle frequently, about twice a day. This will allow you to observe any problems that may exist. The first visual sign of bloat is a notable increase in the fullness of the left side of the animal. If a cow is struggling with bloat you may be able to alleviate the symptoms by inserting a hose into the rumen to allow gasses to escape. Additionally there are oral products on the market that can be fed to aid in recovery. Consult your veterinarian about these products. If neither of these options work, you may want to attempt to use a trocar or cantula to relieve the pressure in the rumen; however, these should be the last resorts and should be observed by a veterinarian.

Using these steps you should be able to effectively manage bloat in your cattle without instances of emergency management. If questions or concerns still exist call myself or your local extension agent to assist you in your specific situation.

Budget Savvy Corn

As markets continue to be volatile and margins are scrutinized we all are looking for a place to save some green, is your corn doing the same? Recently there has been a lot of attention focused on corn hybrids and their use of nitrogen. What if genetic advancements allow us to change our nitrogen recommendations on corn, how about if you use the same nitrogen but increase the yield? Research has already shown that yield response to nitrogen is not only based on amount but also tied to soil type and yield potential so it seems only natural that the specific genetics of the plant may also be a player. Recent research and demonstration has also shown that some of the most striking differences with hybrids is how fast they can recover after a time of stress. Another interesting article was also recently posted on AgWeb looking at some of the possibilities to advancing corn yields in the future by minimizing stress to individual plants. Individual plants must compete with each other for nutrients in order to have consistent growth across the field, so if these plants can get better at competing hopefully they will utilize more of the nutrients available to them in the field.

As we look down the road we may see more ways that corn becomes budget savvy. This shouldn't be a surprise to us since in some sense it has already happened. With new traits we can now plant corn resistant to pests allowing us to spend less on chemicals and applications (while more for the bag of seed) and also saving us some time. As we move forward in the market there is no doubt our corn will continue to get 'smarter' and hopefully widen our margins on the farm.

Cut Costs, don’t eliminate!

As I was working on my father-in-law's dairy farm this weekend I couldn't help but think of the current economic situation facing all dairy farmers and most of agriculture in general. Things are tight and because of this costs need to be reassessed. As I was bedding up some cows I thought of how crucial some costs really are. Take the straw I was using at that point. I could have just eliminated the use of the straw to cut costs, however we all know the long term affects of that would be devastating in cattle health and production. This got me thinking about all the upcoming costs on the agronomic side of farming and where we may try to eliminate costs that may hurt us in the long run. Here are some of my thoughts.

Soil testing is a practice we preach all the time, and the fall is the best time to do it. Although this can be a low cost practice it may be one that gets a scrutinizing eye as we hit hard times. Depending on your current testing practices you may have some room to cut costs here, but they should not be eliminated. If you soil test every year you can probably take a year off. Use last year's soil tests along with this year's crop grown and yield to estimate nutrient removal and thus see what nutrients need to be added for next year's crop. If you haven't soil tested in over three year you ought to consider taking soil samples to check where you are at.

Once you have soil tested the question always is where do I spend money first? The most important area in soil health and nutrient availability to the plant is pH. If you have low pH (low depends on crop but typically no lower than 6.0) lime is the best product you can buy. Dollar for dollar this will return the greatest on your investment. Soil pH is a driver in many other nutrient cycles as well as the microbial population in the soil. If you have only one product you can buy for your soils make it lime. This year we have seen many cases around the state of poorly inoculated soybeans, one of the contributing factors to this has been low pH.

Fertility in the form of commercial fertilizers is always a large expense on most farms. Many farms in this area do have the availability of manure, however many of us need to supplement our manure nutrients with fertilizer. One of my biggest concerns at this point in time is potassium. Due to last year's high prices for potassium many decided to take a year off of buying potassium and mine some of the potassium in the soils. This year due to excellent rainfalls many of us have experienced yields at the high end of our expectations; this means more potassium has been used. Now we are in a situation where very few may want to invest again in potassium even thought the price is falling. This could set us up for some deficiencies. If I were to offer one suggestion on potassium fertilizer at this point it would be this. If you have manure at your disposal get it tested for nutrients. If commercial potassium is more expensive then nitrogen, apply your manure at a rate to supply potassium and supplement with nitrogen. If you are going into corn the use of a mid season nitrogen test such as the PSNT or Chlorophyll meter along with sidedressing can save money as will. In addition to potassium make sure you keep an eye on boron levels on alfalfa. This year we have had great yields so therefore if you are harvesting silage of any type, hay, and/or fodder you have a lot of nutrients in your bunkers, silos, and barns.

As we try to manage this current time of tight economics we need to take a good assessment of cutting costs without hurting ourselves in the future. With good soil tests you may be able to find some areas where you can cut costs, however we want to maintain enough nutrition in the soil to allow for good yields in the years to come. Many times if we get behind in nutrition in the soil it will take a long time to get it back. Additionally, if we don't have soil tests we will need to wait until we see deficiency in the crop before we know we are behind. At that time we have lost yield and that can be a costly mistake.

Selling Considerations; Shell versus Silage

As corn dries down many look to prices and markets to see what options they have. In Franklin County we typically have the option of either selling silage or grain depending on what seems to have the most favorable economics. I am not an expert in the markets so I'm not going to tell you that this is black and white, however I do have a few considerations you should make prior to selling your crop.

The main difference on the agronomic side of silage versus grain is the nutrients removed from the field when we take the whole plant versus just the grain. For this example I'm going to look at only phosphorus (P) and potassium (K). Nitrogen can also play a role but the system is very complex so it is not clear exactly how much we will keep around until next years growing season either with or without cover crops (this is why we test prior to side dressing N).

So if we look at removal of P and K from silage we can estimate (using Penn State's Agronomy Guide) that we will remove approx. 5.0lbs/Ton of P and 11.0lbs/Ton of K. As a rough estimate we typically consider the conversion from bushels of corn to tons of silage as 6.5-7bu/ton of silage. If we use this conversion for our removal rates for grain end up at 2.8lbs of P and 2.1 lbs of K removed (7*book values for grain removal). This means that roughly twice the amount of P is removed and over 5 times the amount of K is removed when comparing silage to grain.

So let's do a quick example to clarify. Initial estimates show a 150 bu/ac grain yield or 21.5 Ton/ac silage yield in a specific field. We are trying to decide if we should sell it to the neighbor or keep it for grain. December futures are showing a price of $3.09/bu or$464/ac on this yield. The difference between grain and silage in nutrients removed at this yield will be 47.5 lbs of P and 191.5 lbs of K. With today's price of $0.25/lb. P and $0.50/lb. K this is a difference of $107.63/ac. just to buy back the nutrients you lost by selling silage. If we add that into our grain price ($464) we need $572/ac. or about $27/ton (on 21.5 Ton/ac) to break even with our grain price of $3.09. Obviously neither of these take into account the cost of harvest etc. so keep in mind who is paying for that when pricing your corn.