Managing Fertililizer

I see we have a new follower who works in nitrogen management. I know we have several consultants and followers who work in lime and fertilizer management. It's a big task for all of us, especially farmers.


Basically, you can't optimize crop growth without nutrient management. I go back to the 17 known essential elements for plant growth. They are all here in some form or another but the farmer has some effect on them and wants to maximize his farm and return a profit to him and his family.



For over 100 years now we have used soil testing to find out what nutrients we have to work with and what we can afford to add for a good return. I always balance my needed nutrients within my budget and to stay environmentally friendly, sometimes referred to the spoon feeding method. I exlplain this as giving a dose when needed and when you can afford to buy the nutrient and put it on. The tissue test helps me to verify the soil test during the crop growing season. Wheat and cereal grains, lawns, pastures and hay crops are prime to be tissue tested now.



As we have changed to less tillage with more residue on top of the soil to hold it in place and feed to the soil organisms, we have changed the way we fertilize to some extent. Basically I soil sample when I can, usually in the fall, and try to address the macro and micronutrients with a fall broadcast. That didn't get completed in last years wet weather so we have been behind in finishing it this spring. That cause a huge rush this past dry month and the articles I wrote on bone tired.



Everyone has their own take on the the macronutrients most often applied, usually every year unless you don't fertilizer soybeans after corn. Those are the three numbers on a fertilizer bag, NPK, Nitrogen, Phosphorous and Potassium.



Let's look at nitrogen first, the one most applied this month in amount and cost. I imgaine most corn growers have at least $50 an acre in their nitrogen cost and the bills are rolling in for a crop we will harvest this fall.



"Whatever its source, nitrogen (N) is essential for achieving optimum yields of grain, forage, and other crops. The same is true of phosphorus (P) and other nutrients. Applying too much nitrogen or phosphorus to cropland, however, can have adverse effects on the environment. Achieving optimum yields without applying excessive nutrients should therefore be a goal of all farmers. Excess nitrogen and phosphorus in surface waters and nitrogen in groundwater cause eutrophication (excess algae growth) in surface waters and health problems in humans and livestock as a result of high intake of nitrogen in its nitrate form. "



Some use those big white tanks you see on county highways and in fields and apply a gas called anhydrous ammonia or NH3 and let the soil convert it to the ammonium form, NH4. Some use it as the sole source, others for a starter and apply more later for various reasons. This year I put on the crops need this way for cost and time savings. I will evaluate this method as the corn grows and make more decisions later.



Many farmers put the safer, liquid form of 28 or 32% UAN or urea ammonium nitrate on with the corn planter and/or the herbicide application as a weed and feed program. Others spread 40 plus percent urea form of nitrogen or a mix of different forms for the crops needs.



Total nitrogen applied to corn will vary from 100 actual pounds plus to over 200 lbs depending on soil, yield goal, and budget. 140-180 lbs of actual nitrogen are pretty typical in my area of southwest Ohio. Wheat will get 50-100 lbs, soybeans usually little or none since they make most of their own, other grasses will vary.



In Missouri, one researcher says "Research throughout the Corn Belt is providing increasing evidence of the value of producing corn without tillage. With most soils and rotations, yields and profits from no-till corn production are similar to or exceed those of conventional tillage. Reduced soil erosion has always been a convincing argument for no-till production. Yet some management problems persist, limiting acceptance of the practice. The broad spectrum of herbicides now available has eased some of the challenging weed control problems in no-till. Research has also identified solutions to potential problems related to no-till nitrogen management.


The soil environment in a non-tilled soil is vastly different from that of a clean-tilled field. Previous crop residues left on the soil surface are one obvious difference affecting many other soil properties and processes. One difference is the effect on soil nitrogen. This publication discusses the effects of surface residues on soil nitrogen and methods of managing fertilizer nitrogen to improve the efficiency of its use in a no-till cropping system. The focus is on corn production; however, many of the management practices can be applied to grain sorghum, wheat or other crops requiring nitrogen in no-till systems."



This explains what I do as well as many farmers across the country. The bottomline is we all approach fertilization from the way we farm and the fertilizers we have available and the money we can justify to spend on them.



And this is just one nutrient that a crop needs out of 17 or 18 known essential elements!



And they say farming is easy? I don't think many people believe that anymore!



Have a great day!



Ed Winkle