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Home My WebLink AboutThe Citizen, 1986-04-16, Page 13THE CITIZEN, WEDNESDAY, APRIL 16, 1986. PAGE 13 g. Lookingat nitrogen for better winter wheat BY JOHN HEARD SOILS AND CROPS SPECIALIST ONTARIO! MINISTRY OF AGRICULTURE AND FOOD Presently producers are plann- ing to apply their Nitrogen and red clover seed to the winter wheat crop. Let's work through the logic involved in making the `right' N application decision. In order for N topdressing to be profitable, an adequate wheat stand must survive the winter. Early topdressing will promote filtering, butthe plants must be there. So far most stands look good, so we'll assume N applica- tion is warranted. Which nitrogen source should be used? Theoretically, there are several factors involved in choos- ing the most efficient N source. Agronomically though, Ontario research has been able to measure no yield differences between spring applied N sources to winter wheat, so fertilizer should be chosen on the price per unit N. Dividing the cost of fertilizer by the percent N in the product gives us the cost per unit N of the fertilizer. If after comparing sever- al sources of N we find the cost per unit N to be similar - then we may wish to consider some individual characteristics of the fertilizer. These characteristics of N fertilizer tend to center around N loss prior to plant use. Urea is known to lose some ammonia N through volatilization when surface applied to soils that are warm and dry. Fortunately, few of our springs are warm and dry enough to facilitate much Loss. Since UAN or 28 percent N is a combination of urea and ammon- ium nitrate, there also exists some potential for urea N loss through volatilization. Some fertilizer com- panies are marketing an acid form of UAN that slows this volatiliza- tion reaction for a small additional cost per unit N. This past week a Guelph researcher presented a scenerio where even ammonium nitrate losses may occur due to denitrification if the upper 1-2" of soil is waterlogged and the soil is warmed by the sun. Gosh! Fellows could lose sleep over their selection of N fertilizer source. Thank goodness, which- ever one of the above sources that they do select, they will get the same yield. If we really want to see N fertility effects on yield, we Charles C. Culbert •Backhoeing & Tiling Open Ditch Weeper Beds Septic Tanks CAW 529-7571 should look at timing of app l ica- -tionrrateof N- and -spread -patterns but not sources. Yield penalties for untimely N application occurs when we apply N too late. N should be applied in April, and timing will depend more on soil conditions than on my advice on dates or growth stages. I mean N will go on in early April when the ground is frozen, or in mid to late April when the ground is sufficiently dry. A reminder is that the best catches of red clover will be from the early seeding period when the soil is frozen. Research from Ridgetown (R.C.A.T.) shows no yield increase due to splitting the N application when total N rates exceed 70 lbs. N/acre. This is for soft white winter wheat. For hard red winter wheats needing 160 - 1901bs. N/acre, a split or multiple split application is preferred. The nitrogen rate for soft white winter wheatvaries with your yield goal. In Publication 296 the recommendation for an 82 bu./ acre crop at current nitrogen prices is 100 lbs. N/acre. For a 67 bu. /acre crop, 80 lbs. N/acre is recommended. Remember to de- duct your fall applied nitrogen from this total. Last year several Huron -Perth farmers produced 100 bu. /acre crops with the 100 Ib. -Nlaere-rate. This indicates that if the growing season is favourable, your yields are not tightly con- strained by N rates. We are warned that high N rates may contribute more to protein content than to yield. If soft white winter wheat protein levels exceed 10.5 percent, then it is higher than the milling industry prefers. Exceeding N rates in Publication 296 could lead to this problem. The most visible wheat response to N occurs when applications are overlaps or misses. Respective responses will be lodging and low yields. Technology such as air -flow applications for dry fertilizer and custom -liquid applicators should reduce the variation on spread pattern, traditionally experienced with spinner spreaders: This effect on spread pattern, and the conven- ience of quick, custom application, should be weighted heavier than N source. FREE ESTIMATES Energy efficient, regular type exhaust fans, thermostats, and more in stock. 0 LEFT WIT One, Two Variable Speed Thermostats FARM DUTY MOTORS All kinds of motors in stock. Pulleys, fan blades It's Not Too Late! ... for soil testing SO%Lab offers: Bring your soil samples to us We have our own laboratory in Auburn Results in three days Soil testing could save you fertilizer dollars Soil Analysis for all field crops Soil Sampling service Pest Monitoring service Crop Information Centre a nd Computerized Programs for • Production Records •Fertilizer Treatments • Production Costing •Pesticide Treatments • Hybrid and Variety Selection For further information — CaII Tom Perry (519) 526-7513 or 526-7774 SOIL & CROP MANAGEMENT SERVICES - Soil Analysis - Crop Production Programs - Pest Monitoring. - BOX 46 AUBURN ONTARIO NOM 1E0