2000 Crops Day Report
Granular Nitrogen Fertilization Techniques in No-till
Eric Eriksmoen, Agronomist
Hettinger Research Extension Center
Many no-till farmers struggle with nitrogen fertilizer management in their small grain crops. Granular nitrogen sources are typically broadcast on the surface, applied with the seed during the planting process or incorporated into the soil prior to planting.
Surface applications of N fertilizers can be accomplished quickly and conveniently. The application depends on rainfall for incorporation into the root zone. A lack of timely rainfall can result in N loss due to volatilization. Some farmers over-apply, to compensate for these losses. A 1/4 to 1/2 inch rainfall will dissolve a pellet and safely leach the nitrogen into the soil sub-surface. Additional rainfall is required to leach the nitrogen into the root zone. The amount of rainfall needed to accomplish this is dependant on soil type and residue cover.
Nitrogen fertilization with the seed during planting is an efficient method, however, only small amounts can safely be applied to avoid seed mortality. The amount that can safely be applied with the seed is dependant on several factors including soil type, the soil moisture, the type of fertilizer used, row spacing, type of opener, crop species and other factors. Additional information is available in Extension Bulletin EB-62, Fertilizer Application with Small Grain Seed at Planting.
Banding N fertilizers in small grains is typically a slow process requiring an additional pass through the field prior to planting. The no-till grain drill is typically the piece of equipment utilized in this process, which makes it an expensive operation. The benefits of this method include the ability to place all of the N fertilizer down at one time and to place it directly into the root zone.
The objectives of this study were to observe differences in yield and grain quality characteristics of hard red spring wheat grown under various techniques of granular N fertilizer application methods in a no-till system.
Trials were grown in a randomized complete block design with four replications at Scranton (Bowman Co.), Regent (Hettinger Co.), New Leipzig (Grant Co.) and at Selfridge (Sioux Co.). Residual N was determined at each location and either 100 or 200 pounds per acre of 46-0-0 (Urea) was utilized, depending on level of residual N. Residual N levels were 46, 168, 122 and 47 pounds per acre at Scranton, Regent, New Leipzig and at Selfridge, respectively, with 200 pounds per acre of urea being utilized in the Scranton and Selfridge studies and 100 pounds per acre of urea being utilized in the other two sites. Fifty pounds per acre of 11-52-0 was applied with the seed at all locations and all treatments. The trials were planted with the spring wheat variety 2375 at a seeding rate of 1.1 million live seeds per acre with a coulter disc opener into soil that had been in winter wheat the previous year. Moderate hail damage and moderate foliar and head diseases caused reduced yields at New Leipzig. Results from each location are shown on the following page.
Test weight tended to not be significantly affected by fertilization technique. Grain protein tended to vary depending on fertilization technique with no added N having the lowest, followed by surface applied N, N applied with the seed and with banded N having the highest grain protein. As would be expected, there was no statistical differences for grain protein at Regent and New Leipzig where residual N levels were high. The highest grain yields tended to be associated with banded N, followed by surface applied N and finally, N applied with the seed where seed mortality resulting in thin stands was evident.