Submitted to: Fluid Journal
Publication Type: Trade journal
Publication Acceptance Date: 10/30/2002
Publication Date: 4/1/2003
Citation: KOVAR, J.L. SEARCHING FOR MORE EFFECTIVE CORN STARTERS IN CONSERVATION-TILLAGE SYSTEMS. FLUID JOURNAL. 2003. V. 11(2). P. 8-11. Interpretive Summary: Early in the growing season, cool soil temperatures often limit the ability of corn roots to absorb sufficient nutrients and water. An application of a small amount of fertilizer at the time of planting may overcome this problem, leading to better plant growth and higher grain yields at the end of the season. With a field experiment, we found that nitrogen and phosphorus fertilizers applied in or near the seed furrow generally had no negative effect on seed germination. Fertilizer mixtures with more nitrogen relative to phosphorus boosted early growth of the crop, as well as corn grain yields. A lack of adequate rainfall during the middle of the growing season probably limited the effect to some extent. Nevertheless, the results suggest that this production practice is an inexpensive and environmental-friendly way to promote maximum soil productivity, which will certainly benefit those involved in production agriculture.
Technical Abstract: Starter fertilizer formulations and placement were investigated in three studies in 2002: i) effect on corn growth and grain yield; ii) changes in P bio-availability in the soil; and iii) differences in hybrid response. Formulation and placement generally had no effect on corn emergence in 2002, with a mean of 86 percent and values ranging from 78 to 90 percent. The exception was 21 gal/A of 7-21-7, applied as a 4-inch surface band over the row, which decreased emergence. In 2002, no one N:P2O5 ratio or starter placement consistently outperformed all others; however, the highest yields were produced with starters containing more N relative to P2O5. Measurements of P availability within the profile were inconsistent. Highest concentration of bio-available P 43 days after application occurred more than four inches below the surface for 15-30-10 (2x0), while application of 60-30-10 (2x0) had little measurable effect on available P in the profile. At 68 days after application, changes in P bio-availability probably reflected differences in root proliferation, rather than the effect of starter application. Finally, preliminary results of a pot experiment suggest that two non-transgenic corn varieties took better advantage of early growing conditions in Clarion silt loam soil than did transgenic isolines.