Submitted to: Fluid Fertilizer Foundation Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 20, 2001
Publication Date: February 20, 2001
Citation: KOVAR, J.L., MALLARINO, A.P. STARTER FERTILIZER FORMULATIONS AND PLACEMENT FOR REDUCED TILLAGE CORN. FLUID FERTILIZER FOUNDATION SYMPOSIUM PROCEEDINGS. 2001. V. 18. P. 188-194.
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 promoted early growth of the plants and tended to boost corn grain yields. A lack of adequate rainfall during the middle of the growing season probably limited the effect. Nevertheless, the results suggest that this production practice is an inexpensive and environmental-friendly way to attain maximum soil productivity, which will certainly benefit those involved in production agriculture.
Recent research has shown that application of starter fertilizer may alleviate nutrient stress associated with poor root growth early in the season, which often results in a yield response. Several studies suggest that both nitrogen (N) and phosphorus (P) are responsible, with specific N:P ratios being more effective in some cases. To investigate, field plots were established on a Canisteo silty clay loam soil in Boone County, Iowa. Before planting, N fertilizer was applied to all plots, which received a total of 200 lb. N/A. The starter fertilizer treatments were: I)control; II)6-20-0 (5 gal/A 10-34-0), in-furrow; III)6-20-6 (8.7 gal/A 7-21-7), in-furrow; IV)15-30-10, dribbled over row and 2x0; V)30-30-10, dribbled over row and 2x0; VI)45-30-10, dribbled over row and 2x0; and VII)60-30-10, dribbled over row and 2x0. Starter fertilizer had no effect on emergence, with a mean of 90.5% and values ranging from 88% to 92%. The N, P, and potassium (K) content of plants at the 4- to 5- leaf stage was in the optimum range. At mid-silk, however, both N and K in ear leaves were below the sufficiency range. A lack of adequate rainfall during the middle of the growing season likely led to this problem. In general, starter application had a tendency to boost yields, but yield response was not consistent. Moreover, no one N:P205 ratio or starter composition/placement combination outperformed the others.