|Mallarino, A - IOWA STATE UNIVERSITY|
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.
Technical Abstract: 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.