Monday, November 13, 2006

Strip-Till Corn Response to Deep Banding Versus Broadcast Application of Phosphorus and Potassium.

Matias Canepa1, Tony Vyn1, and Ann Kline2. (1) Purdue University, 114 Nimitz Dr. Apt. 2, West Lafayette, IN 47906, United States of America, (2) Purdue Univ, Dept of Agronomy, 1150 Lilly Hall, 915 W State St., West Lafayette, IN 47907-1150

Deep banding of fertilizers is practiced, in part, to overcome perceived limitations imposed by soil-conserving tillage systems on availability of less mobile nutrients, such as Phosphorus (P) and Potassium (K), to corn in high yield environments.  Previous studies have suggested that the degree of corn response to deep banding of P and K is dependent on factors such as initial soil-test P and K levels, the degree of stratification for the nutrient(s), and possibly on weather and hybrid factors. From 2001 to 2006, we tested the response of multiple corn hybrids (two each year) to broadcast versus deep-banded P and/or K (at a single high rate) and control treatments on a dark prairie silty clay loam soil near West Lafayette, IN. Strip-tilled corn with additional starter-banded fertilizer followed no-till soybean. The study was located in two fields with similar soil texture but with clearly different soil-test P and K and vertical stratification.  The site for years 2001-2003-2005 tested medium-high for P (24 ppm) and medium for K (142 ppm), and was vertically stratified for exchangeable K but not for available P.  In 2 of these 3 years, broadcast P-K yielded significantly more than the control treatment, whereas banded treatments of P and K alone or combined generally did not yield differently than the control.  The other site for years 2002-2004-2006 tested extremely high for P (93 ppm) and medium for K (141 ppm), with little vertical stratification of P or K in the 0-8 inch depth interval.  In 2002 and 2004 at this site, deep-banded treatments including K yielded significantly more relative to broadcast application of P plus K fertilizers, but not compared to the control.  Corn yield response to P and K fertility placement treatments was never affected by hybrid, but did vary with environment.

Handout (.pdf format, 81.0 kb)