STARTER FERTILIZER APPLICATION RATES AND METHODS FOR CONVENTIONAL AND NO-TILLAGE COTTON. 1992 TENNESSEE DATA

D.D. Howard, Jack Joyner, R.L. Hutchinson, and P.E. Hoskinson

ABSTRACT

Starter fertilizer application methods for cotton production include banding two inches to the side and two inches below the planted seed (2x2) and applying over the top (OT) of the planted seed. Recent research has indicated that applying low rates of fertilizers indirect contact with the seed may increase yields. Research was initiated at the Milan Experiment Station to evaluate the effect of applying in-furrow (I-F) starter fertilizer rates and comparing with 2x2 and over the top application methods for conventional (CT) and no-tillage (NT) cotton production. The research was conducted on a Loring silt loam having high Mehlich I extractable P and K levels. The experimental design was a randomized complete block with treatments replicated five times. The fertilizer 11-37-0 was applied at 1.5, 3.0, and 4.5 gal/A I-F and at 7.5 gal/A either banded 2x2 or banded OT to CT and NT cotton. A total of 80-40-60 lb/A of N, P2O5, and K2O respectively, was applied to all plots either broadcast or a combination of broadcast plus starter. Ammonium nitrate, concentrated superphosphate and muriate of potash were the broadcast fertilizer materials. The cultivar DPL 50 was planted in 40 inch rows on May 1. Measurements to evaluate the fertilizer rates and application methods included: plants per foot of row (P/F) and leaf surface area (LSA) six weeks after applications and lint yield per acre.

Leaf surface area, P/F and yield were affected by fertilizer placement method for both tillage systems. Applying 7.5 gal of 11-37-0 in a 2x2 band resulted in greater LSA, P/F, and yield for both tillage systems when compared with I-F treatments. The I-F treatments resulted in lower P/F than other placement methods for both tillage systems. Applying 3.0 and 4.5 gal/A 11-37-0 I-F reduced P/F when compared with applying 1.5 gal/A I-F for both tillage systems. Rate of fertilizer applied I-F did not affect CT LSA or yield. Applying 1.5 I-F resulted in higher NT LSA and P/F. The LSA and P/F measurements of the OT and check were greater when compared with the 3.0 and 4.5 gal/A I-F treatments. Even though distinct differences in LSA and P/A were observed due to starter placement, yield differences were not as distinct for either tillage system. Regression analysis of the CT data indicated 48% of the yield variation was explained by P/F in a quadratic equation while 53% of the yield variation was explained by LSA in a quadratic equation. For the NT system, 43% of the yield variation was explained by P/F in a linear equation while only 16%of the yield variation was accounted for by LSA in a linear equation. For the year, the NT cotton was earlier that CT cotton. The data indicates that for 1992, I-F fertilizer applications reduced yield for both tillage systems when compared with the 2x2 band method.





[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page

Document last modified July 8, 2004