No-till and strip-till corn production with broadcast and subsurface-band phosphorus and potassium

Fertilizer placement is often designed to improve nutrient availability. Our objective was to determine the effect of P and K rate and placement in no-till and strip-till on grain yield; water, P, and K values in the soil; and the distribution of corn (Zea mays L.) roots. A 4-yr field experiment was setup near Urbana, IL, with a corn-soybean [Glycine max (L.) Merr.] rotation. Tillage/ fertilizer placement was the main plot [no-till/broadcast (NTBC), no-till/deep band (NTDB), and strip-till/deep band (STDB)]; deep band was 15-cm beneath the crop row. Phosphorus fertilizer rate (0, 12, 24, and 36 kg P ha^-1 yr^-1) was the subplot, and K-fertilizer rate (0, 42, 84, and 168 kg K ha^-1 yr^-1) was the sub-subplot. Measurements included grain yield and yield components, grain and shoot P and K concentrations, root parameters, and soil-water, P, and K values. Strip-till/deep band produced greater kernels row^-1 and 9.43 Mg ha^-1 yield that was 7.8% greater than NTBC and 7.9% greater than NTDB. Deep banding increased soil P and K test values beneath the crop row and lowered soil surface test values compared with broadcast applications, but had no effect on root distribution. Across treatments, greatest apparent P and K uptake occurred in the surface layer where most roots were present and where precipitation replenished water to a greater extent than deeper layers. Relative to NTBC, STDB had 24% greater apparent-P and 23% greater apparent-K uptake rates. The results indicate that improved conditions for nutrient uptake provide a competitive advantage for production with STDB relative to no-till treatments.