Corn response to strip‐tillage and phosphorus fertilization in the Northern Great Plains

AbstractStrip‐tillage is an emerging conservation tillage/residue management system for corn production in the Northern Great Plains. Producers in Manitoba are becoming more interested in strip‐tillage as it may provide many of the soil conservation benefits of no‐tillage production without potential limitations of cold soils in the spring common to this region. A 2‐year study evaluated corn (Zea mays L.) response to phosphorus (P) fertilization in strip‐tillage and conventional tillage systems. Fertilization treatments included a control (no P), two rates of P (30 and 60 kg P2O5 ha−1), applied as monoammonium phosphate (11–52–0) either in the fall with a strip‐tillage unit (as a deep‐band, 10–13 cm deep) or in the spring with a corn planter (as a side‐band, 5 cm beside and 2.5 cm below the seed). Spring side‐banded P treatments increased early‐season biomass at 2 of 4 site‐years by up to 103% compared to the unfertilized controls. At the same 2 site‐years, banded P treatments reduced days to silking by 2–3 days, compared to the unfertilized controls. Across all site‐years, spring side‐banded P treatments increased grain yield by an average of 467 kg ha−1 and decreased grain moisture content by 9 g kg−1 compared to the unfertilized control. Overall, side‐banded P at planting was agronomically superior to precision fall deep‐banding. There was also no agronomic penalty for corn grown with strip‐tillage, compared to conventional tillage, suggesting that strip‐tillage is an agronomically promising practice for corn production in southern Manitoba.