Osmotic potential of wheat grown with fertilizer placed in strips or broadcasted

Abstract

Winter wheat (Triticum aestivum L. em. Thell. ‘Osage’) was grown in the greenhouse with fertilizer (urea ammonium phosphate, 28-28-0, 200 kg ha⁻¹) placed in strips with the seed at planting or broadcasted before planting and worked into the surface of the soil to determine how severe osmotic injury is with stripped (banded) compared to broadcasted fertilizer. Control plants grew with no fertilizer. The soil was a Kirkland clay loam (Udertic Paleustoll). In addition to osmotic potential, water potential, stomatal resistance, and height were measured during the experiment. At harvest, vegetative yield and elemental composition of the shoots and roots were- determined.

During the first 20 days after planting, the osmotic potential, as well as the water potential, of plants with fertilizer placed in strips was 2 to 3 bars lower, and the stomatal resistance was 2 to 3 s cm⁻¹ higher, than those of plants grown with the broadcaster fertilizer. Leaves of plants with the stripped fertilizer had 12% more N and 42% more P than leaves of plants grown with the broadcasted fertilizer. Because plants grown with stripped fertilizer had a lower final dry weight, shoots with the stripped fertilizer had — 14% less total N, but + 8% more total P, than shoots grown with the broadcasted fertilizer. The results showed that, 20 days after planting, the osmotic potentials of plants grown with fertilizer placed in strips or broadcasted were the same and that there was an increase in efficiency of fertilizer use with placed P.