Fertilizer phosphorus placement studies on calcareous and non‐calcareous chernozemic soils: Growth, p‐uptake and yield of flax

Abstract

Abstract Flax (Linum usitatissiumL.) was grown in field experiments over a five year period on a calcareous and a non‐calcareous Orthic chernozemic soil that were both low in NaHCO3extractable P. Six rates of P‐fertilizer as mono‐ammonium phosphate (MAP) were applied at seeding using four placement methods: 1. broadcast and cultivated 10 cm into the soil (BC); 2. banded in the seed row with the seed (PWS); 3. banded 2.5 cm below and 2.5 cm to the side of the seed (PSS); 4. banded 2.5 cm directly below the seed (PBS). Soil type, broadcast application of ? (BC) and application of low rates of ? using the PWS method had no significant effect on flax growth, seed yield and P‐uptake. Reduced emergence of flax occurred on the PWS when the rate of ? was 15 kg ha‐1or greater. The reduced crop emergence resulted in reduced seed yield and P‐uptake. With 15 to 25 kg ha‐1P seed yield was reduced by 28% to 62%. P‐fertilizer applied by both the PSS and PBS methods increased flax growth, seed yield and P‐uptake. Both me...