Crop nutrition and grain yield as affected by phosphorus fertilization and continued use of phosphogypsum in an Oxisol under no-till management

Abstract

ABSTRACT The benefits of applying phosphogypsum to the soil are widely known. However, the effect of phosphogypsum on phosphate fertilization efficiency is still unclear. A long-term field experiment was performed on an Oxisol in Parana State, Brazil to evaluate the effects of triple superphosphate (TSP) and phosphogypsum application rates on nutrition and grain yield of soybean, wheat, and black oat under no-till. Applying TSP in the sowing furrow of soybean and wheat increased soybean yield by 14 to 24%, wheat yield by 57%, and black oat yield by 78%. Soybean yields varied in different cropping seasons in response to phosphogypsum application (with no response to increases of up to 15% in yield), while phosphogypsum increased wheat yield by 23% and black oat yield by 59%. The water balance during crop flowering possibly interfered on crop yield response to phosphogypsum. The use of phosphogypsum increased agronomic P-use efficiency by 20%, regardless of the TSP-P application rates. Changes in P-leaf concentration caused by TSP fertilization and phosphogypsum use had a positive impact on crop grain yield. Our results reveal that the continued use of phosphogypsum to alleviate subsoil acidity could increase the phosphate fertilization efficiency and improve crop yield performance under drought stress.