Residue of Phosphorus Sources Broadcast and Applied on Rows in Forages during Off-Season Crops

Abstract

This study aimed to evaluate the residual effect of phosphorus sources and application techniques in the intercropping of forages during off-season crops. The experimental design was randomized blocks in a 4 × 2 + 1 factorial, being four sources of phosphorus [Bayóvar Reactive Phosphate (BRP), Monoammonium Phosphate (MAP), Simple Superphosphate (SS) and Triple Superphosphate (TS)], two application techniques (broadcasting and on rows) and an additional without phosphorus. The experiment was conducted during the off-season crop. The residual effect of phosphorus fertilization increased the growth and the production of biomass of forage sorghum regarding broadcast SS and TS sources. The lowest P contents in the tissue of plants fertilized with SS and TS may be attributed to the diluting effect, as it achieved the highest production of biomass. The application of TS favored a greater dry matter production in Brachiaria brizantha cv. Piatã. At the depth 0.00-0.05 m, there was a higher P content with the application of BRP. However, the production of biomass was low, a factor that may be related to an overestimation of P bound to Ca by the Mehlich-1 extractor. Under cultivation conditions, broadcast SS and TS had a higher residual effect.

Phosphate Fertilizers Broadcast and Applied on Rows in a High Fertility Tropical Soil Cultivated with Two Soybean Seasons

“…The result of the 2017/2018 season is corroborated by the greater e ciency of the use of residual P of soybean in 2014/2015 season (Couto 2018) by sorgo and Urochloa brizantha cv. Piatã cultivated in succession, in 2015 second season in the area with application of the TS (Barbosa et al 2017). This P in crop residues will be transformed into organic P in the soil, which will be releasing slowly in the future thus increasing the P in the soil fractions (Brunetto et al 2011).…”

“…These soils are very weathered and present oxidic characteristics with high xation/adsorption of phosphorus (P), resulting in the low availability of this nutrient for crops (Novais and Smyth 1999;Sousa et al 2016). This fact combined with the requirements of considerable amounts of phosphate fertilizers makes it essential to establish which source and form of application of P (Barbosa et al 2015; Barbosa et al 2017;Withers et al 2018) that can ensure the e cient use of the nutrient and increases in crops yield.…”

“…In the area of this experiment, both sorghum and U. brizantha cv. Piatã, cultivated in 2015 second season in succession to soybean crop 2014/2015, were e cient in recovering the inorganic residual P of the area with the TS(Barbosa et al 2017). And the soybean yield cultivated in succession to forage in the 2015/2016 season showed the highest productivity with the application of TS applied on rows(Couto 2018).…”