Crop sequence and P fertilization effects on soil P fractions under no-tillage

APPELHANS, STEFANIA CAROLINA; NOVELLI, LEONARDO ESTEBAN; MELCHIORI, RICARDO JOSÉ MIGUEL; GUTIERREZ BOEM, FLAVIO HERNÁN; CAVIGLIA, OCTAVIO PEDRO

NUTRIENT CYCLING IN AGROECOSYSTEMS

SPRINGER

Lugar: Berlin; Año: 2021

1385-1314

Increasing cropping intensity may affect phosphorus (P) recycling through cropresidue inputs, which maydiffer in soils with different productivity, Padsorption capacity, and P fertilization level. In three crop sequences: Soybean (Glycine maxL.Merr.)monoculture (S?S), Maize(Zea maysL.) monoculture(M-M), and Wheat (Triticum aestivumL.)/Soybean as a double crop (W/S) in a Vertisol and aMollisol; we assessed thelong-term effect of the crop sequences onsoil inorganic P (Pi) and organic P (Po) fractions, and the short-term effect of P fertilizationon soil Pi and Po fractions, Puptake, and grain yield. Two P fertilizationlevels (50 kg P ha-1, and control) were established in2016 on long-term experiments that includedS?S, W/S, and M-M. Bray1-P, aswell as total P, Po, and Pi inboth the coarse soil ([53lm) fraction (CF) and theNaHCO3extract, and accumulated yield and P uptake were measured. In the long-term, the cropsequences did not change soil Pfractions, but Po-CF and Pi-CFshowed similar values in both soils, suggesting less soil-type dependence than in other labile Pfractions. In the short-term,the P fertilization only increased theextractable Pi fractions (16% in the Mollisol and 25%in the Vertisol), suggesting that P in theCF was not a sink of Pfertilizer. Our study showed that P fertilization in different crop sequencesmay increase labile P fractionsand P recycling depending on soil type, auseful tool to develop P fertilization strategies at the crop sequence level.