The influence of crop residues in vertical soil mobility of potassium

Abstract

This study has been developed to evaluate the influence of applying different types and doses of crop residues on potassium (K) mobility in soil columns. Rhodic Haplustox samples were collected at depths of 0.0-0.10, 0.10-0.20 and 0.20-0.30 m and used to create such soil columns, keeping the same profile distribution. The experimental design was randomized with three replications and the tested treatments were organized in a 4x4 factorial arrangement: 4 types of crop residues (brachiaria+sunflower; Mix (cultivated radish+oat+winter vetch); cultivated radish and wheat) and 4 doses of residues (0, 10, 15, and 20 Mg ha -1 ). The grinded and dried residues were applied to the surface of the columns, which were then irrigated with distilled water and incubated for 10 days to stabilize the reactions. After incubation, the soil columns were disassembled and separated into 0. 0. 05-0.10, 0.10-0.15, 0.15-0.20, 0.20-0.25 e 0.25-0.30 m. As amostras de cada camada foram secas, tamisadas e analisadas para determinação do teor de K trocável. Os resultados obtidos indicam que a aplicação superficial de resíduos de culturas altera os teores de potássio trocável do solo, especialmente na camada 0.0-0.05 m. Aumentando as doses de resíduos pode-se aumentar significativa e linearmente os teores de K trocável do solo nas camadas 0.0-0.05, 0.05-0.10, 0.10-0.15 m. Os resíduos da cultura de nabo forrageiro e do Mix (nabo forrageiro + aveia-preta + ervilhaca peluda) foram os que determinaram os maiores aumentos nos teores do K trocável do solo, podendo atingir profundidades de até 0.30 m. O aumento na adsorção do K nas camadas superficiais do solo indica uma menor necessidade de aplicação de adubos potássicos, podendo reduzir os custos de produção e a poluição ambiental. Palavras-chave: Cobertura vegetal, lixiviação, ciclagem de nutrientes, plantio direto, fertilidade do solo

A dual geochemical‐phytolith methodology for studying activity areas in ephemeral sites: Insights from an ethnographic case study from Jordan

“…The depletion of Cl and K through time could reflect the effects of exposure to sunlight and rain, mainly affecting outdoor animal pens, but also indoor areas after abandonment and removal of the tent. The depletions could also have resulted from anthropogenic inputs of decomposing organic matter and urine through animal dung, and water from household activities such as cleaning (Brito, Telles, Schnitzer, Gaspar, & Guimarães, ; Petrucci, ; Sconce, ). It is difficult to estimate which changes would occur in the other chemical elements and phytolith attributes measured in this study over longer durations of abandonment than the 15 years represented at the Wadi Faynan campsites studied here.…”

The influence of climate conditions and fertilizer rates calculated by different methods on spring wheat crop

“…The potassium concentration decreased at higher temperatures. This can be explained by the fact that in hot weather and dry soils potassium mobility is less, and less of it moves into mobile and plantshaped forms (Brito et al, 2014).…”

Production and composition of oranges cv. Lane Late under maintenance potassium fertilization

“…Furthermore, the roots of cover plants in the orchard interrows may have absorbed K from the deepest soil layers in all treatments, accumulating K in roots and shoot organs, which decompose when senescent, releasing K into regions close to the plant roots (HEINZ et al, 2011;BRITO et al, 2014). Furthermore, senescent leaves and branches deposited on the soil surface may have released K into the soil during their decomposition (TAGLIAVINI et al, 2007).…”

“…The growth of cover plant species that can absorb K from the deepest soil layers, cycling it via the decomposition of shoot residues deposited on the soil surface and decaying senescent roots, is observed in interrows (HEINZ et al, 2011;BRITO et al, 2014). Furthermore, the lack of plant response to fertilization may be related to internal K stores, especially in perennial organs formed in previous years, which may be redistributed to other organs during later cycles (ROCCUZZO et al, 2012).…”