Comparação de métodos de extração da solução do solo

Abstract

RESUMOA composição iônica da solução do solo é de grande relevância para o monitoramento da disponibilidade de nutrientes e manejo da adubação tal como, também, processos de contaminação ambiental. Assim, métodos mais viáveis que estimem a composição iônica desta solução, são bem aceitos na literatura. Esta pesquisa objetiva avaliar o desempenho de métodos de extração da solução do solo como: via pasta de saturação, extratores munidos de cápsulas porosas e relações solo:água de 1:2; 1:5 e 1:10, com e sem processo de filtragem. Utilizaram-se amostras de Neossolo Flúvico em colunas de PVC e soluções saturantes correspondentes a 0; 20; 30; 40; 50; 60; 70; 80; 90; 100; 110 e 120 mmol c L -1 de NaCl, em delineamento em blocos ao acaso com quatro repetições. Os extratores munidos de cápsulas porosas apresentam-se como alternativa viável para extração da solução do solo e monitoramento da condutividade elétrica, do potencial osmótico e composição iônica. Os extratos aquosos em diferentes relações solo:água apresentam potencial de uso para extração e posterior caracterização da fase aquosa do solo. O processo de filtragem pode ser descartado quando o intuito é a determinação somente da condutividade elétrica. Palavras-chave: potencial osmótico, cápsulas extratoras porosas, relações solo:águaComparison of methods for extracting soil solution ABSTRACT The ionic composition of the soil solution is of great importance for monitoring the availability of nutrients and fertilizer management, as well as processes of environmental contamination. Thus, the most viable methods to estimate the composition of the soil solution are well accepted in the literature. This study aims to evaluate the performance of the extraction methods by saturation paste, porous extractor cups and soil:water relations of 1:2, 1:5 and 1:10, with and without filtering process. Samples of Fluvic Neossol were used in PVC columns and saturated with solutions corresponding to 0, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120 mmol c L -1 NaCl, in randomized block design with four replications. The extractors with porous cup are indicated to extract the soil solution for monitoring the electrical conductivity, osmotic potential and ionic composition. The aqueous extract in different soil:water ratio has a potential use for the extraction and subsequent characterization of the aqueous phase of soil. The filtering process can be discarded when the intention is only to determine the electrical conductivity.

Nitrate and potassium concentration in fertigated soil cultivated with wine vines

“…The movement of nitrate and potassium ions in the soil was monitored weekly with the aid of porous cup solution extractors (Souza et al, 2013;Silva et al, 2003) installed 0.4 and 0.6 m deep in the plant row in all treatments and in three blocks (49 batteries with 78 porous cup extractors). A vacuum of -80 kPa was applied one day after fertigation.…”

“…Alongside the extractors, tensiometers were installed 0.40, 0.60 m deep to determine the soil moisture at the moment of the extraction of the soil solution for correcting the latter in relation to the moisture of the saturated paste. Prior to the experiment, soil samples were collected to determine the moisture of the saturated paste (Souza et al, 2013) in each experimental unit; such value was taken as reference and used to correct the values of nitrate (NO 3-), potassium (K + ) and electrical conductivity (EC) in the soil solution, obtained by the porous cup extractors, as performed by Silva et al (2003).…”

Soil Solution Nutrient Availability, Nutritional Status and Yield of Corn Grown in a Typic Hapludox under Twelve Years of Pig Slurry Fertilizations

“…Nevertheless, the complexity and difficulty in extracting soil solution, as well as the low concentration and difficulty of quantifying nutrients, render the use of this method a technical criterion for fertilizer recommendation, being restricted to a few researches (Schlotter et al, 2012;Souza et al, 2013).…”

Watermelon fertigation with electrical conductivity and ph monitoring in the soil solution

“…According to SOUZA et al (2013), the composition knowledge of the liquid phase, commonly called the soil solution, is very important for monitoring the nutrients availability for plants, environmental contamination processes and those related to the understanding of the characterization dynamics and soils evaluation affected by salt.…”