Simposio nacional de la ciencia del suelo

Congreso Nacional de la Ciencia del Suelo
Punta Arenas – 2014
COMPOST EFFECTS ON MICROBIAL BIOMASS AND SOIL P POOLS AS
AFFECTED BY PARTICLE SIZE AND SOIL PROPERTIES

Lata, S. & Marschner, P.
(School of Agriculture, Food and Wine, The University of Adelaide).
e-mail: [email protected]
RESUMEN (o) ABSTRACT
Previous studies have shown that finer composts release nutrients more quickly than coarse composts, but
little is known about the nutrient release from different size fractions of a compost. To assess if compost size
fractions differ in their effect on microbial biomass and soil P pools, a compost from garden waste was
separated by sieving into different particle size fractions (> 5 mm, 3-5 mm and < 3 mm) and then mixed into
three different soils (referred as soil A, B and C) at a rate of 50 mg total P kg-1. These soils were chosen
because the size of soil P pools could be affected by soil properties which may also influence how the P pools
respond to compost addition. Cumulative soil respiration, microbial biomass and soil P pools were determined
after 25 and 50 days. Compost addition increased soil respiration and micobial biomass C and P, with the
greatest increase in respiration with the > 5 mm fraction and in microbial biomass C and P with the < 3 mm
fraction. The size of the P pools was mainly affected by soil type, the compost fractions had similar effects on
soil P pools except for a greater increase in available P concentration by the finest fraction compared to the
coarser size fractions. Soil A with the highest organic matter content had the highest concentrations of Fe/Al
associated P (NaOH-P) and organic P whereas Ca-associated P (HCl-P) dominated in the alkaline soil C. The
size of most P pools, even the so-called stable P pools changed over time in amended and non-amended soils.
It can be concluded that the size of P pools is more strongly affected by soil properties such as organic matter
content, texture and pH than by the compost fractions.
Palabras clave: size fractions, soil properties, temporal changes
COMPOST EFFECTS ON MICROBIAL BIOMASS AND SOIL P POOLS AS
AFFECTED BY PARTICLE SIZE AND SOIL PROPERTIES

Lata, S. & Marschner, P.
(School of Agriculture, Food and Wine, The University of Adelaide).
e-mail: [email protected]
RESUMEN (o) ABSTRACT
Previous studies have shown that finer composts release nutrients more quickly than coarse composts, but
little is known about the nutrient release from different size fractions of a compost. To assess if compost size
fractions differ in their effect on microbial biomass and soil P pools, a compost from garden waste was
separated by sieving into different particle size fractions (> 5 mm, 3-5 mm and < 3 mm) and then mixed into
three different soils (referred as soil A, B and C) at a rate of 50 mg total P kg-1. These soils were chosen
because the size of soil P pools could be affected by soil properties which may also influence how the P pools
respond to compost addition. Cumulative soil respiration, microbial biomass and soil P pools were determined
after 25 and 50 days. Compost addition increased soil respiration and micobial biomass C and P, with the
greatest increase in respiration with the > 5 mm fraction and in microbial biomass C and P with the < 3 mm
fraction. The size of the P pools was mainly affected by soil type, the compost fractions had similar effects on
soil P pools except for a greater increase in available P concentration by the finest fraction compared to the
coarser size fractions. Soil A with the highest organic matter content had the highest concentrations of Fe/Al
associated P (NaOH-P) and organic P whereas Ca-associated P (HCl-P) dominated in the alkaline soil C. The
size of most P pools, even the so-called stable P pools changed over time in amended and non-amended soils.
It can be concluded that the size of P pools is more strongly affected by soil properties such as organic matter
content, texture and pH than by the compost fractions.
Palabras clave: size fractions, soil properties, temporal changes

Source: http://congresosuelos2014.umag.cl/web/wp-content/uploads/2013/11/4.pdf