ABSTRACT
Response of soil physicochemical and microbial properties to organic amendment addition in three soil types

Juan Hirzel1* , Alejandro Antúnez2, and Mauricio Schoebitz3
 
Conventional agricultural practices have progressively reduced soil fertility, largely as a consequence of C depletion. So, the application of organic amendments as a fertilization strategy should enhance soil properties and promote long-term sustainability. This study assessed the effects of a composted organic amendment, “bio-stabilized”, as improver of the soil properties applied at rates of 1% and 2% (w/w), on the chemical, physical, and microbiological properties of three soils with contrasting textures (sandy loam, silt loam, and clay loam) following a 30 d aerobic incubation. The results showed that bio-stabilized application improved chemical properties across all soils, resulting in agronomically adequate nutrient availability and acceptable electrical conductivity levels (< 0.55 dS m-1). In addition, water retention increased at potentials corresponding to different pore-size classes in two soils (500-1500 kPa in the silt loam soil and 33-1500 kPa in the clay loam soil). Microbiological properties increased quantitatively with bio-stabilized application; however, a significant increase in dissolved organic C was observed only in the clay loam soil (from 98.4 to 283.4 mg kg-1). Overall, the application of bio-stabilized at the evaluated rates improved soil properties, with positive implications for agronomic performance and soil sustainability.
Key words: Bio-stabilized, clay loam, compost, sandy loam, silt loam.
1Instituto de Investigaciones Agropecuarias, INIA Quilamapu, Chillán 3800062, Chile.
2Instituto de Investigaciones Agropecuarias, INIA La Platina, Santiago 8820000, Chile.
3Universidad de Concepción, Facultad de Agronomía, Concepción, Chile.
*Corresponding author (jhirzel@inia.cl)