Evaluation of solid and liquid soil organic amendments for agronomic ...

Acta Horticulturae (ISHS) 2014, 1018: 109-114.

Evaluation of solid and liquid soil organic amendments for agronomic use in Chile Angulo, J.1, Ortega, R.1, Martínez, M.M.2, Molina, M.1, and Torres, A.1 1

Centro avanzado de Gestión, Innovación y Tecnología para la Agricultura (CATA), Universidad

Técnica Federico Santa María. Santiago de Chile. 2

University of Bonn, Institut für Nutzflanzenwissenshaften Tropicher Pflanzenbau. Bonn, Germany.

Keywords: humus, compost, compost tea, sanitary safety, agricultural microbiology Abstract Given the importance of the organic amendments and the increase on the use of compost and compost tea in the Chilean agriculture, the objective of this study was to measure the quality of amendments commonly used in northern central Chile. A total of five solid samples (compost and humus) and seven liquid samples (compost and humus tea) were evaluated. Analysis of toxicity, human pathogens, microbiological indicators, and physical-chemical composition were included, as indicated on the compost Chilean normative. The presence of

soil

beneficial

microorganisms

and biochemical

parameters

associated

with

dehydrogenase activity (UDH), urease (UU), acid and alkaline phosphatase (UPac, UPalk), and β-glucosidase (UBG) were also evaluated. Beneficial microorganisms were present in 90% of all analyzed samples, and high enzymatic activity in solid samples (UBG: 103-347 [μg pnitrophenol/h*g],

UPac:

761-1470

[μg

p-nitrophenol/h*g],

UPalk:

811-2615

[μg

p-

nitrophenol/h*g], UU: 151-729 [μg NH4/h*g], UDH: 122-378 [μg TFP/24h*g]). This indicates the potential and active mineralization processes that can contribute to nutrient availability in soils. None of the solid samples met the regulatory limit for organic matter content, indicating deficient compost production processes. Considering all analyzed samples,

20%

did not

meet the sanitary parameter of fecal coliforms (