Parameter Selection for the Evaluation of Compost Quality

This work studies variables measured from the first phase of composting through the acquisition of the final product, with the goal of identifying those that are more strongly related to quality and are most useful for developing an index. The necessity to establish quality control procedures thus e...

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Main Authors: Haydee Peña, Heysa Mendoza, Fernando Diánez, Mila Santos
Format: Article
Language:English
Published: MDPI AG 2020-10-01
Series:Agronomy
Subjects:
Online Access:https://www.mdpi.com/2073-4395/10/10/1567
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author Haydee Peña
Heysa Mendoza
Fernando Diánez
Mila Santos
author_facet Haydee Peña
Heysa Mendoza
Fernando Diánez
Mila Santos
author_sort Haydee Peña
collection DOAJ
description This work studies variables measured from the first phase of composting through the acquisition of the final product, with the goal of identifying those that are more strongly related to quality and are most useful for developing an index. The necessity to establish quality control procedures thus exists for the classification of raw materials in the same way as for the finished products. To accomplish this, three mixtures were prepared, with the goal of achieving a C/N ratio of 30 and a moisture content of 60%. The primary component of each mixture was: fruit processing waste (C1), sewage sludge from the food industry (C2), and the manufacturing waste of fried foods (C3). Temperatures were measured over 107 days, with the corresponding data fit to a logistical model where <i>T</i> °C ~ α / ((1 + exp (− (Time − β) / − γ))) + δ, with interaction compost * time being statistically significant (<i>p</i> < 0.001). This allowed for the temperatures, in keeping with health concerns, to be confirmed. Likewise, a linear regression analysis demonstrated the decomposition of organic matter at 0.82%/week. Statistically, the parameters, measured during the process, with the least variability were selected, which differed in the average contrasts: germination index (cucumber), electrical conductivity, and average moisture. A principal component analysis (PCA) and Spearman’s correlation analysis revealed the best Germination Index (GI) values for C1, due to lower electrical conductivity (EC) and bulk density (Bd) along with higher organic matter content (TOM). For its part, C2 induced a higher Relative emergence (RE) of the cucumber thanks to its higher content of total nitrogen (TN) and lower contribution of Cu, Zn and K. C3 showed a higher presence of salts, less favorable physical characteristics (>Bd and <TPS, total pore space) and higher content of Zn and Cu. Composting carried out with appropriate mixtures can offer high-quality products for use as fertiliser, in soil restoration, and as an alternative substrate to peat and virgin mountain soil.
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spelling doaj.art-efc92389c60444c4a1cc7b9cb214db232023-11-20T17:04:26ZengMDPI AGAgronomy2073-43952020-10-011010156710.3390/agronomy10101567Parameter Selection for the Evaluation of Compost QualityHaydee Peña0Heysa Mendoza1Fernando Diánez2Mila Santos3Laboratorio de Valorización de Residuos Compostables, Universidad Nacional Experimental del Táchira UNET, San Cristóbal 5001, VenezuelaLaboratorio de Valorización de Residuos Compostables, Universidad Nacional Experimental del Táchira UNET, San Cristóbal 5001, VenezuelaDepartamento de Agronomía, Escuela Superior de Ingeniería, Universidad de Almería, 04120 Almería, SpainDepartamento de Agronomía, Escuela Superior de Ingeniería, Universidad de Almería, 04120 Almería, SpainThis work studies variables measured from the first phase of composting through the acquisition of the final product, with the goal of identifying those that are more strongly related to quality and are most useful for developing an index. The necessity to establish quality control procedures thus exists for the classification of raw materials in the same way as for the finished products. To accomplish this, three mixtures were prepared, with the goal of achieving a C/N ratio of 30 and a moisture content of 60%. The primary component of each mixture was: fruit processing waste (C1), sewage sludge from the food industry (C2), and the manufacturing waste of fried foods (C3). Temperatures were measured over 107 days, with the corresponding data fit to a logistical model where <i>T</i> °C ~ α / ((1 + exp (− (Time − β) / − γ))) + δ, with interaction compost * time being statistically significant (<i>p</i> < 0.001). This allowed for the temperatures, in keeping with health concerns, to be confirmed. Likewise, a linear regression analysis demonstrated the decomposition of organic matter at 0.82%/week. Statistically, the parameters, measured during the process, with the least variability were selected, which differed in the average contrasts: germination index (cucumber), electrical conductivity, and average moisture. A principal component analysis (PCA) and Spearman’s correlation analysis revealed the best Germination Index (GI) values for C1, due to lower electrical conductivity (EC) and bulk density (Bd) along with higher organic matter content (TOM). For its part, C2 induced a higher Relative emergence (RE) of the cucumber thanks to its higher content of total nitrogen (TN) and lower contribution of Cu, Zn and K. C3 showed a higher presence of salts, less favorable physical characteristics (>Bd and <TPS, total pore space) and higher content of Zn and Cu. Composting carried out with appropriate mixtures can offer high-quality products for use as fertiliser, in soil restoration, and as an alternative substrate to peat and virgin mountain soil.https://www.mdpi.com/2073-4395/10/10/1567compostable mixturecompostingchemometrics
spellingShingle Haydee Peña
Heysa Mendoza
Fernando Diánez
Mila Santos
Parameter Selection for the Evaluation of Compost Quality
Agronomy
compostable mixture
composting
chemometrics
title Parameter Selection for the Evaluation of Compost Quality
title_full Parameter Selection for the Evaluation of Compost Quality
title_fullStr Parameter Selection for the Evaluation of Compost Quality
title_full_unstemmed Parameter Selection for the Evaluation of Compost Quality
title_short Parameter Selection for the Evaluation of Compost Quality
title_sort parameter selection for the evaluation of compost quality
topic compostable mixture
composting
chemometrics
url https://www.mdpi.com/2073-4395/10/10/1567
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