Open Access
Municipal solid waste management in a decentralized composting scenario: assessment of the process reproducibility and quality of the obtained composts
(MDPI, 2024) Álvarez-Alonso, Cristina; Pérez-Murcia, María Dolores; Sánchez-Méndez, Silvia; Martínez-Sabater, Encarnación; Irigoyen Iriarte, Ignacio; López, Marga; Nogués, Isabel; Paredes, Concepción; Orden, Luciano; García-Rández, Ana; Bustamante, María Ángeles; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Over the last several years, the models for organic waste management have changed to implement circular economy in the productive cycle. In this context, new scenarios have emerged, where the management of different organic waste streams by composting is conducted with decentralized models that manage organic wastes in a more local way. However, in these new models, the standardization of the process control and of the end-product characteristics is necessary to guarantee the quality and agronomic value of the compost obtained, avoiding potential risks for human health and the environment. Thus, the aim of this work was to study two different scenarios of community composting of the organic fraction of municipal solid waste separately collected in order to guarantee the effectiveness and reproducibility of the composting processes and the quality of the composts obtained. For this, the development of the process and the characteristics of the composts at agronomic, hygienic–sanitary and environmental levels were assessed in real conditions and during three cycles of the process. The results obtained show high similarity among the different composting cycles, indicating an important degree of reproducibility among the processes. In addition, the composts obtained showed a good sanitary quality, absence of phytotoxicity and low contents of potentially toxic elements, which guarantee their use in agriculture without posing any risk to human health and to the environment.
Open Access
Quality assessment of composts officially registered as organic fertilisers in Spain
(Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2019) Puyuelo, Belén; Sánchez Arizmendiarrieta, Joseba; Irigoyen Iriarte, Ignacio; Plana, Ramón; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Gobierno de Navarra / Nafarroako Gobernua
Composting of organic wastes is a management strategy linked to circular economy models through the transformation of these wastes into an organic product, compost, which can be used as fertiliser, soil amendment or growing media. However, the concept of ‘compost quality' is not enough defined to take a technical decision about which is its best use or application. In the last decade, different guidelines and regulations about organic fertilisers have been developed. For instance, in Spain the Fertilisers Regulation categorises compost under five kinds according to the raw materials used - organic amendment compost (OaC), manure compost (MaC), green compost (GrC), vermicompost (VC), ‘alperujo' compost (AlC) -, and under three quality levels (A, B or C) depending exclusively on the heavy metals content. This work analyses the national database of all composts (307) marketed in Spain, considering the analytical parameters declared, with the objective of proposing a methodology to define a global quality index. For this assessment, two indicators are employed: a fertility indicator, related to the nutrients content, and a clean indicator, related to the heavy metals content. Results show an average compost formulation 2.5:2.5:2.5 (N:P 2 O 5 :K 2 O). MaC and OaC present the highest fertility indicator, whereas VC the lowest. Regarding the clean indicator, GrC, MaC and VC are cleaner than OaC. In the future, this new quality assessment should be completed by including other indicators related to physical and biological characteristic (e.g. porosity, stability/maturity, phytotoxicity) that could determine the most proper use of compost.
Open Access
Compost de FORM con restos de alimentos cárnicos como componente de sustratos de cultivo
(Sociedad Española de Ciencias Hortícolas, 2014) Storino, Francesco; Irigoyen Iriarte, Ignacio; Ollo Alcasena, María Arantzazu; Aparicio Tejo, Pedro María; Muro Erreguerena, Julio; Producción Agraria; Ciencias del Medio Natural; Nekazaritza Ekoizpena; Natura Ingurunearen Zientziak
La utilización de compost de FORM como fertilizante es una práctica inocua y segura ampliamente implantada en la unión europea y que presenta gran cantidad de ventajas desde un punto de vista agronómico y medioambiental. La utilización de este tipo de compost como materia prima para la elaboración de sustratos de cultivo genera ciertas dudas por sus características, especialmente cuando provienen de sistemas de compostaje descentralizado en los que se han compostado restos de alimentos entre los que se incluyen alimentos de origen animal (carne y/o pescado). El objetivo del este trabajo es evaluar compost domésticos como componente de sustratos para cultivo de ornamentales que incluyen distintas proporciones de restos de alimentos cárnicos. Para este fin se compararon 3 compost domésticos (uno vegetal y dos con 15% carne) y uno comercial. Los compost fueron caracterizados mediante análisis de su composición elemental, pH y CE. Cada compost fue mezclado al 25 y 75 % v/v con sustrato a base de turba (utilizado puro como control). Además las dos mezclas con mayor CE fueron sometidas a lavados sucesivos, monitorizando el descenso de salinidad tras cada lavado y la composición elemental del líquido drenado. Plantas de pensamientos fueron cultivadas en macetas de 2 L con cada uno de los 11 sustratos indicados. Durante seis semanas de cultivo se midió la biomasa vegetal, la altura y el número de tallos, el número de flores y el contenido en clorofila mediante índice colorimétrico SPAD. Las diferencias entre los distintos tratamientos fueron pequeñas. El lavado previo de los sustratos no modifico significativamente la respuesta del cultivo. Se concluyen que los sustratos con compost de FORM que contiene hasta un 15% de restos de alimentos de origen animal no afectan negativamente al cultivo de pensamientos bajo las condiciones del presente ensayo.
Open Access
Short term physiological implications of NBPT application on the N metabolism of Pisum sativum and Spinacea oleracea
(Elsevier, 2011-03-01) Cruchaga Moso, Saioa; Artola Rezola, Ekhiñe; Lasa Larrea, Berta; Ariz Arnedo, Idoia; Irigoyen Iriarte, Ignacio; Morán Juez, José Fernando; Aparicio Tejo, Pedro María; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Producción Agraria; Nekazaritza Ekoizpena
The application of urease inhibitors in conjunction with urea fertilizers as a means of reducing N loss due to ammonia volatilization requires an in-depth study of the physiological effects of these inhibitors on plants. The aim of this study was to determine how the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) affects N metabolism in pea and spinach. Plants were cultivated in pure hydroponic culture with urea as the sole N source. After 2 weeks of growth for pea, and 3 weeks for spinach, half of the plants received NBPT in their nutrient solution. Urease activity, urea and ammonium content, free amino acid composition and soluble protein were determined in leaves and roots at days 0, 1, 2, 4, 7 and 9, and the NBPT content in these tissues was determined 48 h after inhibitor application. The results suggest that the effects of NBPT on spinach and pea urease activity differ, with pea being most affected by this treatment, and that the NBPT absorbed by the plant caused a clear inhibition of the urease activity in pea leaf and roots. The high urea concentration observed in leaves was associated with the development of necrotic leaf margins, and was further evidence of NBPT inhibition in these plants. A decrease in the ammonium content in roots, where N assimilation mainly takes place, was also observed. Consequently, total amino acid contents were drastically reduced upon NBPT treatment, indicating a strong alteration of the N metabolism. Furthermore, the amino acid profile showed that amidic amino acids were major components of the reduced pool of amino acids. In contrast, NBPT was absorbed to a much lesser degree by spinach plants than pea plants (35% less) and did not produce a clear inhibition of urease activity in this species.
Open Access
Rational application of treated sewage sludge with urea increases GHG mitigation opportunities in Mediterranean soils
(Elsevier, 2017-02-01) Calleja Cervantes, María Eréndira; Aparicio Tejo, Pedro María; Villadas Latorre, Pablo José; Irigoyen Iriarte, Ignacio; Irañeta, Iosu; Fernández-González, A.J.; Fernández-López, M.; Menéndez, S.; Producción Agraria; Nekazaritza Ekoizpena; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB
Open Access
The effect of defoliation on the yield of leek (Allium porrum L.)
(Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2010) Irigoyen Iriarte, Ignacio; Domeño Seminario, Itziar; Muro Erreguerena, Julio; Producción Agraria; Nekazaritza Ekoizpena
La pérdida de área foliar es un daño típico en los cultivos causado por ataques de hongos e insectos o por granizo. Se han realizado numerosos estudios para describir los efectos de la defoliación en los principales cultivos herbáceos y leñosos. En este trabajo se describen los resultados obtenidos en dos ensayos, llevados a cabo en el Valle Medio del Ebro (España), para determinar el efecto en el cultivo de puerro de diferentes niveles de defoliación aplicados en varios estados fenológicos. Se aplicaron cuatro niveles de defoliación: control, leve, medio y alto en seis estados fenológicos diferentes. La defoliación se llevó a cabo con una maquina de agua a presión. Se observó una estrecha relación entre la pérdida de cosecha, el porcentaje de defoliación y el estado fenológico en que se aplicó. El estado más crítico fue al inicio del engrosamiento del tallo en el cual se alcanzaron las mayores pérdidas, de un 41% para un 100% de defoliación. Estos resultados experimentales se utilizaron para obtener ecuaciones de regresión en las que se calculó el porcentaje de pérdida de cosecha en relación con el estado fenológico y el porcentaje de defoliación aplicado. Estas ecuaciones pueden ser utilizadas para mejorar los patrones de simulación de crecimiento del puerro en caso de daños foliares provocados por ataques de hongos o insectos o por granizo
Open Access
Foliar application of urea to "Sauvignon Blanc" and "Merlot" vines: doses and time of application
(Springer Nature, 2012-02-19) Lasa Larrea, Berta; Menéndez Villanueva, Sergio; Sagastizabal, Kepa; Calleja Cervantes, María Eréndira; Irigoyen Iriarte, Ignacio; Muro Erreguerena, Julio; Aparicio Tejo, Pedro María; Ariz Arnedo, Idoia; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Producción Agraria; Nekazaritza Ekoizpena
A careful control of the N nutritional status of grapevines can have a determining effect on wine characteristics; therefore a suitable management of N fertilization might allow some wine parameters to be modified, thereby improving product quality. The aim of this study was to determine the effect of foliar application of urea at different doses and different times of the growing season on the parameters of Sauvignon Blanc and Merlot grape juice. The research described herein involved Sauvignon Blanc and Merlot grapevines (V. vinifera L.) at a commercial vineyard and was conducted over 2 years. In the first year, N treatment involved a foliar application at a dose of 10 kg N ha−1 during veraison, whereas in the second year it involved a foliar urea application at two doses (10 and 50 kg N ha−1) and at three different times—3 weeks before veraison, during veraison and 3 weeks after veraison. In this second year, the urea applied at a dose of 10 kg N ha−1 was isotopically labelled with 1% 15N. Chemical parameters, yeast assimilable N, amino acid content, amino acid profile and N isotopic composition were determined for all treatments. Grape and grape-juice parameters for Merlot were found to be more affected by N fertilization than for Sauvignon Blanc and were also more affected during the second year than during the first year, thus indicating that the climatic characteristics of each campaign could affect these parameters. The yeast assimilable N in grape juice was found to be higher for late applications of foliar urea, with application of the higher dose of urea during veraison increasing the amino acid and proline contents in both varieties. The isotopic analysis data showed that the urea applied to leaves was transferred to the berries, with the maximum translocation in Sauvignon Blanc occurring for the post-veraison treatment and in Merlot for the veraison treatment. We can therefore conclude that foliar application of urea could modify grape juice quality and could therefore be used as a tool for obtaining quality wines.
Open Access
Isotopic composition of maize as related to N-fertilization and irrigation in the Mediterranean region
(Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 2011) Lasa Larrea, Berta; Irañeta, Iosu; Muro Erreguerena, Julio; Irigoyen Iriarte, Ignacio; Aparicio Tejo, Pedro María; Natura Ingurunearen Zientziak; Nekazaritza Ekoizpena; Ciencias del Medio Natural; Producción Agraria; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, 17/2004
Nitrate leaching as a result of excessive application of N-fertilizers and water use is a major problem of vulnerable regions. The farming of maize requires high N fertilization and water inputs in Spain. Isotopic techniques may provide information on the processes involved in the N and C cycles in farmed areas. The aim of this work was studying the impact of sprinkler and furrow irrigation and N input on maize (Zea mays L.) yields, and whether isotopic composition can be used as indicator of best farming practices. Trials were set up in Tudela (Spain) with three rates of N fertilization (0, 240 and 320 kg urea-N ha–1) and two irrigation systems (furrow and sprinkler). Yield, nitrogen content, irrigation parameters, N fate and C and N isotope composition were determined. The rate of N fertilization required to obtain the same yield is considerably higher under furrow irrigation, since the crop has less N at its disposal in furrow irrigation as a result of higher loss of nitrogen by NO3 –-N leaching and denitrification. A lower δ13C in plants under furrow irrigation was recorded.The δ15N value of plant increased with the application rate of N under furrow irrigation.
Open Access
Effect of feeding regime on composting in bins
(Taylor & Francis, 2017) Storino, Francesco; Menéndez Villanueva, Sergio; Muro Erreguerena, Julio; Aparicio Tejo, Pedro María; Irigoyen Iriarte, Ignacio; Natura Ingurunearen Zientziak; Nekazaritza Ekoizpena; Ciencias del Medio Natural; Producción Agraria; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Composting in bins is one of the most practical home composting methods. There is currently a need for greater information to improve the management of the composting process and to create home composting programs, which ensure sustainable production of high quality compost. This study investigates how two aspects of the bin feeding regime—the feeding frequency and the amount of waste applied at each feed—influence the process's evolution and the quality of the compost. Compost bins were assayed after introducing the same amount of kitchen and garden waste according to three different frequencies: in a single batch, weekly, or every 3 weeks. A fourth treatment was applied to calculate the potential waste reduction achieved by the composting process, filling the bins to the brim on a weekly basis. Temperature, mass, and volume changes; the microbial diversity (by Biolog); and gas emissions (CO2, CH4, N2O, and NH3) were all determined during the process. At the end of the experiment, all of the composts were weighed and characterized. Results show that the main differences were very dependent on the quantity of waste provided. Large amounts of waste were added increasing the compost's temperature and maturity during the process, while slightly affecting the salinity and phytotoxicity of the final compost but without any clear effects on microbial diversity and gas emission. Therefore, from a technical point of view, the shared use of compost bins among several households (community composting) is preferable to individual us
Open Access
Meat waste as feedstock for home composting: effects on the process and quality of compost
(Elsevier, 2016) Storino, Francesco; Sánchez Arizmendiarrieta, Joseba; Irigoyen Iriarte, Ignacio; Muro Erreguerena, Julio; Aparicio Tejo, Pedro María; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Producción Agraria; Nekazaritza Ekoizpena
Home composting is a powerful tool, which is spreading in different parts of the world, to reduce the generation of municipal waste. However, there is debate concerning the appropriateness, in terms of domestic hygiene and safety, of keeping a composter bin in the household deputed to kitchen waste of animal origin, such as meat or fish scraps and pet droppings. The purpose of our work was to study how the addition of meat scraps to household waste influences the composting process and the quality of the final compost obtained. We compared four raw material mixtures, characterized by a different combination of vegetable and meat waste and different ratios of woody bulking agent. Changes in temperature, mass and volume, phenotypic microbial diversity (by Biolog TM) and organic matter humification were determined during the process. At the end of the experiment, the four composts were weighed and characterized by physicochemical analysis. In addition, the presence of viable weed seeds was investigated and a germination bioassay was carried out to determine the level of phytotoxicity. Finally, the levels of pathogens (E. coli and Salmonella spp.) were also determined in the final compost. Here we show that the presence of meat waste as raw feedstock for composting in bins can improve the activity of the process, the physicochemical characteristics and maturity of the compost obtained, without significantly affecting its salinity, pH and phytotoxicity. Pathogen levels were low, showing that they can be controlled by an intensive management and proper handling of the composter bins.