FERTILODO Operational Group: Use of treated sewage sludge as an amendment for the production of horticultural crops in the Community of Madrid
- Type Operational group
- Status Filled
- Execution 2018 -2021
- Assigned Budget 192.210,00 €
- Scope Autonómico
- Autonomous community Madrid, Comunidad de
- Main source of financing PEPAC 2014-2020
The need to increase crop production is based on the use of mineral fertilizers, which provide essential nutrients to plants. However, these fertilizers are often overdosed, causing diffuse pollution that can lead to groundwater eutrophication. Furthermore, their production increases greenhouse gas emissions, contributing to climate change.
The use of organic waste will bring environmental benefits such as the reduction of aquifer contamination, reduction of erosion of treated soils, increase of soil organic matter and reduction of greenhouse gas emissions.
Two types of organic waste from sewage sludge have been characterized: compost with pruning residues (CP) and thermally dried (ST), and the intended soil. Pot trials were conducted using two doses of CP and ST (including a combined ST treatment with struvite) and compared with mineral NPK fertilization in two successive chard crops. The plants and soil were analyzed after each crop cycle.
The plant material was analyzed for nutritional composition and heavy metal content to confirm its food safety. The soil was analyzed for nutrient, organic matter, and heavy metal content.
Replace inorganic fertilization in soils intended for horticultural production by applying treated sewage sludge to maintain or improve productivity and enhance soil characteristics.
To achieve this, it is intended:
- Define the application rates of different types of sludge in soils.
- To evaluate the response of crops and soil to the application of sludge compared to the application of mineral fertilizer.
- Evaluate the effect of the amendment on the soil by analyzing the physical-chemical and biological properties.
- To assess the effect on the nutritional composition and physicochemical quality of the products obtained.
The organic waste tested showed production yields similar to those obtained with traditional mineral fertilization. The application of these products had no negative effects on the plants, and the same values were obtained for the quality parameters analyzed. The physicochemical characteristics of the soil improved with the application of this type of product, increasing the percentage of organic matter and nutrient content, which translates into increased soil fertility.
Although the dosages used in the trials (3-4.5 t/ha of ST and 30-60 t/ha of CP) have yielded good results, these products should always be dosed based on the physicochemical characteristics of the initial soil and the needs of the crop. The use of these products derived from urban wastewater treatment could save farmers money on mineral fertilizers while minimizing the risk of eutrophication due to leaching, which represents a significant environmental benefit for the protection of agricultural soil and groundwater.
The environmental benefit would be combined with the recovery of waste, in line with the objectives of the circular economy. The application of this type of material would not require the purchase of new equipment, as ST could be applied in the same way as granulated NPK and CP, using existing manure application equipment.
- Coordinator/entity name: Carolina Mancho Alonso
- Postal address: Finca El Encín, A2 Highway, Km. 38.2, Alcalá de Henares, 28805, Madrid
- Coordinator/entity email: carolina.mancho@madrid.org
- Telephone: 918879404
- Carolina Mancho Alonso
- Asociación de Horticultores de Villa del Prado (ahvprado@outlook.com)
- ASAJA-Madrid (pablo@asaja.com)
- Valoriza Servicios Medioambientales S.A. (mterciado@sacyr.com)
- Carolina Mancho Alonso