Perception of photovoltaic energy consumption in the Spanish primary sector. An environmentally profitable alternative.

Agriculture and livestock farming are activities that depend on energy consumption. Photovoltaic self-consumption systems can reduce the production costs of these actors, especially in periods of high-energy price volatility. This work aimed to determine the degree of implementation of photovoltaic self-consumption systems, their relationship with the economic impact of the energy crisis, and the perception of producers to use renewable energy sources in the Spanish agricultural system as it is one of the most important at European level. For this purpose, a survey of the Spanish agricultural and livestock system, involving 396 primary producers, was carried out between December 2022 and March 2023. The results suggest that self-consumption systems are in place in 49.1% of all farms and that these have had a positive effect in alleviating the rising energy costs suffered by the Spanish primary sector. In summary, Spanish primary producers generally have a favorable perception of the use of renewable energies on their farms, especially photovoltaic. However, the cluster analysis shows the fact that there are two types of producers, active and passive, from an environmental point of view. The characterization of this type of producers can help the Spanish Administration to improve the efficiency of its energy strategy, and can be a source of inspiration for the governments of other countries.

Effect of Repeated Plant Debris Reutilization as Organic Amendment on Greenhouse Soil Fertility.

Greenhouse agriculture typically generates large amounts of waste with plant residue (agricultural biomass) being the most abundant. This residue is generated on a seasonal basis, which complicates the external management of the material. Recently, the European Union (EU) has been implementing a policy based on sustainability through the circular economy that seeks to minimize waste generation. The effect of reusing 3.5 kg·m-2 tomato plants from the previous season as the only fertilizer versus no fertilization and inorganic fertilization in 215-day tomato cycles after transplanting was studied in this trial. The study was carried out during three seasons in greenhouse agriculture in Almeria (Spain) with the repeated use of the solarization technique. The plant debris had similar production results during two of the three seasons and fruit quality parameters were similar to inorganic fertilization. In addition, some physicochemical variables improved and the biological depressive effect of solarization was mitigated. The results suggest that the reuse of the tomato plant debris as the only fertilizer could be an alternative to conventional fertilization under the conditions tested.

The Management of Agriculture Plastic Waste in the Framework of Circular Economy. Case of the Almeria Greenhouse (Spain).

In recent decades, ecosystems have suffered diverse environmental impacts caused by anthropogenic activities, including the dumping of plastic waste. This situation has prompted the European Union to introduce a new policy based on the circular economy. In this study, the present state and future perspectives on the generation and treatment of plastic waste in the intensive agriculture of Almeria (Spain) are analyzed. This activity generates 1503.6 kg·ha-1·year-1, on average, of plastic waste with an approximate treatment cost of 0.25 €/kg. The present study shows that the volume of plastic waste from intensive agriculture in Almeria is constantly increasing (48,948.2 tons in 2020/21) and it is suggested that the current management system does not meet the needs of the sector. Although it presents great opportunities for improvement under the framework of the circular economy. Furthermore, this work reports a direct relationship between the price of the raw materials needed for the production of plastic and the volume of recycled plastics. For this reason, it would be advisable for the administration to consider the implementation of a tax rebate system for the sector and specifically when the petroleum derivatives used to manufacture plastic are less expensive, and the recycling option is not so attractive.