Inspirational idea: Improving soil biodiversity to reduce inputs

This inspirational idea is also available in a Slovak version. Translation courtesy of the National Rural Network Slovakia. Read more EIP-AGRI inspirational ideas in Slovak on the NRN website. 

Sustainable soil management practices to reduce the use of inputs and increase crop productivity and quality

The cultivation of vegetables in the south of Spain is threatened by low availability of nutrients in the soil as soil biodiversity has been affected by years of intensive agriculture. One of the case studies from the Horizon 2020 project SoildiverAgro is testing sustainable management practices for potatoes, including the application of commercial products based on micro-organisms, to reduce soil-borne diseases and pests and increase nutrient availability.

Murcia is one of Europe’s main vegetable and fruit producing areas. Irene Ollio, researcher from the project, explains “It is one of the only places in Europe where the climate remains mild enough in the winter to grow broccoli and lettuce year-round; the high demand for these products from the rest of Europe therefore means farmers use many inputs to ensure maximum yields.” Chemical fertilisers and manure are applied to increase fertility and pesticides are used to reduce the incidence of pests and diseases. Intense irrigation is also necessary to keep production output high. 

Irene continues “These practices are costly in the short term and they are also not sustainable in the long term. Extensive use of these inputs causes damage to the soil.” The soil in the area is lacking in biodiversity, in the natural micro-organisms, insects and animals which usually help the soil provide crops with natural defences against pests and diseases. Soils in the region also struggle to retain water and nutrients, meaning the crops cannot take up these essential elements. This also leads to wider environmental impact, for example a sea-water lake in the area is contaminated by nitrates due to run-off. 

The SoildiverAgro project aims to develop sustainable soil management practices which can be used across Europe. The case studies focus on some of the most important agricultural crops, and Case Study 1 focuses on the potato (conventional farming). Potatoes are one of the most consumed foods in the world, alongside rice and wheat. Potato production in Spain has increased in recent years, but it faces challenges related to diseases present in the soil and the continuous need to apply external inputs to guarantee yield and quality.

The objective of Case Study 1 is to introduce sustainable management techniques which increase soil nutrient availability and soil water retention capacity, with the aim of reducing the occurrence of soil-borne diseases and pests. At the same time, this would reduce environmental impacts and input costs, and it would improve the quality of the potato crop. 

The case study is led by the Technical University of Cartagena, working with farmers. A range of management techniques are applied on an experimental farm and will be monitored and analysed over 3 years. Farmers from the area are involved to advise the university researchers on the experiments.

The potatoes were planted in December 2020 and the experiments will last until 2023. Irene explains “The crops are being cultivated under the conventional farming conditions typical for our region meaning ploughing, initial fertilisation (sheep manure), fertigation, application of pesticides and use of weed control measures.” However, there are 4 plots and within each one, different management techniques are being applied. The first is a standard fertilisation application for the area, the second is a reduction of 30% of this standard fertilisation, the third also has a reduction of 30% fertilisation plus the application of two commercial products based on the use of beneficial micro-organisms. 

For each harvest, the potatoes will be analysed in terms of yield, quality of the tubers (firmness, density, starch content, weight and size) and the incidence of pests and diseases. The data is analysed and compared and conclusions will be drawn about the optimal practices. Raúl Zornoza, Mediterranean South case study coordinator says “We have analysed the data from the first harvest in June 2021, preliminary results show that reduction in fertilisation did not affect crop yield or other quality parameters, and a reduction in pests and diseases was observed in the two treatments with application of the micro-organism formulations. We still have a lot of data to analyse for the second and third years of crop cycles.”

Juan A. Fernández, another researcher working on the experiments explains “Plant growth promoting bacteria and mycorrhizae are micro-organisms which can support plants in many ways: fixing atmospheric nitrogen, solubilising minerals such as phosphorus and potassium, regulating nutritional balance, improving growth, protecting against the effects of phytopathogens… so they can be used instead of chemical fertilisers and pesticides.”

The plots are also being cultivated within a typical rotation for this area comprised of potato, broccoli, melon, potato: “Multiple cropping and rotations are common in the area, however they are not optimised to maximise the development of (beneficial) soil organisms. This case study is also testing better multiple cropping and rotations to enhance soil fertility and biodiversity. We evaluate the different micro-organisms living in the soil at different times of the year and the rotation, seeing what impact each crop has on their presence.” – explains Juan.

David Fernández Calviño SoildiverAgro project coordinator “Case Study 1 is one of 15 in the SoildiverAgro project. The case studies are spread across Europe and working on different agricultural sectors and issues. The Case Studies will all share and compare results to create a complete set of management practices and cropping systems that enhance soil genetic and functional biodiversity to reduce the use of external inputs while increasing crop production and quality, the delivery of ecosystem services and contributing to EU agricultural stability and resilience.”

Project information

Contact: 

Juan Antonio Fernández Hernández, Juan.Fernandez@upct.es

Irene Ollio, irene.ollio@upct.es

David Fernández Calviño, davidfc@uvigo.gal +34 988368888 SoildiverAgro project coordinator

• SoildiverAgro Case Study 1
• SoildiverAgro project

Photos: SoildiverAgro Case Study 1