Soildiver agro

Research activities focus on plant health, crop yield and quality, input reduction, soil fertility, pollution and greenhouse gas control and carbon sequestration.

The aim of the activities of Estonian University of Life Sciences and NGO Soil Innovation Cluster (MTÜ Põllukultuuride Klaster) is in the course of the five-year European Union research programme Horizon 2020 and its project SoildiverAgro together with producers to evaluate soil biodiversity in different tilling systems and find management practices that enhance soil genetic and biological diversity to reduce the use of external inputs while increasing crop production and quality. Biodiversity levels in nine different pedoclimatic regions in Europe will be assessed to better understand the interplay between climate, soil characteristics and crop production. The links between agrobiological diversity and ecosystem services are explored. 

Earthworms, insects, bacteria, and fungi form soil biota the diversity of which affects the decomposition and conversion processes of organic matter, and nutrient cycling. Soil organisms dictate nutrient uptake, soil fertility, crop yields, the need for plant protection products and other external inputs, and profitability of production, thus directly affecting farmers. The use of inorganic fertilizers and pesticides in crop production can be reduced through better crop rotations, with catch crops, effective soil interactions and soil organisms. Creating better synergy between soil microorganisms help reduce the use of fertilizers, pesticides and fuel. For example, enhancement of mycorrhizae, a better root system, increases the protection of plants against pathogens and diseases and improves the absorption of phosphorus from soil.

Measuring earthworm communities

The project involves trials in ten fields and five locations over Estonia. The trials will provide data about soil organisms in cereal fields with direct seeding and minimum tillage where pesticide residues and the spread of phytopathogenic fungal spores are tested.
Under the project, in the autumn of 2020, earthworm communities in the trial fields were analysed. Earthworms are of particular significance among soil invertebrates. They are the biggest soil creatures whose activities in the soil improve its structure, including soil aeration and hydrological regime, and accelerate decomposition of plant residues. Earthworms contribute both to the formation of humus and to carbon cycle. The year 2020 was generally favourable for earthworm life and the number of communities in the project trial fields was abundant. The highest abundance was found in Central Estonia; in north of the region Pärnumaa there were even up to 444 specimens per 1 m² of soil, which is twice the average. In total, 13 earthworm species have been determined in Estonia so far. However, not all species tolerate agricultural activities and live in field soils. 

Encouraging earthworm communities

The abundance, age and species composition and life form diversity of earthworms provides producers with feedback about the condition of their soils.

Earthworms have a very important role in decomposing organic matter. They are capable of eating half of their body weight measured by volume in one day and the organic matter passing through them may contain approximately ten times richer material than the surrounding soil.

Earthworms are sensitive towards tilling method, soil compaction, and pesticide use. Intensive tilling damages earthworm communities. Low till agriculture, which disturbs the soil less and decreases the danger of soil compaction, is more favourable for earthworms. Availability of organic matter is also important for their nutrition. Producers can contribute to increasing earthworm population by growing catch crops and using perennial grasses and clovers for crop rotation, which offer an ample supply of plant residues for earthworm nutrition.

What is the value?

Genetic and functional analysis of soil biodiversity makes it possible to establish links between the presence and interaction of soil organisms and the health of crops in different areas.

For farmers

This process is important because the soil organic matter participates directly in plant uptake and determines the yield.  Tiny earthworm burrows help air and water to flow from the surface into deeper soil layers. Earthworms are good indicators for assessing the state of the soil.

Soildiver Agro is organized around 6 geographical areas where 15 case studies will be performed to better understand how soil organism’s benefits can be applied to improve resource uptake, plant growth development and health.

For more information about this initiative, go to Soildiver Agro’s project website.

In Estonia, we conduct two case studies as part of our activities

Case study number 12. Sub-theme 1.

At present, a system for warning and forecasting the spread of pests based on visual inspection. However, for most pathogens, it takes several weeks from the actual infection to the onset of symptoms. Thus, the timing of fungicide treatment based on visually detectable symptoms is often riskier and less effective because infected plants may show symptoms of the disease too late for effective disease control. Targeted disease control to reduce pesticide use should be based on monitoring of phytopathogenic fungi in the area.

As part of the project, a spore catcher (photo below) is installed next to the winter wheat field (Rannu Seeme OÜ). The machine takes measurements of the spores of airborne fungal diseases every 2 hours.  Samples are analysed by molecular methods designed for the direct detection and identification of airborne fungal species. A weather station will be installed to schedule fungicide control more and reduce unnecessary plant treatment with pesticides.

The use of fungicides should be based on accurate information collected on phytopathogenic fungal species. For a more accurate prediction of the incidence of plant diseases, a model prediction system adapted to the existing climatic conditions will be set up in order to transmit the data to the grower quickly. These research measures will help reduce external input through sustainable agricultural management and significant improvements in soil fauna services for pest control. As a result, agro-ecosystems are more resilient and cost-efficient whilst avoiding yield loss and produce healthier crops.

Case study number 12. Sub-theme 2.

Intensive tillage has historically been used in conventional farming, but farming without tillage or with minimal tillage is gaining popularity in Europe, resulting in layer of decay on the fields. When pesticides are used, residues accumulate in the decay layer, from where they are released into the soil. This can reduce biodiversity and, in the long run, endanger the condition of the soil. The case study examines pesticide residues in cereals to determine their accumulation in non-tilled fields and their impact on the soil.

The measures taken by producers for maintaining soil biological diversity don’t solely depend on their awareness but several factors encompassing man-environment relationship. The choice of cultivation type depends on information the producers have about the soils of their fields, their past experience and problems, related requirements and economic factors. Thus, it is vital to create a dialogue between the producers and the researchers for the latter to form an understanding of the factual tilling practices and reasons for the producers’ choices. At the same time, the producers will get information about soil biodiversity and soil organisms and tips how to improve them by choosing different tilling systems.

The aim is to find out the level of pesticide residues and the effect on soil fauna on farm fields, direct-sown and with minimal tillage. Farmers will be provided with an overview of the sequence, norm and types of pesticides found, as well as area-specific data to enable them to adapt the use of pesticides in crops. Specific monitoring of pesticide residues will lead to accurate recommendations for their targeted use in agriculture. Soil biodiversity should improve, leading to healthier crops and higher yields.

Further plans

In the following three years, field trials as part of SoildiverAgro project will continue for measuring pesticides and soil biota diversity, including earthworms; for analysing the genetic profile of archaea, bacteria and fungi, and nematodes; and for assessing the economic profitability of tilling systems and other factors affecting the producers’ activities.

The activities of project Soildiver Agro are funded through Horizon 2020 Programme of the European Union for research and innovation (agreement No 817819).

Useful links
Related publications

Loit, K., Soonvald, L., Astover, A., Runno-Paurson, E., Öpik, M., Tedersoo, L. Temporal and Cultivar-Specific Effects on Potato Root and Soil Fungal Diversity, Agronomy, 10(10): 1535, 10/2020.

Partner: 
Estonian University of Life Sciences – Kaire Loit, Anne Põder, Marian Põldmets, Mari Ivask, Merrit Shanskiy