18th Congress of the European Society for Agronomy

The effects of compost on the feeding activity of soil biota

Not scheduled

15m

Les Dortoirs (1st floor) (The Couvent des Jacobins)

Poster Synergies between disciplines Poster session #1

Speaker

Lucie Chmelikova (Technical University of Munich)

Description

1. Introduction
   Soil organisms play a crucial role in providing essential ecosystem services such as transforming organic matter, nutrient cycling, forming soil, and regulating pests and diseases (Saccá et al. 2017). To support the biological activity in the soil, organic fertilizers like composts are often used (D´Hose et al. 2016, Sánchez-Monedero et al. 2019), especially in organic farming where mineral fertilizers and pesticides are limited. Therefore, a study to investigate how different types of compost affect the feeding activity of soil biota under organic farming conditions using bait-lamina tests was conducted.

2. Materials, methods
   The investigations were carried out in a strip trial on a field managed by an organic farm. The trial included an unfertilized control as well as variants with biowaste compost, green waste compost and farm compost, respectively. Each compost was applied at a rate of 180 kg N/ha as well as at a rate of 360 kg N/ha in May 2020 and in March 2023 Bait-lamina tests were performed using PVC strips containing 16 holes filled with a mixture of 70% cellulose powder, 27% bran flakes, and 3% active coal. From 12 May to 23 May 2023 and from 30 October to 10 November 2023, 16 of these filled PVC strips were placed vertically into the top 15 cm of soil in each plot of the trial. Afterwards, the PVC strips were removed again and air-dried. To measure feeding activity in the soil, the disappearance of the cellulose-bran mixture from the holes of the PVC strips was evaluated on a scale of 0 (holes still filled) to 1 (holes completely empty) in 0.25 steps.

3. Results
   During both sampling periods, all three compost types showed an increase in feeding activity across the entire sampling depth in comparison to the unfertilized control. In May 2023, the biowaste and farm composts had the most pronounced effect, while in November 2023, the green waste compost at full application rate had the highest feeding activity.

4. Discussion
   The temporal differences between the biowaste and green waste composts may be due to variations in their organic compound stability. Green waste composts, made from woody materials with higher lignin contents, may lead to more stable composts, explaining the delayed effect on soil feeding activity. These differences in biological activity may also impact nutrient release from the composts, which warrants further investigation.
   All in all, the bait-lamina tests suggest that composts can enhance soil biological activity, which can support associated ecosystem services.

5. References
   D’Hose, T.; Ruysschaert, G.; Viaene, N.; Debode, J.; Vanden Nest, T.; van Vaerenbergh, J. et al. (2016): Farm compost amendment and non-inversion tillage improve soil quality without increasing the risk for N and P leaching. In: Agriculture, Ecosystems & Environment 225, S. 126–139. DOI: 10.1016/j.agee.2016.03.035.
   Saccá, M. L.; Barra Caracciolo, A.; Di Lenola, M.; Grenni, P. (2017): Ecosystem Services Provided By Soil Microorganisms. In: Lukac, M., Grenni, P. und Gamboni, M. (Hg.): Soil Biological Communities and Ecosystem Resilience. Cham: Springer International Publishing, S. 9–24.
   Sánchez-Monedero, M. A.; Cayuela, M. L.; Sánchez-García, M.; Vandecasteele, B.; D’Hose, T.; López, G. et al. (2019): Agronomic Evaluation of Biochar, Compost and Biochar-Blended Compost across Different Cropping Systems: Perspective from the European Project FERTIPLUS. In: Agronomy 9 (5), S. 225. DOI: 10.3390/agronomy9050225.