Straw management and slurry application affect the soil microbial community composition and its activity

Pintarič, Sara (author), Suhadolc, Marjetka (author), Eler, Klemen (author)

In low-input farming systems, where plant nutrition strongly depends on either organic matter inputs or nitrogen fixation by legumes, it is crucial to understand the effects of different crop residue management strategies on microbially mediated processes that influence nutrient dynamics. To evaluate different straw management options, we conducted a pot experiment with the following treatments: (1) control with no straw added (CON), (2) applying straw to the soil surface (SRF), simulating no-till, and (3) straw incorporating straw to the top 10 cm (INC), simulating minimum tillage. Another factor was slurry fertilization (with 3.2 t d.m. ha$^{-1}$ or without). Throughout the experiment, CO$_2$ efflux ([mu]mol/m$^2$/s) was measured regularly over a period of four months. Soil sampling was performed to monitor the abundance of the total bacterial, crenarchaeal and fungal communities, as well as nitrogen cycle microbial guilds and the dynamics of labile N and C fractions in the soils at different depths. Among straw treatments, significantly higher soil respiration was observed in INC and SRF compared to CON. Slurry fertilization increased soil respiration in all straw treatments. In the top 10 cm soil layer, the fungal abundance increased in INC compared to SRF and CON, whereas bacteria and crenarchaea did not respond. This effect was even more pronounced with slurry addition. The slurry also stimulated the abundance of certain N-cycle guilds, with the greatest increase in bacterial amoA-bearing nitrifiers and nirS, nosZI and nozII-bearing denitrifiers, particularly in the uppermost 0–1 cm soil layer. Straw treatment effects on N-cycle microbial guilds were less pronounced, while the coupled effect of straw incorporation and slurry was beneficial mostly for nosZ, again mainly in the top 1 cm soil layer. Compared to straw management, slurry fertilization had more potent effects on the abundance and performance of the investigated microbial communities.

• Language: English
• Keywords: soil respiration, plant residuals, no-till, conservation tillage, ammonia oxidizers, denitrifiers, functional groups, nitrogen cycle
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 19 str.
• Numbering: Vol. 12, iss. 11, art. 2781
• PID: 20.500.12556/RUL-143398
• UDC: 631.4
• ISSN on article: 2073-4395
• DOI: 10.3390/ agronomy12112781
• COBISS.SI-ID: 134456067
• Publication date in RUL: 19.12.2022

Record is a part of a journal

• Title: Agronomy
• Shortened title: Agronomy
• Publisher: MDPI
• ISSN: 2073-4395
• COBISS.SI-ID: 522953241

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: biologija tal, dihanje tal, rastlinski ostanki, ohranitvena obdelava tal, denitrifikacija, dušikov cikel, slama