A short-term study of soil microbial activities and soybean productivity under tillage systems with low soil organic matter
Graphical abstract
Introduction
Soil organic matter is a critical parameter in adjusting biological activities, and its adequate amount is necessary for successful sustainable agriculture (Belmonte et al., 2018; Torabian et al., 2019). In contrast, the low organic matter of soil might reduce microbial activities in rhizosphere (Tiessen et al., 1994). The formation of soil organic matter is almost a degradation process requiring considerable time. It is suggested that some practical ways such as using cover crops, suitable crop rotation and tillage systems, and application of organic fertilizers instead of chemicals to enhance soil organic matter (Magdoff and Weil, 2004).
Soil tillage is a mechanical action that modifies soil climate for cultivation of crops, which can provide a suitable condition for seed germination, seedling establishment and root growth (Lampurlanes et al., 2016). There are various tillage systems such as conventional, conservation tillage and no-tillage that have specific positive and negative impacts on rhizosphere and ecosystems (Li et al., 2018). Conventional tillage is the most common tillage system leaving less than 15% of crop residues on the soil surface before sowing the next crop. Results of various experiments revealed that conventional tillage causes some soil-related problems such as decreasing soil organic matter, deteriorated water percolation, and increasing soil erosion compared to conservative practices (El Titi, 2002; Weber et al., 2017). However, conservation tillage leaves 30% or more crop residue to cover the soil surface before planting. It is generally designed to reduce soil erosion and preserve organic matter and microbial activities depending on depth and number of plows, cover crops and residues remain on the soil surface (Bausenwein et al., 2008; Ehlers and Claupein, 2017; Hati et al., 2020). Under No-tillage system, soil is usually left undisturbed from harvest of the previous crop up to sowing the new crop (Leon et al., 2017).
On the other hand, tillage practices can alter nodulation process (Anikwe et al., 2016) and nitrogen (N) metabolism in legume plants such as soybean (Glycine max) (Torabian et al., 2019; Virk et al., 2020). Many researches indicated that conservative tillage systems can improve nodulation process by preserving organic matter (El Titi, 2002; de Pontes et al., 2017). For instance, Heidari et al. (2016) showed that conservation tillage in a sandy loam soil texture noticeably enhanced microbial biomass and soil organic carbon in soybean farms. A similar result for soybean has been reported by Aulakh et al. (2017). Microbial activities play an important role in preserving soil organic matter and nutrients bioavailability in an optimum level for agronomical practices (Rashid et al., 2016). The organic matter of soil is the main factor in adjusting interactions of soil biota with plants (Khan et al., 2016). Torabian et al. (2019) reported that conservation and no-tillage systems can modify soil organic matter content and microbial activities of soil. Hughes and Herridge (1989) stated that reduced soil NO3-N under no-tillage increases soybean nodulation and microbial activities of soil. Wang et al. (2020) claimed that soil microbial community structure and activity can be affected by tillage systems. In this regard, Mathew et al. (2012) reported that soil microbial activities were higher in no-tillage soil compared to conventional tillage. Kandeler et al. (1999) stated that the activity of different enzymes such as phosphatase was enhanced under conservation tillage system.
Accordingly, soybean growth and productivity could be influenced by tillage practices (de Pontes et al., 2017). Li et al. (2017) indicated an enhance in root length and density of soybean under no-tillage system under a long-term experiment. Okoth et al. (2014) reported that no-tillage increased biological N fixation and shoot biomass of different soybean cultivars under various kinds of soil texture (sandy clay loam, sandy clay and loamy sand) but did not improve grain yield. Zotarelli et al. (2012) found that organic carbon pools, biological N fixation and grain yields of soybean were improved under no-tillage system with clay soil texture. In most cases, the impacts of conservation and no-tillage on soybean growth and productivity have been positive. However, there are some reports showing negative or insignificant effects of conservation tillage system on symbiotic activities and grain yield. Nouri et al. (2018) reported that there was no noticeable difference in grain yield of soybean under two minimum and conventional tillage systems.
Due to the various responses of soil microbial activities and crop performance to tillage systems, this research was designed and conducted in order to evaluate the possible short-term impacts of three prevalent tillage systems (conventional, minimum and no-tillage systems) on soil microbial activities and soybean productivity under low organic matter of soil.
Section snippets
Experimentation
The field experiment took place over a two-year period (2018 and 2019) in Tabriz, East Azerbaijan province, Iran (37°58′22.1″N and 46°02′31.6″E, 1280 m above sea level). The climate is subtropical according to Koeppen's classification with average 360 mm annual rainfall. Major soil (Inceptisol soil) characteristics and weather conditions of experimental site are presented in Table 1. The experiment was designed as randomized complete block with a split plot arrangement and four blocks including
Soil properties
Averaged across cultivars and years, soil temperature, pH and NO3-N concentration were affected by tillage systems (Table 2). The lowest values of soil temperature, pH and NO3-N concentration were observed under no-tillage condition. In contrast, the highest values of these parameters were recorded under conventional tillage. Reductions of soil NO3-N concentration under no-tillage and minimum tillage were 35% and 27%, respectively, compared to conventional tillage. Minimum and no-tillage
Discussion
The results of a short-term study (two years) about the impacts of different tillage systems on various parameters of soil physicochemical attributes and soybean productivity in a well irrigated plot with low organic soil revealed that soil organic matter could not be affected by tillage practice. This proves that stabilization of organic matter requires a long time. Bessam and Mrabet (2003) reported that after 4 years of no-tillage an extra 5.62 t ha−1 of soil organic carbon was sequestered in
Conclusion
Our results revealed that tillage methods can modify soybean nodulation and productivity under low content of soil organic matter content. No-tillage system improved some of the microbial activities of soil such as acid phosphatase and β-glucosidase, while reduced dehydrogenase activity, nodulation, N uptake, and crop productivity. In contrast, nodulation, N uptake, and soil microbial biomass and activities, especially dehydrogenase activity were improved by minimum tillage. The effects of
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
We appreciate the University of Tabriz and Agriculture Research, Education and Extension Organization of Iran for helping us to conduct the research.
References (53)
- et al.
Role of exogenous nitrogen supply in alleviating the deficit irrigation stress in wheat plants
Agric. Water Manag.
(2018) - et al.
Application of eco-physiological quotients (qCO2 and qD) on microbial biomasses from soils of different cropping histories
Soil Biol. Biochem.
(1990) - et al.
Soil physicochemical quality in contrasting tillage systems and its effect on nodulation and nodulation effectivity of groundnut, Bambara groundnut and soybean in a degraded Ultisol in Agbani, Enugu Southeastern Nigeria
Rhizosphere
(2016) - et al.
The effect of soil moisture on soil microbial activity studied by microcalorimetry
Thermochim. Acta
(1995) - et al.
Exploring soil microbial communities and soil organic matter: variability and interactions in arable soils under minimum tillage practice
Appl. Soil Ecol.
(2008) - et al.
Effect of long-term soil management on the mutual interaction among soil organic matter, microbial activity and aggregate stability in a vineyard
Pedosphere
(2018) - et al.
Soil oxygen status and dehydrogenase activity
Soil Biol. Biochem.
(1998) - et al.
Diversity of arbuscular mycorrhizal fungi in the Brazilian's Cerrado and in soybean under conservation and conventional tillage
Appl. Soil Ecol.
(2017) - et al.
A review of tillage effects on crop residue management, seedbed conditions and seedling establishment
Soil Tillage Res.
(2001) - et al.
Nitrate accumulation and leaching potential reduced by coupled water and nitrogen management in the Huang-Huai-Hai Plain
Sci. Total Environ.
(2018)
The effects of biocidal treatments on metabolism in soil—V: a method for measuring soil biomass
Soil Biol. Biochem.
Microbial biomass, fungal and bacterial residues, and their relationships to the soil organic matter C/N/P/S ratios
Geoderma
Long-term analysis of soil water conservation and crop yield under different tillage systems in Mediterranean rainfed conditions
Field Crop Res.
No tillage and sugar beet foam amendment enhanced microbial activity of degraded acidic soils in South West Spain
Appl. Soil Ecol.
Soybean root traits after 24 years of different soil tillage and mineral phosphorus fertilization management
Soil Tillage Res.
Conservation agriculture practices increase soil microbial biomass carbon and nitrogen in agricultural soils: a global meta-analysis
Soil Biol. Biochem.
Assessing microbial activities in metal contaminated agricultural volcanic soils–an integrative approach
Ecotoxicol. Environ. Saf.
Bacteria and fungi can contribute to nutrients bioavailability and aggregate formation in degraded soils
Res. Microbiol.
Soybean nodulation and nitrogen fixation in response to soil compaction and surface straw mulching
Soil Tillage Res.
Do tillage systems influence nitrogen fixation in legumes? A review
Soil Tillage Res.
An extraction method for measuring soil microbial biomass C
Soil Biol. Biochem.
Weed control using conventional tillage, reduced tillage, no-tillage, and cover crops in organic soybean
Agriculture
Long-term effects of tillage and straw management on soil organic carbon, crop yield, and yield stability in a wheat-maize system
Field Crop Res.
Influence of no-tillage and frequency of a green manure legume in crop rotations for balancing N outputs and preserving soil organic C stocks
Field Crop Res.
Biological nitrogen fixation by soybean and fate of applied 15 N-fertilizer in succeeding wheat under conventional tillage and conservation agriculture practices
Nutr. Cycl. Agroecosyst.
Long-term changes in soil organic matter under conventional tillage and no-tillage systems in semiarid Morocco
Soil Use Manag.
Cited by (10)
Responses of soil greenhouse gas emissions to no-tillage: A global meta-analysis
2023, Sustainable Production and ConsumptionSoil physicochemical and biological properties in soybean areas under no-till Systems in the Brazilian Cerrado
2023, Science of the Total EnvironmentCitation Excerpt :However, there are limited reports regarding the direct relationship between the stratification of soil properties and soybean yield (Cook and Trlica, 2016; Huang et al., 2022; Jacobs et al., 2022). Besides, although the NT management has been touted as a perspective way of conservation agriculture, the NT effects on crop production stability and agroecosystem quality remain controversial since the results varied widely among current studies due to the spatial heterogeneity of climate and soil conditions (Pittelkow et al., 2015; Farhangi-abriz et al., 2021; Wulanningtyas et al., 2021). With the growing worldwide adoption of NT, a knowledge gap still exists regarding the effects of NT on soil physicochemical and biological properties, especially in high-yield soybean cultivation areas.
A meta-analysis to estimate the potential of biochar in improving nitrogen fixation and plant biomass of legumes
2024, Biomass Conversion and BiorefineryImpact of no-tillage on soil quality and crop yield in Asia: A meta-analysis
2023, Land Degradation and Development