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The aim of this research was to study the effect of different plants on soil organic matter (SOM) composition. The composition of SOM was studied in a field experiment established in 1964 on a carbonaceous glacial till soil with very low initial SOC concentration (1.28 g kg-1). The effects on SOM composition of bare fallow, barley, grasses, and clover-grasses mixture, were studied using 13C nuclear magnetic resonance (NMR) spectroscopy which is a common tool to characterize SOM. In 2014 the soil samples were collected from 0-5 cm soil layer, air-dried samples sieved through a 2-mm sieve and pretreated with 10% HF solution before NMR spectroscopy analysis. Samples of bulk soil and density fractionated mineral fraction (John et al., 2005) were analyzed. Also, a sample from barley treatment collected in 1966 was analyzed.
O/N-alkyl C was the most abundant C type at the start of the experiment and also in all treatments after 50 years. During 50 years the proportions of O/N-alkyl C and alkyl C increased but contributions of carboxyl C and aromatic C decreased. The ratio of alkyl C/O-alkyl C, which describes the degree of soil organic matter decomposition, decreased from 0.47 (in 1966) to 0.40-0.44 in treatments with plants. In bare fallow treatment, the SOM decomposition stage did not change a lot during the time. In soil mineral fraction the differences between treatments appeared more clearly and the degree of decomposition decreased in line: bare fallow>barley>clover-grasses>grasses (0.49>0.40>0.36>0.34) and this was due to higher O/N-alkyl-C content in treatments with plants. The higher O/N-alkyl C contribution in soil heavy fraction can be attributed to microbially synthesized carbohydrates (Yeasmin et al., 2020) and depended on the amount and properties of C input into the soil in different treatments.
In conclusion, the SOM composition was influenced by plant composition and the effect was more pronounced in soil mineral fraction. The SOM degree of decomposition was higher in treatment with annual crop (barley during 50 years). Under perennial grasses and clover-grasses mixture, the soil organic matter decomposition degree was lower.
This work was supported by the Estonian Research Council grant PSG147.
References
John, B., Yamashita, T., Ludwig, B., & Flessa, H. (2005). Storage of organic carbon in aggregate and density fractions of silty soils under different types of land use. Geoderma, 128(1–2), 63–79. https://doi.org/10.1016/j.geoderma.2004.12.013
Yeasmin, S., Singh, B., Smernik, R. J., & Johnston, C. T. (2020). Effect of land use on organic matter composition in density fractions of contrasting soils: A comparative study using 13C NMR and DRIFT spectroscopy. Science of the Total Environment, 726, 138395. https://doi.org/10.1016/j.scitotenv.2020.138395
Karin Kauer; Sandra Pärnpuu. NMR spectroscopy approach to study soil organic matter formation under different plant composition during 50 years. 2021, 1 .
AMA StyleKarin Kauer, Sandra Pärnpuu. NMR spectroscopy approach to study soil organic matter formation under different plant composition during 50 years. . 2021; ():1.
Chicago/Turabian StyleKarin Kauer; Sandra Pärnpuu. 2021. "NMR spectroscopy approach to study soil organic matter formation under different plant composition during 50 years." , no. : 1.
The decomposition of fresh crop residues added to soil for agricultural purposes is complex. This is due to different factors that influence the decomposition process. In field conditions, the incorporation of crop residues into soil does not always have a positive effect on aggregate stability. The aim of this study was to investigate the decomposition effects of residues from two different cover crops (Brassica napus var. oleifera and Secale cereale) and one main crop (wheat straw) on soil aggregate stability. A 105-day incubation experiment was conducted in which crop residues were mixed with sandy loam soil at a rate of 6 g C kg−1 of soil. During the incubation, there were five water additions. The decomposition effects of organic matter on soil conditions during incubation were evaluated by determining the soil functional groups; carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) emissions; soil microbial biomass carbon (MBC); and water-stable aggregates (WSA). The functional groups of the plant residues and the soil were analyzed using Fourier transform infrared spectroscopy (FTIR) and a double exponential model was used to estimate the decomposition rates. The results show that the decomposition rate of fresh organic materials was correlated with the soil functional groups and the C/N ratio. Oilseed rape and rye, with lower C/N ratios than wheat straw residues, had faster decomposition rates and higher CO2 and N2O emissions than wheat straw. The CO2 and N2O flush at the start of the experiment corresponded to a decrease of soil aggregate stability (from Day 3 to Day 10 for CO2 and from Day 19 to Day 28 for N2O emissions), which was linked to higher decomposition rates of the labile fraction. The lower decomposition rates contributed to higher remaining C (carbon) and higher soil aggregate stability. The results also show that changes in the soil functional groups due to crop residue incorporation did not significantly influence aggregate stability. Soil moisture (SM) negatively influenced the aggregate stability and greenhouse gas emissions (GHG) in all treatments (oilseed rape, rye, wheat straw, and control). Irrespective of the water addition procedure, rye and wheat straw residues had a positive effect on water-stable aggregates more frequently than oilseed rape during the incubation period. The results presented here may contribute to a better understanding of decomposition processes after the incorporation of fresh crop residues from cover crops. A future field study investigating the influence of incorporation rates of different crop residues on soil aggregate stability would be of great interest.
Gheorghe Stegarescu; Jordi Escuer-Gatius; Kaido Soosaar; Karin Kauer; Tõnu Tõnutare; Alar Astover; Endla Reintam. Effect of Crop Residue Decomposition on Soil Aggregate Stability. Agriculture 2020, 10, 527 .
AMA StyleGheorghe Stegarescu, Jordi Escuer-Gatius, Kaido Soosaar, Karin Kauer, Tõnu Tõnutare, Alar Astover, Endla Reintam. Effect of Crop Residue Decomposition on Soil Aggregate Stability. Agriculture. 2020; 10 (11):527.
Chicago/Turabian StyleGheorghe Stegarescu; Jordi Escuer-Gatius; Kaido Soosaar; Karin Kauer; Tõnu Tõnutare; Alar Astover; Endla Reintam. 2020. "Effect of Crop Residue Decomposition on Soil Aggregate Stability." Agriculture 10, no. 11: 527.
Nitrification inhibitors have been proposed as a tool to mitigate nitrous oxide (N2O) emissions from agriculture, which are caused mainly by fertilization. The nitrification inhibitor 3,4-Dimethylpyrazole phosphate (DMPP) was tested in a winter rapeseed field after dairy slurry application in Central Estonia. N2O emissions were monitored using the closed chamber method. Soil and leachate chemical parameters were also analyzed. N2O emissions increased from pre-slurry application values of 316 and 264 µg m−2 h−1 for the control and treatment plot, respectively, to maximum values of 3130.71 and 4834 µg m−2 h−1, with cumulative emissions during the study period of 12.30 kg ha−1 for the control plot and 17.70 kg ha−1 for the treatment plot. The intense precipitation period that began with the application of the slurry resulted in changes in soil moisture and water-filled pore space (WFPS), modifying the nitrification/denitrification balance. Positive significant correlations (p = 0.016 and p = 0.037, for the control and treatment plot, respectively) were found between N2O fluxes and WFPS. Future studies should consider the role of nitrifier and denitrifier communities in order to better assess in-field nitrification inhibitor effectiveness.
Jordi Escuer-Gatius; Merrit Shanskiy; Ülo Mander; Karin Kauer; Alar Astover; Hanna Vahter; Kaido Soosaar. Intensive Rain Hampers the Effectiveness of Nitrification Inhibition in Controlling N2O Emissions from Dairy Slurry-Fertilized Soils. Agriculture 2020, 10, 497 .
AMA StyleJordi Escuer-Gatius, Merrit Shanskiy, Ülo Mander, Karin Kauer, Alar Astover, Hanna Vahter, Kaido Soosaar. Intensive Rain Hampers the Effectiveness of Nitrification Inhibition in Controlling N2O Emissions from Dairy Slurry-Fertilized Soils. Agriculture. 2020; 10 (11):497.
Chicago/Turabian StyleJordi Escuer-Gatius; Merrit Shanskiy; Ülo Mander; Karin Kauer; Alar Astover; Hanna Vahter; Kaido Soosaar. 2020. "Intensive Rain Hampers the Effectiveness of Nitrification Inhibition in Controlling N2O Emissions from Dairy Slurry-Fertilized Soils." Agriculture 10, no. 11: 497.
Changes in soil organic carbon (SOC) content depending on different factors are extensively investigated when the soil is in steady-state equilibrium between formation and decomposition of soil organic matter. However, studies of SOC formation and dynamics in initally organic matter free soil are rare. Evolution of soil organic carbon was studied in a field experiment established in 1964 on a carbonaceous glacial till soil with very low initial SOC content (1.28 g kg−1). The effects on SOC content changes of bare fallow, barley and different perennial fodder crops such as grasses, clover-grass mixture, galega, hybrid lucerne and a turfgrass mixture, with or without mineral N and PK fertilisation and manure, were studied. There were 19 treatments in total and most had unchanged plant cover composition throughout the experiment. During 1964–2014, SOC stock increased in all treatments, by 0.11 Mg ha−1 y−1 in bare fallow and by at most 0.50 Mg ha−1 y−1 in the treatment with hybrid lucerne and manure. Average SOC sequestration rate was 0.35 ± 0.11 Mg ha−1 y−1. SOC changes were highly correlated with estimated C inputs and were therefore higher in treatments with perennials than with an annual barley crop. C retention efficiency for total crop-derived C inputs and for organic amendments was 6.1% and 22%, respectively. Water-soluble C measured in 2014 increased linearly with SOC, indicating that the quality of recently formed SOC was not strongly affected by the treatments. However, water-soluble C as a fraction of SOC was significantly lower in treatments with legumes than in treatments with bare fallow or a barley or grass crop. These results demonstrate that the quantity and quality of C inputs were both main drivers for observed changes in SOC. However, C retention efficiency of C inputs was relatively low. This may be related to soil texture with high sand proportion, suggesting that SOC sequestration rates in light-textured soils may be lower than expected even in case of low initial SOC content.
Karin Kauer; Alar Astover; Rein Viiralt; Henn Raave; Thomas Kätterer. Evolution of soil organic carbon in a carbonaceous glacial till as an effect of crop and fertility management over 50 years in a field experiment. Agriculture, Ecosystems & Environment 2019, 283, 106562 .
AMA StyleKarin Kauer, Alar Astover, Rein Viiralt, Henn Raave, Thomas Kätterer. Evolution of soil organic carbon in a carbonaceous glacial till as an effect of crop and fertility management over 50 years in a field experiment. Agriculture, Ecosystems & Environment. 2019; 283 ():106562.
Chicago/Turabian StyleKarin Kauer; Alar Astover; Rein Viiralt; Henn Raave; Thomas Kätterer. 2019. "Evolution of soil organic carbon in a carbonaceous glacial till as an effect of crop and fertility management over 50 years in a field experiment." Agriculture, Ecosystems & Environment 283, no. : 106562.
Karin Kauer; Berit Tein; Diego Sanchez De Cima; Liina Talgre; Vyacheslav Eremeev; Evelin Loit; Anne Luik. Soil carbon dynamics estimation and dependence on farming system in a temperate climate. Soil and Tillage Research 2015, 154, 53 -63.
AMA StyleKarin Kauer, Berit Tein, Diego Sanchez De Cima, Liina Talgre, Vyacheslav Eremeev, Evelin Loit, Anne Luik. Soil carbon dynamics estimation and dependence on farming system in a temperate climate. Soil and Tillage Research. 2015; 154 ():53-63.
Chicago/Turabian StyleKarin Kauer; Berit Tein; Diego Sanchez De Cima; Liina Talgre; Vyacheslav Eremeev; Evelin Loit; Anne Luik. 2015. "Soil carbon dynamics estimation and dependence on farming system in a temperate climate." Soil and Tillage Research 154, no. : 53-63.
Mailiis Tampere; Karin Kauer; Indrek Keres; Evelin Loit; Are Selge; Rein Viiralt; Henn Raave. The effect of fertilizer and N application rate on nitrogen and potassium leaching in cut grassland. Zemdirbyste-Agriculture 2015, 102, 381 -388.
AMA StyleMailiis Tampere, Karin Kauer, Indrek Keres, Evelin Loit, Are Selge, Rein Viiralt, Henn Raave. The effect of fertilizer and N application rate on nitrogen and potassium leaching in cut grassland. Zemdirbyste-Agriculture. 2015; 102 (4):381-388.
Chicago/Turabian StyleMailiis Tampere; Karin Kauer; Indrek Keres; Evelin Loit; Are Selge; Rein Viiralt; Henn Raave. 2015. "The effect of fertilizer and N application rate on nitrogen and potassium leaching in cut grassland." Zemdirbyste-Agriculture 102, no. 4: 381-388.
Mailiis Tampere; Karin Kauer; Indrek Keres; Evelin Loit; Are Selge; Rein Viiralt; Henn Raave. Effects of sward botanical composition on nitrogen and potassium leaching in cut grassland Žolyno botaninės sudėties įtaka azoto ir kalio išplovimui iš šienaujamo žolyno. Zemdirbyste-Agriculture 2014, 101, 389 -394.
AMA StyleMailiis Tampere, Karin Kauer, Indrek Keres, Evelin Loit, Are Selge, Rein Viiralt, Henn Raave. Effects of sward botanical composition on nitrogen and potassium leaching in cut grassland Žolyno botaninės sudėties įtaka azoto ir kalio išplovimui iš šienaujamo žolyno. Zemdirbyste-Agriculture. 2014; 101 (4):389-394.
Chicago/Turabian StyleMailiis Tampere; Karin Kauer; Indrek Keres; Evelin Loit; Are Selge; Rein Viiralt; Henn Raave. 2014. "Effects of sward botanical composition on nitrogen and potassium leaching in cut grassland Žolyno botaninės sudėties įtaka azoto ir kalio išplovimui iš šienaujamo žolyno." Zemdirbyste-Agriculture 101, no. 4: 389-394.
The effect of returning turfgrass clippings on mown turf, in terms of the value of clippings as a nitrogen source as well as management interactions on grass growth, has not been well examined. The objective of the present research was to study the impact of N rate and weather during the growing season on the effect of returned clippings and on efficiency of returned clippings. The experiment was carried out between 2004 and 2008. Over a five-year period, a field experiment was conducted on a sward of Festuca rubra rubra and Poa pratensis. Measured experimental factors included two clipping treatments, with clippings removed or clippings returned, as well as seven fertilizer rates. The swards' dry matter yield was significantly influenced by clippings treatment, applied N rate, year, and these interactions. Returning turfgrass clippings provide significant positive effects on the dry matter yield only when plants are fertilized with N. Without N fertilization, the effect was negative or absent. Returned clippings impact (RCLI) increased with N rate up to 213 kg N ha−1 and then started to decrease. The annual effect of returned clippings at N level 240 kg ha−1 depended mainly on the amount of returned clippings in May and June, as well as on precipitation during May. The annual efficiency of returned clippings at the same N level was mostly associated with precipitation in May and June and the average temperatures in July. We conclude that the annual effect of returning grass clippings on mown turf is beneficial only with mineral fertilizer. Also, if the moisture condition is a limiting factor to the decomposition of clippings then the moisture conditions must be improved with the irrigation.
Karin Kauer; Toomas Laidna; Indrek Keres; Tiina Köster; Evelin Loit; Merrit Shanskiy; Argaadi Parol; Are Selge; Rein Viiralt; Henn Raave. Impact of returned clippings on turfgrass growth as affected by nitrogen fertilizer rate, time of return, and weather conditions. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2013, 63, 579 -587.
AMA StyleKarin Kauer, Toomas Laidna, Indrek Keres, Tiina Köster, Evelin Loit, Merrit Shanskiy, Argaadi Parol, Are Selge, Rein Viiralt, Henn Raave. Impact of returned clippings on turfgrass growth as affected by nitrogen fertilizer rate, time of return, and weather conditions. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2013; 63 (7):579-587.
Chicago/Turabian StyleKarin Kauer; Toomas Laidna; Indrek Keres; Tiina Köster; Evelin Loit; Merrit Shanskiy; Argaadi Parol; Are Selge; Rein Viiralt; Henn Raave. 2013. "Impact of returned clippings on turfgrass growth as affected by nitrogen fertilizer rate, time of return, and weather conditions." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 63, no. 7: 579-587.
The goal of this research was to study the impact of cut plant residues, returned to or removed from the grassland sward, on the dry-matter yield of swards and on the organic carbon (Corg) concentration of soil. The experiment was carried out during 2004–2008. The variables of the experiment were (i) sward type: turfgrass sward (Festuca rubra rubra and Poa pratensis) and grass–clover sward (Phleum pratense, Lolium perenne, and Trifolium repens) and (ii) treatment of residues: the cut plant residues were returned (RRT) to the plots or removed (RRM) from the plots after the mowing. The fertilizer treatments were as follows: N0P0K0, N80P11K48, N160P22K96, and N400P56K240 kg ha−1 for the turfgrass sward and N0P0K0 and N80P26K50 kg ha−1 for the grass–clover sward. The Corg and Ntot concentrations in the 20-cm soil layer were measured at the beginning and at the end of the experiment at depths of 0–5 cm and 5–20 cm. Nitrogen was returned as plant residues to the grass–clover sward in treatment N0P0K0 at 190 kg ha−1 and N80P26K50 at 204 kg ha−1 and consequently the returned cut plant residues increased the yield by 31% and 22%, respectively. The amount of N returned as residues to turfgrass sward was 31–236 kg ha−1 but it had no significant influence on the sward dry-matter yield. During the 5 years of the experiment the Corg content in 0- to 5-cm soil layer of grass–clover sward in treatment RRT increased by 42.9% and in RRM by 32.0% as an average of both fertilization treatments. At the depth 5–20 cm the Corg concentration did not change in treatment RRT, but in treatment RRM with fertilization the Corg concentration decreased by 8.2%. In turfgrass soil the Corg concentration increased in RRT treatment by 21.6% and in treatment RRM by 7.2% during 5 years. In the lower soil layer the concentration of Corg decreased with removal and return of plant residues. The fertilization did not influence the changes of Corg concentration in turfgrass swards soil.
Karin Kauer; Raimo Kõlli; Rein Viiralt; Tiina Köster; Merrit Noormets; Toomas Laidna; Indrek Keres; Argaadi Parol; Triin Varul; Are Selge; Henn Raave. Effect of Cut Plant Residue Management and Fertilization on the Dry-Matter Yield of Swards and on Carbon Content of Soil. Communications in Soil Science and Plant Analysis 2013, 44, 205 -218.
AMA StyleKarin Kauer, Raimo Kõlli, Rein Viiralt, Tiina Köster, Merrit Noormets, Toomas Laidna, Indrek Keres, Argaadi Parol, Triin Varul, Are Selge, Henn Raave. Effect of Cut Plant Residue Management and Fertilization on the Dry-Matter Yield of Swards and on Carbon Content of Soil. Communications in Soil Science and Plant Analysis. 2013; 44 (1-4):205-218.
Chicago/Turabian StyleKarin Kauer; Raimo Kõlli; Rein Viiralt; Tiina Köster; Merrit Noormets; Toomas Laidna; Indrek Keres; Argaadi Parol; Triin Varul; Are Selge; Henn Raave. 2013. "Effect of Cut Plant Residue Management and Fertilization on the Dry-Matter Yield of Swards and on Carbon Content of Soil." Communications in Soil Science and Plant Analysis 44, no. 1-4: 205-218.
In grassland areas where herbage production has no economic value, the cut grass is often left on the sward surface where its decomposition is influenced by weather conditions. Although the influence of temperature and humidity on decomposition has been investigated under controlled lab conditions, experimentation has generally been under ideal moisture conditions that have not tested the combinations of climatic limitations that might occur in the field. The decomposition of mown turfgrass clippings deposited at different times of vegetation period was studied in situ using nylon bags during the first 8 weeks after deposition to investigate the effect of weather conditions (the air temperature, relative humidity, precipitation) on decomposition. Decomposition is the highest in the case of high air humidity and temperature of 10°C. Limiting factors for decomposition at temperatures above 10°C is the air humidity and below 10°C the air temperature. The general tendency was that the rate of decomposition increased with increasing air temperature up to 10°C, but with further increases of air temperature the decomposition rate slowed down. Relative air humidity had a variable impact (at the beginning of the decomposition process (weeks 1–2) the influence was negative, during weeks 3–8 of the decomposition process the effect was positive), and hence had no generalized relationship with decomposition over the studied decomposition period (weeks 1–8). The most significant influence of weather conditions on the decomposition rate was recorded directly after cutting. If the cutting was done during hot weather conditions, the material was drying fast and therefore decomposed slowly. Our results indicate that for fast decomposition of clippings it is important to maintain the freshness of material. Lower decomposition rates occurred during conditions of hot and dry weather, and also cooler (temperature near to 0°C) weather, and can be compensated as soon as favourable weather arrives.
Karin Kauer; Henn Raave; Tiina Köster; Rein Viiralt; Merrit Noormets; Indrek Keres; Toomas Laidna; Argaadi Parol; Are Selge. The decomposition of turfgrass clippings is fast at high air humidity and moderate temperature. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2012, 62, 224 -234.
AMA StyleKarin Kauer, Henn Raave, Tiina Köster, Rein Viiralt, Merrit Noormets, Indrek Keres, Toomas Laidna, Argaadi Parol, Are Selge. The decomposition of turfgrass clippings is fast at high air humidity and moderate temperature. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2012; 62 (3):224-234.
Chicago/Turabian StyleKarin Kauer; Henn Raave; Tiina Köster; Rein Viiralt; Merrit Noormets; Indrek Keres; Toomas Laidna; Argaadi Parol; Are Selge. 2012. "The decomposition of turfgrass clippings is fast at high air humidity and moderate temperature." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 62, no. 3: 224-234.
To what extent is restoration of vegetation in coastal grasslands delayed by accumulation of nutrients after abandonment of traditional management and subsequent reed encroachment? How does nutrient flow in the plant–soil system react to reintroduction of grazing? Coast of Baltic Sea, western Estonia. Abandoned, continuously managed and restored coastal meadows were selected in four different study regions and their vegetation composition sampled. Nitrogen, P, K, Na, Ca and Mg concentrations and C/N ratios were determined in both vegetation and soil. Differences between management groups were evaluated. Comparison among different management groups revealed several differences in both relative and total amount of nutrients in soil and vegetation. Most soil properties of restored sites were similar to those in abandoned sites. Carbon stock in the soil profile doubled after abandonment, total N concentration in the top soil layer increased while plant available P concentration decreased. The phytomass and chemical composition of phytomass rapidly changed back to a ‘normal’ level after restoration. Species composition remained different, but species typical of coastal grasslands were present in restored sites. There was a strong site specificity in the results. Re‐establishment of grazing had a rapid impact on plant biomass of coastal grasslands. Species composition responded more slowly, but target species returned relatively quickly. Slow recovery of soil properties, however, means that the results of restoration may be fragile and return of tall‐growth vegetation is very probable if managent intensity declines. Long restoration periods should be planned to reach pre‐abandonment environmental conditions when using non‐destructive restoration methods.
Marek Sammul; Karin Kauer; Tiina Köster. Biomass accumulation during reed encroachment reduces efficiency of restoration of Baltic coastal grasslands. Applied Vegetation Science 2011, 15, 219 -230.
AMA StyleMarek Sammul, Karin Kauer, Tiina Köster. Biomass accumulation during reed encroachment reduces efficiency of restoration of Baltic coastal grasslands. Applied Vegetation Science. 2011; 15 (2):219-230.
Chicago/Turabian StyleMarek Sammul; Karin Kauer; Tiina Köster. 2011. "Biomass accumulation during reed encroachment reduces efficiency of restoration of Baltic coastal grasslands." Applied Vegetation Science 15, no. 2: 219-230.
In Estonia, areas threatened by erosion are mainly situated in the south-east, where erosion-affected soils (EAS) account for 6–37% of the total area. The main tasks of this research were: (i) To characterize the humus status of EAS by their subdivisions, (ii) to define the humus status forming peculiarities of EASs, and (iii) to analyse the distribution and association of EASs with uneroded soils. To characterize the humus status of EAS epipedon thickness (cm), humus concentration (g kg−1) and humus pool (Mg ha−1) were used. For the determination of humus status parameters via sampling points, the transect method was used. The humus status of EAS varied widely (average humus concentration varies from 12–45 g kg−1 and humus pools from 39–191 Mg ha−1). The mean humus pools in eroded (n = 174), transitional (n = 224) and deluvial/colluvial (n = 159) soils are accordingly 51 ± 18 (mean ± SD), 90 ± 23 and 138 ± 67 Mg ha−1, respectively. The mean decrease in humus pools of eroded (E) soils on arable lands is 32–53 Mg ha−1, but the mean increase in deluvial (D) soils is 14–76 Mg ha−1. The greatest humus pool relocation coefficients D/E (2.8–3.3) are characteristic of the soils of hilly end moraine areas.
Raimo K[Otilde]Lli; Olav Ellermäe; Karin Kauer; Tiina Köster. Erosion-affected soils in the Estonian landscape: Humus status, patterns and classification. Archives of Agronomy and Soil Science 2010, 56, 149 -164.
AMA StyleRaimo K[Otilde]Lli, Olav Ellermäe, Karin Kauer, Tiina Köster. Erosion-affected soils in the Estonian landscape: Humus status, patterns and classification. Archives of Agronomy and Soil Science. 2010; 56 (2):149-164.
Chicago/Turabian StyleRaimo K[Otilde]Lli; Olav Ellermäe; Karin Kauer; Tiina Köster. 2010. "Erosion-affected soils in the Estonian landscape: Humus status, patterns and classification." Archives of Agronomy and Soil Science 56, no. 2: 149-164.
Soil organic carbon (SOC) retaining capacities of epipedon (EP), subsoil (SS) and soil cover (SC) as a whole, are soil type specific. Depending on individual and sites characteristics, the generalized humus status indices of soil types (EP and SC thickness and SOC stocks) may vary. Land use and land use change primarily influence the properties and fabric of the EP, but the humus status (SOC concentration and stock, fabric of horizons) of the SS remains practically unchangeable. The mean mineral soils SOC stocks, EP quality and SOC distribution in soil profiles depend mainly on the water regime, mineral composition (texture, calcareousness), development of eluvial processes and the land use peculiarities of soils. The mean area weighted SC SOC stock of Estonian mineral soils is 99.9 Mg ha–1, thereby the mean hydromorphic soils SOC retention capacity considerably exceeds the SOC retention capacity of automorphic soils (means are accordingly 127.5 and 78.9 Mg ha–1). The sustainable management of SOC is based on adequate information about actual SOC stocks and theoretically established or optimal humus status levels of soil types. The aggregate of SOC retained in the mineral soils of Estonia (3,235,100 ha) amounts to 323 ± 46 Tg (1 Tg = 1012 g). Approximately 42% of this is sequestered into stabilized humus, 40% into instable raw-humous material and 18% into forest (grassland) floor and shallow peat layers
Raimo Kõlli; Tiina Köster; Karin Kauer; Illar Lemetti. Pedoecological Regularities of Organic Carbon Retention in Estonian Mineral Soils. International Journal of Geosciences 2010, 01, 139 -148.
AMA StyleRaimo Kõlli, Tiina Köster, Karin Kauer, Illar Lemetti. Pedoecological Regularities of Organic Carbon Retention in Estonian Mineral Soils. International Journal of Geosciences. 2010; 01 (03):139-148.
Chicago/Turabian StyleRaimo Kõlli; Tiina Köster; Karin Kauer; Illar Lemetti. 2010. "Pedoecological Regularities of Organic Carbon Retention in Estonian Mineral Soils." International Journal of Geosciences 01, no. 03: 139-148.
The weight of the tractor is not the only factor affecting soil compaction. Soil-management practices, such as the use of fertilizers and pesticides, also affect soil properties through an increased number of overriding. The aim of the current study was to investigate compaction effects on soil physical properties, such as dry bulk density and penetration resistance, and the growth of spring barley (Hordeum vulgare L.) as a monoculture. The five-year experiment was conducted on the Estonian University of Life Sciences’ research field at Eerika, near Tartu in 2001–2005. The soil of the experimental site is sandy loam Stagnic Luvisol. The treatments included were no compaction, one pass, three passes, and six passes. All passes were track-by-track. Measurements of soil and plant were made in the earing phase of barley and measurements of yield in the maturity phase of barley. The compaction treatment was conducted using an MTZ-82 tractor (total weight 4.84 Mg). Neither fertilizers nor herbicides were used. 5 years after compaction distinguishable subsoil and topsoil compaction was detected. Soil deformation increases with the number of passes; in the case of six passes soil bulk density increased by 0.15 Mg m−3 and penetration resistance by 3 MPa. However, there were no significant differences in the soil bulk density and penetration resistance between treatments compacted with one and three passes. The effect of compaction on soil bulk density was higher when the soil was compacted under wet conditions. Compaction decreased the quantity of barley shoots, their phytomass, and grain yield by more than 80%. In the second year of the experiment the dry weight of above ground biomass decreased by almost three times and shoots’ density by 1.5 times, compared with the first year results. In the third year of the experiment the biomass, plant density, and grain yield of barley were stabilized and no further decreases were detected in the following two experimental years. The results from the experiment revealed that even a low weight tractor can induce subsoil compaction and a high decrease of plant productivity by repeated passes over time.
Enola Reintam; Katrin Trükmann; Jaan Kuht; Edvin Nugis; Liina Edesi; Alar Astover; Merrit Noormets; Karin Kauer; Kadri Krebstein; Kaire Rannik. Soil compaction effects on soil bulk density and penetration resistance and growth of spring barley ( Hordeum vulgare L.). Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2009, 59, 265 -272.
AMA StyleEnola Reintam, Katrin Trükmann, Jaan Kuht, Edvin Nugis, Liina Edesi, Alar Astover, Merrit Noormets, Karin Kauer, Kadri Krebstein, Kaire Rannik. Soil compaction effects on soil bulk density and penetration resistance and growth of spring barley ( Hordeum vulgare L.). Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2009; 59 (3):265-272.
Chicago/Turabian StyleEnola Reintam; Katrin Trükmann; Jaan Kuht; Edvin Nugis; Liina Edesi; Alar Astover; Merrit Noormets; Karin Kauer; Kadri Krebstein; Kaire Rannik. 2009. "Soil compaction effects on soil bulk density and penetration resistance and growth of spring barley ( Hordeum vulgare L.)." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 59, no. 3: 265-272.