Humus Forms Research Articles

Impact of Agricultural Practices and their Management Techniques on Soil Carbon Sequestration: A Review

Carbon emissions through various sources possess a great threat to the environment. An increase in carbon concentration in the atmosphere resulted in increased temperature. Escalating warmness in the environment started melting of glaciers, day by day water level in oceans also increasing at an alarming rate. Forests, oceans and agricultural soils act as a sink for atmospheric carbon. Sinking sites help in making the balance of various gases in the atmosphere. Managing agricultural soils provides a good opportunity for more carbon storage. Adoption of conservation tillage, incorporation or on surface management of crop residue and balanced fertilization helps in reducing carbon removal from soil. More organic matter means more humus formation and more carbon retention in soil. Such management practices not only boost soil carbon-storing capacity but also increase soil fertility through hiking nutrient availability to plants and microbial populations in the soil. Higher plant growth results in more assimilation of CO2 in the photosynthesis process.

European beech leads to more bioactive humus forms but stronger mineral soil acidification as Norway spruce and Scots pine – Results of a repeated site assessment after 63 and 82 years of forest conversion in Central Germany

To reduce the effects of extended coniferous monoculture plantations on forest floor and topsoil processes, like amplified acidification or nutrient immobilization in organic layers, small interspersed groups of European beech were planted at the beginning of the 20th century amid large coniferous stands (CS) in Central Germany. Today, these so-called “Green Eyes” (GE) are 82-year old. In our study we focused on two different timelines to investigate the effects of forest conversion on vegetation composition, forest floor and mineral soil properties, encompassing a long-term (>80 year) comparison from tree planting in the 1930s to 2018 and a shorter timeframe nearly spanning 20 years (1999–2018). Since long-term forest conversion experiments (>60 years) across sites sharing a common forest land-use history are scarce, our study allows to contribute to a better evaluation of the long-term effects on changes in soil properties. We linked standard methods assessing soil pH, organic C and total N concentrations as well as stocks as indicators of soil quality changes in forest floor and mineral soil (down to 40 cm depth) to patterns in ground vegetation dynamics (most GE were characterized only by a few herbaceous species). Our results exhibited an effect of forest conversion on the activation in forest floor turnover resulting in increased turnover rates in the GE (GE contain only half of the forest floor OM of CS), hence forming more bioactive humus forms (mull, moder) and a noticeable higher forest floor pH (+0.6 units) compared to CS. The OC translocation from the forest floor into the topsoil is higher under GE (+0.7% OC content), probably building up a stable SOC pool hence contributing to C sequestration. The positive effects of European beech on forest floor quality are related to a stronger acidification of the subsoil during the past 20 years (-0.5 pH units). The base pump effect (uptake of Ca2+, Mg2+, K+ and assimilation into tree biomass in exchange release of H+) in GE led to more acidic conditions (-0.2 pH units) in the deeper mineral soil compared to CS. This bio-acidification may serve as one reason for subsoil acidification, as observed in our study, pointing out that mineral soil acidification is still an important issue in central European forests. Future restoration of soil base cation pools will still depend on the rate of bio-acidification, on the amount of acidifying air pollutant (and base cation) depositions and on forest management practices (e.g. intensity of biomass removal, soil regeneration-oriented liming).

Wastewater silt sludge application in the case of <i>Carthamus tinctorius</i> cultivation on light chestnut soils of the Volgograd Region, Russia

Aim. The aim of research was to study various methods of basic soil cultivation and a domestic wastewater silt sludge application which could possibility be directed to soil fertility saving and increase in crop yields.Materials and Methods. The object of research was a safflower variety called Alexandrite. Experimental variants were carried out according to a 4-fold repetition. Experiment installation, observations and accounting were carried out in accordance with the field experiment methodology named after B.A. Dospehov.Results. Field research was undertaken in order to study the various methods of a basic tillage and a domestic wastewater silt sludge application possibility under arid conditions of the Volgograd region on light chestnut solonetz soils. The amino acid composition of safflower (Carthamus tinctorius) seeds has been estimated. The data from the study of soil microbiological activity and the effect of non-traditional fertilizers on the increase in the activity of soil biota are presented. The crop yields and economic evaluation of the Carthamus tinctorius cultivation were determined.Conclusion. Modern resource-saving soil cultivation technologies and nontraditional fertilizers are required to: maintain the fertility of slightly humus soils in this arid climate zone, increase amino acids levels in plants, increase soil biological activity, as well to increase safflower crop yields. The proposed technical solutions, employing Rancho chisel tillage with as the basic tillage together with the introduction of non-traditional fertilizers-meliorants, provides structural restoration of soil aggregates, intensification of the humus formation process, increase in soil microbiological activity and - as a result - an increase in the yield of the cultivated Carthamus tinctorius crop.

Positive feedback loop between earthworms, humus form and soil pH reinforces earthworm abundance in European forests

Abstract In many terrestrial ecosystems, earthworms operate at the interface between plants and soil. As ecosystem engineers, they affect key ecosystem functions such as decomposition, nutrient cycling and bioturbation. Their incidence and abundance depends on several soil properties, yet simultaneously they also impact soil properties themselves. The existence of a positive feedback loop in which earthworm activity maintains their own niche—by promoting turnover rate in the forest floor, thereby increasing topsoil pH and creating suitable living conditions for themselves—has been suggested before, yet lacks supporting evidence. Here we assessed how tree species litter traits relate to such below‐ground interactions in forests across Europe. Specifically, we hypothesized a below‐ground feedback loop between burrowing earthworm biomass, humus form and pH, affected by litter quality. We tested this hypothesis by means of structural equation modelling. Our results demonstrate that litter nutrient concentrations affect both burrowing and litter dwelling earthworm biomass, which in turn directly impacts humus form and indirectly soil pH. At a continental scale, that is, including all edaphic conditions, soil pH did not feed into earthworm biomass nor could we link leaf structural recalcitrance (e.g. lignin) or functional diversity to below‐ground interactions. However, in forests where moisture is not limiting, soil acidity proved an important factor determining the context of below‐ground interactions. Therefore, we were able to confirm the hypothesized feedback loop for forest ecosystems with soil pH ≤ 5. In calcareous and/or periodically dry forests, other factors than soil chemistry and litter quality became determinant for earthworm biomass. The activity of burrowing earthworms is pivotal in below‐ground ecosystem functioning of mesic forest soils, impacting litter accumulation and forest floor conditions above‐ground, the pH and nutrient status below‐ground and ultimately their own living conditions. This highlights earthworm bioturbation as a key mechanism for understanding plant–soil interactions in forests. A free Plain Language Summary can be found within the Supporting Information of this article.

Composition of soil bacterial and fungal communities in relation to vegetation composition and soil characteristics along an altitudinal gradient.

The objective of the present study was to evaluate how altitudinal gradients shape the composition of soil bacterial and fungal communities, humus forms and soil properties across six altitude levels in Hyrcanian forests. Soil microbiomes were characterized by sequencing amplicons of selected molecular markers. Soil chemistry and plant mycorrhizal type were the two dominant factors explaining variations in bacterial and fungal diversity, respectively. The lowest altitude level had more favorable conditions for the formation of mull humus and exhibited higher N and Ca contents. These conditions were also associated with a higher proportion of Betaproteobacteria, Acidimicrobia, Acidobacteria and Nitrospirae. Low soil and forest floor quality as well as lower bacterial and fungal diversity characterized higher altitude levels, along with a high proportion of shared bacterial (Thermoleophilia, Actinobacteria and Bacilli) and fungal (Eurotiomycetes and Mortierellomycota) taxa. Beech-dominated sites showed moderate soil quality and high bacterial (Alphaproteobacteria, Acidobacteria, Planctomycetes and Bacteroidetes) and fungal (Basidiomycota) diversity. Particularly, the Basidiomycota were well represented in pure beech forests at an altitude of 1500m. In fertile and nitrogen rich soils with neutral pH, soil quality decreased along the altitudinal gradient, indicating that microbial diversity and forest floor decomposition were likely constrained by climatic conditions.

Modified montmorillonite and illite adjusted the preference of biotic and abiotic pathways of humus formation during chicken manure composting

The study aimed to identify the preference of pathways of humus formation. Five lab-scale composting experiments were established: the control (CK), montmorillonite addition (M), illite addition (I), thermal treatment montmorillonite addition (M-) and thermal treatment illite addition (I-). Results showed humus content was increased by 11.5%, 39.3%, 37.2%, 30.9% and 27.6% during CK, M-, M, I- and I composting. Meanwhile, Redundancy analysis indicated the bands of bacteria community related to humic acid (HA) were more abundant in the M- and I- treatments. Furthermore, structural equation model and variance partitioning analysis demonstrated that M- and I- treatments promoted precursors to synthesize HA by coordinated regulation of biotic pathway and abiotic pathway, the increase of HA in the M and I treatments mainly through the abiotic pathway. In summary, an effective method was proposed to improve humus production by adjusting the preference of biotic and abiotic pathways of humus formation.

Does the enrichment of post-arable soil with organic matter stimulate forest ecosystem restoration—A view from the perspective of three decades after the afforestation of farmland

The restoration of forest ecosystems on former agricultural land faces numerous challenges resulting mainly from differences in soil properties between post-arable and continuously forested ground. We revisited a 34-year-old but very well-documented experiment with enrichment in organic matter of the arable sandy soil aiming to accelerate humus formation and soil biota regeneration in Scots pine plantation. The goal of our study was to determine whether the addition of a mixture of pine bark with sawdust or lupine cultivation would change the selected soil properties and, as a result, would shift soil microarthropods of post-agricultural plantations towards those occurring in pine monocultures on continuously forested land. The effect of tillage depth was also studied.The soil properties of the experimental plantation differed significantly from those of the forest soil with respect to the pH, nitrogen (N) content, C/N ratio, sum of exchangeable base cations and degree of soil saturation with base cations. Moreover, the diversity and taxonomic and functional structures of Collembola assemblages differed considerably from the assemblages of pine monoculture of the same age growing on continuously forested land. The expectation of the experiment was not met; however, a certain significant ameliorative effect on some soil properties was observed with some treatments. The total organic carbon content (TOC), C/N ratio and cation exchange capacity increased as a result of the addition of bark and sawdust. In plots where deep tillage was applied, the TOC and N contents were lower than those in plots with shallow soil cultivation. A significant increase in the number of hemiedaphic forms at the expense of euedaphic and atmobiotic forms was observed in plots with lupine, while a mixture of pine bark and sawdust caused an increase in the number of euedaphic forms.Soil pH was identified as a key parameter that determined the difference between forest and post-agricultural collembolan assemblages. The variability of the structure of post-agricultural assemblages depends on N and exchangeable Mg2+ contents and hydrolytic acidity. The enrichment of post-arable soil with organic matter and tillage had long-lasting effects on soil properties but did not stimulate restoration of forest collembolan assemblages on former farmland.

Combined fertilizers versus dolomitic limestone: A comparative study from a forest habitat with Norway spruce

Abstract The research paper with character of case study deals with the influence of amelioration on soil as well as the Norway spruce nutrition and growth, with the focus on dolomitic limestone and combined fertilizer applications. The study was performed in the 7-year-old forest stand (Nízký Jeseník Mountains, Czech Republic, 100% Norway spruce, podzol, mor humus form, slightly undulated slope, 770 m a.s.l.). The soil properties (soil reaction, nutrient status, C/N ratio and cation exchange capacity), the plant nutrition, the plant biomass production and the health status were measured. Neither the expected significant increase in pH due to liming in the root zone nor the increase in calcium and magnesium in the soil was confirmed. In the dolomitic limestone treatment, the highest hydrolytic acidity reaching 260 mmol+/kg, the worst development of assimilatory organs, the growth and health status of individuals were ascertained one year after the usage. The application of combined fertilizers resulted in the highest response in the needle biomass production (0.35 g/100 needles compared to less than 0.30 g/100 needles in the dolomitic limestone treatment), in the potassium and phosphorus nutrition status (suboptimal 4–4.5% of potassium in dolomitic limestone and the control treatment compared to optimal 5.5–7.5% in the combined fertilizers treatments) and simultaneously to the optimization of the health status. Specifically, in forest stands, the effect of dolomitic limestone is rather overestimated and furthermore, chemical amelioration requires the detailed knowledge of the forest site.

Carbon dioxide emission and humus status of Albic Stagnic Luvisol under different fertilization regimes

The increase in the carbon dioxide content in the atmosphere, which enhances the greenhouse effect and leads to climate change, is the fundamental scientific problem of nowadays. Modern approaches to fertility management technologies of acid soils based on the principles of resource conservation and environmental safety are presented. They are based on the results of the study of carbon dioxide emission intensity, humus status, and crop rotation productivity in a classic long-term agricultural experiment under the influence of long-term use of various fertilizer systems with the application of ameliorant doses calculated by pH buffering capacity and hydrolytic acidity. The organo-mineral fertilizer system with the addition of 10 t of manure per ha of crop rotation area + N65P68K68, liming with a CaCO3 dose calculated according to pH buffering capacity (2.5 t/ha) contributes most to the optimization of soil processes. At the same time, it ensures the rational use of fertilizers and ameliorants, preservation of fertility, optimizes the processes of humus formation and carbon dioxide release. A high level of productivity of Albic Stagnic Luvisols forms under these conditions – 7.38 t/ha of grain units. Application of 1.0 and 1.5 lime norms calculated according to soil hydrolytic acidity with organic-mineral and mineral fertilizer systems on Albic Stagnic Luvisols in a short four-field crop rotation is not only a high-cost measure. However, it causes significant carbon loss in the form of CO2 due to additional mineralization. It is accompanied by calcium leaching and creates environmental problems in the conditions of the periodic washing-off water regime. Therefore, liming by CaCO3 dose calculated according to acid-base buffering capacity should be carried out before each of the following rotations in order to harmonize the environmental and productive functions of Albic Stagnic Luvisols in the short crop rotation. The obtained research results will be used to improve the methodology for determining carbon dioxide emissions and predicting the effect of various fertilizer and liming systems on its balance in the soil.

Considerations regarding improving the ecological and environmental performance of agriculture

Abstract The agri-environment economy provides a significant database for environmental policy decisions. The prioritization of an actionable behavior regarding the agri-environment vulnerabilities, favors the orientation of the agriculture through more environmentally responsible methods, represents a current trend, with a broad support within the Common Agricultural Policy (CAP). The promotion of an agricultural model capable of ensuring its own sustainability implies the existence of a set of common values and rules in which to buy as many producers as possible, with a common objective, respectively to reduce greenhouse emissions and to promote an ecological responsibility of the production model. Agriculture can significantly contribute to achieving the objectives of reducing the negative effects of climate change, not only from the perspective of ensuring the conservation of carbon reservoirs, which are still present in the soil, or by expanding their size and favoring the formation of humus, but in particular by reducing the consumption of energy needed in agricultural production and the supply of biomass needed for renewable energy production., much greener. The transition to a low carbon economy, more environmentally responsible, in the national agricultural sector can contribute, both to the significant increase of food security, but also to the optimization of the agricultural production structures, which will thus conform more easy to environmental requirements. It becomes primarily the role of implementation in agriculture of feasible standards more environmentally friendly, and environmentally friendly in this context, the research in the field and the continuous training acquiring new values. An important role is played by the implementation of best practice methods in the proper management of the land and the promotion of organic production models can significantly contribute to increasing the carbon absorption in the soil and, at the same time, to indicate possible improvments in their performance.

Análise de Nutrientes Lixiviados pela Chuva na Serapilheira sob a Perspectiva das Formas de Humus em Floresta Ombrófila Densa de Médio Montana do Bioma Mata Atlântica – Parque Nacional da Tijuca – RJ

A serapilheira é indicadora da integridade de ecossistemas florestais quando analisamos sob a perspectiva das “Formas de Humus”. Sendo o material orgânico disposto em camadas internas que variam no peso e espessura e expressa a ciclagem de nutrientes, que sintetiza o funcionamento dos ecossistemas. A pesquisa propõe entender que nutrientes são liberados pela ação da chuva lixiviando o material orgânico na copa e no solo, bem como pelas camadas internas da serapilheira numa floresta urbana de clima tropical. Foram construídos pluviômetros experimentais que coletavam a chuva e a depositava em recipientes abaixo de cada camada de serapilheira para análise química. Como resultados, percebemos que as diferentes camadas vão nutrir o solo de maneira diferenciada quando esse processo acontece com formas de humus mull-moder. O cálcio é liberado em maior quantidade pelas camadas F e MFB, o potássio e o magnésio têm maior disponibilização pela camada L, indicando que durante esse processo esses nutrientes são mais consumidos do que liberados. O sódio é abundante nas chuvas antes de atingir a serapilheira.

Land use and management effects on volcanic soils in West Sumatra, Indonesia

In this study, we aimed to assess the influence of land use and management on the fertility characteristics and pedogenic indicators of volcanic soils. Our study area was a mountainous area located in West Sumatra, Indonesia, where local farmers intensively cultivate vegetables by applying high amounts of chemical fertilizers and agrochemicals. Some negative impacts of conventional management were observed in the vegetable fields: soil acidification and loss of organic matter, with descended soil pH and increased acidity as well as decreased contents of exchangeable bases and with decreased amount of organic C. These impacts were not effectively mitigated by positive factors such as increased P availability and decreased capacity for P fixation. Continued cultivation over the years compounded the effects of these changes. Organic farming was advantageous in terms of soil fertility maintenance as it alleviated negative impacts compared to conventional farming. Natural fallow was effective in replenishing soil fertility as indicated by a significant increase in organic C, total N, and exchangeable Ca and Mg contents compared to the vegetable fields. The degree of replenishment was enhanced with a longer period under fallow; however, the natural fallow decreased P availability and increased P fixation capacity. Calliandra calothyrsus fallow further accelerated soil acidification, regardless of the rapid increase in the organic C and exchangeable bases contents. The adverse effects of Calliandra fallow were associated with the formation of humus–aluminum complexes to an extent that it changed from Sil-andic to Alu-andic Andosols.

Techno-moder: A proposal for a new morpho-functional humus form developing on Technosols revealed by micromorphology

Human impact on soil systems is now widely acknowledged. “Technosols” appeared in soil classification only a decade ago and the notion of “techno humus system” has emerged even more recently. Yet the variety of humus forms that could develop on Technosol remains largely unknown. To contribute to filling this knowledge gap, we studied the humus form developing on two Technosols resulting from the activity of a former coking plant and compared it with one developed on a Cambisol as a reference for the area. We used field description and micromorphology on thin sections coupled with a point-and-count method to precisely describe the surface of the humipedons of the area studied. A total of 13,841 counts and identifications were performed on 11 thin sections and spread into 17 fabric units. Micromorphology on thin soil sections revealed that epi-saprophagous organisms transformed most of the neo-formed organic matter on the Technosols studied, leading to an accumulation of feces on the surface of the humipedon. Our results suggested that the humus form developing on the Technosols was similar to a moder and exhibited the same ectorganic horizons (OL, OF, zOH), whilst overlaying a technogenic one composed mostly of coal fragments. We would like to propose the term “techno-moder” for this new humus form, developing in the absence of an A horizon. On the other hand, micromorphology allowed us to classify the humus form developed on the Cambisol as a eumull containing anthropic coal by-products. Specification of the humus form developing on such soils could represent a promising way to specify pedological processes such as organic matter decomposition, soil aggregation and also to enrich the humus form classification on Technosols.

ПОРІВНЯЛЬНА ХАРАКТЕРИСТИКА ВМІСТУ КАЛЬЦІЮ ТА СТУПЕНЯ КИСЛОТНОСТІ У ҐРУНТАХ ТЕРНОПІЛЬСЬКОЇ ОБЛАСТІ

The soils of Ukraine have been well studied, however this did not prevent them from the intensive degradation processes. About a third of the arable land is eroded, about 20% of organic matter is lost, almost all the arable land in the subsoil is compacted, the nutrient forms of mobile phosphorus and especially calcium are significantly reduced, calcium, occupying the bulk of the cation exchange capacity of the soil, serves as a regulator. Calcium is a coagulator of soil colloids, protects them from destruction and removal to the lower horizons of the profile; promotes the formation and preservation of humus and its stable compounds; creates proper physical conditions, plays a crucial role in structure formation; binds moving forms of compounds of aluminum, iron, manganese, which adversely affect the cultural vegetation. Calcium is also a direct nutrient of plants and soil microorganisms and plays an exclusive mobilizing role in soil, increasing the content of basic nutrients available to plants, primarily phosphorus.
 In the work we carried out chemical assessment of soils of Kozova, Zboriv Shumsk, Pidhaytsi and Berezhany districts of Ternopil region. We also studied the acidity, content of exchangeable calcium and natural factors that determine the peculiarities of agricultural natural resource use and influence. Correlation relationships between the studied values are established.

Humus balance in a short crop rotation of Right Bank Forest Steppe of Ukraine depending on fertilization systems of typical chornozemic soil

Four year research (2015–2018) at Bila Tserkva National Agrarian University proved that plant residues and non-market products of the field five course grain row rotation are important sources for soil humus formation. On the unfertilized areas, fertilized withn8 t/ha of animal manure + N76P64K57, 12 t/ha of animal manure + N95P82K72 and 16 t/ha of animal manure + N112P100K86 humus percentage formed due to humification of plants matter was correspondently 51.4; 40.3; 37.7 and 36.1 %, with animal manure – 0; 15.3; 17.2 and 18.7 %, with by-products of farming – 44.0; 40.8; 41.7 and 42.1 %, with herbage of white mustard – 4.6; 3.6; 3.4 and 3.1 %. With the increase of fertilizers level this index regarding plants matter and green manure decreases, while animal manure provides for the index slight increase. On the unfertilized areas humus balance under cultivated crops as sunfl ower and corn is negative, but under other crops in rotation it is positive. On the fertilized areas under all crops this index is positive. When applying the biggest amount of fertilizers, annual gain in soil humus is 1.1 t/ha. Humus balance is negative on all the variants of research under the condition of disposal of non-market products from the fi elds of crop rotation. Along with plants matter, plant by-products and herbage of white mustard the amount of humus provided to the soil was equal to the application of correspondently 14–33, 12–36 and 1.3–2.6 t of animal manure per hectare of tilled fi eld. Under zero, the fi rst, the second and the third levels of soil fertilization, soil received correspondently 4.08; 5.98; 7.46 and 8.73 t of plants matter 68–71 % of which are root and the others are above surface. The percentage of by-products of crops in the rotation increases with fertilizers amount increase. Soy, winter wheat, sunfl ower and spring barley have a bigger gain in above surface rather than root mass due to increase of fertilizers amount. The highest productivity from one hectare of tilled fi eld in a crop rotation (5.63 t of dry matter, 7.84 t of fodder units, 0.671 t of digestible protein) is gained due to application of 16 t/ha of animal manure + N112P100K86, though the most economically viable amount is 12 t/ha animal manure + N95P82K72. Key words: humus balance, soil, fertilizers, crop, by-products, plants matter, crop rotation, grain crops, index of ecologization, productivity.

Humus formation driven by ammonia-oxidizing bacteria during mixed materials composting

The aim of this study was to identify the effects of ammonia-oxidizing bacteria (AOB) inoculation on humus formation. Both nitrogen conversion and humus formation were considered as the main processes, because NH4+-N-like compounds not only substrates of nitrification, but also precursors of humus. During composting, the inoculation of AOB indeed increased humus concentration by fixing NH3 emission as NH4+-N, but it has also promoted nitrogen transformation. While the main reason was the changed bacteria community structure caused by inoculating AOB. Moreover, the relationship between bacteria and nitrogen transformation and humus formation has become closer. And bacteria were more likely to synthesize humus. Therefore, it is conjectured that AOB inoculation could not only provide NH4+-N for humus formation, but also enhance the anabolism of microorganisms. This suppose has been confirmed by structural equation model in this study. Therefore, AOB inoculation has a driving effect on promoting humus formation.

THE RELATIONSHIPS BETWEEN THE SITE INDEX OF MARITIME PINE PLANTING AREAS AND SOME ECOLOGICAL FACTORS (CASE OF SINOP-BEKTAŞA REGION)

Türkiye’de odun hammaddesine olan talep artışını karşılamak için ağaçlandırma çalışmalarına ağırlık verilmesi zorunluluk haline gelmiştir. Ağaçlandırma çalışmalarında genellikle kanaatkâr ve hızlı gelişen türlerin kullanılması tavsiye edilmektedir. Bu itibarla, ülkemizde Sahilçamı (Pinus pinaster Ait.) endüstriyel ağaçlandırmalarda kullanılacak iyi bir tür olarak gözükmektedir. Bu nedenle, Sahilçamı’ nın gelişimini ve büyümesini etkileyen en önemli yetişme ortamı faktörlerini ve etki derecelerini saptayarak dönem sonunda en yüksek geliri elde etmek için verimliliğin en yüksek olduğu yerlerden çalışmaya başlamak önem arz etmektedir. Dolayısıyla, bu türün en iyi gelişme gösterdiği Batı Karadeniz Bölgesi’nde yetişme ortamı özelliklerini araştıran çalışmaların yetersiz olduğu görülmektedir. Bu çalışmada, Sinop-Bektaşa Orman İşletme Şefliği sınırları içerisinde yayılış gösteren Sahilçamı ağaçlandırma alanındaki toprakların mutlak derinlik, mekanik bileşim (tekstür), toprak tepkimesi, organik madde miktarı, dış toprak durumu ve humus formu gibi bazı özellikleri ile verimlilik (bonitet endeksi) arasındaki ilişkiler belirlenmeye çalışılmıştır. Bu amaçla, Sinop-Bektaşa Orman İşletme Şefliği sınırları içerisindeki Sahilçamı meşcerelerinden, 35 adet örnek alandan toplam 145 adet toprak örneği alınmıştır. Alınan toprak örnekleri üzerinde toprak türü, toprak reaksiyonu, organik madde, faydalanabilir su kapasitesi (FSK) vb. gibi özellikler belirlenmiştir. Ayrıca her bir örnek alan için 20 yaşındaki üst boy değerleri hesaplanmıştır. Hesaplanan verimlilik endeksi iyi, orta, düşük olmak üzere 3 gruba ayrılmıştır. Her bir örnek alandaki verimlilik endeksi ile bazı toprak özellikleri arasındaki ilişkiler istatistiksel olarak ortaya konulmuştur. Sonuç olarak; verimlilik endeksi ile % kil miktarı, % toz miktarı, ortalama % organik madde ve ortalama % FSK arasında pozitif, % kum miktarı arasında negatif ilişkiler bulunmuştur.

Understanding the effects of early degradation on isotopic tracers: implications for sediment source attribution using compound-specific isotope analysis (CSIA)

Abstract. Application of compound-specific isotope analysis (CSIA) in sediment fingerprinting source apportionment studies is becoming more frequent, as it can potentially provide robust land-use-based source attribution of suspended sediments in freshwater and marine systems. Isotopic tracers such as δ13C values of vegetation-derived organic compounds are considered to be suitable for the CSIA-based fingerprinting method. However, a rigorous evaluation of tracer conservativeness in terms of the stability of isotopic signature during detachment and transport of soil during erosion is essential for the suitability of the method. With the aim to identify potential fractionation and shifts in tracer signature during early degradation of organic matter in surface soils, we measured concentrations and δ13C values of long-chain fatty acids and n-alkanes from fresh plant biomass (as vegetation is a direct source of these compounds to the soils), degraded organic horizon (O horizon), and mineral soil (A horizon) from various forest types with different humus forms (five sites). The bulk δ13C values showed continuous 13C enrichment through the degradation stages from fresh plant material to the O and A horizons, ranging between 3.5 ‰ and 5.6 ‰. Compound-specific δ13C values showed a general 13C enrichment for both long-chain fatty acids (up to 5 ‰) and n-alkanes (up to 3.9 ‰) from fresh plant biomass to the O horizon overlying the A horizon. However, only slight or no further changes occurred from the O to the A horizon. We also compared compound-specific δ13C values between two soil particle size classes (<2 mm and <63 µm) from four sites and found no significant differences of tracer values between them, with even less fractionation for the long-chain n-alkanes within the soil particle fractions. This points to the conclusion that sampling and analysing bulk soil material might be valid for the isotopic tracer applications. We further conclude that our results support the suitability of studied isotopic tracers as a representative source soil signature in the CSIA-based sediment source attribution, as they demonstrated necessary stability in the plant–soil system during organic matter degradation.

Humus content for different use of sod-podzolic sandy soil and the amount of CO2 emissions lost

The results of studies of changes of humus content under different soil tillage systems and fertilization of sod-podzolic sandy loam during 4 rotations of grain-sowing crop rotation are presented in the paper and the amounts of CO 2 emission losses are established. Fertilizer systems have been found to have a greater impact on humus content than soil tillage systems. During the 36-year study period, humus loss on a background without fertilizer for plowing a year was 0.13 t / ha, while for fieldless cultivation - 0.11 t / ha. At application of 1 ha of crop rotation area 7.8 t of manure and N 57 P 63 K 70 kg of mineral fertilizers and systematic tillage with rotation of the slice accumulates 0.11 t / ha of humus annually, while for fieldless cultivation - 0.31 t /Ha. It is established that in Polissya zone in sod-podzolic sandy loam soil in rotation with one field of perennial legumes without fertilizer maintenance of deficient humus balance only by reducing the load during the main cultivation is impossible. It was found that during the systematic rotation of fertilizer application during the four rotations of the organo-mineral fertilizer system, grain yields increased on average from 36 to 62%, triticale in the spring by 2.5 times. Against the background of the fertilization system with the elements of biologicalisation (3.9 tonnes of manure + N8 + 1.2 tonnes of straw + 3.3 tonnes of siderata per 1 ha of crop rotation area), on the contrary, crop rotation yields declined mainly by 8-46%. Thus, higher yields from the organo-mineral fertilizer system, as compared to the control, led to more organic feedstock entering the soil for organic matter accumulation and carbon sequestration, which resulted in better humus formation and sequestration of organic carbon. At an average CO 2 emission intensity of 6.3 kg / ha / h. from the soil, during the day the amount of emissions is about 167 kg per 1 ha, and for the whole growing season about 20.1 t / ha of carbon dioxide. Thus, on turf-podzolic sandy loam soils during crop growing, unproductive CO 2 losses range from 2.1 to 4.2 kg / ha / h. Further studies on establishing the role of soil cultivation methods with modern tools in shaping the fertility of Polissya light soils and minimizing the unproductive emission losses of organic matter are promising.

К изучению спорообразующих бактерий и микромицетов естественных и окультуренных ценозов

The article provides some information about spore–forming bacteria (bacilli) and micromycetes of natural (virgin) cenosis under herbaceous vegetation and agrocenosis (cereals). It was established that in both cenoses there are 3 strains of spore–forming bacteria and 4 strains of micromycetes. Bacilli and micromycetes actively decompose complex polysaccharides to monosaccharides, which are easily absorbed by plants. Bacilli and micromycetes have a strong enzymatic effect on plant residues, transforming decomposition products in the process of humus formation. Together with invertebrate animals, they are included in the decomposition chain of phytomass residues. Bacilli and micromycetes, being active under mesophilic conditions, are also significant in arid soils.