Soil solution calcium carbonate equilibrium as a driver of soil organic matter and heavy metals transfer and turnover in focus of humic substances soil fertility effect

Mobile and potentially mobile forms of heavy metals are probably one of the most important toxic hazards in the environment. Besides pH, which is a factor influencing the mobility/availability of heavy metals to the greatest extent, the content and mainly the quality of soil organic matter play a very important role in the evaluation of heavy metal behaviour in the environment. The fraction of metals bound to organic compounds is exclusively associated with humic substances and particularly with humic acids (HA). A relationship between the parameters reflecting the actual structure of humic acids and mobile or potentially mobile fractions of heavy metals was studied in 12 soil localities representing different soil types. It can be stated on the basis of the acquired data that heavy metals tend to form complexes with soil organic matter that are different for each metal. The results suggest that copper is bound mainly in an unavailable form (significant correlations of fraction IV with HA parameters) and cadmium prefers exchangeable forms (significant correlations of fraction I with HA parameters) and is more available. It can be assumed on the basis Spearman’s correlations that mobile fractions of cadmium are predominantly bound to the aliphatic part of humic substances, and copper prefers strong bonds to humic acids with a high degree of humification.

Download Full-text

Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽

10.3390/agronomy11061067 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1067

Author(s):

Aleksandra Ukalska-Jaruga ◽

Romualda Bejger ◽

Guillaume Debaene ◽

Bożena Smreczak

Keyword(s):

Molecular Weight ◽

Organic Matter ◽

Soil Organic Matter ◽

Humic Substances ◽

Humic Acids ◽

Agricultural Soils ◽

Fulvic Acids ◽

Sorption Properties ◽

Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

Download Full-text

Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure

Biomolecules ◽

10.3390/biom11030448 ◽

2021 ◽

Vol 11 (3) ◽

pp. 448

Author(s):

Mahrous Awad ◽

Zhongzhen Liu ◽

Milan Skalicky ◽

Eldessoky S. Dessoky ◽

Marian Brestic ◽

...

Keyword(s):

Heavy Metals ◽

Organic Matter ◽

Soil Organic Matter ◽

Soil Ph ◽

Contaminated Soil ◽

Contaminated Soils ◽

Extraction Procedure ◽

Sequential Fractionation ◽

Relationship Of ◽

The Relationship

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

Download Full-text

The quantity and quality of soil organic matter and humic substances following dry-farming and subsequent restoration in an upland pasture

CATENA ◽

10.1016/j.catena.2021.105249 ◽

2021 ◽

Vol 202 ◽

pp. 105249

Author(s):

Fayez Raiesi

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Humic Substances ◽

Upland Pasture ◽

Dry Farming

Download Full-text

Assessment of Potato Farmland Soil Nutrient Based on MDS-SQI Model in the Loess Plateau

Sustainability ◽

10.3390/su13073957 ◽

2021 ◽

Vol 13 (7) ◽

pp. 3957

Author(s):

Yingying Xing ◽

Ning Wang ◽

Xiaoli Niu ◽

Wenting Jiang ◽

Xiukang Wang

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Fertility ◽

Soil Quality ◽

Soil Nutrients ◽

Organic Matter Content ◽

Soil Nutrient ◽

Matter Content ◽

Soil Organic Matter Content ◽

Farmland Soil

Soil nutrients are essential nutrients provided by soil for plant growth. Most researchers focus on the coupling effect of nutrients with potato yield and quality. There are few studies on the evaluation of soil nutrients in potato fields. The purpose of this study is to investigate the soil nutrients of potato farmland and the soil vertical nutrient distributions, and then to provide a theoretical and experimental basis for the fertilizer management practices for potatoes in Loess Plateau. Eight physical and chemical soil indexes were selected in the study area, and 810 farmland soil samples from the potato agriculture product areas were analyzed in Northern Shaanxi. The paper established the minimum data set (MDS) for the quality diagnosis of the cultivated layer for farmland by principal component analysis (PCA), respectively, and furthermore, analyzed the soil nutrient characteristics of the cultivated layer adopted soil quality index (SQI). The results showed that the MDS on soil quality diagnosis of the cultivated layer for farmland soil included such indicators as the soil organic matter content, soil available potassium content, and soil available phosphorus content. The comprehensive index value of the soil quality was between 0.064 and 0.302. The SPSS average clustering process used to classify SQI was divided into three grades: class I (36.2%) was defined as suitable soil fertility (SQI < 0.122), class II (55.6%) was defined as moderate soil fertility (0.122 < SQI < 0.18), and class III (8.2%) was defined as poor soil fertility (SQI > 0.186). The comprehensive quality of the potato farmland soils was generally low. The proportion of soil nutrients in the SQI composition ranged from large to small as the soil available potassium content = soil available phosphorus content > soil organic matter content, which became the limiting factor of the soil organic matter content in this area. This study revolves around the 0 to 60 cm soil layer; the soil fertility decreased gradually with the soil depth, and had significant differences between the respective soil layers. In order to improve the soil nutrient accumulation and potato yield in potato farmland in northern Shaanxi, it is suggested to increase the fertilization depth (20 to 40 cm) and further study the ratio of nitrogen, phosphorus, and potassium fertilizer.

Download Full-text

Differences in soil organic matter and humus of sandy soil after application of biochar substrates and combination of biochar substrates with mineral fertilizers

Acta fytotechnica et zootechnica ◽

10.15414/afz.2020.23.03.117-124 ◽

2020 ◽

Vol 23 (3) ◽

pp. 117-124

Author(s):

Dušan Šrank ◽

Vladimír Šimanský

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Carbon Content ◽

Humic Substances ◽

Sandy Soil ◽

The Other ◽

Mineral Fertilizers ◽

Other Hand ◽

Sheep Manure ◽

The Impact

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.

Download Full-text

Organik Matter: It’s Role in Sustainable Farming of Sugarcane

Perspektif ◽

10.21082/p.v14n1.2015.61-71 ◽

2016 ◽

Vol 14 (1) ◽

pp. 61

Author(s):

Djajadi Djajadi

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Fertility ◽

Green Manure ◽

Organic Fertilizer ◽

Soil Health ◽

High Yield ◽

Cane Yield ◽

Sustainable Farming

ABSTRACTOrganik matter has an important role in determining soil health of sugarcane, i.e. soil capacity to support sugarcane to produce sustainable high yield. Soil organic matter influences soil physical, chemical, and biological properties, so that a consequence of declining soil organic matter is poorer soil fertility and lower yield. This paper has an objective to elucidate the important role of organic matter on sustainable farming of sugarcane. The important role of organic matter in soil fertility has been known for a long time before Green Revolution concept was introduced. With more intensity in sugarcane farming and more increasing of sugar demand, application of organic fertilizer started to be substituted by chemical fertilizer. Using green manure and/or biofertilizer has a chance to be spread out to the farmers due to more practical and more efficient than solid organik fertilizer, such as dung manure or compost. Future research should be focusing on the efectivity of green manure and or biofertilzer sources in improving soil fertility and cane yield, minimizing soil pathogen, reducing soil erosion of sugar cane land monoculture, and improving awareness of farmers about soil degradation as consequences of sugarcane monoculture planting for years.Keywords: Organic matter, sugarcane, soil health sustainable farming Bahan Organik: Peranannya dalam Budidaya Tebu BerkelanjutanABSTRAKBahan organik tanah berperan penting dalam menentukan kesehatan tanah tebu, yaitu kapasitas tanah yang dapat mendukung produksi tebu yang tinggi secara berkelanjutan. Kadar bahan organik tanah mempengaruhi sifat fisik, kimia dan biologi tanah. Paper ini bertujuan untuk menguraikan tentang peranan bahan organik dalam memperbaiki sifat fisik, kimia dan biologi tanah pertanaman tebu. Pentingnya peran bahan oganik tersebut sudah disadari dari dulu, sehingga sebelum revolusi hijau penggunaan pupuk organik sudah umum dilakukan petani. Dengan semakin intensifnya budidaya tebu dan semakin meningkatnya kebutuhan gula, pemanfaatan pupuk organik sudah jarang dilakukan. Diperlukan usaha untuk meningkatkan dan mempertahankan kadar bahan organik pada lahan tebu, antara lain berupa gerakan masal dalam bentuk gerakan nasional melalui program aplikasi bahan organik. Pemanfaatan pupuk hijau dan/atau pupuk hayati berpeluang untuk diterapkan karena lebih praktis dan efisien daripada penambahan pupuk organik padat. Penelitian ke depan perlu difokuskan untuk mengkaji jenis-jenis pupuk organik dan pupuk hayati yang efektif memperbaiki kesuburan, dalam menekan serangan penyakit, meminimalkan erosi pada lahan-lahan tebu monokultur, dan meningkatkan kesadaran petani tebu tentang terjadinya degradasi lahan akibat penanaman tebu yang terus menerus.Kata kunci: Bahan organik, tebu, kesehatan tanah, budidaya berkelanjutan

Download Full-text

CO2-C losses and carbon quality of selected Maritime Antarctic soils

Antarctic Science ◽

10.1017/s0954102012000648 ◽

2012 ◽

Vol 25 (1) ◽

pp. 11-18 ◽

Cited By ~ 9

Author(s):

Juliana Vanir De Souza Carvalho ◽

Eduardo De Sá Mendonça ◽

Newton La Scala ◽

César Reis ◽

Efrain Lázaro Reis ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Temperature ◽

Soil Carbon ◽

Humic Substances ◽

Microbial Activity ◽

Chemical Characteristics ◽

Maritime Antarctic ◽

Antarctic Soils ◽

Humification Degree

AbstractPolar Regions are the most important soil carbon reservoirs on Earth. Monitoring soil carbon storage in a changing global climate context may indicate possible effects of climate change on terrestrial environments. In this regard, we need to understand the dynamics of soil organic matter in relation to its chemical characteristics. We evaluated the influence of chemical characteristics of humic substances on the process of soil organic matter mineralization in selected Maritime Antarctic soils. A laboratory assay was carried out with soils from five locations from King George Island. We determined the contents of total organic carbon, oxidizable carbon fractions of soil organic matter, and humic substances. Two in situ field experiments were carried out during two summers, in order to evaluate the CO2-C emissions in relation to soil temperature variations. The overall low amounts of soil organic matter in Maritime Antarctic soils have a low humification degree and reduced microbial activity. CO2-C emissions showed significant exponential relationship with temperature, suggesting a sharp increase in CO2-C emissions with a warming scenario, and Q10 values (the percentage increase in emission for a 10°C increase in soil temperature) were higher than values reported from elsewhere. The sensitivity of the CO2-C emission in relation to temperature was significantly correlated with the humification degree of soil organic matter and microbial activity for Antarctic soils.

Download Full-text