Soil Research Articles

Tolerance to glyphosate and antibiotic resistance in gram-negative bacteria isolated from soils of different agricultural management systems in Ceará, Brazil

Brazil is among the world’s largest consumers of pesticides, with glyphosate (GLY) being the most commercialized herbicide in the country. Studies showed microorganisms suffer selective pressure when exposed to pesticides, developing tolerance to pesticides and resistance to antibiotics (ABs), in a phenomenon known as “cross-resistance”. The present work aimed to evaluate the occurrence of glyphosate-tolerance and AB-resistance in bacteria isolated from different agricultural management systems in Ceará State, Brazil. Gram-negative bacteria isolated from agroforestry (S1), conventional farming (S2) and uncultivated (S3) soils were cultured in the presence of 1.6% acid glyphosate. Overall, 58 strains were isolated. Soils S1 and S2 presented several multidrug resistant (MDR) strains, the majority resistant to ampicilin. Although there was a small percentage of strains resistant to ertapenem (33%, soil S1), the fact they were found is concerning, as Carbapenem antibiotics are used to treat clinical cases of MDR bacteria, which are not common outside hospital settings. Stenotrophomonas maltophilia (soil S2), resistant to six of the eight ABs tested, was identified by MALDI-TOF mass spectrometry, and was found as one of the most common opportunistic bacteria in ICUs of Ceará hospitals.

Contribution to the Improvement of Vegetative Propagation by Greenhouse Cuttings of Odorous Verbena (Aloysia citrodora)

Currently several species are threatened with extinction due to climatic factors, population pressure and the strong global demand for a continuous and uniform supply of fragrant, aromatic and medicinal plants. The multiplication and domestication of these species remains the only way to save them from extinction, our study is within the framework of propagation by cuttings of odorous verbena (Aloysia citrodora). In fact, some parameters influencing the success of cuttings have been studied, namely the nature of the substrate, the effect of certain rooting products and the position of the cutting in relation to the mother plant (basal or apical), the tests were carried out in a tunnel greenhouse at the ibn tofail university, faculty of sciences kenitra, Morroco. Out of 144 trials, the success rate of cuttings according to the type of substrate was 91.66%, 75% and 83.33% respectively for substrates S1 (soil only), S2 (1/2 sand and 1/2 compost) and S3 (1/3 soil; 1/3 compost and 1/3 peat). For the three products, we didn’t make combinations. but we followed the effect of each product alone, For the treatment effect, 77%, 0% and 69% respectively were obtained for Product 1 (auxin), Product 2 (based on mineral matter and amino acids) and Product 3 (seaweed extract). With regard to the position of the cutting, high percentages were obtained for cuttings from the basal position.

Trace Metals Distribution and Fractionation in Soils Around the Abandoned “Ichmoul” Pb-Zn Mill-Mine, North-East of Algeria

In order to assess the environmental impact of soil polluted with trace metals, representative soils were collected surrounding the abandoned Pb–Zn mine mill (SM soils), and the new temporary ore storage site (SS soils), which are located in the vicinity of Medina (Aures), North-east of Algeria. Total digestion has been used to determine the total content of Zinc, Copper, Lead, Cadmium, and Arsenic, then it was analysed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sequential extraction Tessier scheme was also used to extract the chemical forms of Zn, Cu, and Pb, and their concentrations in each fraction were analyzed by atomic absorption spectrometry. Lead was the most abundant trace metals, its concentration in mg.kg-1 ranged between (67.20 – 46000), followed by Zinc (26 - 1853), Copper (32 – 495), Arsenic (8 – 116), and Cadmium (0.3 - 7.30). Sequential extraction shows that Zinc was mainly associated with reducible and residual fractions. Copper was bound predominantly with the minerals in the residual fraction, followed by the organic matter. Lead was bound mainly with carbonate fraction in SM soils, while Pb in the SM soils was mainly associated with the reducible fraction. The Pb, Zn, Cu mobility factor was significantly higher in SM soils than in SS soils. These results indicate that anthropic activities related to ore concentration and mining process lead to increased concentration of trace metals in surrounding soils, hence their mobility and bioavailability, this consists a potential risk to the environment and biota.

Soil Ethics: A New Look at Life on Soil

Soil Ethics: A New Look at Life on Soil

Editorial: Advances in Magnetism of Soils and Sediments

Editorial: Advances in Magnetism of Soils and Sediments

Effect of foliar application of jasmonic acid and drought stress on yield and some agronomic and physiologic traits of quinoa (Chenopodium quinoa Willd) cultivars

Introduction Quinoa plant (Chenopodium quinoa Willd) is a grain- like crop with high nutritional values and resistant to abiotic stresses such as drought and salinity stress. Drought stress is one of major stresses, which had the undesirable effects on qualitative and quantitative yield of crops in arid and semi-arid regions of the world. On the other hand, Jasmonate (Jasmonic acid), are a new plant growth regulator that plays an important role in increase the resistance of plants to environmental stresses such as drought stress. That's why this experiment aims to investigate the impact of drought stress and foliar application Jasmonic acid on yield and some agronomic and physiologic characteristics of Quinoa cultivars. Material and methods This experiment was carried out in split factorial design based on randomized complete block design with three replications in Kerman agricultural research and education center (Joupar station) during 2018. The main factor was included non-stress (normal irrigation) and drought stress (based on 60% and 90% of usable soil moisture discharge) and foliar application of JA in three levels (0, 1 and 2 mg/l) and varieties (Giza1, Titicaca, Q29) as factorial arranged in sub factor. The measured traits were seed yield, inflorescence number in plant, seed 1000 weight, biological yield, plant height, harvest index, relative water content and chlorophyll index. Results and discussion The results showed that drought stress reduced the seed yield and some agronomic and physiologic traits of Quinoa. The application of JA, especially concentration of 2 mg/L improved these traits compared to the control treatments. The highest seed yield and biological yield were obtained from interaction of normal irrigation and 2 mg/l JA and Titicaca cultivar by 3316 and 13265 kg/ha, respectively. The lowest seed yield and biological yield related to interaction of drought stress and non-application of JA and Giza1 cultivar by 1682 and 7733 kg/ha, respectively. The highest plant height was achieved from the interaction of Titicaca cultivar under non-stress conditions and application of 2 mg/l JA by 142.4 cm. The highest chlorophyll leaf index (SPAD index) was observed under non stress conditions and spraying of 1 mg/l JA in Giza1 by 58.8. Conclusions According to the result of this research, it can be suggested that JA as a growth regulator, can increase seed yield and productivity of quinoa cultivars, especially Titicaca cultivar through the reducing the negative effect of drought stress and improving plant growth

Nanocontaminants in soil: emerging concerns and risks

Nanocontaminants in soil: emerging concerns and risks

Perbandingan Metode Soil Adjusted Vegetation Index (SAVI) dan Forest Canopy Density (FCD) untuk Identifikasi Tutupan Vegetasi (Kasus; Area Pembuatan Jalan Baru Singaraja-Mengwi)

This research uses Landsat 8 OLI/TIRS image which objective to determine the accuracy level of SAVI method and FCD model in the identification of vegetation cover. It is done as an effort to assist in determining the right method of monitoring the change of vegetation cover in the forest area. Therefore, this research compares the vegetation index of Soil Adjusted Vegetation Index (SAVI) because it is able to suppress the background of the soil so that the vegetation cover is able to be displayed according to the conditions in the field. While the FCD model uses four variables such as; Advanced Vegetation Index (AVI), Bare Soil Index (BI), Shadow Index (SI), and thermal index using the Split-Windows Algorithm (SWA) method. Comparison results between SAVI and FCD models indicate that the higher accuracy of SAVI is 84% and FCD model is only 82%. It is possible because the limited use of research areas that show SAVI is superior due to heterogeneous conditions and it approaches the conditions in the field than the FCD model that is more group and only able to be realized in three classes. Based on the results, it was concluded that the vegetation index can be used in monitoring the limited area of research but it is also not absolute because it is possible that FCD model is better.

How Do Micro‐ and Nanoplastics Move through Soil?

How Do Micro‐ and Nanoplastics Move through Soil?

Variable-rate seeding in soybean according to soil attributes related to grain yield

Variable-rate seeding in soybean according to soil attributes related to grain yield

New England Soil

New England Soil

Effects of biomass conditioner on soil nutrient and microbial community characteristics of alpine desertified grassland in northwest Sichuan, China

Biomass conditioner made from agricultural and animal husbandry waste for resource disposal could be used to improve desertified soil, which is one of the effective ways of ecological management on desertified grasslands in northwest Sichuan. To clarify the effects of different raw material conditioners on alpine desertified grassland in northwest Sichuan, we analyzed the effects of three conditioners on soil nutrients and microbial community characteristics. With no conditioner as the control (CK), three different biomass conditioners were set up with an application rate of 12 t·hm-2, including mushroom dregs (JZ), straw (JG) and biochar (SWT). The results showed that all biomass conditioners could significantly increase soil available nutrients and active organic carbon by 23.0%-521.6%. Among the three conditioners, JG had the best effect, with an improvement range for soil nutrient and organic carbon of 65.1%-521.6%. Because biomass conditioner was only applied in the first year, soil available nutrients and active organic carbon in the second year decreased by 4.5%-92.3% compared with that of the first year, while soil organic carbon and microbial biomass carbon content of the second year increased by 5.6%-458.0%. The biomass conditioners changed the relative abundance of the dominant bacteria in the microbial community. JG significantly affected bacterial flora, while JG and JZ affected fungal flora. Compared with CK, JG significantly reduced the diversity of soil bacteria and fungi. The Shannon index was decreased by 2.9% and 31.8%, while the Simpson index was increased by 175.0% and 320.9%, respectively. Results of the redundancy analysis showed that the contents of soil available nutrients and active organic carbon were important factors affecting microbial community composition. The contents of soil nitrate and microbial biomass carbon had greater impacts on bacterial community composition, explaining 65.9% of community variations. The contents of soil available potassium and microbial biomass carbon had a greater impact on fungal community composition, explaining 83.2% of community variation. According to the comprehensive comparison, straw conditioner could significantly increase soil available nutrients and active organic carbon, and benefit the growth of beneficial bacteria and fungi, which could be used as a promotion measure to improve soil quality of alpine desertified grassland in northwest Sichuan.

Effect of the co-application of olive waste-based compost and biochar on soil fertility and Zea mays agrophysiological traits

Purpose The deterioration of agricultural soil can be alleviated by maintaining an appropriate level of soil organic matter by using organic amendments such as compost and biochar. The aim of this study was to investigate the effects of olive waste-based compost, wood-based biochar and their combination on the chemical and microbial properties of loamy clay soil and the agrophysiological traits of maize. Method Zea mays was grown under greenhouse conditions for 3 months in pots filled with alkaline soil collected from 0-30 cm depth. The experiment was arranged in a completely randomized design with 5 replicates and 3 treatments: compost-soil [1:10 (v/v)], biochar-soil [1:20 (v/v)] and (1:2)-ratio biochar-compost combination (BCC). ResultsBiochar addition singly or in BCC increased soil TOC, EC, and pH. Furthermore, adding biochar to compost increased the levels of macro- and micronutrients compared to those under single application of biochar. The soil fertility improved significantly with regard to available phosphorus and potassium, nitrogen, and micronutrients. Single application of biochar had a negative impact on mycorrhizal symbiosis and was statistically insignificant for soil viable cultivable microorganisms. Conclusion Overall, single application of compost gave the best results in terms of plant growth and soil fertility improvement; thus, a synergistic effect of both amendments was not observed, which could be due to the quantity of the applied biochar and the duration of the experiment.

An example of fast old field succession in a traditionally managed rural landscape on the Slovenian Karst

We report an exceptionally fast grassland recovery process from a karst plateau in SW Slovenia. Vegetation of old fields with different ages was sampled using a chronosequence of fields abandoned 1, 3, 6, 9, 13, 15 and 100 years ago. We prepared dendrogram dividing the data set into 9 clusters that were further analyzed: diagnostic species, ecological conditions and life forms were evaluated. The initial stage of succession was characterized by segetal weeds and indicated high levels of soil nutrients. The second stage was dominated by dense patches of perennial forbs (most of them ruderal species) preferring also high levels of soil nutrients. The third stage was dominated by caespitose hemicryptophyte grasses, many of them of sub-Mediterranean origin. The first two stages took 13 years and both could be considered as early successional stages developing on nutrient rich soils. These stages were switched to late successional stage characterized by seminatural grassland species. The quick succession can probably be attributed to the rich species pool of natural grassland flora, the small size and annual mowing of abandoned agricultural fields and the close proximity of seed sources.

Physico-chemical changes and maturity evaluation of composts from wood residue mixed with sewage sludge and chicken manure

Purpose Using the effective approaches for modifying the recycled wood as a novel bulky agent improves the quality of soil amendment. This study aimed to compare the stability and maturity of the soil amendments produced by the compostation of forest industrial waste and sewage sludge on seed germination. Method Three materials, namely sawdust, sewage sludge, and chicken manure were mixed at different ratios (dry weight basis) to reach the initial bulk density of 0.40 Kg.L-1, the temperature of 30 °C, the C/N ratio of 25, and the moisture content of 60 %. A pilot-scale composting process was applied to monitor the aeration rate, temperature, and moisture contents during the process over time. The comparison of physico-chemical, phytotoxicity, and germination indices among the samples was performed in three repetitions. Results The results of this study indicated that the sustainable conditions (i.e., the temperature of 70 °C, aeration rate of 0.30 L.Kg-1DM.min-1, and moisture content of 50-60 %) can have a significant effect on the thermophilic stage for compost curing without any inhibitory repercussion. Increasing the germination index of cress (Lepidium sativum) up to 79 % proved that the toxicity of industrial sewage sludge was declined through the elimination of heavy metals. Conclusion This study revealed that the availability of bulky agents such as wood residue can reinforce the microbial activity by continuously decreasing the C/N ratio to the minimum value of 13.2.

What Can You Do with a Degree in Agronomy, Crops, or Soils?

What Can You Do with a Degree in Agronomy, Crops, or Soils?

Antibacterial activity of metabolites isolated from Streptomyces SSp. On Soil Sample of West Azerbaijan, Iran

Background: The study for new antibiotics is of great importance in investigating programs around the worldwide for pharmaceutical, industrial and agricultural applications. Streptomyces like filamentous soil bacteria are used as an essential biological tool for their ability to producing a wide range of new secondary metabolites such as antibiotics. Identification and isolation of new species seemed to be important in the presentation of significantly adequate antibiotics, because antibiotic resistance infectious diseases are the second leading cause of death worldwide, inducing research and development of new antibiotics. Therefore, in this study, we aimed to isolate and characterize novel strains of Streptomyces spp. with high antibiotic production ability. Methods: Soil samples were collected randomly from primitive soils of Urmia, West Azerbaijan province, from Iranin 2019. The isolates of Streptomyces spp. were carried out in a specific culture medium. Their primary and secondary antibacterial activity againstgram-positive bacteria Listeria monocytogenes, Bacillus cereus and Staphylococcus aureus, alsogram-negative Escherichia coli was checked out. Finally, the antibacterial properties of strains based on 16S rRNA sequencing were analyzed by MEGA X software. Results: Totally, 150 colonies were isolated from four soil collected samples. In the primary screening of 10 isolates, insulated antibacterial activity and in the secondary screening, 3 examples were selected. The microorganisms showed antibacterial activity. Sequencing of the 16S rRNA gene from C-B1-12, D-D3-7, and C-Y2-2 isolates showed similarity to Streptomyces indiaensis. Conclusions: The results of this study indicated that there are new isolates in the soil samples of West Azerbaijan province that are capable of producing new antibacterial agents.

Mutation of the Seaside Architecture in Algeria and its Impact on Coastal Landspace. A Case Study: Ain El Turc, Algeria

The sea strongly contributes to the identity of coastline areas. Moreover, it has been demonstrated that the coastline is a geographical entity which calls for specific organization. From an architectural point of view, design elements have been associated with the assets (or constraints) of the site. Thus, the view is associated with the bow window, protection against the climate with canopies and protruding roofs, and quality of the soil and bedrock. Integration into the site is also highly desirable, both in form (ship) and in construction materials. The urbanization of coastal areas in Algeria is a colonial fact. In pre-colonial times, little importance was given to these areas, whereas later they became a priority: port sites, the speed of communications with Europe, rich agricultural plains, a mild climate and welcoming beaches. The developments and seaside constructions carried out during this period were part of the logic of attractiveness to welcome more European settlers and promote the sedentarization and growth of those already living in Algeria. After independence, political and economic choices did not unfortunately take into account the geographical and climatic specificity of Algeria’s coastal zones. Thus, population growth and rural depopulation have led to a sharp increase in the demand for real estate, which has resulted in unbridled urbanization, regardless of the seaside vocation of these territories. In this article, based on the case of the seaside resort of Ain El Turc, which has colonial architectural production of an exceptional quality that takes into account the specificities of the coastline and the presence of the sea, the aim is to assess and verify if this architecture was perpetuated after independence. To this end, we have highlighted, through bibliographic research, the characteristics of seaside architecture from the 19th and 20th centuries and those of the contemporary time. An analysis of all the dwellings located in the Saint Rock district in the municipality of Ain El Turc consisted in identifying these characteristics and establishing a classification of these constructions.

The decreasing a negative impact of climate change on Indonesian food security

The negative Impact of climate change and food security are crucial issues for Indonesia with a large population. Agricultural sector as a contributor about 5-7 percent to CO 2 emissions, is a victim of climate change as this sector is very sensitive to the change of climate such as rise of temperature, drought, El Nino and La Nina and rise sea level. The decline in production due to climate change and extreme climate is very risky for Indonesia's food security. Various studies and studies have been conducted to evaluate the impact of climate change. However, since 2009, voluntary commitment of Indonesian Government to reduce 26 percent of CO 2 emissions set up the strong effort in many sectors to adapt with climate change. In agriculture, improving soil quality is key in maintaining food production. Soil conservation using vegetative or engineering technique is one of the most important technology. Nutrient management by applying balance fertilization, the use of organic material and ameliorant such as biochar, zeolite and other natural mineral are beneficial for plant production. All these ameliorants will be very useful in maintain soil organic matter (SOM) and soil carbon which very important in increasing water holding capacity. Water harvesting is one option to capture high precipitation and important to irrigate agricultural area. Besides, the use of cropping calendars, high yielding varieties which adapt to biophysical stress will be very useful. Other effort is also needed to control the peat fire, peat drainage and deforestation.

Microelements in Soils and Cenopopulation of Medicinal Plants

The article provides an analysis of the cenopopulation and element composition of the medicinal Capparis spinosa L. distributed in calcisols formed on eroded alluvial- proluvial rock-gravel rocks in the south of the Fergana Valley. The predominance of immature plants in the cenopopulation was detected in the Arsif hills, and quantitative indicators of micronutrients in the vegetative and generative organs of Capparis spinosa L. were determined. The study of biomorphological characteristics of the plant during the growing season (April-October) was carried out in the identified 10 observational experimental field populations. Soil, plant element analysis was performed by neutron-activation method. In this case, the samples were irradiated in a nuclear reactor with a neutron flux of 5 × 1013 neutrons/cm2sec, and their quantities were determined in accordance with the half-life of chemical elements. It has also been compared with research materials conducted by world scientists on the importance and pharmacological properties of botanicals in medicine and the food industry, as well as their botanical characteristics.