Pemanfaatan Biochar sebagai Pembawa Rhizobium terhadap Pembentukan Bintil Akar dan Hasil Tanaman Kedelai (Glycine max L. Merril)

The Utilization of Biochar as a Carrier of Rhizobium for the formation of root nodules and Yield of Soybean (Glycine max L. Merril). This study aims to determine the effect of the type of raw materials and particle size of biochar as a Rhizobium carrier on the formation of nodules in soybean plants. This research was conducted from September to November 2020 at the Experimental Station and Laboratory of Soil and Environmental Sciences, Faculty of Agriculture, Udayana University. The research design used was a randomized block design with nested patterns with 2 factorials and 3 replications. The treatment factors consisted of B1 = bamboo biochar, B2 = albasia wood biochar, B3 = corncob biochar, B4 = young coconut skin biochar, P1 = (0,15-0,50 mm), P2 = (>0,50-1,68 mm), P3 = (>1,68-3,36 mm). The parameters observed included effective nodule, nodule size, total bacterial population, ammonium, nitrate, and plant yield. The result of the analysis showed that the type of biochar raw materials had a very significant effect on the parameters of effective nodules, nodules size, total bacterial population and plant yield, but had no significant effect on soil chemical parameters. The treatment of biochar particle size had a very significant effect on the parameters of effective nodules, total bacterial population, and plant yield, and had a significant effect on the size of nodules, but had no significant effect on soil chemical parameters. The conclusion of this study is that the type of raw material for albasia wood biochar is effective as a Rhizobium carrier, which is indicated by the high number of effective nodules, nodules size and total bacterial population of 0,15-1,68 mm particles.

Flood Pulse Irrigation of Meadows Shapes Soil Chemical and Microbial Parameters More Than Mineral Fertilization

While mineral fertilization increases agricultural yields, it also bears the risk of contaminating non-target ecosystems and negatively affecting soil chemical parameters and microbial communities. This calls for alternative and more sustainable agricultural practices that reduce the use of fertilizers. Flood pulse irrigation could be an alternative to mineral fertilization of hay meadows, since it increases the yield with little or no application of fertilizer. However, the positive and negative implications of flood pulse irrigation on soil chemical parameters and particularly soil microbial communities are still largely unknown. In this study, we assessed shifts in soil microbial communities (SMC) as a response to changes in soil chemical parameters after flood pulse irrigation and/or fertilization of meadows. We determined soil chemical (Corg, Ntot, water extractable N, P, K, pH) and microbial (phospholipid-derived fatty acids, PLFA) parameters of 12 meadows in a 2 × 2 factorial design, comprising flood pulse irrigation and fertilization. Corg, Ntot, and water content as well as microbial biomass were higher in flood-irrigated than in non-flooded soils. Soil microbial biomass positively correlated with Corg, Ntot, and water extractable N. Gram-negative bacteria significantly increased, whereas the fungi/bacteria ratio significantly decreased in flood-irrigated soils compared to non-flooded soils. Arbuscular mycorrhizal fungi were positively correlated with soil pH. Flood pulse irrigation seemed to promote the build-up of a larger soil carbon and nitrogen pool as well as higher water content and microbial biomass. By this, it potentially mitigated negative mineral fertilization effects such as changed soil pH and reduced carbon use efficiency. We conclude that flood pulse irrigation may represent a sustainable alternative to mineral fertilization.

Accuracy assessment of bare soil map of Hungary based on Sentinel satellite data

<p>As Earth observation (EO) data is increasing in volume, fast and reliable data-processing tools are also required especially for analyzing large areas with high spatial resolution. Google Earth Engine (GEE) platform provides wide sets of EO imagery and elevation data in a cloud-based processing environment. This research focused on i) the generation of bare soil map of Hungary and ii) the accuracy assessment of created soil maps representing soil texture (clay, sand, silt) and soil chemical parameters (SOC, pH and CaCO<sub>3</sub>).</p><p>In this study Copernicus Sentinel-1 SAR and Sentinel-2 optical images acquired on a mid-term time period between 2017 April and 2020 December were used to generate a median composite. Optical images were filtered for cloud coverage less than 50% and a cloud mask was also implemented on all remaining images. The threshold values for Normalized Difference Vegetation Index and Normalized Burn Ratio indices were 0.55 and 0.35 respectively to differentiate bare soil pixels.</p><p>We tested the prediction accuracy of bare soil composite supplemented by various environmental datasets as additional predictor variables in different scenarios: (i) using solely bare soil composite data (ii) composite data, elevation and its derived parameters (e.g. slope, aspect) (iii) composite data and spectral indices and (iv) all aforementioned data in fusion.</p><p>For validation two types of datasets were used: i) the reference points of the Hungarian Soil Information and Monitoring System with a five-fold cross-validation method and ii) the recently compiled national maps for soil texture and soil chemical parameters.</p><p><strong>Acknowledgment:</strong> Our research was supported by the Hungarian National Research, Development and Innovation Office (NKFIH; K-131820 and K-124290) and by the Scholarship of Human Resource Supporter (NTP-NFTÖ-20-B-0022).</p>

Testing a thermometer of the past: abiotic and biotic drivers of the brGDGT-based temperature proxy along a subarctic elevation gradient.

<p>BrGDGTs are used in a variety of paleoclimate archives to reconstruct changes in temperature and pH. However, the temperature dependency, currently determined on a global scale, can be confounded on smaller spatial scales. To determine the unique effect of temperature on the brGDGT distribution in northern Scandinavia, 37 soils have been collected along a Swedish and Norwegian altitude gradient (14 to 1200 m asl). At this site, we measured in-situ soil temperature (1 year), as well as soil chemical parameters (pH, Ca, K, Mg, Mn, Fe, Mn, Al, total P, total N). Furthermore, we reconstructed the composition of the bacterial community in the same soils, using 16S rDNA, to allow direct comparison with the brGDGT lipid signatures.</p><p>Although we sampled over a limited range in pH values (3.3-5.4), large changes in brGDGT concentration are observed over the pH gradient. In low pH soils (>4.0), total brGDGT concentration (normalized per g soil) is increased, caused by an increase in the concentration of brGDGT Ia. This results in increased MBT’<sub>5ME</sub> values (0.53-0.7) in these soils. In high pH soils (pH>5.0) an increased concentration in 6-methyl brGDGTs is observed. These soils are characterized by a lower MBT’<sub>5ME</sub> values, driven by a decrease in the fractional abundance of brGDGT Ia. Along the altitudinal gradient, pH (and soil calcium) is the main driver of the MBT’<sub>5ME</sub> proxy (r= -0.60, p<0.01).</p><p>Along the Swedish and Norwegian altitudinal gradient, where a substantial change in temperature (-4.7 to 2.7 °C MAAT) was crossed, the MBT’<sub>5ME</sub> only shows a poor correlation with atmospheric MAAT values (r= 0.47, p<0.01). When comparing the MBT’5ME with in-situ measured soil temperatures (-2.5 to 4.3), that reflect the growth conditions of the soil bacteria better, the correlation is not improved (mean annual soil temperature: r= 0.32, p=0.05). A correlation with seasonal temperatures (Growing Degree Days [GDD]) results in a better dependency between the MBT’<sub>5ME</sub> and soil temperature (r= 0.44, p<0.01), which can reflect that brGDGT are generally produced in non-frozen soil conditions.</p><p>However, at the Swedish and Norwegian altitudinal gradient, there is a significant correlation observed between the temperature (GDD) and soil chemical parameters. In general, soil pH is increased at lower temperatures (r=-0.32, p=0.04, n=37). Considering all soil chemical parameters, the total concentration of K decreases closely with an increase in soil temperature (GDD: r= -0.63, p<0.01, n=37). The mechanism behind this is probably an interplay between local geology, and a temperature dependent extent of chemical and biological weathering. Because of this correlation, it is not clear whether MBT’<sub>5ME</sub> varies exclusively in response to soil chemistry, with an indirect response to temperature changes.</p><p>Although the environmental driver determining the brGDGT signal can not be determined unequivocally, the bacterial community composition is clearly determined by soil pH. In those high pH soils (pH> 4.9) where increased concentrations of 6-methyl brGDGTs are produced, several Acidobacterial OTUs (specifically Acidobacteria subgroup 6) are increased. This indicates that the mechanism behind the changed fractional abundances is a pH-modulated bacterial community shift.</p>

Soil chemical parameters and microbiological quality of biquinho pepper irrigated with treated wastewater in protected environment

The aim of this work was to evaluate the soil chemical parameters and microbiological quality of biquinho pepper fruits irrigated with treated wastewater and different irrigation depths. The experiment was carried out in protected environment with the application of four irrigation depths corresponding to 50, 75, 100 and 125% of the crop evapotranspiration with three concentrations of 0, 50 and 100% of treated wastewater in the cultivation of biquinho pepper in pots. The experimental design was in randomized blocks in a 3 x 4 factorial scheme, totaling 12 treatments, with three replications. The soil chemical parameters were determined before and after the growing the pepper with treated wastewater. Reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method using data obtained from an Automatic Weather Station installed inside the protected environment. The microbiological quality was analyzed by quantifying fecal coliforms and the presence of Salmonella sp. recommended by Brazilian National Agency for Sanitary Surveillance (ANVISA). All pepper samples were in accordance with the limits recommended by the legislation and, therefore, the use of wastewater in pepper irrigation did not represent a risk to public health. The soil chemical parameters were changed in different ways after the application of the treated wastewater, being motivated by both soil and wastewater chemical characteristics.

Effets combinés du biocharbon et du fumier sur les propriétés physico-chimiques d’un sol ferrugineux tropical sous culture de mil en zone semi-aride du Burkina Faso

Objectifs : L’une des contraintes majeures des systèmes de production agricole au Burkina Faso demeure la dégradation des sols. La présente étude menée à Kongoussi (Burkina Faso) avait pour objectif de déterminer les effets du Biocharbon utilisé comme amendement sur le sol et les paramètres agronomiques du mil. Méthodologie et résultats : Un dispositif en blocs simple comportant 3 traitements en 5 répétitions a été utilisé. Les traitements comprenaient T0= Fumier + NPK, T1= Biocharbon + Fumier + NPK, T2= Biocharbon + NPK. Les matières fertilisantes ont induit une amélioration des paramètres chimiques du sol. Les meilleurs paramètres chimiques du sol ont été observés avec T1 (Biocharbon + Fumier + NPK) qui a permis l’obtention du plus grand rendement grains du mil comparativement à ceux obtenus avec les traitements T0 (Fumier + NPK) et T2 (Biocharbon + NPK) qui étaient statistiquement équivalents. Conclusions and application des résultats : La combinaison du biocharbon au fumier améliore la fertilité du sol et le rendement du mil. Cela constitue une solution intéressante en vue restaurer et ou maintenir la fertilité des sols, accroitre les rendements des cultures tout en réduisant les effets néfastes des changements climatiques à travers la séquestration du carbone dans le sol. La technologie du Biocharbon constitue une alternative intéressante pour la valorisation des résidus culturaux peu ou pas exploités pour améliorer durablement la qualité des sols et assurer la sécurité alimentaire tout en protégeant l’environnement. Mots-clés : fertilité des sols ; Biocharbon ; amendement organique ; séquestration du carbone, ABSTRACT Combined effects of biocharbon and manure on physico-chemical properties of a tropical ferruginous soil under millet cultivation in the semi-arid zone of Burkina Faso Objectives: One of the major constraints of agricultural production systems in Burkina Faso is the low soil fertility. The objective of this study conducted in Kongoussi (Burkina Faso) was to determine the effects of Biochar used as soil amendment in combination with manure on soil fertility and some agronomic parameters of millet. Methodology and results: A simple block disign with 3 treatments in 5 replicates was used. The randomly distributed treatments included T0= Manure + NPK, T1= Biochar + Manure + NPK, T2= Biochar + NPK. The Lompo et al., J. Appl. Biosci. 2021 Effets combinés du biocharbon et du fumier sur les propriétés physico-chimiques d’un sol ferrugineux tropical sous culture de mil en zone semi-aride du Burkina Faso. 16173 applied fertilizers improved some soil chemical parameters. The best soil chemical parameters were observed with T1 (Biochar + Manure + NPK), which induced the highest millet grain yield as compared to those obtained with T0 (Manure + NPK) and T2 (Biochar + NPK), which were statistically equivalent. Conclusions and application of findings : The combination of biochar with manure improves soil fertility and millet yield. This is an interesting solution to restore and/or maintain soil fertility, to increase crop yields while reducing the adverse effects of climate change through carbon sequestration into the soil. The Biochar technology is an interesting alternative for the valorization of crop residues little or not well exploited in order to sustainably improve soil quality and food security while protecting the environment. Keywords: Crop production ; Soil fertility ; Biochar ; organic amendment, carbon sequestration.

The Effect of Farmyard Manure and Mineral Fertilizers on Sugar Beet Beetroot and Top Yield and Soil Chemical Parameters

In order to recommend the dose of fertilization for sugar beet under currently unstable weather conditions, we analysed beetroot and top yields, sugar content (SC), and the effect of fertilization on soil chemistry over a three-year period (2016–2018). All three years were characterized by different weather conditions. The year 2016 was very warm and very dry. The year 2017 was warm with normal precipitation. The year 2018 was extraordinary warm and very dry. We compared the following ten fertilization treatments: unfertilized control, farmyard manure (FYM), mineral fertilizers NPK1–4, and FYM + NPK1–4. The applications of FYM, NPK, and FYM + NPK resulted in significantly higher yields of beetroots and tops as compared with the control, while no significant differences were recorded among FYM, NPK, and FYM + NPK treatments. The SC was not affected by the fertilization. The application of NPK resulted in a lower pH value, while the highest values were recorded for the control and FYM treatments. The application of FYM + NPK increased the content of organic carbon (Corg) in the soil, the total content of nitrogen (Ntot), and P and K concentrations. According to the results of the linear-plateau model, the recommended dose of N is 112 kg ha−1, corresponding to a beetroot yield of 66 t ha−1.

Community structure and diversity of the microbiomes of two microhabitats at the root–soil interface: implications of meta-analysis of the root-zone soil and root endosphere microbial communities in Xiong’an New Area

The diversity of the microbial compositions of the root-zone soil (the rhizosphere-surrounding soil) and root endosphere (all inner root tissues) of Pinus tabulaeformis Carr. and Ginkgo biloba L. were evaluated in Xiong’an New Area using high-throughput sequencing; the influence of the soil edaphic parameters on microbial community compositions was also evaluated. Our results showed that both the taxonomic and phylogenetic diversities of the root endosphere were lower than those of the root-zone soil, but the variation in the endosphere microbial community structure was remarkably higher than that of the root-zone soil. Spearman correlation analysis showed that the soil organic matter, total nitrogen, total phosphate, total potassium, ratio of carbon to nitrogen, and pH significantly explained the α-diversity of the bacterial community and that total nitrogen differentially contributed to the α-diversity of the fungal community. Variation partitioning analysis showed that plant species had a greater influence on microbial composition variations than did any other soil property, although soil chemical parameters explained more variation when integrated. Together, our results suggest that both plant species and soil chemical parameters played a critical role in shaping the microbial community composition.

Linking Soil Chemical Parameters and Fungal Diversity in Qatar

Given the vast expanse of Qatar’s dryland ecosystems, agricultural productivity and soil stability is highly dependent on the diversity of soil microbiota. The soil environment is a heterogeneous habitat shaped by various components like chemical (organic matter, salinity and nutrients) and biological (fungal diversity and vegetation) properties that form multitudes of different microhabitats. Soil microbial diversity changes along environmental gradients. It is hypothesized that a “stable” microhabitat is one that is inhabited by a large diversity of established microorganisms that are best adapted to the niche. Microorganisms like fungi serve as the underlying biological drivers for biochemical processes within the soil. The key objective of this study is to evaluate the fungal diversity and abundance present within the Qatari soil using molecular-based tools and evaluate potential relationships between the identified fungal communities with chemical properties of the habitat. We found that the composition of fungi and AMF varied between different habitats around Qatar. Despite the lack of significant differences in the measured soil chemical parameters between sampled sites, it is evident that AMF species are more abundant than compared to that of other fungal species in most of the study sites; thus, suggesting that other factors like land use may also be an essential component explaining the variation in fungal communities.