Edaphic Environment Research Articles

Distinct responses of Scytonema hyalinum and Leptolyngbya sp. to water availability and biocrust formation.

Soil cyanobacteria are considered pioneer microorganisms in the formation of biocrusts, which, in turn, are recognized as ecosystem engineers in edaphic environments due to their influence on erosion control, nutrient cycling, and water dynamics in the soil. Thus, cyanobacteria have considerable potential for use in the recovery of degraded soil. However, greater knowledge on the ecophysiological characteristics of biocrust-forming cyanobacteria is needed. Therefore, the aim of the present study was to assess the development of Scytonema hyalinum and Leptolyngbya sp. (cyanobacteria) under different conditions of water availability and investigate the improvement in soil quality. The strains were inoculated in Petri dishes containing soil collected from a desertification-prone region. Water availability (with and without water limitation) was controlled over 78 days of the experiment. Cyanobacterial development (measured by chlorophyll-a concentration) was better in treatments without water limitation. Higher water availability favored the formation of biocrusts by Leptolyngbya sp., which increased soil resistance, and the vigorous growth of S. hyalinum, whose trichomes aggregated on the soil surface and also contributed to greater soil stability. The results confirmed that water is an important factor in the development of both strains. More importantly, the results demonstrated that, due to their distinct eco-physiological characteristics, the species have the potential to be used complementarily in restoration projects for degraded areas, as Leptolyngbya exhibited a greater capacity for soil stabilization, while S. hyalinum exhibited greater growth.

Physical and chemical indicators of soil quality in gully environments, State of Rio de Janeiro (Southeast Brazil)

Water erosion is one of the primary causes of agricultural soil degradation in Brazil, leading to diminished crop productivity and soil acidification, thereby impairing its ability to store carbon, nutrients, and water. Identifying the intensity of erosion can be achieved by utilizing indicator attributes that are highly sensitive to changes in the edaphic environment. The study analyzed the physical and chemical attributes of soil in areas with gullies exhibiting varying degrees of degradation/stabilization. The study was conducted across four areas with varying degrees of gully formation: a) initial, intermediate, mature, and senile. Samples were collected from both the external and internal sides of each gully at the end of the dry season. Among the physical attributes assessed, soil density and total porosity were found to be the most significantly altered. Evaluation of microaggregates provided insights into soil quality through fractions including water-dispersible clay, water-reflocculable clay, and non-water-dispersible clay. Total carbon, total nitrogen, and the C/N ratio elucidated the dynamics of soil and nutrient loss across different stages of erosion formation and stabilization processes, with lower values observed on the internal side of the gullies compared to the exterior side. Vegetation was observed to influence the results of the physical and chemical attributes. Overall, the values tended towards equilibrium between the faces at the senile stage, indicating greater stabilization. Keywords: agricultural sustainability, agroecosystem degradation, food security, soil attributes.

Revegetation of areas degraded by mining in the cerrado: the use of sewage sludge in soil rehabilitation

Among the activities that negatively impact areas of the Brazilian Cerrado biome, mining is one of the most significant for the country’s economy, representing around 8% of its Gross Domestic Product (GDP). However, mining causes serious environmental damage, requiring chemical, physical and biological rehabilitation of the exposed substrate to start ecosystem recolonization. Mine rehabilitation for revegetation requires adding large amounts of organic matter to exposed substrates. Studies on using domestic sewage sludge as an organic matter and nutrient source for plants have yielded significant results in ecological restoration protocols. This article presents a traditional narrative review of the literature related to the ecological, chemical, and physical processes in the application of sewage sludge for rehabilitating mining substrates in the Cerrado. It analyzed 95 articles, from 1985 to 2023, across 72 scientific journals. The results show that applying sewage sludge at rates bellow 100 t ha-1 (dry basis) raised soil pH and iron concentration, stabilized carbon, increased water availability, and decreased invasive plant recruitment. Additional techniques include sowing plants with functional characteristics similar to those of invasive species, increasing the functional diversity of species in plant communities, and identifying and manipulating ecological filters to stimulate the recruitment of native plant species. Soil-plant feedbacks determine crucial points for ecosystem balance and regulate available resources. Treatment with sewage sludge at rates bellow < 100 t ha-1 (dry basis) optimized the physical, chemical, and biological characteristics of exposed substrates, accelerating the colonization of plant communities and demonstrating the need for continuous monitoring of interactions between the edaphic environment and plants to establish biological diversity.

A resilient mutualistic interaction between cucumber mosaic virus and its natural host to adapt to an excess zinc environment and drought stress.

A perennial pseudometallophyte Arabidopsis halleri is frequently infected with cucumber mosaic virus (CMV) in its natural habitat. The purpose of this study was to characterize the effect of CMV infection on the environmental adaptation of its natural host A. halleri. The CMV(Ho) strain isolated from A. halleri was inoculated into clonal virus-free A. halleri plants, and a unique plant-virus system consisting of CMV(Ho) and its natural wild plant host was established. In a control environment with ambient zinc supplementation, CMV(Ho) infection retarded growth in the above-ground part of host plants but conferred strong drought tolerance. On the other hand, in an excess zinc environment, simulating a natural edaphic environment of A halleri, host plants hyperaccumulated zinc and CMV(Ho) infection did not cause any symptoms to host plants while conferring mild drought tolerance. We also demonstrated in Nicotiana benthamiana as another host that similar effects were induced by the combination of excess zinc and CMV(Ho) infection. Transcriptomic analysis indicated that the host plant recognized CMV(Ho) as a mutualistic symbiont rather than a parasitic pathogen. These results suggest a resilient mutualistic interaction between CMV(Ho) and its natural host A. halleri in its natural habitat.

Diversity of Microbial Functional Genes Promotes Soil Nitrogen Mineralization in Boreal Forests.

Soil nitrogen (N) mineralization typically governs the availability and movement of soil N. Understanding how factors, especially functional genes, affect N transformations is essential for the protection and restoration of forest ecosystems. To uncover the underlying mechanisms driving soil N mineralization, this study investigated the effects of edaphic environments, substrates, and soil microbial assemblages on net soil N mineralization in boreal forests. Field studies were conducted in five representative forests: Larix principis-rupprechtii forest (LF), Betula platyphylla forest (BF), mixed forest of Larix principis-rupprechtii and Betula platyphylla (MF), Picea asperata forest (SF), and Pinus sylvestris var. mongolica forest (MPF). Results showed that soil N mineralization rates (Rmin) differed significantly among forests, with the highest rate in BF (p < 0.05). Soil properties and microbial assemblages accounted for over 50% of the variability in N mineralization. This study indicated that soil environmental factors influenced N mineralization through their regulatory impact on microbial assemblages. Compared with microbial community assemblages (α-diversity, Shannon and Richness), functional genes assemblages were the most important indexes to regulate N mineralization. It was thus determined that microbial functional genes controlled N mineralization in boreal forests. This study clarified the mechanisms of N mineralization and provided a mechanistic understanding to enhance biogeochemical models for forecasting soil N availability, alongside aiding species diversity conservation and fragile ecosystem revitalization in boreal forests.

Community-based, cost-effective multispecies mangrove restoration innovation to maximize soil blue carbon pool and humic acid and fulvic acid concentrations at Indian Sundarbans.

Sundarbans is the world's largest and most diverse contiguous mangrove ecosystem. In this pilot study, three plots (around1ha each) were selected, where one site (S1) had 1year of community involvement, another site (S2) had a community network to support the restoration initiatives for 2years, while a control site (C) was devoid of any post plantationcommunity protection. Rhizophora mucronata (Rhizophoraceae), Sonneretia caseolaris (Lythraceae) and Avicennia marina (Acanthaceae) were planted at the sites in 2012. After 6years (in 2017), at S1, the monitoring showed low survival rate for salinity-sensitive species, 2% for R. mucronata and 4% for S. caseolaris. At S2, R. mucronata has high survival rates, i.e. 71%, followed by S. caseolaris with 40%, whereas at C, the survival rate of both species was 0%. At S1 and C, the salinity-tolerant A. marina replaced the planted mangroves partially (S1) or entirely (C). At S2, available soil P increased by 17.5%, in 6years, and the overall blue carbon pool showed a linear increase from 64.4 to 88.6Mg C ha-1 (34.3% rise). S1 showed a minimum increment in P and the blue carbon pool (6.9% rise), while site C showed fluctuations in the blue carbon pool with only a 3.1% increase. Humic acid and fulvic acid concentrations in the S2 site indicate positive functional carbon sequestration in the edaphic environment. The community involvement increased the plantation cost (567.70 USD) of S2, in comparison to S1 (342.52 USD) and C (117.34 USD), but it has resulted in better restoration and survival of the mangroves. The study concludes that community participation for at least 2years can play a significant role in the conservation of mangrove ecosystems and the success of restoration initiatives in tidal, saline wetlands and would aid in compliance with the United Nations Sustainable Development Goal 14 (Life Below Water) targets.

Effect of salt stress on relative membrane injury, lipid peroxidation content and reactive oxygen species content of isabgol (Plantago ovata Forsk.) genotypes

Under the uncongenial growth condition imposed by salts in the edaphic environment, several biochemical changes take place in plants, which help them to survive under such a hostile environment. In the present study, an attempt has been made to obtain basic information about the effect of salt stress on relative membrane injury, lipid peroxidation content and reactive oxygen species content in isabgol (Plantago ovata Forsk.) genotypes. The changes in relative membrane injury, lipid peroxidation content and reactive oxygen species (ROS) content of P. ovata genotypes viz. GI-2, HI-96, PB-80 and HI-5 were studied under NaCl salt stress at different EC levels viz. control (without salt), 5 and 10 dS/m of nutrient supplemented NaCl salt solutions in sand filled polythene bags during 1st week of November 2022 in the Department of Botany Government College, Hisar. RMI, lipid peroxidation (MDA content) and ROS content of leaves increased with increasing EC levels in all the isabgol genotypes as studied at 58 days after showing. The highest increase in RMI was found in the genotype PB-80 and lowest in the genotype GI-2 at higher (10 dS/m) EC level over control. Increase in lipid peroxidation content which was measured in terms of MDA content was found highest in the genotype PB-80 while the lowest increase was detected in the genotype HI-5 at higher level (10 dS/m) of salt stress over control. Highest enhancement in ROS content of leaves in the genotype PB-80 and lowest increase in the genotype GI-2 was observed at higher (10 dS/m) EC level over control. The relative order of these parameters in various genotypes under salt stress was PB-80 greater than HI-5 greater than HI-96 greater than GI-2.

A meta-analysis of physicochemical changes in the rhizosphere and bulk soil under woodlands

Monoculture for timber production has been replacing natural environments as the demand for renewable energy sources increases. The lack of nutrient compensation may increase the risk of soil depletion, thus changing soil properties. To summarize the impact of forestry activities in edaphic environments, we present a meta-analysis on the rhizosphere effects of coniferous and broadleaved trees established as monoculture and natural regeneration on soil physicochemical properties. Records of soil attributes published in peer-reviewed journals from eight countries were collected. Clay content changed only in monoculture sites, decreasing 55.51% in the rhizosphere, while silt and sand presented significant variations in both monoculture and naturally regenerated areas. Conifers affected the soil more than broadleaved trees, evidenced by higher pH reduction (-2.96% vs. -1.98%) and higher increase of Al3+ (197.43% vs. 50.68%), K+ (80.40% vs. 69.90%), CEC (24.61% vs. 17.35%), and total organic carbon (82.21% vs. 69.89%). Also, the rhizosphere affected regeneration soils more than monoculture, indicated by higher Al3+ (50.68% vs. ns) and available P (32.31% vs. ns), K+ (203.44% vs. ns), CEC (34.90% vs. 20.93), and total organic carbon (91.55% vs. 63.23%). These results indicate higher nutrient availability in naturally regenerated than monoculture sites, as higher species diversity and better plant litter quality are expected. This meta-analysis shows that coniferous and naturally regenerated trees had a higher influence on the rhizosphere and soil properties than broadleaved and monocultures. Management practices must be revisited to ensure the long-term sustainability of forestry activity, and studies in tropical zones must be intensified.

Modeling the Influence of Changes in the Edaphic Environment on the Ecosystem Valuation of the Zone of Influence of the Ozogoche and Atillo Lake Systems in Ecuador

Ecosystem valuation (EV) of soil resources is essential for understanding changes in environmental services in monetary terms. A lack of this information, which includes economic indices, hinders the optimal management of natural resources. This study evaluated the influence of changes in the edaphic ecosystem on the EV of the zone of influence of the Ozogoche and Atillo lake systems in Ecuador. The classification was carried out through spectral indices and support vector machines (SVMs), and the EV was determined through opportunity costs including environmental service provisioning and indirect use. The land use and EV classification methods were performed efficiently; the degradation trend was constant. The Modified Water Difference Index was the most efficient in the extraction of water bodies, with an accuracy of 91%. The SVMs algorithm, in recognizing coverage in general, had an overall accuracy of 85%. The adjustment made to the SVMs algorithm to improve the selection of hyperparameters was effective; a robust architecture of the algorithm in terms of automation was achieved. Between 2000 and 2020, moorland, water and wetland degraded by 19%, 2% and 3.4%, respectively. In 2000, the EV as a function of avoided CO2 content was USD 8.00 × 106; in 2010 and 2020, it was USD 6.00 × 106 and USD 5.00 × 106, respectively.

Assessing Soil Quality Under Different Land-Uses Through Constructing Minimum Datasets from Soil Profiles in a Fragile Ecosystem of Northeastern Region of India

ABSTRACT The conversion of forest to agricultural land has been a major worldwide concern and a cause of deterioration of soil quality. The study examined the influence of land uses on the soil quality index (SQI) using minimum datasets (MDS) constructed from soil profiles through two methods namely, additive (SQIa) and weighted (SQIw). In this study, 29 geo-referenced soil profiles (116 layers) up to a depth of 150 cm were collected in Northeastern India, representing forest, jhum, jhum fallow, and agricultural land uses. Principal component analysis (PCA) with multiple correlation analysis is found to be a suitable statistical method for selecting the key soil quality indicators. From PCA, organic carbon (OC), sand, clay, available P and available S were selected as soil quality indicators in MDS. Our results showed that these MDS significantly varied within the profiles depending on the land-uses. The estimated values of SQIs showed that SQIa was higher than SQIw across the soil depths and land-uses. For the surface soil, SQIa values were in the order of forest (2.97) > jhum fallow (2.82) > agriculture (2.68) > jhum land (1.97) and for profile soil jhum fallow (2.38) > forest (2.37) > agriculture (2.33) > jhum (1.88). Similarly, SQIw followed the trend of forest > jhum fallow > agriculture > jhum for all the three studied depths. The statistical analysis showed that the surface, subsurface, and profile soil had no significant impact on SQIw for agriculture, fallow jhum, and forest. The overall data indicated that jhum land had a significantly lower SQI than other land-uses for all soil depths. From this study, the information generated can be useful to assess the soil quality in different land-uses for managing soil health in similar areas of the Northeastern region of India. The findings are also useful in the ecosystems in which soils develop in an acid edaphic environment.

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AbstractAimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega‐phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white‐sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (&gt;66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long‐standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.

Checklist e distribuição geográfica das espécies de Myrtaceae que ocorrem em campinaranas da Amazônia brasileira

ABSTRACT White-sand vegetation (campinarana) is a type of vegetation restricted to oligotrophic and highly leached white sand soils in the Amazon phytogeographic domain that includes grassland to forest phytophysiognomies. Campinaranas cover about 5% of this phytogeographic domain and are impacted by various anthropic activities that put plant species, especially endemic ones, at risk. Myrtaceae has significant representativeness in oligotrophic edaphic environments, but floristic and taxonomic studies on the family in campinaranas are still few and geographically limited. We present a checklist of Myrtaceae species known from campinaranas of the Brazilian Amazon based on the survey of herbarium specimens and literature data in order to assess the level of endemism of these species for this vegetation type. We compiled occurrence records of 72 species and six genera. Myrcia and Eugenia were the genera with the highest number of species. Overall, 38 species (53%) occurred only in the Amazon and two were endemic to campinaranas (Eugenia campina and Myrcia psammophila). Four species are new records for the Brazilian Amazon: Blepharocalyx salicifolius, Eugenia hatschbachii, Myrcia anceps and Myrcia racemosa. The specific richness of Myrtaceae in Brazilian campinaranas is likely to be underestimated since extensive areas, especially those farther from the riverbanks, in the states of Amazonas and Roraima, have not yet been intensively surveyed.

Carrying capacity for tree biomass of a subtropical mangrove along a river in Japan inferred from forest structural features

AbstractA subtropical mangrove along the Miyara River in Ishigaki Island, Japan was studied for evaluating the carrying capacity for biomass of the mangrove stands. The stem diameters D, tree height H, and fine roots mass were measured, while aboveground biomass (AGB) and belowground coarse root biomass (BGBcoarse) were estimated. The AGB, BGBcoarse, and fine root mass were estimated as 130, 31, and 13 Mg ha−1 in the Rhizophora stylosa; 271, 94, and 11 Mg ha−1 in the downstream Bruguiera gymnorrhiza; and, 228, 81, and 6.4 Mg ha−1 in the upstream B. gymnorrhiza stand, respectively. The AGB and BGBcoarse in the R. stylosa stand were significantly lower than B. gymnorrhiza stands, and fine root mass was significantly higher than upstream B. gymnorrhiza stand. Significantly lower mean individual phytomass wt specific to tree density ρ of R. stylosa stand than B. gymnorrhiza stand in the ρ − wt relationship denoted the lower carrying capacity for AGB of R. stylosa than that of B. gymnorrhiza. The results showed that high soil pore water salinity and low pH at the downstream did not limit biomass and potential canopy height Hmax of mangrove along a river gradient but AGB and BGBcoarse differed between different species at the same edaphic environment. Analysis of aboveground and belowground biomass variations between stands of two mangrove species along environmental gradients from upstream to downstream could be useful in assessing the consequences of sea level rise in relation to climate change on the evolution of blue carbon dynamics.

Toxicological effects induced by two carbamates on earthworms (Eisenia fetida): Acute toxicity, arrested regeneration and underlying mechanisms

Eisenia fetida is recognised as advantageous model species in ecotoxicological and regeneration investigations. The intensive utilization of carbamate pesticides (CARs) imposes heavy residue burdens and grave hazards on edaphic environments as well as soil fauna therein. However, precise mechanisms whereby the specific CAR exerted toxic effects on earthworms remain largely elusive, notably from regenerative perspective. Herein, acute responses and regenerative toxicity of two carbamates (metolcarb, MEB and fenoxycarb, FEB) against E. fetida were dissected using biochemical, histological as well as molecular approaches following OECD guidelines at the cellular, tissue and organismal level. The acute toxicity data implied that MEB/FEB were very toxic/medium to extremely toxic, respectively in filter paper contact test and low to medium toxic/low toxic, respectively in artificial soil test. Chronic exposure to MEB and FEB at sublethal concentrations significantly mitigated the soluble protein content, protein abundance while enhanced the protein carbonylation level. Moreover, severely retarded posterior renewal of amputated earthworms was noticed in MEB and FEB treatments relative to the control group, with pronouncedly compromised morphology, dwindling segments and elevated cell apoptosis of blastema tissues, which were mediated by the rising Sox2 and decreasing TCTP levels. Taken together, these findings not only presented baseline toxicity cues for MEB and FEB exposure against earthworms, but also yielded mechanistic insights into regenerative toxicity upon CAR exposure, further contributing to the environmental risk assessment and benchmark formulation of agrochemical pollution in terrestrial ecosystem.

Localized osmotic stress activates systemic responses to N limitation in Medicago truncatula-Sinorhizobium symbiotic plants.

In mature symbiotic root nodules, differentiated rhizobia fix atmospheric dinitrogen and provide ammonium to fulfill the plant nitrogen (N) demand. The plant enables this process by providing photosynthates to the nodules. The symbiosis is adjusted to the whole plant N demand thanks to systemic N signaling controlling nodule development. Symbiotic plants under N deficit stimulate nodule expansion and activate nodule senescence under N satiety. Besides, nodules are highly sensitive to drought. Here, we used split-root systems to characterize the systemic responses of symbiotic plants to a localized osmotic stress. We showed that polyéthylène glycol (PEG) application rapidly inhibited the symbiotic dinitrogen fixation activity of nodules locally exposed to the treatment, resulting to the N limitation of the plant supplied exclusively by symbiotic dinitrogen fixation. The localized PEG treatment triggered systemic signaling stimulating nodule development in the distant untreated roots. This response was associated with an enhancement of the sucrose allocation. Our analyses showed that transcriptomic reprogramming associated with PEG and N deficit systemic signaling(s) shared many targets transcripts. Altogether, our study suggests that systemic N signaling is a component of the adaptation of the symbiotic plant to the local variations of its edaphic environment.

Soil Quality Assessment in Response to Water Erosion and Mining Activity

Erosion significantly decreases the depth of a soil, the nutrients available for plants, the organic matter and, consequently, the productivity of the edaphic environment. Due to the above considerations, the objective of this study was to evaluate, through various properties, the quality of two eroded soils, one eroded by water and the other by mining activity, amended with biosolids. The quality for both soils was estimated through the selection of a minimum set of data by means of principal component analysis (PCA) and the subsequent realization of correlations, multiple regressions and finally calculations of normalized values (Vn) of those properties considered as indicators of soil quality. According to the results, inorganic nitrogen (NI) and respiratory activity (RA) were the properties selected as indicators to assess quality. For soil eroded by water and by mining activity, NI presented a low and very low quality, respectively (class 4 and 5 of quality according to the calculation of Vn). The quality of RA in soil eroded by mining extraction was very high (quality class 1 according to Vn), and thus it can be considered an ideal indicator for the evaluation of soil quality due to its sensitivity to anthropogenic changes (mining) in soil.

Detection and Identification of Fungal Plant Associated Diseases on Begonia

Begonia species is one of the ornamental plants that have unique leaf appearance and metabolites. Research objectives are to isolate, identify and preserve microfungi on Begonia spp. Purposive sampling methods at the Begonia greenhouse of Bogor Botanical Garden, Bogor, were used to collect the microfungi in August 2022. Seven species of Begonia were checked for microfungi. Namely, Begonia blirik, B. crested, B. fiandani, B. natunaensis, and Begonia spp. Morphological character showed that microfungi found are Botrytis spp., Colletotrichum spp. and sterilia miselia. The edaphic environment data were also monitored. This is the first study of microfungi diversity on Begonia spp. in Indonesia. The microfungi will be illustrated and described in this paper.

Irrigation Management Strategies to Increase Crop-Water Productivity and Grain Quality of Direct Seeded Rice in North West IGP: A Review

Due to its great productivity and profitability, rice (Oryza sativa L.) is farmed in alluvial irrigated tracts of northwest India. For half of the world's population as well as in our country, rice serves as the main source of calories. However, excessive groundwater use in rice farming has resulted in an alarming decline in water table, indicating overuse of groundwater. Therefore, it is necessary to investigate alternative, resource-conserving methods that can sustain rice production. Direct seeded rice presents a compelling option when the future of rice production is in jeopardy due to worldwide water constraint and rising labour costs. The oldest method of crop establishment in this regard, direct seeded rice (DSR), is becoming more and more well-liked constraints minimal input requirements. It has certain benefits, including labour savings, a reduction in water and manpower requirements, early crop maturity, cheap production costs, improved soil physical conditions for crops, a reduction in methane emissions, and greater options for being the best match in various cropping systems. For dry-seeded rice, management strategies that cut irrigation water use and boost crop-water production are needed. Some of the interventions in this respect include cultivars with short growing seasons, tillage, and irrigation scheduling. High crop-water productivity is ensured with optimal yields thanks to irrigation scheduling that aims to eliminate over- or under-irrigation. Tillage changes the edaphic environment of the soil, which impacts crop development. Because of their shallow root systems, rice plants are unable to use the water in the deeper layers of the soil. In order to increase the deep root growth of rice cultivars, deep tillage has become the preferable method. The present research evaluates irrigation management options to raise crop-water productivity and grain quality of DSR in northwest IGP based on the available evidence.

Microgeographic variation in early fitness traits of Pinus sylvestris from contrasting soils.

The possibility of fine-scale intraspecific adaptive divergence under gene flow is established by theoretical models and has been confirmed empirically in tree populations distributed along steep altitudinal clines or across extreme edaphic discontinuities. However, the possibility of microgeographic adaptive divergence due to less severe but more frequent kinds of soil variation is unclear. In this study, we looked for evidence of local adaptation to calcareous versus siliceous soil types in two nearby Mediterranean Pinus sylvestris populations connected via pollen flow. Using a greenhouse experiment, we tested for variation in early (up to three years of age) seedling performance among open-pollinated maternal families originating from each edaphic provenance when experimentally grown on both types of natural local substrate. Although seedlings were clearly affected by the edaphic environment, exhibiting lower and slower emergence as well as higher mortality on the calcareous than in the siliceous substrate, neither the performance on each substrate nor the plasticity among substrates varied significantly with seedling edaphic provenance. We found no evidence of local adaptation to a non-extreme edaphic discontinuity over a small spatial scale, at least during early stages of seedling establishment. Future studies on microgeographic soil-driven adaptation should consider long-term experiments to minimize maternal effects and allow a potentially delayed expression of edaphic adaptive divergence.

Systematics, Ecology and Taxonomy of Collembola: Introduction to the Special Issue

Springtails (Collembola) are very small terrestrial arthropods commonly found to be associated with edaphic environments [...]