Soil Nutrient Deficiency Research Articles

Review on Millets: A Sustainable Ancient Superfood for the Modern World

Millets are frequently referred to as "superfoods" or "nutricereals" because of their high nutritional content, ability to withstand climatic change, and reduced resource requirements when compared to other common grains. Millets have historically been consumed in larger quantities and are beneficial to diets worldwide, but both their cultivation and consumption are drastically reducing. To provide food and nutrition security, resource sustainability, and economic development, millet may be essential. Therefore, it is imperative to develop strategies aimed at reversing the global trends of declining millet production and consumption and raising consumer knowledge of the dietary and health benefits of millets. For thousands of years, millets, a class of small-seeded, nutrient-rich grains have been an essential part of human existence, particularly in Asia and Africa. Pearl millet, finger millet, foxtail millet, Indian barnyard millet, kodo millet, tiny millet, and proso millet are the millets that are produced most widely around the world, especially in India. In Ayurveda, millets are explained under the Dhanya Varga and are known by the names Trina Dhanya, Kudhanya, and Kshudra Dhanya in different Samhitas. Furthermore, millets have long been employed by indigenous people as an ethnomedical and hunger-reduction tool. Since millets are usually grown on degraded, nutrient-deficient soil with little rainfall, they are an extremely resilient crop. Instead millets are high in dietary fibre, proteins, vitamins, minerals, antioxidants, phytochemicals, and other nutrients, they are a cure-all for a wide range of illnesses. Due to shifting agro-climatic conditions that have resulted in a decrease in the yield of major staple grains, millets have emerged as a viable solution to address current issues in agriculture, food security, and public health. Millets have demonstrated excellent nutritional makeup and great adaptability. In light of government and civil society initiatives to promote millet farming in India, this review paper offers a succinct overview of millets, emphasising their historical significance, use in folklore, cultivation techniques, health benefits, and potential to contribute to sustainable farming systems and food security. For this study paper, a thorough review of numerous literatures, journals, published papers, and books was conducted.

Precision agriculture based on convolutional neural network in rice production nutrient management using machine learning genetic algorithm

Precision Agriculture technology can use high-tech sensors and analytical tools to help farmers better manage their crop yields, allowing them to demonstrate their techniques on the field. The greater use of remote sensing technologies in farm productivity and nitrogen management tools to increase yields and reduce operational costs contributes to reduced energy consumption. This concept describes the need to fulfill nutrient and crop production objectives for the near and long term. Based on our proposed approach, we concluded that the predictors of individual flow occurrences are variables linked to surface temperatures, moisture, and nitrogen availability. We have developed an automated Convolutional Neural Network creation approach genetic algorithms approach to handling image classification problems more efficiently. The best feature of the method is that it is “automated” and doesn't need domain knowledge about CNNs. When compared to conventional encoding, we compare the performance and adaptability of our processing. Moreover, the comparison of individual Genetic algorithms with CNN schemes employed for training the systems was compared to that of other GENCNN schemes ResNet-34, ResNet-50, AlexNet, DenseNet, VGGNet in terms of convergence speed and overall accuracy, among other things. Our studies data indicate that our Soil Nitrogen Management significantly reduced commercial system costs while providing notable outcomes. The experimental results of soil nutrient deficiency 99%and 97% show that the suggested method may be used to automatically identify the most efficient GENCNN model compared to existing models in a wide range of domains.

Effects of continuous cropping on fungal community diversity and soil metabolites in soybean roots.

Microbial community imbalance is the main cause of soybean intercropping, but the mechanism of soybean soil fungal community diversity change induced by continuous cropping is still unclear. This study analyzes the fungal community diversity and the change of fungal communities in compartments of different root systems of intercropped soybeans by high-throughput sequencing (endosphere, rhizoplane, and rhizosphere) between continuous cropping and maize-soybean rotation. The results showed that the community composition and the diversity of compartments of different root systems of intercropped soybeans are different, and fungal diversities showed a decreasing trend from rhizosphere to endosphere. Continuous cropping significantly increased fungal community diversities in different root compartments and changed their formation, enrichment, and depletion processes. Continuous cropping brings about the enrichment of soil pathogens, but only partial soil pathogens could colonize from the rhizosphere to the endosphere. All these suggested that root compartments had selective effects on root-associated fungal community diversity. Additionally, metabolomics assay revealed that continuous cropping soybean markedly altered soil metabolic profiling. Correlation analysis results showed that fungal community diversity was significantly correlated with soil metabolites. To sum up, under different planting patterns, the diversity and the functional mode of soybean soil microbial community have changed. Continuous cropping has increased the abundance of pathogenic fungi in soybean soil, resulting in changes in the correlation between soil fungi and metabolites, and then changed the soil metabolic spectrum.IMPORTANCESoybean yield can be affected by soybean soil fungal communities in different tillage patterns. Soybean is an important food crop with great significance worldwide. Continuous cultivation resulted in soil nutrient deficiencies, disordered metabolism of root exudates, fungal pathogen accumulation, and an altered microbial community, which brought a drop in soybean output. In this study, taking the soybean agroecosystem in northeast China, we revealed the microbial ecology and soil metabolites spectrum, especially the diversity and composition of soil fungi and the correlation of pathogenic fungi, and discussed the mechanisms and the measures of alleviating the obstacles.

Soil fertility status, productivity challenges, and solutions in rice farming landscapes of Azerbaijan

Rice, a fundamental staple globally, plays a pivotal role in addressing food security and nutrition. This study explores the intricate interplay between soil characteristics, productivity challenges, and solutions in Azerbaijan's rice farming landscapes, acknowledging the agricultural importance of rice and its contribution to human nutrition. This study aims to assess the physical and chemical properties of soil samples from Azerbaijan's rice cultivation areas, with a focus on nutrient content and the identification of elements limiting productivity and plant nutrition. By synthesizing these perspectives, the study enriches the understanding of the complex relationship between soil fertility class and rice productivity, offering insights for sustainable rice farming. Soil samples were collected from representative rice fields across Azerbaijan and analyzed for various parameters, including soil texture, pH, electrical conductivity, organic matter, and nutrient content. The soil sampling and preparation process maintained the integrity of collected samples, providing a reliable basis for scientific analysis. The results reveal diverse soil properties, with clayey texture prevailing. Soil acidity, salinity, and nutrient deficiencies pose challenges, emphasizing the need for corrective measures. The majority of soils exhibit unsuitable pH levels and elevated sodium content, necessitating interventions such as soil acidification and sodicity remediation. Soil salinity issues highlight the importance of drainage and leaching practices. Low organic matter and nutrient deficiencies, particularly zinc and manganese, underscore the need for targeted interventions, including foliar applications. Overall, Azerbaijan's rice-cultivated areas face challenges related to soil fertility, salinity, and nutrient deficiencies, impacting productivity. Corrective measures, such as soil reclamation, proper fertilization, and foliar applications, are crucial for enhancing crop yields. The study contributes valuable insights for local practices and the broader global pursuit of sustainable rice farming, emphasizing the importance of tailored strategies in addressing specific regional challenges.

A Review on Protected Cultivation of Vegetables: Opportunities and Challenges

Protected farming techniques are set of agricultural practices that are designed to produce a plant in a controlled environmental condition by using soil cover and / or crop covers to control pests and effect of climate. While a protected farming method can increase the productivity of vegetable crops as well as growth and yield. It is evident that protected farming has been found beneficial for farmers. In addition to its great importance, it challenges many biotic and abiotic factors such as photo-stress, water stress, heat stress, weed growth, soil nutrient deficiencies, high wind velocities and atmospheric carbon dioxide, pest and diseases. The various benefits of a protected vegetable crop are quality, profitability, and a good level of marketing for farmers. Protected cultivation is an imminent technique for raising vegetables, flowers and other high rated as well as consumable crops. In advance agriculture, protected structures held an excessive potential for more production with greater productivity. The chapter contains the status, challenges and opportunities of protected cultivation and related government schemes for horticultural plants in India especially Uttar Pradesh. It has been found that the cumulative area has been acquired under NHM-protected cultivation in India. Financial support or funding is also provided by the government agency to spread this methodology throughout the country. Recourses are used wisely in these structures because modern methods/techniques were applied.

Can foliar application of natural biostimulants reduce nitrate and fiber content in fresh green bean under soil nutrient deficiency?

BackgroundThere is a growing body of literature that recognizes the importance of natural biostimulants in the agricultural productivity. This potential can play an important role in addressing the issue of cultivation on sandy soil, which is well-known with soil nutrient deficiency stress. In the current study, the selected biostimulants (i.e., chitosan, amino acids, yeast extract, and humic acid) were foliar applied on green bean in the open field of alkaline sandy soils.ResultsThe main results that obtained after harvesting the fresh green bean pods were confirmed that all studied biostimulants improved the quantity and quality of green bean production compared to the control. Chitosan was the best applied biostimulants for producing green bean in a lower fiber and nitrate content of pods, a higher crude protein content of pods, and higher NPK content in the leaves.ConclusionThe role of studies biostimulants in promoting green bean productivity under nutrient deficiency stress may back to increase the uptake of nutrients (NPK), plant physiological (higher dry matter) and biochemical attributes (higher crude protein). More studies are needed using different applied doses and more different kinds of natural biostimulants.

Fe2O3 nanoparticles from Athrixia phylicoides DC and their effect on Cicer arietinum L. growth performance

Chickpea is mostly grown in nutrient-deficient soils where supplies are made through conventional fertilisers which present certain environmental issues such as soil degradation, and water and soil contamination. Thus, the use of other technologies such as nanotechnology is being implemented as a remedy to achieve sustainable agriculture without altering the environment. This study reports the effect of different concentrations of green synthesised Fe2O3 nanoparticles on the performance of chickpeas grown under glasshouse conditions. The characterisation techniques confirmed the synthesis of spherical Fe2O3 NPs with an average diameter of 47,16 nm. These nanoparticles were less toxic to human embryonic kidney and lung adenocarcinoma cells. Furthermore, results confirmed the increase in the number of leaves and nodules, as well as the grain weight, for both Kabuli and Desi genotypes, as compared to the control plants. Similarly, the water use efficiency of Kabuli was increased with the Fe2O3 nanoparticles but reduced for the Desi genotype. The N2 fixation, C shoot content and concentration as well as the δ13C values were improved with the nanoparticles application. Thus, the use of Fe2O3 nanoparticles could be an alternative for the iron fertilisation of chickpeas to reduce the environmental risks posed by conventional inorganic fertilisers.

Efficient Detection of Soil Nutrient Deficiencies through Intelligent Approaches

Exploring the use of intelligent approaches, particularly artificial intelligence (AI) and machine learning (ML), in detecting soil nutrient deficiencies, is a crucial aspect of agriculture. Traditional methods of soil nutrient analysis, although effective, are beset with limitations, including high costs, time-intensiveness, and lack of real-time data. Emerging intelligent approaches address these challenges by providing real-time, accurate data on soil nutrient levels, thereby enabling timely and precise fertilization. Several case studies, including the Indian startups CropIn and Fasal, demonstrate the successful application of these technologies in agriculture, leading to improved crop yields, reduced fertilizer costs, and enhanced sustainability. The article also discusses ongoing research and prospects, highlighting the potential of AI not only in detection but also in predictive analysis. Finally, the piece provides a roadmap for farmers and stakeholders interested in adopting these intelligent approaches, emphasizing the importance of understanding the technology, choosing suitable tools, and fostering a mindset of change and continuous learning. Overall, intelligent approaches to soil nutrient detection promise a more productive, sustainable, and economically viable future in farming.

Nutrient status assessment and mapping of intensively managed paddy soils in southeastern hilly areas of Bangladesh

AbstractBackgroundPeople living in the southeastern hilly areas of Bangladesh are primarily dependent on agriculture and face the problem of nutrient deficiency in soils. This research was conducted to assess the fertility status of paddy soils for better fertilizer management. Grid sampling (1 km × 1 km) was followed to collect soil samples, avoiding unusual spots (e.g., non‐agricultural land, settlements, hills, and forests). In total, 300 samples were collected (150 from each upazila) to assess the status of soil physical properties (soil texture) and chemical properties (pH, electrical conductivity, organic matter, and nutrients [nitrogen (N), phosphorus (P), potassium (K), sulfur (S), magnesium (Mg), boron (B), and zinc (Zn)]).ResultsResults revealed that most of the soils were sandy to silt loam in texture. The soils were found to be strongly acidic with values of 4.79 and 4.73 in Ukhiya and Teknaf, respectively. Most of the soils were found to be nonsaline, except the paddy soils close to the sea and/or salt‐affected cultivated land. Soil organic matter in Ukhiya and Teknaf was low (1.47% and 1.43%, respectively). The soils in both upazilas were deficient in N, P, K, S, and Zn, but not in Mg in both upazilas and B in Teknaf.ConclusionIt is imperative that adequate amounts of nutrient provision are available to maintain soil health and produce a sustainable crop yield. We believe that these are the first digital soil maps developed at upazila level using ArcGIS software, which will be available for future reference.

Leaf morpho-physiological traits of Populus sibirica and Ulmus pumila in different irrigation regimes and fertilizer types.

The impacts of climate change, such as increased soil dryness and nutrient deficiency, highlight the need for environmentally sustainable restoration of forests and groundwater resources. However, it is important to consider that extensive afforestation efforts may lead to a depletion of groundwater supply due to higher evapotranspiration rates, exacerbating water scarcity issues. Consequently, we conducted a study to examine how the fast-growing tree species Populus sibirica (Horth ex Tausch) and Ulmus pumila (L.) respond morpho-physiologically to varying watering regimes and types of fertilizers, aiming to better understand their specific water and nutrient requirements. We used two-year-old nursery-growth seedlings (N=512) of P.sibirica and U. pumila with initial root collar diameter (RCD) and the height of 0.51±0.02mm and 68±2.94 cm and 0.33±0.01mm and 51±1.14 cm, respectively. The leaf area (LA), specific leaf area (SLA), chlorophyll concentration, stomatal conductance (gs), chlorophyll fluorescence, and predawn and midday leaf water potential were measured across treatments. Four different irrigation regimes and two different fertilizer types were applied: no irrigation (control, 0 L h-1), 2 L h-1 = 0.25 mm m-2, 4L h-1 = 0.5mm m-2, 8 L h-1 = 1.0 mm m-2 and 120 g and 500 g tree-1 of NPK and compost (COMP). Twelve plots (600 m2) were established in the study site for each species and treatments. During the first growing season (2021), the LA of P. sibirica was larger in the 4-8 L h-1 without fertilizer, but it was smaller in the 4 L h-1+ COMP during the second growing season (2022). The 2 L h-1 without fertilizer and 2 L h-1 + NPK had larger LA compared with the control (CONT) for the first and second growing seasons, respectively, for U. pumila. P. sibirica seedlings at 4 L h-1 without fertilizer had the highest SLA for 2021 and at 2 L h-1 + NPK for 2022, whereas CONT and 4 L h-1 had the highest SLA than the other treatments for 2021 and 2022 growing seasons, respectively, for U. pumila. The chlorophyll concentration of P. sibirica seedlings in the first year was generally higher in CONT, while the 2 L h-1 without any fertilizer yielded a significantly higher chlorophyll concentration of U. pumila. Chlorophyll fluorescence parameters (PIABS and Fm) were generally lower in CONT with/without NPK or COMP for both species. The CONT with NPK/COMP generally had a higher gs compared with the other treatments in both experimental periods for U. pumila, whereas CONT and 2 L h-1+ NPK-treated P. sibirica seedlings had a significantly greater gs during the first year and second year, respectively. The predawn and midday leaf water potentials of both species were generally the lowest in CONT, followed by 2 L h-1+ NPK/COMP during the first growing season, but a different pattern was observed during the second growing season. Overall, the morpho-physiological traits of the two species were affected by watering and fertilizer treatments, and the magnitude of the effects varied depending on growing season, amount of irrigation, and fertilizer type, and their interactions.

Differences in background environment and fertilization method mediate plant response to nitrogen fertilization in alpine grasslands on the Qinghai-Tibetan Plateau

Grassland degradation threatens ecosystem function and livestock production, partly induced by soil nutrient deficiency due to the lack of nutrient return to soils, which is largely ascribed to the intense grazing activities. Therefore, nitrogen (N) fertilization has been widely adopted to restore degraded Qinghai-Tibetan Plateau (QTP) grasslands. Despite numerous field manipulation studies investigating its effects on alpine grasslands, the patterns and thresholds of plant response to N fertilization remain unclear, thus hindering the prediction of its influences on the regional scale. Here, we established a random forest model to predict N fertilization effects on plant productivity based on a meta-analysis synthesizing 88 publications in QTP grasslands. Our results showed that N fertilization increased the aboveground biomass (AGB) by 46.51 %, varying wildly among plant functional groups. The positive fertilization effects intensified when the N fertilization rate increased to 272 kg ha−1 yr−1, and decreased after three years of continuous fertilization. These effects were more substantial when applying ammonium nitrate compared to urea. Further, a machine learning model was used to predict plant productivity response to N fertilization. The total explained variance and mean squared residuals ranged from 49.41 to 75.13 % and 0.011–0.058, respectively, both being the highest for grasses. The crucial predictors were identified as climatic and geographic factors, background AGB without N fertilization, and fertilization methods (i.e., rate, form, and duration). These predictors with easy access contributed 62.47 % of the prediction power of grasses' response, thus enhancing the generalizability and replicability of our model. Notably, if 30 % of yak dung is returned to soils on the QTP, the grassland productivity and plant carbon pool are predicted to increase by 5.90–6.51 % and 9.35–10.31 g C m−2 yr −1, respectively. Overall, the predictions of this study based on literature synthesis enhance our understanding of plant responses to N fertilization in QTP grasslands, thereby providing helpful information for grassland management policies.Conflict of interest: The authors declare no conflict of interest.

Effect of Sesbania and Triticale rotation on plant characteristics and soil quality in coastal saline-alkaline land: A two-year field experiment

Soil salinization and nutrient deficiency limit agricultural production in the Yellow River Delta region. This study investigates the green manure-forage grass rotation on soil quality and productivity. A two-year field experiment was conducted to investigate the effects of different varieties of Sesbania cannabina and ᵡTriticosecale Wittm rotations on soil properties, biological characteristics, and adaptability in coastal saline-alkali land. Four cropping rotation systems were set: Gaoyuan 2 – Lujing 2 (G2L2), Gaoyuan 2 – Lujing 5 (G2L5), Gaoyuan 1640 – Lujing 2 (G1640L2), and Gaoyuan 1640 – Lujing 5 (G1640L5). The G2L5 rotation demonstrated superior enhancement of soil quality. The soil organic matter increased by 35.8%, and the soil electric conductivity (CEC) increased by 20.2%. Compared with T. Wittm, S. cannabina had a significant positive effect on soil physical and chemical properties. S. cannabina L5 showed improved performance in mass density, fresh weight of stem, leaf and aboveground part, etc. After S. cannabina returned to the field, T. Wittm G2 had greater plant height, thousand-grain weight, and stem weight, and the yield reached 322 kg per 667 m2. In conclusion, G2L5 is the recommended planting model in saline-alkali soil. This research offers valuable insight for the efficient planting and sustainable development of coastal saline-alkali land.

Effect of fertigation levels on fertilizer use efficiency, yield, quality and economics of Robusta coffee

AbstractRobusta coffee production largely depends upon irrigation and nutrition management practices. These factors determine the increase in productivity and quality of coffee. Therefore, restrictions of Robusta coffee production due to soil nutrient deficiencies can be removed by applying the right quantities of fertilizers at the right time with the right method. A long‐term experiment was conducted to study the impact of different fertigation levels on the yield, nutrient use efficiency and quality of Robusta coffee. The present experiment was conducted on a randomized block design consisting of six treatments with four replications over a period of 5 years from 2017 to 2021 at the Central Coffee Research Institute (CCRI), Balehonnuru, India. The results revealed that among different fertigation levels, fertigation with 75% and 100% of the recommended dose of fertilizer resulted in significantly higher yields (2117 kg ha−, 1821 kg ha−1) and yield attributing parameters, namely, total number of nodes/branches (49.1, 44.1), number of bearing nodes/branches (35.0, 29.4) and number of fruits/branches (758, 679) in Robusta coffee, based on the pooled mean (2017–2021). Therefore, adoption of the fertigation level with 75% of the recommended dose of fertilizers not only increased the productivity of Robusta coffee but also ensured a higher efficiency of nutrients (25%–30%) and cost–benefit ratio (1:2.48).

Stemflow temporal dynamics differ significantly between standing live and dead branches of two xerophytic shrub species

Shrub mortality due to self-thinning and climate change is a natural consequence of the long residence times of standing dead branches in unmanaged shrub plantations. Stemflow (SF) represents a key point source of input water and nutrients into the soil in shrub ecosystems. However, little information is available about how shrub mortality affects SF variables. In this study, we measured the SF volume (SFV), funneling ratio (FR), SF intensity, time lag to rain, and rainfall characteristics for live and standing dead branches of two major shrub species comprising Caragana korshinskii and Salix psammophila during the rainy season in 2022 on the Chinese Loess Plateau. The results demonstrated that the SF variables and temporal dynamic processes differed between standing live and dead branches of the two shrubs. For C. korshinskii, the mean SFV and FR were 1.9 and 1.8 times higher for live branches than dead branches, respectively, whereas for S. psammophila, the mean SFV and FR were 1.3 and 1.6 times higher for dead branches than live branches. These contradictory results can be explained by differences in the canopy structures of the species, such as the surface area that contributes to the generation of SF in the upper canopy, branch angles, and the degree of branch bark decomposition and decay. In addition, the SF variables were significantly temporally dependent on the rainfall characteristics. SFV, SFI, and SFD were positively and linearly correlated with the rainfall amount, intensity, and duration at the inter-event scale (P < 0.001). The influence of rainfall intensity on SF time lag to rain were not significant at the intra-event scale (P > 0.05). Considering the enrichment ratio due to canopy dry deposition and bark decomposition, the periodic flattening of dead S. psammophila branches to restore their growth is less significant than allowing them to die and renew naturally. These findings may serve as a reference for developing management practices for shrub species in areas with soil water and nutrient deficiencies.

Agroecology: Searching in the wrong place

This paper presents a defence of ecologically based monodominance. The promotion of ‘agroecology’ has been validated by the belief that natural vegetation forms a multi-species ‘balance’ under pest pressure. Agroecologists consider monoculture crops as an artificial construct unknown in nature. To achieve this ecological balance crop fields should be re-diversified to species-diverse ‘polycultures’, as mimics of natural vegetation. This simple view of herbivorous insects forcing vegetation diversity held sway with various authors until around 1970. Post-1970 there was an increasing recognition of, and focus on, natural monodominant vegetation. The driving force behind natural plant monodominance, especially in herbaceous species, seemed to be seasonal ecological stress, including fire, flood, silt formation and soil nutrient deficiency. These abiotic stresses were capable both of winnowing out less adapted species, but also encouraging the evolution of adaptations to the stress (as seen, for example, in the distinctive features of monodominant mangroves and sea-grasses). The result was plant species with the ability to grow as monodominants, but, importantly, the evolved ability to resist any extra biotic pressure from herbivores – both features invaluable for monoculture agriculture. Agroecology never considered the possibility of adaptative evolution to biotic stress to allow monodominance (the ‘fight’ stratagem of plant species). In addition, agroecology only recognizes the ‘flight’ stratagem for short-distance escape (plant species ‘hiding’ in mixed-species vegetation). This ignores a major feature of modern agriculture, which heavily relies on long-distant crop introduction, through trans-oceanic crop introduction: the ultimate ‘flight’ mechanism to remove susceptible species from co-evolved herbivorous insects and disease by long-distant dispersal. In failing to understand the evolution of monodominance, current agroecological principles are without a solid scientific basis ecologically. There is still an opportunity to revise the current thinking to develop a more ecologically-based form of agroecology.

Optimizing phosphorus management to increase grain yield and nutritional quality while reducing phytic acid concentration in black rice (Oryza sativa L.)

Rice with a black-colored pericarp (hereafter, black rice) has attracted considerable attention because of its high nutritional value. It is traditionally grown in infertile agroecosystems, where soil nutrient deficiency would affect grain yield and nutritional quality of the rice. This study examined the effects of phosphorus (P) application (0, 100, 250, 500, 1,000, and 1,300 mg P2O5 pot−1) on the growth, grain yield, and certain quality parameters of unpolished black (“Asamurasaki”) and white (“Takanari”) rice. The results showed that black rice grew poorly under P limitation, resulting in fewer tillers and a lower grain yield, while maintaining higher photosynthetic efficiency than white rice. However, black rice produced under P stress exhibited higher levels of Zn, Fe, and antioxidant (total phenolic and flavonoid content) than white rice, making it more nutritious. The optimal P application rates for black and white rice were 250 and 500 mg P2O5 pot−1, respectively, to achieve high yields. At the optimal rate, black rice exhibited high Fe, Zn and antioxidant levels compared to that at higher P application rates and had lower phytic acid levels, which could alleviate its inhibition of mineral absorption in the digestive tract. Moreover, low grain P due to P stress decreased the lightness L* value in the CIE-Lab system, improving the visual grain quality. Therefore, optimal P management is crucial for maintaining optimal grain yield with low phytic acid concentration and enhancing the nutritional quality of black rice for human consumption.

Fly Bioash Ameliorates Acid Luvisol and Increases Sunflower (Helianthus annuus L.) Yield in Field Conditions without Compromising the Risk of Radioactive Contamination

Fly bioash (FBA) as a by-product of biomass-fuelled facilities exhibits alkaline properties and is enriched with phytonutrients, thereby offering the potential to effectively ameliorate acidic and nutrient-deficient soils. However, concerns about health risks due to a potential FBA radioactive contamination are still not well studied, notably under field conditions. This study examined pH changes and concentrations of natural (238U, 232Th, 226Ra, 40K) and anthropogenic (137Cs) radionuclides after application of very alkaline (pH &gt; 12) FBA in: (i) highly acid (pHKCl = 4.1) Luvisol and (ii) sunflower (Helianthus annuus L.) seeds, grown in organic farming and rain-fed conditions. FBA (originated from a modern cogeneration, fuelled on certified deciduous forest wood chips) was applied at increasing doses; 0, 4.5, 8.6, 13, and 17.2 t/ha. After 54 months of application, FBA significantly increased soil pHKCl by up to 1.8 unit and the seed yield by 15%, compared with no amended Control, without compromising soil electrical conductivity (salinity). The activity concentrations (Ac) of all observed radionuclides, measured using high-resolution gamma-ray spectrometry, were not altered under FBA application, neither in the surface (0–30 cm) Luvisol horizon nor in the sunflower seed. Moreover, the Ac of 238U, 232Th, and 137Cs in the seed were below detection limit, whereas the Ac of 40K and 226Ra were lower by up to 2.6 and 61 times, respectively, than their corresponding Ac in the soil treatments. The radiological footprint of FBA exhibited lower Ac for most of the observed radionuclides compared with both (i) Croatian non-arable topsoils (with reductions of 238U 3.6 times, 232Th 1.8 times, 226Ra 1.7 times, and 137Cs 1.5 times) and (ii) widely used mineral N/P/K fertilisers in conventional agroecosystems (with reductions of 238U 12.5 times; 226Ra 1.3 times, and 40K 2.4 times). Our findings provide evidence that the application of FBA as a soil conditioner does not pose radiological health or environmental risks, contributing to more sustainable agri-food production and circular bioeconomy. However, it is essential to conduct further studies to comprehensively investigate the effects of FBA application on soil and crop quality across diverse environmental conditions and extended spatiotemporal scales.

Exploitation alters microbial community and its co-occurrence patterns in ionic rare earth mining sites

The exploitation of ion-adsorption rare earth elements (REEs) deposits results in serious ecological and environmental problems, which has attracted much attention. However, the influences of exploitation on the prokaryotic communities and their complex interactions remain poorly understood. In the present study, bacterial and archaeal communities, as well as ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), in and around REEs mining area were investigated through high throughput sequencing and quantitative polymerase chain reaction (qPCR). Our results indicated that mining soil was characterized by poor soil structure, nutrient deficiency, and high concentrations of residual REEs. Oligotrophic bacteria (e.g., Chloroflexi and Acidobacteriota) were dominant in unexploited soil and mining soil, while copiotrophic bacteria (Proteobacteria and Actinobacteriota) were more abundant in surrounding soil. Nutrient was the key factor affecting microbial variation and abundance in mining soil. The bacterial community was more sensitive to REEs, while the archaeal communities were relatively stable. As the key members for ammonia oxidation, AOA outnumbered AOB in all the soil types, and the former was significantly influenced by pH, nutrients, and TREEs in mining soil. The microbial co-occurrence network analysis demonstrated that exploitation significantly influenced topological properties, decreased the complexity, and resulted in a much unstable network, leading to a more fragile microbial ecosystem in mining areas. Notably, the abundance of keystone taxa decreased after exploitation, and oligotrophic groups (Chloroflexi) replaced copiotrophic groups (Proteobacteria and Actinobacteriota) as the key to rebuilt a co-occurrence network, suggesting potentially important roles in maintaining network stability. The current results are of great significance to the ecological risk assessment of REEs exploitation.

The Effects of Soil Type, Exposure and Elevation on Leaf Size and Shape in Quercus cerris L.

One of the main environmental factors that influence plant species and community diversity are soil types, exposure and elevation. This study aimed to evaluate differences in leaf size and shape of Quercus cerris L. along environmental gradients in the Šumadija region in Serbia by using geometric morphometrics methods. The results showed significant differences between Q. cerris individuals inhabiting sites with different soil types, exposures and elevations. Individuals growing on nutrient deficient soils had smaller leaf size, elongated petiole, wide leaf blade, and higher values of fluctuating asymmetry compared to individuals growing on nutrient-rich soils whose leaf size was larger, more variable in shape and had lower values of fluctuating asymmetry. Additionally, individuals inhabiting higher elevations had elongated and narrow leaves and short petioles. Leaf size was also greater in individuals from lower elevations and north-exposed sites. The results of this study suggest that leaf morphological traits are affected by habitat differences and exhibit considerable plasticity in response to environmental demands.

Selenium Nano-Biofortification under Soil Nutrient Deficiency: A Comparative Study between Green Bean and Pepper

Selenium Nano-Biofortification under Soil Nutrient Deficiency: A Comparative Study between Green Bean and Pepper