The Impact of Pesticide Residues on Soil Health for Sustainable Vegetable Production in Arid Areas

The assessment of pesticide residues in agricultural soils is an essential prerogative in maintaining environmental health standards. Intensive vegetable cultivation is practiced in the Al-Kharj area of the eastern Najd region of Saudi Arabia, where excessive applications of agrochemicals are reported to pollute vegetable-growing soils, challenging the sustainable management of soils and groundwater resources. This study aimed to monitor the levels of thirty-two types of pesticide residues in the soils of vegetable fields and the estimated potential health risk for humans due to non-dietary exposure to pesticides in soils in the Al-Kharj region. Pesticide residues were evaluated at 0–10 cm and 10–20 cm depths at 20 sampling sites from Al-Kharj. Gas chromatograph-mass spectrometry, coupled with a quadrupole mass spectrometer with a GC column, was used in the analysis. The results indicated that agrochemical residues show prolonged soil pollution that may cause adverse impacts on human and environment. Herbicides Atrazine, Isoproturpon, and Linuron have been detected in the soils, and these pose many problematic environmental threats. Bromoxynil, Pendimetholin, and Diclofop-methyl could be used as per the recommendations to sustainably manage soil and water resources in the Al-Kharj area. Resmethrin, Methidathion, Ethoprophos, Tetramethrin, Bromophis-methyl, Bifenthion, Permethrin, Fenoxycarb, Cyfluthrin, Phosmet, and Azinophos-methyl can be used safely in the Al-Kharj agricultural area, maintaining sustainable soils and water resources. Applications of Carbaryl require sufficient care, while Endosulfan, Deltamethrin, Lindane, Chlorpyrifos, Chlorpyrifos-methly, Dimethoate, Heptachlor, and Mevinphos, which are detected in soils, require policy guidelines to limit the use to ensure sustainability. Policy interventions need to be formulated to increase the sustainability of soil management and groundwater resources in the Al-Kharj region to ensure the safety of people who are in direct contact with the agrochemicals used and to ensure the safety of agricultural products generated in this region

Toxic Metals and Metalloids in Hassawi Brown Rice: Fate during Cooking and Associated Health Risks

Rice has been a dietary staple for centuries, providing vital nutrients to the human body. Brown rice is well known for its nutrient-dense food profile. However, owing to multiple causes (anthropogenic and non-anthropogenic), it can also be a potential source of toxic heavy metals in the diet. Brown Hassawi rice samples were collected from the Al-Ahsa region and analyzed for its content of toxic metals. The results reveal that all the tested metals varied significantly in the brown rice samples, while As and Pb in all three samples exceeded their respective maximum allowable limits (MALs), followed by Cd, which nearly approached the MAL in two samples out of three. Brown rice samples were cooked in rice:water systems, viz., low rice:water ratios (1:2.5, 1:3.5) and high rice:water ratios (1:5, 1:6), along with soaking as a pre-treatment. Soaking was unproductive in removing the heavy metals from the rice, whereas cooking dissipated all metals from the rice, except for Cd, which was statistically non-significant. The high-water cooking of the rice was more effective in the dissipation of metals from the rice as compared to low-water cooking conditions. Through the consumption of rice, the estimated daily intake (EDI) of heavy metals is 162 g per person per day for As, which is above the provisional maximum tolerable daily intake (PMTDI) regardless of cooking circumstances. The hazard risk index (HRI) also highlighted the fact that As can be a potential health hazard to rice consumers in the Al-Ahsa region of Saudi Arabia. These results indicate the potential health risks caused by the consumption of this rice by humans. Regular monitoring is recommended to manage and control elevated concentrations and related health hazards as a result of the use of Hassawi rice contaminated by the accumulation of metals and metalloids

Bioaccumulation of Heavy Metals in a Soil–Plant System from an Open Dumpsite and the Associated Health Risks through Multiple Routes

Screening various plant species to act as hyperaccumulators and associated health risks could serve as a sustainable solution for the bioremediation heavy metals (HMs). For the first time, the present study explored the phytoremediation potential of native plants, soil enrichment, and human health risks associated with the contamination of HMs in soil and plant samples collected from a municipal solid-waste open dump site. Soil and plant samples (n = 18 + 18) from the dumpsite and (n = 18) from the control site were analyzed for selected HMs, i.e., Chromium (Cr), Lead (Pb), Nickel (Ni), Iron (Fe), and Zinc (Zn). The phytoremediation potential of plants was assessed using the bioaccumulation factor (BAF), bioaccumulation coefficient (BAC), and translocation factor (TF), while soil pollution levels were evaluated using the contamination factor (CF), geoaccumulation index (Igeo), enrichment factor (EF), potential ecological risk index (PERI), and human health risk indices. The results revealed that based on TF and BAC values, Alhagi maurorum Medic., Astragalus creticus Lam., Cichorium intybus L., Berberis lycium Royle, and Datura stramonium L. were hyperaccumulators for Cr while Parthenium hysterophorus L. was a promising species for both Ni and Cr. Similarly, CF values for Fe, Ni, Pb, and Cr were >6, thereby showing very high contamination, while Igeo values for Fe, Ni, Pb, and Cr were (class 6, >5), showing that the soil was extremely polluted. Furthermore, EF values for Fe, Ni, Pb, Cr, and Zn were 2 1 in both adults and children. Likewise, in the case of carcinogenic effects, the CRI values were lower than the tolerable limits (1 × 10−6–1 × 10−4) in both adults and children. Moreover, almost all studied plants could be utilized for the phytoextraction of mentioned HMs. In future, the present study can help in the implementation of public policies to ensure sustainability and developmental activities in contaminated sites. Based on these results, it is concluded that there is a dire need of monitoring solid waste dumpsites due to various types of potential risks associated with the contamination of HMs. Moreover, to minimize the potential health problems arising from the dumpsite, it is substantive that special attention should be paid to work on sustainable and eco-friendly remedial measures

Taxonomic novelties and global biogeography of Montagnula (Ascomycota, Didymosphaeriaceae)

Whilst conducting surveys of lignicolous microfungi in Yunnan Province, we collected a large number of taxa that resemble Montagnula (Didymosphaeriaceae, Pleosporales). Our phylogenetic study on Montagnula involved analysing sequence data from ribosomal RNA genes (nc18S, nc28S, ITS) and protein-coding genes (rpb2, tef1-α). We present a biphasic approach (morphological and molecular phylogenetic evidence) that supports the recognition of four new species in Montagnula viz., M. lijiangensis, M. menglaensis, M. shangrilana and M. thevetiae. The global diversity of Montagnula is also inferred from metabarcoding data and published records based on field observations. Metabarcoding data from GlobalFungi and field observations provided insights into the global diversity and distribution patterns of Montagnula. Studies conducted in Asia, Australia, Europe, and North America revealed a concentration of Montagnula species, suggesting regional variations in ecological preferences and distribution. Montagnula species were found on various substrates, with sediments yielding a high number of sequences. Poaceae emerged as a significant contributor, indicating a potential association between Montagnula species and grasses. Culture-based investigations from previously published data revealed Montagnula species associations with 105 plant genera (in 45 plant families), across 55 countries, highlighting their wide ecological range and adaptability. This study enhances our understanding of the taxonomy, distribution, and ecological preferences of Montagnula species. It emphasizes their role in the decomposition of organic matter in grasslands and savannah systems and suggests further investigation into their functional roles in ecosystem processes. The global distribution patterns and ecological interactions of Montagnula species underscore the need for continued research and conservation efforts

Differential Response of Brassica Cultivars to Potentially Toxic Elements and Their Distribution in Different Plant Parts Irrigated with Metal-Contaminated Water

The increasing concentration of potentially toxic elements (PTEs) in agricultural soils has greatly disturbed the quality and productivity of soils. In this study, we investigated the uptake and distribution of cadmium (Cd), lead (Pb), and nickel (Ni) by two Brassica cultivars (Khanpur raya and Sandal canola) grown on soil irrigated with metal-contaminated water. Distilled water was spiked with salts to prepare irrigation water with various levels of metals (Ni application at 90, Cd at 20, Pb at 500, Ni + Pb at 20 + 500, Ni + Cd at 90 + 20, Cd + Pb at 20 + 500, and Ni + Cd + Pb at 90 + 20 + 500 mg L−1). These treatments were compared with water without the addition of any salt. The results indicated that compared to the control treatment, increasing metal concentrations decreased the shoot weight (44.25%, 29.03%), root length (33.33%, 12.74%), and shoot length (19.73%, 11.06%) in Khanpur raya and Sandal canola, respectively. Compared to the control treatment, irrigation with contaminated water decreased the photosynthesis rate (98.42%, 99.34%), chlorophyll content (18.27%, 13.73%), respiration rate (7.97%, 6.47%), and transpiration rate (9.90%, 33.33%) in both varieties, respectively. Notably, the concentrations of Ni (0.01 and 0.003), Cd (0.01 and 0.012), and Pb (0.03 and 0.05%) in the seeds were increased, as well as in Khanpur raya and Sandal canola, respectively, compared to the controls. Furthermore, the PTE accumulation in different components was recorded, with the order of soil > root > shoot > seed. It was observed that brassica cultivars differed significantly in their response to the growth and accumulation of PTEs in edible parts. It was concluded that Khanpur raya did not exhibit a decline in growth due to PTEs in irrigation water and prevented the translocation of PTEs towards edible parts compared to Sandal canola and thus can be safely grown in soils receiving PTE-contaminated water

Taxonomic novelties and global biogeography of Montagnula (Ascomycota, Didymosphaeriaceae)

Whilst conducting surveys of lignicolous microfungi in Yunnan Province, we collected a large number of taxa that resemble Montagnula (Didymosphaeriaceae, Pleosporales). Our phylogenetic study on Montagnula involved analysing sequence data from ribosomal RNA genes (nc18S, nc28S, ITS) and protein-coding genes (rpb2, tef1-α). We present a biphasic approach (morphological and molecular phylogenetic evidence) that supports the recognition of four new species in Montagnula viz., M. lijiangensis, M. menglaensis, M. shangrilana and M. thevetiae. The global diversity of Montagnula is also inferred from metabarcoding data and published records based on field observations. Metabarcoding data from GlobalFungi and field observations provided insights into the global diversity and distribution patterns of Montagnula. Studies conducted in Asia, Australia, Europe, and North America revealed a concentration of Montagnula species, suggesting regional variations in ecological preferences and distribution. Montagnula species were found on various substrates, with sediments yielding a high number of sequences. Poaceae emerged as a significant contributor, indicating a potential association between Montagnula species and grasses. Culture-based investigations from previously published data revealed Montagnula species associations with 105 plant genera (in 45 plant families), across 55 countries, highlighting their wide ecological range and adaptability. This study enhances our understanding of the taxonomy, distribution, and ecological preferences of Montagnula species. It emphasizes their role in the decomposition of organic matter in grasslands and savannah systems and suggests further investigation into their functional roles in ecosystem processes. The global distribution patterns and ecological interactions of Montagnula species underscore the need for continued research and conservation efforts

Soil Nutrient Status and Morphometric Responses of Guava under Drip Irrigation and High-Tech Horticultural Techniques for Sustainable Farming

In the current study, efforts were made to standardize fertigation for providing the recommended doses of fertilizers (RDF) i.e., 300, 260, and 200 g/plant/year for N, P, and K, respectively, together with optimization of irrigation scheduling so that guava plants could avoid the frequent episodes of nutritional stress, water scarcity, or overwatering. The experiment’s execution was confined to a three-factor randomized block design, with a total of 19 treatments that were replicated four times. Briefly, these treatments included drip irrigation and nutrient (NPK) application through fertigation dosages (RDF; 100, 80, and 60%) with and without silver-black plastic mulching. Different applied fertilizer dosages, together with different levels of irrigation and soil mulching, had a significant impact on the guava plant’s vegetative, reproductive, and nutritional aspects. Under silver-black plastic mulch, drip irrigation at cumulative pan evaporation (CPE) 80 and 100% of the prescribed dosage of fertilizers, better macronutrient availability in the soil, and improved plant development were recorded (M1DI2F1). Overall, using drip fertigation to provide NPK fertilizers close to the root zone increased the availability of nutrients to the plants as compared to the traditional fertigation and irrigation methods. Thus, this sustainable high-tech horticultural approach could be analyzed for its efficacy or applied to other crops to obtain adequate economic outcomes