Characteristics of soil CO2 emission and ecosystem carbon balance in wheat-maize rotation field with 4-year consecutive application of two lignite-derived humic acids.

Humic acid originating from lignite is a popular resource of organic fertilizer. The effects of humic acid application on crop biomass and soil CO2 emission charged the regional agro-ecosystem carbon balance. Two kinds of humic acid, obtained from lignite via H2O2-oxidation (OHA) and KOH-activation (AHA), were applied in a wheat-maize rotation located field at three levels of 500 (OHA1; AHA1), 1000 (OHA2; AHA2), and 1500 kg hm-2 (OHA3; AHA3), only chemical fertilizer treatment (CF) as control to investigate the change of soil CO2 emission, crop yield and ecosystem carbon balance in 2016-2019. During the four experimental years, the trend of cumulative efflux of soil CO2 was increasing in medium and high dosage humic acid treatments. The grain yield of wheat and maize had the same trend as the cumulative efflux of soil CO2 due to the increase of soil NO3--N and soil available P directly affected by humic acid application. The main factor of cumulative soil CO2 efflux improvement was soil NO3--N and soil available P in 2016, while soil available potassium became key factor in 2019 with the step regression. Net ecosystem productivity (NEP) was used to assess ecosystem carbon balance, which was positive values showed atmospheric CO2 sink under all the fertilization treatments and increased with the increase of humic acid use level. AHA2 and AHA3 treatments charged the higher NEP in 2019 than 2016. Meanwhile, AHA treatment presented a higher NEP average than OHA treatment with the same applied level. Crop yield and soil available P was the directly positive factor to NEP over four years under the fertilization by SEM analysis. It is recommended that AHA be applied at 1000 kg hm-2 together with chemical fertilizers to achieve the higher crop yield and a sink of the atmospheric CO2 in agricultural fields in North China.

Alleviation of drought stress by root-applied thiourea is related to elevated photosynthetic pigments, osmoprotectants, antioxidant enzymes, and tubers yield and suppressed oxidative stress in potatoes cultivars.

The growth and productivity of plants are enhanced by the use of thiourea (TU) under stressful conditions. When TU is applied as a rooting medium, it improves plant growth characteristics and other physiological parameters in stressed environment. A pot experiment was conducted in the botanical garden of the Government College University, Faisalabad 38000, Pakistan to examine the TU-mediated fluctuations in some crucial physio-biochemical parameters and the oxidative defense of potatoes under a restricted water supply. For this purpose, two potato cultivars (potato-SH-5 and potato-FD-73) were sown in pots containing 10 kg of soil. Water was regularly applied to the pots until germination. After 2 weeks of germination, drought stress with 65% field capacity was imposed, while the control was subjected to 100% field capacity. TU, as a rooting medium, was applied at the vegetative stage (0 (no application), 0.5, 0.75 mM). A substantial reduction in the total number of leaves, leaf area, tuber biomass (fresh and dry weight), photosynthetic pigments, membrane permeability, and leaf relative water content (RWC) was recorded in plants under drought stress conditions as compared to control plants. The damaging effects of water stress were more critical for cv. potato-FD-73 as compared to cv. potato-SH-5. In contrast, drought stress enhanced the malondialdehyde (MDA) and hydrogen peroxide (H2O2) content while also increased antioxidant enzyme activities (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and triggered the accumulation of soluble proteins, soluble sugars, proline, and phenolic and anthocyanin contents. However, TU applied as rooting medium at 0.5 and 0.75 mM was effective in reducing the detrimental effects of water stress in both cultivars. Furthermore, increasing levels of TU enhanced chlorophyll pigments, dissolved proteins, complete dissolved sugars, and enzymatic capabilities of POD, SOD, and CAT, while reducing the MDA and H2O2 in both cultivars under stress conditions. In conclusion, TU improved the yield and chlorophyll pigments of potato plants by mitigating the adverse effects of drought stress through reduced EL, MDA, and H2O2 contents and improved activities of enzymatic and non-enzymatic antioxidants and osmoprotectants.

Antimicrobial activities of different solvent extracts from stem and seeds of Peganum Harmala L.

Wild medicinal herbs have been used as folk and traditional medicines all across the world since well before recorded history. This present study was designed to test the antimicrobial activities of five different solvent extracted samples (n-hexane, n-butanol, ethyl acetate, methanol, and water) of Peganum harmala using stems and seeds. Two different strains of Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), two Gram-positive bacteria (Bacillus subtilus and Staphylococcus aureus), and one fungal strain (Candida albicans) were used. The antimicrobial activities were measured using a disc diffusion assay. Two concentrations of the extracts (1 and 2mgDisc-1) were used. Ethyl acetate fraction was found more affective among the tested solvents and showed maximum activity (zone of inhibition) against S. aureus (65.53 and 81.10%), E. coli (46.22 and 61.29%) while n-butanol and water fractions gave maximum activity against S. aureus (78.86 and 70.00%) and K. pneumonia (57.00 and 61.39%) respectively. Water fraction showed maximum activity against C. albicans (60.00 and 81.88%). In the case of the stem, Ethyl acetate again showed more activity against B. subtilus (38.57 and 42.10%) and S. aureus (36.66 and 46.66%) while n-butanol showed maximum activity against K. pneumonia (24.55 and 32.44%) and E. coli (27.93 and 37.61%). Methanol was found more effective against C. albicans (25.71 and 43.80%). Seed extracted samples were found more effective compared to the stem. Ethyl acetate, butanol, and aqueous extracted samples showed good activity against the tested microbes, so these fractions are recommended for study their mechanism of actions and isolation of bioactive metabolites responsible for antimicrobial activities. The P. harmala should be evaluated for their bioactive compounds to be used in future studies. Our objective is to provide the framework for future study on the roles of P. harmala as traditional medicines.

Mechanistic Impact of Zinc Deficiency in Human Development.

Zinc (Zn) deficiency in humans is an emerging global health issue affecting approximately two billion people across the globe. The situation prevails due to the intake of Zn deficient grains and vegetables worldwide. Clinical identification of Zn deficiency in humans remains problematic because the symptoms do not appear until impair the vital organs, such as the gastrointestinal track, central nervous system, immune system, skeletal, and nervous system. Lower Zn body levels are also responsible for multiple physiological disorders, such as apoptosis, organs destruction, DNA injuries, and oxidative damage to the cellular components through reactive oxygen species (ROS). The oxidative damage causes chronic inflammation lead toward several chronic diseases, such as heart diseases, cancers, alcohol-related malady, muscular contraction, and neuro-pathogenesis. The present review focused on the physiological and growth-related changes in humans under Zn deficient conditions, mechanisms adopted by the human body under Zn deficiency for the proper functioning of the body systems, and the importance of nutritional and nutraceutical approaches to overcome Zn deficiency in humans and concluded that the biofortified food is the best source of Zn as compared to the chemical supplementation to avoid their negative impacts on human.

Antifungal activity of Zinc nitrate derived nano Zno fungicide synthesized from Trachyspermum ammi to control fruit rot disease of grapefruit.

Grapefruit (Citrus paradisi) is a widely grown citrus and its fruit is affected by a variety of biotic and abiotic stress. Keeping in view the hazardous effects of synthetic fungicides, the recent trend is shifting towards safer and eco-friendly control of fruit diseases. The present study was aimed to diagnose the fruit rot disease of grapefruit and its control by using zinc oxide green nanoparticles (ZnO NPs). Fruit rot symptoms were observed in various grapefruit growing sites of Pakistan. Diseased samples were collected, and the disease-causing pathogen was isolated. Following Koch's postulates, the isolated pathogen was identified as Rhizoctonia solani. For eco-friendly control of this disease, ZnO NPs were prepared in the seed extract of Trachyspermum ammi and characterized. Fourier transform infrared spectroscopy (FTIR) of these NPs described the presence of stabilizing and reducing compounds such as phenols, aldehyde and vinyl ether, especially thymol (phenol). X-ray diffraction (XRD) analysis revealed their crystalline nature and size (48.52 nm). Energy dispersive X-ray (EDX) analysis elaborated the presence of major elements in the samples, while scanning electron microscopy (SEM) confirmed the morphology of bio fabricated NPs. ZnO NPs exhibited very good anti-fungal activity and the most significant fungal growth inhibition was observed at 1.0 mg/ml concentration of green NPs, in vitro and in vivo. These findings described that the bioactive constituents of T. ammi seed extract can effectively reduce and stabilize ZnO NPs. It is a cost-effective method to successfully control the fruit rot disease of grapefruit.

S-Fertilizer (Elemental Sulfur) Improves the Phytoextraction of Cadmium through Solanum nigrum L.

Soil contamination with toxic heavy metals [such as cadmium (Cd)] is becoming a serious global problem due to the rapid development of the social economy. This study was carried out to assess the beneficial role of two different kinds of (S)-fertilizer in the phytoremediation of Cd contaminated soil through Solanum nigrum L. Gypsum (Gyp) and Elemental sulfur (ES) was applied alone and in combination with different ratios (0, 100:0, 0:100, 50:50 mg kg-1) accompanied by different Cd levels (0, 25, 50 mg kg-1). After seventy days of sowing, plants were harvested for determination of growth, physiological characteristics, oxidants and antioxidants, along with Cd uptake from different parts of the plant. Cd toxicity significantly inhibited growth, physiology and plant defence systems, and also increased Cd uptake in the roots and shoots of Solanum nigrum L. The application of Gyp 100 mg kg-1 boosted plant growth and physiology along with oxidants and antioxidants activity as compared to ES 100 mg kg-1 alone, and combine application of GYP+ES 50 + 50 mg kg-1. The application of ES 100 mg kg-1 showed an effective approach to decreasing Cd uptake as compared to Gyp 100 mg kg-1. Overall results showed that the combined application of GYP+ES 50 + 50 mg kg-1 significantly enhanced the phytoremediation potential of S. nigrum in Cd contaminated soil. Thus, it is highly recommended to apply the combined application of GYP+ES for phytoremediation of Cd contaminated soil.

Combined application of zinc and iron-lysine and its effects on morpho-physiological traits, antioxidant capacity and chromium uptake in rapeseed (Brassica napus L.).

Environmental contamination of chromium (Cr) has gained substantial consideration worldwide because of its high levels in the water and soil. A pot experiment using oil seed crop (rapeseed (Brassica napus L.)) grown under different levels of tannery wastewater (0, 33, 66 and 100%) in the soil using the foliar application of zinc (Zn) and iron (Fe)-lysine (lys) has been conducted. Results revealed that a considerable decline in the plant growth and biomass elevates with the addition of concentrations of tannery wastewater. Maximum decline in plant height, number of leaves, root length, fresh and dry biomass of root and leaves were recorded at the maximum level of tannery wastewater application (100%) compared to the plants grown without the addition of tannery wastewater (0%) in the soil. Similarly, contents of carotenoid and chlorophyll, gas exchange parameters and activities of various antioxidants (superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX)) were also reduced significantly (P < 0.05) with the increasing concentration of tannery wastewater (33, 66 and 100%) in the soil. In addition, a combined application of Zn and Fe-lys reduced the accumulation and uptake of toxic Cr, while boosting the uptake of essential micronutrients such as Zn and Fe in different tissues of the plants. Results concluded that exogenous application of micronutrients chelated with amino acid successfully mitigate Cr stress in B. napus. Under field conditions, supplementation with these micronutrient-chelated amino acids may be an effective method for alleviating metal stress in other essential seed crops.

Bio-diesel production of sunflower through sulphur management in a semi-arid subtropical environment.

Energy security is a prime focus of policy makers to support agriculture, industrialisation, and transportation. Due to limited conventional energy sources, there is a need to harness non-conventional energy sources. In this regard, one of the proposed approaches is using biomass (e.g. energy crops) to produce biofuel-a renewable source of energy. Sunflower has several agronomic features to be exploited for a renewable, non-conventional, and environment-friendly source of bioenergy. Sulphur (S) fertilisation holds key for realising sunflower potential for seed and oil yield. In response to variable S supply rates, here we compared and quantified sunflower yield (seed, oil, and biodiesel) and biodiesel quality according to the ASTM international standards. We used a combined approach of field experimentation and rigorous lab analysis. Firstly, in a field experiment laid out in randomised complete block design with split-plot arrangement, response of two local sunflower hybrids (FH-331 and FH-689) to four S supply rates (0, 25, 50, 75 kg S ha-1) was evaluated in terms of agronomic traits. Experimental data showed that fertilisation of S significantly influenced growth and yield (seed, oil) traits; the response was different between two hybrids which also interacted with S supply rate. FH-331 recorded the highest achene yield at S fertilisation of 75 kg S ha-1, whereas FH-689 recorded the highest achene yield at 50 kg ha-1; achene yield of FH-331 was 13.6% higher than FH-689. Compared to control, S at 75 kg S ha-1 increased oil yield of FH-331 by 22% whereas S at 50 kg ha-1 increased oil yield by 23% of FH-689. Seed samples were analysed for different biodiesel quality parameters. The ranges of all quality parameters of sunflower biodiesel such as viscosity, calorific values, acid value, iodine value, saponification value, cetane number, and pour point were in ASTM standard range. We conclude that sunflower is a promising and sustainable option for producing biodiesel, the potential of which can be increased by optimal S management under field conditions.

The impact of aqueous and N-hexane extracts of three Fabaceae species on seed germination and seedling growth of some broadleaved weed species.

Weed infestation is a persistent problem for centuries and continues to be major yield reducing issue in modern agriculture. Chemical weed control through herbicides results in numerous ecological, environmental, and health-related issues. Moreover, numerous herbicides have evolved resistance against available herbicides. Plant extracts are regarded as an alternative to herbicides and a good weed management option. The use of plant extracts is environmentally safe and could solve the problem of herbicide resistance. Therefore, laboratory and wire house experiments were conducted to evaluate the phytotoxic potential of three Fabaceae species, i.e., Cassia occidentalis L. (Coffee senna), Sesbania sesban (L.) Merr. (Common sesban) and Melilotus alba Medik. (White sweetclover) against seed germination and seedling growth of some broadleaved weed species. Firstly, N-hexane and aqueous extracts of these species were assessed for their phytotoxic effect against lettuce (Lactuca sativa L.). The extracts found more potent were further tested against germination and seedling growth of four broadleaved weed species, i.e., Parthenium hysterophorus L. (Santa-Maria), Trianthema portulacastrum L. (Pigweed), Melilotus indica L (Indian sweetclover). and Rumex dentatus L. (Toothed dock) in Petri dish and pot experiments. Aqueous extracts of all species were more toxic than their N-hexane forms for seed germination and seedling growth of lettuce; therefore, aqueous extracts were assessed for their phytotoxic potential against four broadleaved weed species. Aqueous extracts of all species proved phytotoxic against T. portulacastrum, P. hysterophorus, M. indica and R. dentatus and retarder their germination by 57, 90, 100 and 58%, respectively. Nevertheless, foliar spray of C. occidentalis extract was the most effective against T. portulacastrum as it reduced its dry biomass by 72%, while M. alba was effective against P. hysterophorus, R. dentatus and M. indica and reduced their dry biomass by 55, 68 and 81%, respectively. It is concluded that aqueous extracts of M. alba, S. sesban and C. occidentalis could be used to retard seed germination of T. portulacastrum, P. hysterophorus, M. indica and R. dentatus. Similarly, aqueous extracts of C. occidentalis can be used to suppress dry biomass of T. portulacastrum, and those of M. alba against P. hysterophorus, R. dentatus. However, use of these extracts needs their thorough testing under field conditions.