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Nutrient disorder and presence of disease-causing agents in soilless media negatively influence the growth of muskmelon. To combat these issues, use of environmentally-friendly sanitation techniques is crucial for increased crop productivity. The study was conducted under greenhouse and field conditions to investigate the effect of two different sanitation techniques: steaming and formalin fumigation on various media's characteristics and their impact on muskmelon yield. Media: jantar, guar, wheat straw and rice hull and peat moss of 10% air-filled porosity and sanitized with formalin and steaming. Steaming of guar, jantar, and wheat straw increased the phosphorus (P) and potassium (K) concentrations by 13.80–14.86% and 6.22–8.45% over formalin fumigation. Likewise, P and K concentrations in muskmelon were higher under steaming. Steaming significantly inhibited the survival of Fusarium wilt sp. melonis, root knot nematode sp. meloidogyne and nitrifying bacteria in media than formalin fumigation. In conclusion, steaming decreased the prevalence of nitrifying bacteria and pathogens which thus improved the NO3−–N:NH4+–N ratios, P and K nutritional balance both in the media and muskmelon transplants. Hence, steaming as an environment-friendly approach is recommended for soilless media. Further, optimization of steaming for various composts with different crops needs to be investigated with steaming teachnique. [ABSTRACT FROM AUTHOR]

Recently nanoparticles (NPs) are ubiquitous in the environment because they have unique characteristics which are the reason of their wide use in various fields. The release of NPs into various environmental compartments mainly ends up in the soil through water bodies which is a serious threat to living things especially plants. When present in soil, NPs may cause toxicity in plants which increase significance to minimize NPs stress in plants. Although gibberellic acid (GA) is one of the phytohormones that has the potential to alleviate abiotic/biotic stresses in crops plant, GA-mediated alleviation of cerium oxide (CeO2) NPs in plants is still unknown, despite the large-scale application of CeO2-NPs in various fields. The present study was performed to highlight the ability of foliar-applied GA in reducing CeO2-NPs toxicity in wheat under soil exposure of CeO2-NPs. We observed that CeO2-NPs alone adversely affected the dry weights, chlorophyll contents, and nutrients and caused oxidative stress in plants, thereby reducing plant yield. GA coupled with CeO2-NPs reversed the changes caused by CeO2-NPs alone as indicated by the increase in plant growth, chlorophylls, nutrients, and yield. Furthermore, GA alleviated the oxidative stress in plants by enhancing antioxidant enzyme activities under CeO2-NPs exposure than the NPs alone which further provided the evidence of reduction in oxidative damage in plants by GA. Overall, evaluating the potential of GA in reducing CeO2-NPs toxicity in wheat could provide important information for improving food safety under CeO2-NPs exposure. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) availability in arable soils is a serious issue while little is known about the role of co-composted organic amendments and zinc oxide nanoparticles (ZnO-NPs) foliar spray on biomass and Cd accumulation in wheat grains. The current study investigated the soil application of organic amendment (composted biochar and farmyard manure) at a level of 0, 1, and 2% w/w and foliar spray of ZnO-NPs (0, 100, and 200 mg/L) on biomass, yield, and Cd in wheat grains cultivated in an aged Cd-contaminated agricultural soil. The results indicated that organic amendment increased the biomass, chlorophyll concentrations, yield, and activities of peroxidase and superoxide dismutase of wheat while decreased the electrolyte leakage and Cd concentrations in different parts of wheat such as shoots, roots, husks, and grains. This effect of organic amendment was further enhanced by the foliar spray of ZnO-NPs in a dose-additive manner. Cadmium concentration in grains was below threshold level (0.2 mg/kg DW) for cereals in combined application of 200 mg/L ZnO-NPs and 1% organic amendment as well as in higher treatment (2%) of organic amendment and NPs. Thus, combined use of organic materials and NPs might be a suitable way of reducing Cd and probably other toxic trace element concentrations in wheat and other cereals. [ABSTRACT FROM AUTHOR]

Phosphorus (P) availability is limited to crop plants especially in alkaline calcareous soils due to formation of various precipitates. In such soils, use of P solubilizing bacteria (PSB) along with suitable organic amendment such as biochar (BC) might be the possible solution to provide suitable P concentration to plants. Interactive effect of PSB, BC (0 and 2% w/w), and three application rates of P fertilizers (no fertilizer, half dose, full dose) on P availability and plant growth in a calcareous soil was investigated. The maize (Zea mays L.) seeds were primed with PSB in sugar solution and later sown in clay pots filled with soil (10 kg) and mixtures of BC and fertilizers. Three plants were maintained in each pot and grown for 45 days. Soil parameters such as soil pH, EC, nitrogen (N), and Olsen's P concentrations were determined after harvesting the plants. The plant growth, biomass, P, and N concentrations in plants were also determined. The results depicted that the PSB-primed plants grown in biochar-amended soil supplied with half and full fertilizers showed maximum growth. No significant effect on the seed germination was observed, but the uptake of P was high in those plants where PSB and BC were applied as a cumulative treatment. Only PSB treatment also showed better results except in no fertilizer treatment as compared with PSB + BC + no fertilizer treatment where BC provided P. The plants yielded higher biomass with full fertilizer doses, but significant and maximum increments were observed in BC + PSB + full fertilizer treatment. Similarly, the uptake of N was high in BC treatment plants as compared with the PSB and control. The application of BC and inoculation of PSB can reduce the demand of fertilizer as well as can be proved as a natural conditioner that can sustain and improve the soil's physical, chemical, and biological conditions. However, field investigations under different agroclimatic conditions are required before final recommendations. [ABSTRACT FROM AUTHOR]

Soil degradation with different stress conditions like accumulation of cadmium (Cd) contents in soil and drought stress has become one of the most dangerous issues that obstruct the sustainable agriculture production. Silicon nanoparticles (Si NPs) play beneficial roles in combating various biotic and abiotic stresses but their role under combined metal and drought stress is not studied. A pot study was designed to determine the effect of Si NPs on wheat (Triticum aestivum L.) growth and uptake of Cd grown in Cd contaminated soil with different water levels under ambient conditions. Four different levels of Si NPs (0, 25, 50, and 100 mg/kg) were applied in the soil before 1 week of wheat sowing and two water levels (70% and 35% soil water-holding capacity) were introduced after 50 days of seed sowing for the remaining growth period. The lowest biomass, yield, and photosynthesis were observed in the control plants while oxidative stress and the highest Cd concentrations in shoots, roots, and grains were observed in the control plants, and the drought stress further enhanced this effect on the plants. The Si NPs treatments improved the plant growth indicators and photosynthesis, and reduced the Cd concentrations in wheat tissues, especially in grains either without or with drought stress. The Si NPs reduced the oxidative stress in leaves as was indicated by the reduced production of hydrogen peroxide, electrolyte leakage, and malondialdehyde contents, and increase in superoxide dismutase and peroxidase activities. The improvement in wheat growth and a reduction in oxidative stress and Cd concentration in tissues were dependent on the levels of Si NPs and the effect was the highest with the highest level of NPs used. [ABSTRACT FROM AUTHOR]

Purpose: The majority studies used the biochar or nanoparticles alone in metal-contaminated soils while less is known about the combined use of these amendments in metal-contaminated soils. We aimed to explore the efficiency of iron oxide nanoparticles (Fe NPs) and biochar on cadmium (Cd) uptake in rice in pot trial. Materials and methods: An experiment was performed under ambient environmental conditions in a Cd-contaminated soil with and without biochar addition (1.0% w/w), and different Fe NP concentrations (0, 10, 20, 30 mg/L) were foliar sprayed at different time intervals (at 3rd, 4th, and 5th weeks of nursery transplantation in the pots) during the plant growth. After harvesting, rice growth, photosynthesis, Cd and Fe contents in rice tissues, and soil bioavailable Cd and soil pH were measured. Results and discussion: Iron NPs enhanced the dry weights of rice tissues, chlorophyll concentrations, and gas exchange characteristics and the impact of NPs was further increased when the biochar was applied along with NPs. Iron NPs significantly decreased the intake of Cd in rice shoots by 31 and 42% and in rice roots by 26 and 39% with the foliar spray of Fe NPs (30 mg/L) without and with biochar, respectively. Foliar spray of Fe NPs reduced the total Cd accumulation by shoots, whereas the total Cd accumulation in the roots increased. The co-presence of Fe NPs and Cd enhanced the Fe concentrations in shoots of rice by 52 and 33% and in roots of rice by 32 and 21% when 30 mg/L Fe NPs were supplied with and without biochar, respectively. The effects of Fe NPs were higher with biochar application than without biochar except Fe concentrations in rice seedlings where the opposite trend was observed. Conclusions: The increase in biomass, Fe concentrations in tissues, and decrease in Cd levels in plants clearly demonstrate that Fe NPs + biochar could be a promising technique for the utilization of Cd-contaminated soils in the future. [ABSTRACT FROM AUTHOR]

Soil degradation by salinity and accumulation of trace elements such as cadmium (Cd) in the soils are expected to become one of the most critical issues hindering sustainable production and feeding the increasing population. Biochar (BC) has been known to protect the plants against soil salinity and heavy metal stress. A soil culture study was performed to evaluate the effect of BC on wheat (Triticum aestivum L.) growth, biomass, and reducing Cd and sodium (Na) uptake grown in Cd-contaminated saline soil under ambient conditions. Soil salinity decreased the plant growth, biomass, grain yield, chlorophyll contents, and gas exchange parameters and caused oxidative stress in plants compared with Cd stress alone. Salt stress increased Cd and Na uptake and reduced the potassium (K) and zinc (Zn) uptake by plants. AB-DTPA-extractable Cd and soil electrical conductivity (ECe) increased under salt stress compared to the soil without NaCl stress. Biochar application improved the plant growth and reduced the Cd and Na uptake except in plants treated with higher BC and salt stress (5.0% BC + 50 mM NaCl). Biochar application reduced the oxidative stress in plants and modified the antioxidant enzyme activities, and reduced the bioavailable Cd under salt stress. The positive effects of BC under lower salt stress while the negative effects of BC under higher BC and salt levels indicated that BC doses should be used with great care in higher soil salinity levels simultaneously contaminated with Cd to avoid the negative effects of BC on growth and metal uptake. [ABSTRACT FROM AUTHOR]

We investigated effect of biochars (BCs) and nitrogen (N) fertilizers on soil selected characteristics, growth of maize, and soil N transformations in a pot experiment. Maize was grown in soil amended with control (no BC), and three BCs different in feedstock (rice-straw biochar (RSBCC), vegetable-waste biochar (VMBC), poultry-manure biochar (PMBCC), and N application (control, 0.25 g N kg−1 soil using urea and NH4NO3). At harvest, agronomic parameter, soil (pH, EC, SOM, total N, and NO3-N), and plant analyses were done. The results showed the improvement in soil nutrient contents and yield with application of BC and N. The soil pH diminished in BC treatments where N was used. The soil EC was increased in RSBC treatment than the control but decreased in NH4NO3 application irrespective of all BC treatments. The SOM was improved in all BC treatments under N. The NH4 concentration in plants and total soil N were significantly enhanced in BC treatments even without N. The plant growth and nutrient uptake were more influenced in NH4NO3 than urea. Comparing BCs showed overall better performance of PMBC than RSBCC and VWBC. Overall, the combined supply of PMBCC and NH4NO3 has advantages of improving plant growth, and soil fertility by changing N dynamics. [ABSTRACT FROM AUTHOR]

In the present study, efficiency of different biochars (BCs) on cadmium (Cd) immobilization and its bioavailability to spinach were investigated. In the first experiment, Cd-spiked soil was amended with treatments (T1 = control, T2 and T3 = cotton stalk biochar (CBC) 2% and 5%, T4 and T5 = rice straw biochar 2% and 5%) and incubated for 120 days. In the second experiment, spinach was grown in pots using three soils (a normal soil, a Cd-spiked soil, and a sewage-irrigated soil) after application of CBC and rice straw biochar (RBC) (2% w/w each) in each soil. In the field experiments, spinach was grown at two sites with six treatments including T0 = control, T1 and T2 (RBC 5 and 10 ton ha−1), T3 and T4 (CBC 5 and 10 ton ha−1). The results of our experiments showed a significant impact of BCs on soil pH, EC, soil organic matter, and Cd bioavailability. The plant growth parameters were also influenced positively by application of BC in both pot and field experiments. In field experiments, plant population and fresh biomass at different sites varied significantly. The Cd concentration in plants was lower when grown in treated soils. Moreover, there was a significant increase in soluble Si and phosphorus concentrations in plants and this had significant correlation with Cd concentration in plants. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained a mistake. The Research Group number information in the Acknowledgement section was incorrect. The correct information is given below. [ABSTRACT FROM AUTHOR]

The cadmium (Cd) has been regarded the toxic trace element to plants and humans, while there is very little information available about the application of titanium dioxide (TiO2) and silicon (Si) nanoparticles (NPs) in the mitigation of Cd stress in crops and particularly in rice (Oryza sativa). The experiment is aimed to investigate how foliar applications of Si and TiO2 NPs affected Cd uptake, photosynthesis and antioxidant enzyme system in rice. The rice seedlings were grown in Cd-contaminated soil and various concentrations of both NPs were foliar applied at different time intervals. The data indicate that both NPs significantly increased the rice biomass while decreasing Cd concentration in tissues. The NPs application enhanced the chlorophyll concentrations and gas exchange attributes of rice leaf. The NPs decreased electrolyte leakage, and malondialdehyde content and improved the activities of superoxide dismutase, preoxidase, catalase, and asorbate peroxidase in rice shoots over the control. The effectiveness of NPs in mitigating Cd toxicity varied with the type and dose of NPs applied. The results depicted that foliar use of NPs was effective in improving biomass, photosynthesis and diminishing Cd accumulation in rice, which was mainly attributed to the reduced oxidative burst and improvement in antioxidant defense system resulting from NPs application. [ABSTRACT FROM AUTHOR]

Biochar is considered a promising amendment for the reduction of metal concentration in plants; however, the effects of biochar in terms of dose and feedstock on metal uptake by plants remain widely unclear. In the current study, three individual biochars were prepared at 450 °C from different feedstocks (wheat straw, sukh chain (Pongamia pinnata), and cotton sticks). The main aim was to evaluate their ability to remediate cadmium (Cd)-spiked soil in terms of growth response and Cd uptake by wheat (Triticum aestivum) tissues. Biochars were separately applied at 0, 1, and 2% (w/w) in Cd-spiked soil and wheat was grown until maturity in pots and then morphological and physiological parameters and Cd concentrations in grains, roots, and shoots were determined. The post-harvest soil was analyzed for extractable Cd concentrations. Plants grown in Cd-spiked soil treated with biochars had higher seed germination, lengths of roots, shoots, and spikes, grains per spike and leaf relative water contents, chlorophyll contents, and dry weight of roots, shoots, and grains as compared to the untreated control. Biochar treatments significantly decreased the Cd concentrations in shoots, roots, and grains as well as total Cd uptake by grains. Soil extractable Cd concentrations were significantly decreased with biochar treatments. The application of 2.0% wheat straw biochar was the most efficient treatment in increasing grain yield and decreasing Cd in grains as well as soil extractable Cd than the other two biochars and doses applied. [ABSTRACT FROM AUTHOR]

Unfortunately, in the original publication of the article, Prof. Yang Sik Ok’s affiliation was incorrectly published. The author’s affiliation is as follows. [ABSTRACT FROM AUTHOR]