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In this investigation, cultivation of an economically important medicinal plant (Senna, Cassia angustifolia Vahl.) was explored in saline soil for improving productivity and quality through effective nutrient management practices. Field experiments were conducted in two consecutive growing seasons in saline soils of semi-arid region, where recommended dose fertilizer (RDF) supplied through organic (vermicompost) and inorganic (chemical) source alone or in combination with local microbial consortia (MC). Plant growth and nutrition significantly improved due to integration of organic and inorganic fertilizer alone or in combination with MC. The results also reflected in economic yield (leaf + pod) of senna where 29–37% increase in leaf and 57–76% increase in pod yield was recorded over control. The results revealed that integration of organic and chemical fertilizer along with MC recorded significant higher leaf (1682 kg ha−1) and pod (488 kg ha−1) yield as compared to the other treatment. Sennocide content in leaf and pod was significantly improved by organic as well as integrated application of organic and inorganic fertilizer. However, the highest sennocide content in leaf (2.81%) and pod (3.11%) was recorded in integrated application of organic fertilizer and MC. Additionally, integrated application of organic and chemical fertilizer was found effective in restoring organic carbon, increasing the amount of available nutrients (N, P, and K), and enhancing the biological activity of the saline soil. Therefore, integration of organic and chemical fertilizer as well as MC has potential to improve yield and quality of senna through enhanced soil fertility and biological function. [ABSTRACT FROM AUTHOR]

Biological potassium fertilizer (BPF) is a promising technology to improve potassium availability in the soil through the bio-activation of endogenous K-reserves. A group of microorganisms has been recognized for K solubilization from insoluble silicate minerals (e.g. biotite, feldspar, illite, muscovite, orthoclase and mica) and these microorganisms can potentially perform a key role in enhancing K supply to plants. This group of microorganisms includes both bacteria and fungi, commonly known as potassium-solubilizing microorganisms (KSMs). The KSMs have been found effective in solubilizing K (34–38% of the total K) from insoluble minerals by releasing organic acids. The efficiency of KSM in solubilizing native K reserves is highly dependent on the type of soil, nature of K bearing minerals and other soil environmental conditions. As far as the effect of KSM application on crop performance is concerned, the application of KSM improved crop yield by on average 17%, obtained from 20 greenhouse and 12 field trials. However, K-bearing minerals inoculated with KSM were found to be more effective in light texture soils with a crop having a long gestation period. This communication presents the K solubilizing potential of different KSMs and their application as BPF in agriculture as well as associated challenges behind large-scale adoption. [ABSTRACT FROM AUTHOR]

Kalmegh (Andrographis paniculata) is an annual herb with wide medicinal and pharmacological applications due to the presence of andrographolide, an important bioactive compound. Influence of organic nutrient sources on biological yield and bioactive principle of kalmegh was studied through field experiment for two consecutive years. The experiment was carried out in a split plot design where, organic sources (farmyard manure, vermicompost and castor cake) were applied as main plot treatments and microbial consortium and jivamrut were applied as subplot treatments. The highest fresh (17,347 kg ha−1) and dry (8050 kg ha−1) herbage yields were recorded with vermicompost followed by castor cake application. Bioactive compound (andrographolide) content in kalmegh was significantly influenced by the application of organic manures, microbial consortium and jivamrut. The result also reflected in total bioactive compound (andrographolide) yield where 9.7–53.7% increase in the main plot and 10.7–22.4% increase in the sub-plot treatment was recorded. Andrographolide yield was much higher with vermicompost and castor cake than the rest of the treatments. The application of vermicompost and castor cake resulted in significantly higher herbage and bioactive compound yield, which was significantly correlated with soil properties. Soil fertility and biological properties also improved with the application of organic sources, particularly vermicompost. Significant correlation between the soil properties and yield and bioactive compound content indicates that organic sources have beneficial impact on yield and quality of kalmegh through improving soil properties. Thus, application vermicompost could be a promising nutrient source particularly in organic cultivation of kalmegh. [ABSTRACT FROM AUTHOR]

The potassium supplying capacity of the waste mica powder (WMP) was evaluated through chemical and biological means. Four different size fractions of the WMP were studied in laboratory by different chemical extractants. At the same time, experiment of the plant growth was conducted in pot using K-deficient soil. The K release from the WMP by different extractants followed an increasing trend with an increase in the fineness of the particles. The highest K release was recorded by boiling 1 M HNO3 (376.4–1726.4 mg kg−1) followed by 1 M ammonium acetate (33.5–226.5 mg kg−1), 0.01 M citric acid (31.6–158.3 mg kg−1) and water (12.0–112.0 mg kg−1) irrespective of the various size fractions. Significantly, higher cumulative K release from the WMP in successive extraction was recorded with 1 M boiling HNO3 that predicts its slow-release property. The K release by different extractants was correlated significantly and positively with the biomass yield and K uptake by plants. 1 M boiling HNO3 extractable K showed higher correlation values with the biomass yield and K uptake. Therefore, it suggests that the extractant might be a better indicator of K supplying capacity of the WMP. The plant intervention was able to extract 32.8% of total K from the WMP simultaneously improving the exchangeable and non-exchangeable K pool in soil. These above-mentioned results conclude that plants can get access to a significant amount of K from the WMP and it could be an effective source of K in highly weathered tropical soils under K deficiency. [ABSTRACT FROM AUTHOR]

This study described a preparation of a low‐cost adsorbent by entrapment of palmarosa distillation wastes into alginate as supporting matrix and use of it for methylene blue (MB) dye removal from aqueous solution. Fourier transform infrared spectroscopy (FTIR) data of adsorbent confirms the entrapment for formation of composite beads. The effects of adsorption parameters (adsorbent dose, temperature, initial dye concentration, and pH) were investigated. Time to reach the equilibrium was dependent on dye concentration and it was 120 min for lower concentration and 240 min for higher concentration. The analysis of the kinetic data by pseudo‐first‐order and pseudo‐second‐order models displayed that MB adsorption followed pseudo‐second‐order model. The equilibrium data of MB adsorption were described by applying the Langmuir, Freundlich, and Temkin models. The observations from adsorption isotherms indicated that Langmuir model is the best fitted model and the maximum adsorption capacity (at the optimum pH 9.0) improved from 5.71 to 6.45 mg/g as the temperature increased from 298 to 328 K. The thermodynamic studies demonstrated that MB adsorption on to the adsorbent was spontaneous, feasible, and endothermic. Low desorption of the dyes from the adsorbent indicates that the dyes might have been chemisorbed on to the adsorbent surface. A single‐stage batch adsorber was designed and quantity of adsorbent required for treating 1–10 L of stained water was determined based on the Langmuir isotherm model equation. Results indicate that the composite bead could be an alternative for relatively costly adsorbents used for remediation of MB dye bearing industrial effluents. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018 [ABSTRACT FROM AUTHOR]

Soil needs simultaneous replenishment of various nutrients to maintain its inherent fertility status under extensive cropping systems. Replenishing soil nutrients with commercial fertilizer is costly. Among various fertilizers, deposits of potassium (K) ore suitable for the production of commercial K fertilizer (KCl) are distributed in few northern hemisphere countries (Canada, Russia, Belarus, and Germany) which control more than 70% of the world's potash market. Naturally occurring minerals, particularly silicate minerals, could be used as a source of K, but not as satisfactorily as commercial K fertilizers. In this context, bio-intervention (in combination with microorganisms and/or composting) of silicate minerals has been found quite promising to improve plant K availability and assimilation. This is an energy efficient and environmentally friendly approach. Here we present a critical review of existing literature on direct application of silicate minerals as a source of K for plant nutrition as well as soil fertility enhancement by underpinning the bio-intervention strategies and related K solubilization mechanisms. An advancement of knowledge in this field will not only contribute to a better understanding of the complex natural processes of soil K fertility, but also help to develop a new approach to utilize natural mineral resources for sustainable and environmental friendly agricultural practices. [ABSTRACT FROM AUTHOR]

A simple multi-residue method based on modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach was established for the determination of 17 organochlorine (OC), 15 organophosphorous (OP) and 7 synthetic pyrethroid (SP) pesticides in an economically important medicinal plant of India, Senna (Cassia angustifolia), by gas chromatography coupled to electron capture and flame thermionic detectors (GC/ECD/FTD) and confirmation of residues was done on gas chromatograph coupled with mass spectrometry (GC-MS). The developed method was validated by testing the following parameters: linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effect, accuracy–precision and measurement uncertainty; the validation study clearly demonstrated the suitability of the method for its intended application. All pesticides showed good linearity in the range 0.01–1.0 μg mL−1for OCs and OPs and 0.05–2.5 μg mL−1for SPs with correlation coefficients higher than 0.98. The method gave good recoveries for most of the pesticides (70–120%) with intra-day and inter-day precision < 20% in most of the cases. The limits of detection varied from 0.003 to 0.03 mg kg−1, and the LOQs were determined as 0.01-0.049 mg kg−1. The expanded uncertainties were <30%, which was distinctively less than a maximum default value of ±50%. The proposed method was successfully applied to determine pesticide residues in 12 commercial market samples obtained from different locations in India. [ABSTRACT FROM PUBLISHER]

We are racing to manage a phenomenally increasing volume of organic wastes from urban, industrial and agricultural entities. Composting is one of the preferred ways to convert biodegradable wastes into nutrient-rich soil conditioners. The age-old technique of composting process is being improved with innovative scientific means. Biochar, a widely studied soil amendment, is a carbonaceous material that can hold nutrients from endogenic/exogenic sources. Biochar-compost, a biochar-complemented compost, may provide a wide range of benefits expected from both materials. Compost and biochar can improve physicochemical and microbiological attributes of soils by supplying labile and stable carbons, and nutrients. Compost may also supply beneficial microbes. This means biochar-compost is a synergic soil amendment that can improve soil quality, increase crop production, and remediate contaminated soils. Having stable carbon, large reactive surface with nutrient loads, biochar can interact widely with organic biomass and modify physicochemical and-microbial states during a composting process while making biochar-compost. Production and application methods of biochar, compost and biochar-compost are covered for agricultural and contaminated soils. Metal and organic contaminations are also discussed. A case study on making and field-testing a mineral-enhanced biochar and a biochar-compost to improve rice yield, is presented at the end. [ABSTRACT FROM AUTHOR]

High cost of chemical fertilizers and poor nutrient content in conventional organic sources (manure, compost, charcoal etc.) can be addressed through development of enriched organic amendments. However, there is a need to evaluate enriched organic amendments as a potential alternative of chemical fertilizers. Therefore, an effort was made to prepare enriched organic amendments through blending distillation waste of aromatic plant biomass (DWB) with naturally available low-grade rock phosphate (RP) and waste mica (WM). Enrich compost (ENC) was produced from DWB in a natural composting process, blended with mineral powder, whereas biochar fortified mineral (BFM) was prepared by blending biochar, derived from DWB through hydrothermal reaction, with mineral powder. The main aims of the present study were to investigate the impacts of ENC and BFM applications on soil properties, and herbage yield and quality of a medicinal herb Senna ( Cassia angustifolia Vahl.). The performances of ENC and BFM at two different rates (2.5 and 5 t ha -1 ) were compared with the application of conventional farmyard manure (FYM, 5 t ha -1 ) and chemical fertilizers (CF, NPK 60-40-20 kg ha -1 ) in two different soils in a pot experiment. Both, ENC and EBC improved soil quality and fertility by increasing soil organic carbon, available nutrients, microbial biomass and enzyme activity. The ENC and BFM increased total herbage yields by 21 and 16.3 % compared to FYM. In both soils, the CF treatment produced the maximum dry herbage yields (32.7-37.4 g pot -1 ), which however were comparable to ENC (31.9-33.7 g pot -1 ) and BFM (30.7-35.1 g pot -1 ) treatments. Bioactive compound (sennoside) production in senna was significantly improved by ENC and BFM compared to CF. The present study indicates that ENC and BFM could not only help to overcome the limitation of conventional FYM, but also have the potentials to substitute costly chemical fertilizers, particularly in medicinal plant cultivation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)