Exploring the influence of invasive weed biochar on the sorption and dissipation dynamics of imazethapyr in sandy loam soil.

The management of invasive weeds on both arable and non-arable land is a vast challenge. Converting these invasive weeds into biochar and using them to control the fate of herbicides in soil could be an effective strategy within the concept of turning waste into a wealth product. In this study, the fate of imazethapyr (IMZ), a commonly used herbicide in various crops, was investigated by introducing such weeds as biochar, i.e., Parthenium hysterophorus (PB) and Lantana camara (LB) in sandy loam soil. In terms of kinetics, the pseudo-second order (PSO) model provided the best fit for both biochar-mixed soils. More IMZ was sorbed onto LB-mixed soil compared to PB-mixed soil. When compared to the control (no biochar), both PB and LB biochars (at concentrations of 0.2% and 0.5%) increased IMZ adsorption, although the extent of this effect varied depending on the dosage and type of biochar. The Freundlich adsorption isotherm provided a satisfactory explanation for IMZ adsorption in soil/soil mixed with biochar, with the adsorption process exhibiting high nonlinearity. The values of Gibb's free energy change (ΔG) were negative for both adsorption and desorption in soil/soil mixed with biochar, indicating that sorption was exothermic and spontaneous. Both types of biochar significantly affect IMZ dissipation, with higher degradation observed in LB-amended soil compared to PB-amended soil. Hence, the findings suggest that the preparation of biochar from invasive weeds and its utilization for managing the fate of herbicides can effectively reduce the residual toxicity of IMZ in treated agroecosystems in tropical and subtropical regions.

Effect of soil amendments on the sorption behavior of atrazine in sandy loam soil.

The sorption behavior of pesticides applied during cultivation of crops is affected by amendments such as farm yard manure (FYM) and vermicompost (VC) during land preparation. Among pesticides, atrazine, a widely used herbicide in many crops, was analyzed for its kinetics and sorption behavior through the addition of FYM and VC in sandy loam soil. The pseudo-second-order (PSO) model best fit the kinetics results in the recommended dose of FYM and VC mixed soil. More atrazine was sorbed onto VC mixed soil than FYM mixed soil. In comparison to control (no amendment), both FYM and VC (1, 1.5, and 2%) increased atrazine adsorption, but the effect varied with dosage and type of amendment. The Freundlich adsorption isotherm adequately explained atrazine adsorption in soil/soil + (FYM/VC) mixtures, and the adsorption was highly nonlinear. The values of Gibb's free energy change (ΔG) were negative for both adsorption and desorption in soil/soil + (FYM/VC) mixtures, suggesting sorption was exothermic and spontaneous in nature. The results revealed that the application of amendments used by farmers interferes the availability, mobility, and infiltration of atrazine in the soil. Therefore, the findings of this study suggest that amendments such as FYM and VC can be effectively used to minimize the residual toxicity of atrazine-treated ago-ecosystems in tropical and sub-tropical regions.

Exploring invasive weed biochar as soil amendment: A study on fodder oats productivity and soil biological properties.

Biochar is known for the improvement of soil health, fertility, crop productivity, and quality in many agro-ecosystems globally, but information regarding fodder yield, quality, and soil microbial activity responses to biochar application remains very limited. The objective of this study was to prepare biochar from invasive weeds, i.e., Parthenium hysterophorus L. and Lantana camara L., and use it as a soil amendment along with inorganic fertilizers for oats (Avena sativa L.) growth, fodder yield, quality, and soil microbial activities in a two-year pot experiment. Treatments were comprised of control, 100% RDF (Recommended dose of fertilizers), 75% RDF along with three doses (2.5, 5.0, and 10 t/ha) of Parthenium hysterophorus L. biochar (PB) and Lantana camara L. biochar (LB), PB (10 t/ha), and LB (10 t/ha). Results showed that application of 75% RDF along with 10 t/ha LB gave significantly higher green (∼8%) and dry (∼7.8%) fodder yield and crude protein (∼6%) and decreased acid detergent fibre (ADF) and neutral detergent fibre (NDF) by 5.70 and 6.04% as compared to the 100% RDF treatment. The same treatment had a significantly higher population of bacteria (7.33 × 108 colony forming unit (CFU)/g soil), alkaline phosphatase activity (19.56 µg pNP/g soil/h), microbial biomass carbon (156.67 µg/g soil) and dehydrogenase activity (12.59 µg TPF/g/24 h), whereas the maximum fungal population (13.33 × 104 CFU/g soil) and acid phosphatase activity (14.45 µg pNP/g soil/h) were found in 75% RDF along with 10 t/ha PB and control treatment, respectively. This study concluded that application of invasive weed biochar along with inorganic fertilizers can benefit fodder yield and quality of oats by increasing plant height and number of tillers directly and by improving nutrient availability and water holding capacity (WHC) of soil indirectly, besides improving soil health. The findings from this study will provide a potential strategy for invasive weed management.

Green fodder cultivation improves technical efficiency of dairy farmers in semi-arid tropics of central India: a micro-analysis.

This study assessed the impact of improved green fodder production activities on technical efficiency (TE) of dairy farmers in climate vulnerable landscapes of central India. We estimated stochastic production frontiers, considering potential self-selection bias stemming from both observable and unobservable factors in adoption of fodder interventions at farm level. The empirical results show that TE for treated group ranges from 0.55 to 0.59 and that for control ranges from 0.41 to 0.48, depending on how biases are controlled. Additionally, the efficiency levels of both adopters and non-adopters would be underestimated if the selectivity bias is not appropriately accounted. As the average TE is consistently higher for adopter farmers than the control group, promoting improved fodder cultivation would increase input use efficiency, especially in resource-deprived small holder dairy farmers in the semi-arid tropics.

Range grasses to improve soil properties, carbon sustainability, and fodder security in degraded lands of semi-arid regions.

Tropical grasses are the primary source of forage for livestock and a valuable resource for improving soil health and environmental sustainability in semi-arid regions. A study was carried out in a semi-arid region of central India to determine the short-term (6-year) impact of nine range grasses on soil physio-chemical and biological properties, carbon stock, and forage security. The experiment was carried out in a randomized block design with three replications. Results show that the majority of the grass roots were distributed in the upper soil layer (0-10 cm, 63.5-76.5 %), and then in the middle (10-20 cm, 21.3-25 %) and lower (20-30 cm, 2.2-11.5 %) layers. Perennial tussock grass (Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult) had a higher root volume (2219 mm3), followed by Guinea grass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs] (1860 mm3). A lower soil bulk density (BD, 1.11-1.23 g cm-3), higher gravimetric water content (GMW, 14.0-17.8 %), and soil organic carbon (0.38-0.73 %) were recorded for grass-cultivated plots compared to the barren land (1.38 g cm-3, 13.0 %, and 0.28 %, respectively). The perennial tussock grass and Guinea grass resulted in the highest soil microbial biomass carbon (SMBC, 70.1 mg kg-1 soil) and enzyme activities (dehydrogenase, 17.09 µg TPF g-1 day-1 and fluorescein diacetate activity 4.94 µg fluorescein g-1 h-1). The considerable improvement in soil properties with minimal inputs resulted in a higher sustainable yield index and carbon sustainability index in plots planted with Guinea grass (0.9 and 89.29) and perennial tussock grass (0.89 and 71.61). Therefore, the cultivation of either Guinea grass or perennial tussock grass as an intercrop or sole crop in the semi-arid environment can be an ecologically sound strategy to improve soil health, C sequestration, and fodder supply.

Validation of salivary glucose as a screening tool of diabetes mellitus.

Background: Improved prognosis and delay of clinical complications in diabetes mellitus can be ensured by early screening and regular monitoring after diagnosis. This requires venipuncture at regular intervals of time causing anxiety and discomfort to the patient. Hence, development of a painless, non-invasive procedure is desirable for which saliva is a potential tool. Also, this would provide easy and cost-effective means for large scale screening and epidemiological intervention. Aim: To measure fasting plasma glucose (FPG) and compare and correlate with salivary glucose levels in normal and diabetic individuals. Also, the correlation between glycated hemoglobin (HbA1c) and salivary glucose is studied in the diabetics and controls. Methods: Blood and salivary glucose was estimated by GOD-POD method and glycated hemoglobin by HPLC. Statistical analysis was done on SPSS 16. Mean, Standard deviation, independent t test, ANOVA (f test), Pearson's correlation coefficient along with regression analysis was carried out and comparison was done between the control and diabetic groups and the different subgroups within the diabetic group. Results: A significant difference between the salivary glucose levels in subjects indicating that a deranged glycemic status is reflected in saliva. Also, salivary glucose increases in proportion to an increase in the FPG and HbA1C of the diabetics. The regression coefficient was calculated and a formula was derived for prediction of FPG and HbA1c using salivary glucose. Conclusion: Saliva can be used as a screening tool for diabetes. Standardization of the technique and setting up a reference range will also make it useful in diagnosing diabetes mellitus.