Nutrient uptake and pharmaceutical compounds of Aloe vera as influenced by integration of inorganic fertilizer and poultry manure in soil.

Aloe vera had been used for numerous medical and cosmetic applications since ancient times. The study aimed to investigate the integrated effects of inorganic fertilizer (IF) and poultry manure (PM) on the nutritional and pharmaceutical constituents of A. vera. Eighteen month old A. vera seedlings were used following completely randomized design with three replications. Six combinations of IF [Nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) at the rate of 150, 80, 120 and 30 kg ha-1, respectively] and PM (at the rate of 5 t ha-1) were considered viz., IF00PM00 (IF = 0%, PM = 0%), IF100PM00(IF = 100%, PM = 0%), IF75PM25 (IF = 75%, PM = 25%), IF50PM50 (IF = 50%, PM = 50%), IF25PM75 (IF = 25%, PM = 75%) and IF00PM100 (IF = 0%, PM = 100%) as treatments. Different treatment combinations of IF and PM exerted significant influence on the nutritional and pharmaceutical contents of A. vera. Concentrations and uptake of the concerned nutrients were gradually increased with the increased levels of PM except NPKS which were highest in sole application of IF. The aloin concentration of leaf was gradually increased with the increased level of PM and by 42.44% over control. The highest chlorophyll, total phenolic and flavonoid concentrations were found in the plants receiving the treatment IF25PM75 except protein content which was obtained from IF100PM00. Significant and positive relationships between N and S with P concentrations and P and S with K concentrations of A. vera leaf were noticed. Aloin, total phenolic and flavonoid concentrations were significantly and positively correlated with Mg, Fe and Mn concentrations of A. vera leaf. Farmers may be advised to cultivate A. vera applying 75% PM at the rate of 5 t ha-1 along with 25% IF (N, P, K and S at the rate of 150, 80, 120 and 30 kg ha-1, respectively) for obtaining better quality leaf in terms of nutrients and pharmaceutical compounds under the agro-climatic conditions of the study area.

Nitrogen use efficiency and critical leaf N concentration of Aloe vera in urea and diammonium phosphate amended soil.

Aloe vera L. is widely cultivated in many countries due to its importance as an all-purpose herbal or medicinal plant. The growth and yield of this plant can be enhanced by application of fertilizer. It is expected that a higher and balanced nutrient supply will result in higher crop production maintaining soil health, which is possible when the applied fertilizers are done in way that is efficient. So, there is a need to understand the amount of applied and type of fertilizer that will give the best output for farmers and to formulate economical market products. This study was conducted to investigate the effect of N fertilizer on leaf yield, its uptake and requirement, critical concentration, use efficiency and economics of Aloe vera L. Plants were grown at six levels of N: 0, 40, 80, 100, 150 and 200 kg ha-1 from urea and diammonium phosphate (DAP) following completely randomized design with three replicates under field condition. The highest values of yield and yield attributes and profit based on benefit cost ratio (3.81 for urea and 2.91 for DAP) were obtained with 150 kg N ha-1 (urea) and 100 kg N ha-1 (DAP). Leaf biomass yield increased by 18-128 % in urea-N and 30-139 % in DAP-N fertilized plant over control while DAP > urea by 7.59 %. Sucker production (mean number) was urea-N (4.95 Plant-1) > DAP-N (2.28 Plant-1). Both gel and leaf N concentration and uptake was highest at 200 kg ha-1 for both sources. For 80 % leaf biomass yield, minimum requirement of N was ca 74.90 (urea) and 89.60 kg ha-1 (DAP). Growth and yield parameters to N application exhibited significant and positive correlations. Critical leaf N concentration was ca 0.88% (DAP) and 0.90% (urea) while mean and maximum NUE was 34% and 64 % (urea) and 43% and 69% (DAP), respectively. Farmers can be advised to apply N at the rate of 150 kg ha-1 from urea for producing economically higher yield and better-quality A. vera leaves.

Sulphur fertilization enhanced yield, its uptake, use efficiency and economic returns of Aloe vera L.

Sulphur plays a vital role in the formation and biosynthesis of protein, chlorophyll, and few amino acids. To investigate the effect of sulphur fertilizer on leaf biomass yield, critical sulphur concentration, sulphur requirement and uptake by Aloe vera L., a pot experiment was carried out following completely randomized design with six levels of sulphur viz., 0, 15, 30, 45, 60 and 80 kg ha-1 with three replications. The results of the study revealed that the growth attributes, leaf and gel yield, and sulphur uptake significantly improved with sulphur application and the best results were obtained from the application of 45 kg sulphur ha-1. On average, addition of sulphur enhanced the leaf biomass yield by 47.5% and sulphur use efficiency by 38% compared to control. The effect of sulphur on the growth parameters and their significant and positive correlations with yield signifies the importance of sulphur on the yield and quality of A. vera. The calculated minimum amount of sulphur for 80% leaf biomass production was 21.1 kg sulphur ha-1 with a critical leaf sulphur concentration of 0.23% in A. vera. Moreover, sulphur addition to soil substantially enhanced the economic returns of A. vera. Therefore, addition of 45 kg sulphur ha-1 could be a better option for obtaining higher yield and economic return of A. vera.

Public perception and health implication of loom-dye effluent irrigation on growth of rice (Oryza sativa L.) and red amaranth (Amaranthus tricolor L.) seedlings.

Loom-dye effluent discharge has constituted a major environmental threat to the people of Belkuchi Upazila of Sirajganj District. The present study was conducted to characterize loom-dye effluents and investigate their health implications by the growth analysis of rice and red amaranth seedlings along with a survey study among the individuals associated with loom-dyeing, weaving, and crop farming activities. A total of twenty-eight loom-dye effluent samples were collected for physicochemical characterization; among them, only three loom-dye effluents, i.e. pink, violet, and black dyes, at concentrations of 0, 10, 25, 50, 75, and 100% were applied as irrigation water to rice and red amaranth. The plant growth experiment was laid out following a completely randomized design with three replicas. Chemical analyses of loom-dye effluents showed the presence of a significant amount of plant nutrients and heavy metals. The mean concentrations of Pb, Cd, Cr, Fe, Mn, Zn, and Cu were 0.938, 0.046, 0.212, 7.109, 0.609, 0.351, and 0.191 mg L-1, respectively. Among the metals, the concentrations of Pb, Cr, Fe, and Mn were above the recommended limit proposed by the irrigation water guideline value. Application of ≤ 25% pink and violet dye effluent and ≤ 10% black dye effluent had significant (p < 0.05) and positive impacts on growth and yield parameters. Heavy metal content in seedlings increased with increasing effluent application rate and crossed the utmost permissible limit at higher concentration. Survey data discovered a moderate knowledge level among the respondents, which might account for the indiscriminate discharge of loom-dye effluent into the surrounding environment. Attitudes, practices, and protective behaviours of the respondents also reflect the caused for long-term pollution through loom-dye effluents. To reduce its negative effects on the health and crop environment, the loom-dye effluents should not be discharged indiscriminately and used for crop irrigation without proper treatment. Furthermore, training programs ought to be introduced to educate the individuals involved in the discharge and subsequent use of loom-dye effluents.

Heavy metals in handloom-dyeing effluents and their biosorption by agricultural byproducts.

The Madhabdi municipality in the Narsingdi district of Bangladesh is a well-known area for textile, handloom weaving, and dyeing industries. These textile industries produce a considerable amount of effluents, sewage sludge, and solid waste materials every day that they directly discharge into surrounding water bodies and agricultural fields. This disposal poses a serious threat to the overall epidemic and socio-economic pattern of the locality. This research entailed the collection of 34 handloom-dyeing effluent samples from different handloom-dyeing industries of Madhabdi, which were then analyzed to determine the contents of the heavy metals iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mn), lead (Pb), and cadmium (Cd). Average concentrations of Fe, Cr, Cu, Pb, Mn, and Zn were 3.81, 1.35, 1.70, 0.17, 0.75, and 0.73 mg L-1, respectively, whereas Cd content was below the detectable limit of the atomic adsorption spectrophotometer. The concentrations of Fe, Cr, Cu, Pb, and Mn exceed the industrial effluent discharge standards (IEDS) for inland surface water and irrigation water guideline values. A biosorption experiment of the heavy metals (Fe, Cr, Cu, Mn, and Zn) was conducted without controlling for any experimental parameters (e.g., pH, temperature, or other compounds present in the effluent samples) by using four agricultural wastes or byproducts, namely rice husk, sawdust, lemon peel, and eggshell. Twenty grams of each biosorbent was added to 1 L of effluent samples and stored for 7 days. The biosorption capacity of each biosorbent is ranked as follows: eggshell, sawdust, rice husk, and lemon peel. Furthermore, the biosorption affinity of each metal ion was found in the following order: Cu and Cr (both had similar biosorption affinity), Zn, Fe, Mn. The effluents should not be discharged before treatment, and efficient treatment of effluents is possible with eggshell powder or sawdust at a rate of 20 g of biosorbent per liter of effluents.