Influence of various commercially available organic manures on growth, yield and nutrient accumulation in mint plants (Mentha sp.)

A pot experiment was set up using completely randomized design (CRD) to compare the influences of different commonly available organic manures in the markets of Dhaka, Bangladesh on the growth parameters and nutrient contents in Mint plants (Mentha sp.). Eight different manures were used as treatments for the comparison, viz. ACI, Alo, Annopurna Vermicompost, Cow dung, Kazi, Mazim, Modern Vermicompost and Trichocompost GBD, along with a control, taking three replications of each treatment. After 2.5 months (75 days) the plants were harvested. Trichocompost GBD showed the highest average number of leaves (130.33 plant-1), plant height (27.67 cm plant-1), number of branches (11.00 plant-1) and number of stolons at harvest (1.67 plant-1). The maximum average single leaf area (2.01 cm2 plant-1) and fresh weight (1.68 g plant-1) were observed in Kazi. ACI was observed to have the highest dry weight (0.26 g plant-1), whereas cow dung had the longest root (8.57 cm plant-1). Nutrient accumulation in leaf and stem exhibited the highest N in ACI, highest P and K in Alo, and highest S in Kazi. Correlation analysis of the explored traits with nutrient concentration of plant shoots was performed to elucidate the impact of plant nutrient contents on the analysed parameters. J. Biodivers. Conserv. Bioresour. Manag. 2021, 7(1): 73-84

Ionic homeostasis, biochemical components and yield of Italian zucchini under nitrogen forms and salt stress

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.

Peanut/Cotton Intercropping Increases Productivity and Economic Returns by Regulating Nutrient Accumulation and Soil Microbial Communities Under both Normal and Saline Soil Conditions

Background Intercropping has been widely adopted by farmers for it often enhances crop productivity and economic returns; however, the underpinning mechanisms from the perspective of belowground interspecific interactions are only partly understood especially when intercropping under saline soil conditions. By using permeable (100 µm) and impermeable (solid) root barriers in a multi-site field experiment, we aimed to study the impact of root-root interactions on nutrient accumulation, soil microbial communities, crop yield, and economic returns in a peanut/cotton intercropping system under non-saline, secondary-saline, and coastal saline soil conditions. Results The results indicate that intercropping (IC) decreased the peanut pods yield while increased the seed cotton yield, and consequently enhanced the economic returns compared with monoculture of peanut (MP) and cotton (MC). The higher accumulations of nutrients such as nitrogen (N), phosphorus (P), and potassium (K) were also observed in IC not only in the soil but also in vegetative tissues and reproductive organs. Bacterial community structure analysis under normal growth conditions reveals that IC dramatically altered the soil bacterial abundance composition in both peanut and cotton strips of the top soil whereas the bacterial diversity was barely affected compared with MP and MC. At blossom-needling stage, the metabolic functional features of the bacterial communities such as fatty acid biosynthesis, lipoic acid metabolism, peptidoglycan biosynthesis, and biosynthesis of ansamycins were significantly enriched in MP compared with other treatments. Conversely, these metabolic functional features were dramatically depleted in MP while significantly enriched in IC at podding stage. Permeable root barrier treatments (NC-P and NC-C) counteracted the benefits of IC and the side effects were more pronounced in impermeable treatments (SC-P and SC-C). Conclusion Peanut/cotton intercropping increases crop yield as well as economic returns under non-saline, secondary-saline, and coastal saline soil conditions probably by modulating the soil bacterial abundance composition and accelerating nutrients accumulation.