Study on mitigation of ammonia volatilization loss in urea through adsorbents

Volatilized ammonia loss (VAL) and toxicity are major disadvantages on urea amendment. In order to mitigate, slow (or) controlled release urea based fertilizers are prepared with low cost materials. Therefore, micro and nano-sized adsorbents such as zeolite, biochar were impregnated with urea @1:1 ratio for fertilizer formulations. The objective of the study was to evaluate the VAL rate. To study the effect of soil texture, incubation experiment on two different soils of Tamil Nadu (TypicHaplustalf and VerticUstropepts) with 4 physically mixed, 4 fabricated, conventional urea and control without urea determined. Fertilizer formulations were surface applied @ 250 kg N ha-1 and assessed the VAL rate for 16 days. The trapped ammonia was observed with colour change from pink to greenish and titrated with diluted sulfuric acid. Initial 3 days VAL rate was high on urea, physically mixed adsorbent fertilizers than urea impregnated fertilizers and colour change was observed on every 4-6 h of both soils. In contrast, the urea impregnated fertilizers had colour change after 9-10 h regardless of adsorbent and soils. The fabricated fertilizer observed VAL rate on gradual with low quantity on T5- Zeourea (13.5 days, 15.1 days) T6- Nano-zeourea (15.5 days, 16 days), T9- Biourea (7.5 days, 7.1 days) and T10- Nano-biourea (9 days, 9.7 days) than T2- Urea (5.5 days, 4.6 days) of Alfisols and Inceptisols respectively. Cumulative VAL rate percentage was low on T5- Zeourea (30 %, 34 %), T6- Nano-zeourea (28 %, 29.3 %) T9- Biourea (39 %, 41.5 %) and T10- Nano-biourea (36 %, 37.5 %) of Alfisols and Inceptisols, respectively on comparison with other fertilizer type.It is concluded that the surface amendment of physically mixed fertilizers not influenced any change on both soils. Urea impregnation influenced on days and cumulative VAL percentage. Our study elucidates that micro and nano porous adsorbents are potential substrate to reduce VAL rate of urea in both soils

Mycorrhizal symbiosis and bioavailability of micronutrients in maize grain

Field experiments were conducted in calcareous and non-calcareous soils in order to study the biofortification of Fe and Zn in maize grain using arbuscular mycorrhizal fungal (AMF) symbiosis. Treatments consisted of two levels of FeSO4 (12.5 and 25 kg ha-1), two levels of ZnSO4 (12.5 and 25 kg ha-1) and two mycorrhizal treatments [with (M+) or without (M-)] inoculum carrying Glomus intraradices) replicated four times in a factorial RBD. The results revealed that AMF colonization significantly increased soil available Fe (M- 1.9; M+ 2.1 mg kg-1) and Zn (M- 4.16; M+ 4.50 mg kg-1). Siderophore production in M+ plants (51.4 μmol cm-3 hr) were higher than M- plants (39.5 μmol cm-3 hr) and the increase observed irrespective of levels of Fe and Zn. Increased availability of Fe and Zn in soil in combination with enhanced concentrations in plants assisted M+ plants to maintain higher micronutrient contents in grains (Fe M- 31.2, M+ 35.3; Zn M- 45.1, M+ 52.4 mg kg-1). Mycorrhizal plants produced grains with had 10- 15% higher Fe and Zn contents while anti-nutritional factor “phytic acid” had decreased (M- 1.13; M+ 1.07 mg g-1). Overall, the data suggest that mycorrhizal fungal inoculation assists in biofortification kernels with Fe and Zn besides circumventing the impact of anti-nutritional factors

Role of arbuscular mycorrhizal (Glomus intraradices) fungus inoculation on Zn nutrition in grains of field grown maize

Abstract Bioavailability of zinc (Zn) concentrations in maize grains is low causing malnutrition in humans. This study is aimed to use mycorrhizal fungal inoculation as one of the biological strategies to improve Zn concentrations in field grown maize. Treatments consisted of three levels of Zn (0, 2.5 and 5 kg Zn ha -1 ), two levels P (30 and 60 P kg ha -1 ) and two mycorrhizal fungal inoculation with (AMF+) and without arbuscular mycorrhizal (AMF-) fungus (Glomus intraradices Schenck & Smith) replicated three times in a FRBD. AMF+ plants had significantly (P ≤ 0.01) higher root length (AMF-16.8; AMF+ 23.5 cm) and volume, leaf area and chlorophyll concentrations regardless of P or Zn fertilization but the response to AMF inoculation was higher at lower levels of Zn fertilization. Maize grains of AMF+ plants had higher Zn and tryptophan concentrations by 15 and 8.6%, respectively, in comparison to AMF-plants. The plant available Zn concentration in soil had a highly significant correlation with Zn content in roots (r = 0.93), shoots (r = 0.91) and grains (r = 0.91). AMF symbiosis enhances Zn supply to the host plant by improving the available Zn and P enabling the plant to maintain higher nutritional status and produce grains fortified with Zn and tryptophan concentrations in field grown maize

Effect of nanoemulsion of hexanal on honey bees (Hymenoptera; Apidae)

This work was carried out with the aid of a grant from Canada’s International Development Research Centre (IDRC), and with financial support from the Government of Canada, provided through Global Affairs Canada (GAC)The study was carried out to assess the toxicity of nanoemulsion of hexanal formulation on common honey bee species visiting mango orchards. Nano emulsion of hexanal at varying concentrations was tested using a dry film method. All the tested nanoemulsion of hexanal formulation and standard check pure hexanal, were less toxic to honey bees. Findings indicate these plant product derivatives are safe for worker honey bee populations. Hexanal is a plant-derived compound used to inhibit the phospholipase D enzyme in the skin of fruit and it is associated with the extension of shelf life of fruit

The Foliar Application of Rice Phyllosphere Bacteria induces Drought-Stress Tolerance in <i>Oryza sativa</i> (L.)

This study assessed the potential of Bacillus endophyticus PB3, Bacillus altitudinis PB46, and Bacillus megaterium PB50 to induce drought tolerance in a susceptible rice cultivar. The leaves of the potted rice plants subjected to physical drought stress for 10 days during the flowering stage were inoculated with single-strain suspensions. Control pots of irrigated and drought-stressed plants were included in the experiment for comparison. In all treatments, the plant stress-related physiochemical and biochemical changes were examined and the expression of six stress-responsive genes in rice leaves was evaluated. The colonization potential on the surface of the rice leaves and stomata of the most successful strain in terms of induced tolerance was confirmed in the gnotobiotic experiment. The plants sprayed with B. megaterium PB50 showed an elevated stress tolerance based on their higher relative water content and increased contents of total sugars, proteins, proline, phenolics, potassium, calcium, abscisic acid, and indole acetic acid, as well as a high expression of stress-related genes (LEA, RAB16B, HSP70, SNAC1, and bZIP23). Moreover, this strain improved yield parameters compared to other treatments and also confirmed its leaf surface colonization. Overall, this study indicates that the foliar application of B. megaterium PB50 can induce tolerance to drought stress in rice