Zinc- and magnesium-doped hydroxyapatite-urea nanohybrids enhance wheat growth and nitrogen uptake.

The ongoing and unrestrained application of nitrogen fertilizer to agricultural lands has been directly linked to climate change and reductions in biodiversity. The agricultural sector needs a technological upgrade to adopt sustainable methods for maintaining high yield. We report synthesis of zinc and magnesium doped and undoped hydroxyapatite nanoparticles, and their urea nanohybrids, to sustainably deliver nitrogen to wheat. The urea nanohybrids loaded with up to 42% nitrogen were used as a new source of nitrogen and compared with a conventional urea-based fertilizer for efficient and sufficient nitrogen delivery to pot-grown wheat. Doping with zinc and magnesium manipulated the hydroxyapatite crystallinity for smaller size and higher nitrogen loading capacity. Interestingly, 50% and 25% doses of urea nanohybrids significantly boosted the wheat growth and yield compared with 100% doses of urea fertilizer. In addition, the nutritional elements uptake and grain protein and phospholipid levels were significantly enhanced in wheat treated with nanohybrids. These results demonstrate the potential of the multi-nutrient complexes, the zinc and magnesium doped and undoped hydroxyapatite-urea nanoparticles, as nitrogen delivery agents that reduce nitrogen inputs by at least 50% while maintaining wheat plant growth and nitrogen uptake to the same level as full-dose urea treatments.

Catalytic Degradation of Dichlorvos Using Biosynthesized Zero Valent Iron Nanoparticles.

The removal of dichlorvos contamination from water is a challenging task because of the presence of direct carbon to phosphorous covalent bond, which makes them resistant to chemical and thermal degradation. Although there have been reports in the literature for degradation of dichlorvos using nanomaterials, those are based on photocatalysis. In this paper, we report a simple and rapid method for catalytic degradation of dichlorvos using protein-capped zero valent iron nanoparticles (FeNPs). We have developed an unprecedented reliable, clean, nontoxic, eco-friendly, and cost-effective biological method for the synthesis of uniformly distributed FeNPs. Yeast extract was used as reducing and capping agent in the synthesis of FeNPs, and synthesized particles were characterized by the UV-visible spectroscopy, X -ray diffraction, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). TEM micrographs reveal that the nanoparticles size is distributed in the range of 2-10 nm. Selected area electron diffraction pattern shows the polycrystalline rings of FeNPs. The mean size was found to be 5.006 nm from ImageJ. FTIR spectra depicted the presence of biomolecules, which participated in the synthesis and stabilization of nanoparticles. As synthesized, FeNPs were used for the catalytic degradation of dichlorvos in aqueous medium. The degradation activity of the FeNPs has been investigated by the means of incubation time effect, oxidant effect, and nanoparticle concentration effect. The ammonium molybdate test was used to confirm the release of phosphate ions during the interaction of dichlorvos with FeNPs.

Thermal requirement of indian mustard (Brassica juncea) at different phonological stages under late sown condition.

Indian mustard [Brassica juncea (L.) Czern & Coss.] is a long day plant, which requires fairly cool climatic condition during growth and development for obtaining better seed yield. Various workers have correlated crop growth and development with energy requirement parameters, such as growing degree days (GDD), photo-thermal unit (PTU), helios thermal unit (HTU), photo-thermal index (PTI) and heat use efficiency (HUE). Therefore, GDD requirement for different phenological stages of 22 newly developed Indian mustard varieties was studies during winter (rabi) seasons of 2009-10 and 2010-11 at student instructional farm of C.S. Azad University of Agriculture and Technology, Kanpur, (Utter Pradesh). Study revealed that RH-8814, NRCDR-02 and BPR-549-9 recorded higher GDD (1703.0, 1662.9 and 1648.0), PTU (19129.8, 18694.2 and 18379.8), HTU (11397.7, 11072.2 and 10876.0), PTI (13.25, 13.14 and 13.08) and HUE (4.11, 3.84 and 3.71) at physiological maturity, while higher HUE was recorded (9.62, 8.99 and 8.91 kg ha-1 degrees-day) at days after sowing (DAS) to 50 % flowering. On the basis of study mustard genotypes RH-8814, NRCDR-02 and BPR-549-9 were identified as most heat-tolerant, as they maintained higher values for energy related parameters. Seed yield was highly positively correlated with GDD (r = 0.61, 0.65 and 0.75), PTU (r = 0.66, 0.64 and 0.74), HTU(r = 0.79, 0.68 and 0.73) at the above these three phenological stages, while negatively correlated with PTI at anthesis and at maturity. Hence, these parents could be used in crossing programme for achieving further improvement.