Effects of Amino Acid Selenium Foliar Fertilizer on Selenium Content and Quality of Mango

[Objectives]This study was conducted to explore the treatment methods of amino acid selenium fertilizer suitable for increasing the selenium content of mangoes and improving the quality of mangoes,so as to provide a theoretical basis for the production of selenium-enriched mangoes.[Methods]With Tainong mango as a test material,the amino acid selenium foliar fertilizer was applied by eight treatment methods to investigate the changes of selenium,soluble solid,vitamin C,and titratable acid contents in mango flesh and peel.[Results]Spraying amino acid selenium foliar fertilizer increased the selenium content of mango flesh.The selenium contents of the treatment groups T2,T3,T4 and T5 reached the selenium-enriched standard,and the T2 treatment group had the highest selenium content(0.020 mg/kg).The selenium contents in the peel of all treatment groups were greater than the corresponding selenium content in the flesh.Except for T1,the vitamin C contents of other treatment groups sprayed with amino acid selenium fertilizer increased compared with the control,and that of the T2 treatment group increased significantly(P<0.05).Compared with the control,the soluble solids of the treatment groups sprayed with amino acid selenium fertilizer once also increased.The treatment method of spraying amino acid selenium fertilizer with a dosage of 12000 ml/hm2 once(T2)achieved the best effect of increasing the selenium content and improving the quality of mangoes.[Conclusions]This study provides a scientific basis for increasing the selenium content of mangoes and improving the current situation of insufficient selenium intake.

Synthesis of an eco-friendly nanocomposite fertilizer for common bean based on carbon nanoparticles from agricultural waste biochar

The burning of agricultural waste is a major cause of environmental pollution.In this study,we sought to prepare biochar from agricultural waste as a source material for the preparation of carbon nanoparticles(CNPs).Surface morphology,hydrodynamic particle size,and purity and crystallinity of CNPs were extensively investigated using transmission electron microscopy(TEM),zeta sizing,and X-ray diffraction(XRD)spectroscopy,respectively.The CNPs were subsequently immersed in a solution of potassium nitrate(KNO_(3))to prepare a CNPs/NK nanocomposite(CNPs loaded with nitrogen(N)and potassium(K))as a nanocomposite fertilizer for common bean(Phaseolus vulgaris L.).The CNPs/NK nanocomposite was sprayed as a foliar fertilizer at 0,10,20,30,and 40 mg L^(-1) on common bean plants 25 d after sowing on a farm in Shebin El-Kom,El-Monifia,Egypt.The growth,yield,and quality of common bean were investigated during two successive growing seasons(2017 and 2018).The highest seed yields of 2.04 and 2.01 t ha^(-1) and the highest values of growth parameters including plant height of 61.5 and 59.2 cm,number of leaves per plant of 35 and 35,number of flowers per plant of 83.3 and 82.7,and plant fresh weight of 148.7 and 152.8 g plant^(-1) were obtained when using the CNPs/NK nanocomposite at a concentration of 20 mg L^(-1) during the 2017 and 2018 growing seasons,respectively.