Search

Golden pomelo is delicious and nutritious and has gained great popularity. Golden pomelo will generate bitter taste with the extension of storage time, which seriously affect the development of the related industry. To explore the reason behind, the present work used Meizhou's golden pomelos the research object to investigate the source of bitterness. After grading, the content of titratable acid, soluble solids content, maximum adhesion force, limonin content, nomilin content, naringin content were simultaneously determined by methods such as the random forest method. The results showed that the soluble solids content was extremely significant and positive correlated (R=0.78) with sensory scores. Nomilin (R=-0.69) content and naringin (R=-0.59) content were significantly and negatively correlated with sensory scores. The bitterness source of the golden pomelo after a long-term storage was closely related to its soluble solids content. This study can provide a certain theoretical basis for the research on debittering of golden pomelo and rapid assessment of the fruit quality. [ABSTRACT FROM AUTHOR]

Maize straws were collected from different treatments of two long-term fertilization studies, their carbon (C) / nitrogen (N) ratios were determined, and their C and N mineralization rates in soil were compared in an aerobic incubation test. The results showed that comparing with no fertilization, applying chemical fertilizers (NPK) or chemical fertilizers plus manure (MNPK) increased the N content and decreased the C/N ratio of maize straw. The amounts of mineralized and immobilized C and N of the straws from different fertilization treatments differed with incubation time. The straws from treatments NPK, MNPK, and N240 had significantly higher C mineralization rates than that from the treatment without fertilization. After incubation for 60 days, the straw from treatment NPK had the highest C mineralization rate (1324% of added organic C), and the immobilized N from the straws of fertilized plots, especially of MNPK plot, was lesser, compared to unfertilized plots. Adding maize straw into soil increased the metabolic quotient (qCO2) of soil microorganisms, but the difference among the treatments was not significant. During incubation, the amounts of soil microbial biomass C and N from different treatments differed with time. Therefore, in agricultural practices, the differences in the nutrient contents of straw due to different fertilization should be considered when the straw was to be added into soil. [ABSTRACT FROM AUTHOR]

Maize straws were collected from different treatments of two long-term fertilization studies, their carbon (C)/nitrogen (N) ratios were determined, and their C and N mineralization rates in soil were compared in an aerobic incubation test. The results showed that comparing with no fertilization, applying chemical fertilizers (NPK) or chemical fertilizers plus manure (MNPK) increased the N content and decreased the C/N ratio of maize straw. The amounts of mineralized and immobilized C and N of the straws from different fertilization treatments differed with incubation time. The straws from treatments NPK, MNPK, and N240 had significantly higher C mineralization rates than that from the treatment without fertilization. After incubation for 60 days, the straw from treatment NPK had the highest C mineralization rate (13.24% of added organic C), and the immobilized N from the straws of fertilized plots, especially of MNPK plot, was lesser, compared to unfertilized plots. Adding maize straw into soil increased the metabolic quotient (qCO2) of soil microorganisms, but the difference among the treatments was not significant. During incubation, the amounts of soil microbial biomass C and N from different treatments differed with time. Therefore, in agricultural practices, the differences in the nutrient contents of straw due to different fertilization should be considered when the straw was to be added into soil.