Search

Biochar modifications and fortifications are used to increase soil nutrient retention and increase crop yields, but the effects on phosphate (Pi) availability for plants are unknown for saline-alkaline soils. We used peanut shells (Peanut-S) as the starting material for biochar (Biochar) and MgO-modified biochar (MgO-Biochar) to study the Pi adsorption mechanisms under field conditions. Compared with Biochar and Peanut-S, MgO-Biochar adsorbed Pi in aqueous solution 20% better and reached equilibrium at twice the rate at twice the rate. MgO-Biochar also showed better Pi adsorption in saline soils and the maximum Pi adsorption capacity was 1.46 times higher than Biochar. We found that electrostatic attraction, precipitation and exchangeable anions contributed to the adsorption of phosphate and MgO-Biochar possessed the greatest adsorption capacity. MgO-Biochar application increased the soil available P content and resulted in higher rice yields in field experiments in the saline soil conditions found in the Yellow river delta region. Overall, our study offers a theoretical and practical foundation for the remediation of saline soil using MgO-modified biochar.

The quality of Melaleuca alternifolia essential oil is affected by various drying methods. The aim of this study was to investigate the effect of drying methods on the composition of the essential oil. Melaleuca alternifolia essential oil samples subjected to different drying methods were extracted using the methyl tert-butyl ether (MTBE) method and analyzed by gas chromatography-mass spectrometry (GC-MS). In total, 26 volatile compounds, comprising 8 moneterpenes, 6 sesquiterpenes, 4 moneterpenes derivatives, 5 sesquiterpene derivatives, and 3 other derivatives, were identified. We found that the drying methods affected not only the composition of volatile compounds but also the content of different volatiles. The sun-dried essential oil showed the highest amount of volatile compounds, 1895.85 ng/g. Moneterpene derivatives were a major component in M. alternifolia essential oil, especially terpinen-4-ol and 1, 8-cineole.

The glucose, fructose, sucrose, and organic acids in the pulp of “Jinhuang” mango were analyzed using the HPLC method and the effect of bagging on fruit quality was researched during the postharvest storage. The results showed that there was a certain difference in the content of sugar and acid among the three treatments. The effect of bagging treatments on fructose, glucose, and sucrose in the fruit of “Jinhuang” mango was mainly reflected in sucrose. The treatments of white bagging (WB) and black bagging (BB) delayed the production of sucrose and the decomposition of citric acid, and increased the content of ascorbic acid and quinine. Based on sugar-acid ratio, the flavor of the three treatments was evaluated as: CK> WB> BB. The fruit quality of “Jinhuang” mango was affected by bagging treatments to a certain extent.

In order to study the effect of bagging on the aroma quality of mangoes, experiments were performed on “Tainong No.1” mangoes with 2 types of bags, namely white single-layer bags (WB) and yellow/black double-layer bag (BB). With non-bagging fruits as the control group, the aroma compounds in the mangoes in different postharvest stages were analyzed via solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results indicated that 19 aroma compounds were detected in testing fruits, which were mainly terpenoids. We observed that the effect of bagging on the synthesis of aroma compounds in the mangoes differed among different postharvest stages. Compared with the control group, bagging inhibited the aroma synthesis in the fruits in the early postharvest stages, but facilitated it in the later stages. Additionally, the white single-layer fruit bags had a better effect on the aroma synthesis in postharvest mangoes; hence, it is advisable to use white single-layer fruit bags for mango production.

Boron (B) is an important element for the plant. The aim of work was to study the effect of B on fruit quality of pineapple. The experiment was carried out with ‘Comte de paris’ variety in pots. The results demonstrated that B had positive effect on fruit weight, TSS, the ratio of TSS/acidity, Vitamin C, the content of aroma volatile compounds. The B had no effect on the content of the three sugars (sucrose, fructose and glucose) and titrable acidity. There was a positive effect on fruit quality by application of B fertilizer in production of pineapple.

To investigate the phosphorus (P) leaching risk caused by applying manure fertilizer, six different manure fertilizers, namely, 0 (CK), 3,000 (F200), 4,500 (F300), 7,500 (F500), 10,500 (F700), and 15,000 kg ha(-2) (F1000), were applied to the surface soil (0-20 cm) prior to vegetable planting. The maximum Olsen P decreased with increasing amounts of the manure fertilizer. Total P did not change with treatments below 7,500, but decreased in the higher manure treatments. Water dissolved P (WDP) was highest in the upper (0-20 cm soil) layer, intermediate in the middle (20-40 cm soil) layer, and lowest in the lower (40-60 cm soil) layer. The 7,500, 10,500, and 15,000 treatments increased the WDPs in both the middle and lower soil layers and enhanced the degree of P saturation in the lower layer. This indicates that vertical leachate movement of P accumulation in the middle soil layer may be underestimated and the P leaching risk is enhanced using manure fertilizer levels7,500 kg ha(-2).

This paper investigated the best extraction process of total flavonoids from Piper sarmentosum Roxb. leaves. The optimal extraction solvent was first determined to be ethanol, and then the effects of ethanol concentration, extraction temperature, extraction time and the ratio of liquid to solid on the extraction yield of total flavonoids were determined by single factor method. Based on the above experiments, the orthogonal experimental design of three factors and three levels was established. The best extraction conditions of total flavonoids from Piper sarmentosum Roxb. leaves were concluded: extraction time 1.5h, liquid-solid ratio 175:1, ethanol concentration 75%, extraction time 1.5h, and the effect of solid-liquid ratio was greater than that of ethanol concentration, and the effect of ethanol concentration was greater than that of time. Furthermore, the antioxidant properties of total flavonoids were also determined from P. sarmentosum leaves in the regions of Suixi, Lianjiang, and Cunjin based on the DPPH, FRAP and MCC methods.

In this study, a solid-phase extraction column dedicated to the detection of resveratrol was directly used for purification after adjusting the pH of the sample, without resorting to a new method for sample extraction. The compounds cis-resveratrol, trans-resveratrol, cis-piceid, and trans-piceid were thus detected in wine simultaneously by high-performance liquid chromatography (HPLC). This method offers rapid and easy operation and involves low consumption of organic solvents, paving the way for efficient determination of the variety and other parameters of grapes used in wine samples..

Here in this paper, xanthine oxidase (XOD) was immobilized onto the chitosan (CHT) modified electrode by a simple way of cross-linking with glutaraldehyde (GTD) and 3-aminopropyltriethoxysilane (KH). The electrode displayed a sharp peak to the oxidation of xanthine at a potential about 0.67 V and the optimum of pH for determination was investigated. Under the optimum conditions, the biosensor fabricated on the KH/GTD/XOD/CHT modified electrode showed excellent response to the oxidation of xanthine within the range of 0.5 to 18 μmol/L with a low detection limit of 0.0215 µmol/L, a good stability and a high selectivity. The sensor can also be used for the determination of hypoxanthine. The electrochemical results indicated that the immobilized enzyme still retained its biological activity and this provided a new way for the construction of biosensors and determination of xanthine.