Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-30 Cooperative journals: 《广西植物》
Abstract： To investigate the effects of different biochar applications on soil enzyme activity in Eucalyptus plantation forests in North Guangxi, and provide theoretical references for the rational application of biochar to Eucalyptus plantations. Based on field experiments, biochar was prepared anaerobically at 500 ℃ from branches of Eucalyptus plantation harvesting residues, and with 6 treatment group, such as 0 (CK), 0. 5% (T1), 1% (T2), 2% (T3), 4% (T4), and 6% (T5) , to analyze the changes in soil enzyme activities under different application rates after one year importation. The results were as follow: (1) The soil enzyme content decreased gradually as the soil layer deepened. (2) In the same soil layer, the contents of catalase, urease, dehydrogenase and β-glucosidase increased with the increase of biochar application, and the highest contents were found at 6% of biochar application. (3) With the increase of biochar application, the contents of acid phosphatase, sucrase, leucine aminopeptidase and cellobioglucosidase showed a trend of increasing and then decreasing. Acid phosphatase and leucine aminopeptidase had the highest contents at 2% of biochar application. Sucrase and cellobioglucosidase had the highest contents at 4% of biochar application. In general, the biochar application increased the soil enzyme activities of Eucalyptus plantations. The results of this study can provide a scientific basis for the application of forestry waste biochar in Eucalyptus plantations.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-04-29 Cooperative journals: 《广西植物》
Abstract： In order to understand characteristics and significance of carbon (C), nitrogen (N), phosphorus (P) and stable carbon isotope composition (δ13C) in plant leaves of three typical aquatic plants under different growth environment, three life forms aquatic plants including emerging plant (Phragmites australis), emersion plant (Eichhornia crassipes) and submerged plant (Ceratophyllum demersumin) of the Huixian karst wetland are selected. The differences of carbon isotope compositions of interspecies and different habitat conditions were studied. The percentage of HCO3 － uptake from water by aquatic photosynthesis was estimated using the double-meta model. The results showed that: (1) the foliar δ13C of three diffirent plant life forms ranged from -28.47‰～-21.69‰ with an average of -24.83‰. There were significant differences between species, and its the sequence of relative value was Ceratophyllum demersum, Eichhornia crassipes and Phragmites australis. Among the three types of plants, Phragmites australis and Ceratophyllum demersum show the lowest and highest δ13 C, respectively. (2) For three types of halophytes，δ13C showed significantly positive correlations with foliar C, N, and P. The δ13C was also positively correlated with the contents of organic matter, available nitrogen, total nitrogen, available phosphorus and total phosphorus of sediment. All types of halophytes showed a negative correlation among δ13C, C/N, N/P, and C/P. The foliar N/P ratio of halophytes was 10.34, indicating a co-limitation by N and P for halophyte growth in the Huixian karst wetlands. These results suggested that three halophytes were adapted to environment through a high water use efficiency at the expense of decreased nitrogen use efficiency, and might improve C sequestration by increasing phosphorus use efficiency in the habitat of low water availability.The value of HCO3 － carbon sequestration by photosynthesis was 159.60 t·a-1·km-2 for Phragmites australis ,10.80 t·a-1·km-2 for Eichhornia crassipes, 9.24t·a-1·km-2 for Ceratophyllum demersum , with a mean value of 59.88 t·a-1·km-2. Different plant life forms, pathways of carbon fixation in photosynthesis and micro-environment were the important factors on affecting plant foliar δ13C in the Huixian karst wetland.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-08-27 Cooperative journals: 《广西植物》
Abstract：为探讨桉树不同林龄土壤微生物活性的响应特征，采用时空互代法，选择广西北部低山丘陵地区1~5 a生桉树人工林为研究对象，分析了土壤微生物、酶活性在不同土层和季节的变化规律。结果表明：(1)土壤微生物和酶活性在土层中有明显的垂直分布特征，均随土层加深而趋于降低，且各土层间差异显著。(2)细菌、放线菌数量随季节的大小顺序为秋季>夏季>春季>冬季，真菌的变化规律为春季>夏季>秋季>冬季，而酶活性随季节变化表现为夏、秋季活性较高，春、冬季活性较低。(3)细菌、真菌、脲酶、过氧化氢酶随林龄增大表现出先减小后增大的趋势，放线菌则呈现先减小后增大再减小的趋势，而蔗糖酶、酸性磷酸酶随林龄的增大趋于增大。(4)林地土壤中三大类群微生物与四种土壤酶之间存在极显著正相关关系，说明土壤微生物与土壤酶活性相互影响，两者之间关系密切，共同影响土壤的质量。不同土层土壤微生物和酶活性的季节响应特征差异较大，总体在冬季最低，主要与气温、水分条件、凋落物养分的归还等影响有关。不同季节、土层、林龄之间的交互作用对土壤微生物和酶活性有显著影响。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-09-07 Cooperative journals: 《广西植物》
Abstract： Selenium (Se) is an essential element for humans. Se deficiency can result in many diseases such as Keshan and Kashin-Beck diseases, and can cause immune deficiency and even cancer. However, most Se supplements in the market come from inorganic Se addition, which are unsafe and expensive. Natural Se sand is a readily available product which is air permeable and watertight. It is a kind of good matrix for producing Se enrichment plant. Green cabbage is a common vegetable that provides nutrition to human. This project aims to test the efficiency of Sand Se in cultivating green cabbage and provide Se as a nutrition source. Experiments include five group: a control group (CK) without fertilization, and four experimental groups: CT: natural Sand Se, CT1: chicken manure: Sand Se =1:1, CT2: chicken manure: Sand Se =1:2, CT3: chicken manure. Results showed that Sand Se addition increased significantly Se concentration of green cabbage by 45%、61% and 64%. Compared with the CK and CT3 group, the yield, leaf thickness and water use efficiency of the green cabbage increased significantly by 45%, 22.78% and 56.66%, respectively, under chicken manure: Se sand =1:2 treatment. Soil manganese and zinc concentration accounted for 72% variation of the green cabbage biomass and soil zinc accounted for 66% variation of the water use efficiency. These results also indicated that sand Se, particularly when mixed with chicken manure, can not only provide Se as a nutrition but also is beneficial to green cabbage yield. This study results provide useful information for supplying economic and healthy Se green cabbage.
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