Impact of fertilization on cover crops and microbial community on a bauxite‐mined soil undergoing reclamation     

Rafael S. Teixeira  Ivan F. Souza  Rafael S. Santos  Lucas C. Gomes  Silvano R. Borges  Leonardus Vergütz  Ivo R. Silva 《植物养料与土壤学杂志》2019,182(4):515-523

The reclamation of bauxite‐mined areas can be favored by the application of organic and/or chemical fertilization to restore the vegetation. Otherwise, the impact of fertilizations on soil microbiota or plant–microbe interactions as land reclamation progresses is less understood. To address this issue, we evaluated the impact of organic and chemical fertilization on plants and soil microbial community within the first 36 months of land reclamation in a bauxite‐mined site. The experiment was set up according to a split‐plot design in which the main plots received fertilizations [non‐fertilized control (NF), chemical fertilization (CF; NPK and rock phosphate), organic fertilization (OF; poultry litter), and CF+OF combined], and the subplots received cover crops [no cover crops (NC), grass (B; Brachiaria), legume (S, Stylosanthes), and B+S combined]. Cover crops biomass yield was assessed annually with five field campaigns per year. We used phospholipid fatty acids (PLFAs) to infer the impacts of mining and restoration practices on actinobacteria, Gram‐negative and Gram‐positive bacteria, arbuscular mycorrhizal fungi, and fungi. Accordingly, PLFAs were determined before bauxite mining (pre‐mining), six months after topsoil reconfiguration (post‐mining), and after 14 and 36 months following the application of the fertilizations and cover crops. PLFAs results indicated that in post‐mining, the living microbiota was significantly lower than in pre‐mining. Cover crops biomass yield was highest for B and B+S fertilized with CF+OF at 14 and 36 months. Both parametric and non‐parametric statistics showed a temporal variation in the response of living microbes to the treatments applied. After 14 months, living microbes showed greatest response to OF, while at 36 months their response was strongest in the treatments with highest plant biomass production (B and B+S). These results suggest that in the early stages of land reclamation, living microbial biomass benefit the most from organic fertilizers. As this initial boost decline, living microbes are more likely to thrive in areas undergoing reclamation where they can develop synergistic interactions with plants.  相似文献   

Production and evaluation of potassium fertilizers from silicate rock          下载免费PDF全文

Wedisson Oliveira Santos  Edson Marcio Mattiello  Leonardus Vergutz  Rodolfo Fagundes Costa 《植物养料与土壤学杂志》2016,179(4):547-556

Rising price and limited geographical availability of traditional sources of potassium (K) fertilizers have stimulated a search for alternative K sources in different parts of the world. We evaluated mineral transformations and agronomic properties of an alternative source of K produced through thermal and chemical treatment of the verdete rock (VR). Chemical and mineralogical characteristics were evaluated before and after each treatment. Four K sources (verdete rock, KCl, acidified verdete, and calcinated verdete) were applied to a Typic Hapludox at different rates. Eucalyptus and sequentially cropped maize and grass were grown in the treated soils. Verdete rock, which contained glauconite and microcline as K crystalline minerals, had very low solubility in water and in citric acid. Thermal and chemical treatments increased the concentration of water soluble K and citric acid soluble K. These treatments also caused crystalline K minerals to collapse and form sylvite and arcanite. Untreated verdete rock was not suitable as a K source for maize (Zea mays L.) and eucalyptus (Eucaliptus urograndis I144). Thermal and chemical treatments increased agronomic performance of VR to be similar to KCl. When K was applied as K‐calcined verdete, 82% of the total K was recovered in maize and grass cultivations. Less K was recovered in plant following addition of K‐acidified verdete and KCl (72% and 77%, respectively). Potassium recoveries by eucalyptus were about 52, 53, and 60% of the amount applied of calcined verdete, acidified verdete, and KCl, respectively. Both calcination and thermal treatment increased the K uptake and dry matter production for all plant species tested to be similar to KCl suggesting that this silicate rock could be beneficiated to be an effective K fertilizer.  相似文献   

Characteristics, efficacy and safety testing of standardized extract of Croton tiglium seed from Indonesia as laxative material     

Saputera  Mangunwidjaja D  Raharja S  Kardono LB  Iswantini D 《Pakistan journal of biological sciences: PJBS》2008,11(4):618-622

Identification and taxonomy analysis conducted at Herbarium Bogoriense at Research Centre for Biology, Indonesian Institute of Sciences Bogor. The name of the plant was C. tiglium L. The result of analysis on C. tiglium, ethanol extract as laxative material using the intestinal transit method showed treatment group that received dosage 0.06 mL/30 g b.wt. (72.5%) was significantly different compared to negative control (48.4%) or positive control (50.6%) which showed the weak effect as laxative at the dosage of 0.75 mL/30 g b.wt. It showed that ethanol extract of C. tiglium seed at dosage 0.06 mL/30 g is effective as laxative. The test result of the treatment using dosage 0.06, 0.04, 0.026 and 0.07 mL/28 g of body weight showed the mice population response 100, 60, 40 and 40% consecutively. The Thompson and Weil analysis result showed the ED50 was at 0.027 mL or equal to 639,5 g kg(-1) b.wt. The LD50 was at 0.0707 equals with 1674,5 mg kg(-1) b.wt. Safety limit is the range of dosage that cause the lethal effect and the dosage that gives the intended effect. The safety limit is represented by the comparison of LD50/ED50. Calculation result that the extract safety limit was LD50/ED50 = 0.0707/0.027 = 2.7.  相似文献