| Humic acid is the natural organic polymers and found in soil, peat, lignite, weathering coal or swamp. Composition of humic acid of separate source are different, because the humification leval is different. Because of its special chemical and biological acitivity, humic acid were applied in industry, agriculture and medicine business. The application in agriculture spread wide range. In recent years, along with the popularizing of the green fertilizer, humic acid fertilizer received the attention of merchant and welcome of farming practitioners. Yunnan and xinjiang have lignite and weathering coal in many place and the reserves are large, sources range are wide.Including high quality humic acid in most of coal. Exploit these natural resources reasonably, to realize its maximum value to contribute to the development of agricultural economy and realization of the green agriculture is required for time.The content and composition of humic acid are different because of the sources are different.The humic acid (HA) of direct extraction, its molecular weight is large, content of fulvic acid (FA) is low and contains low reactive group.Looking for the method of improving the yeild of humic acid (HA) and fulvic acid (FA) is always the central point of relevant researchers focus on. The content of the oxidizing agent as the active group based on the total lignite humic acid, humic total free acid group, and the humic acid containing a carboxyl group, a phenolic hydroxyl group were significantly increased, i.e., the oxygen-containing oxidizing lignite significantly increased. Oxidant species, concentration of the oxidant, and the ratio of oxidized coal and the oxidant content of times the influence of these groups, wherein the concentration of the oxidizing agent and the ratio of coal and oxidant greater impact. Oxidant species acetone, nitric acid, etc., but its environmentally unfriendly, it will cause pollution, and the application of its products nitro field fulvic acid has limitations. The experimental use of non-toxic properties of H2O oxidizing properties of H2O2and its reaction products of fulvic acid oxidation of lignite reached a high yield and environmental effects, in its process on the basis of the original has been little improvement on better preparation process, while lignite byproduct obtained Serum (Brown Coal D istillate, BCD), the BCD solution was less than the maximum molecular weight of the material500(GC-MS measurement), the BCD is performed fulvic fulvic acid preparation process rotary evaporation of acid concentrated distillate obtained during.It has been reported that humic acid and humic acid-related products can effectively alleviate the heavy metals (Wu Liping,1990), drought (Zheng Ping1991; Li Shanxiang,1996), salt (Meng Letter,2000) caused by stress on plants damage. Enhanced ion selective absorption, increasing the synthesis of nucleic acids and proteins and chlorophyll, humic acids (Humic acid, HA) and fulvic acid (Fulvic acid, FA) in favor of this kind of plant hormones and substances accumulate energy in photosynthesis (Liu Shilei,2007; Li Bao Cai,1994; Yunlong,2003; Yang Min,2007; Song Xiaomin,2007); changing the activity of certain enzymes in favor of changing the respiration rate of plants for energy exchange (LianHua Dong,2006); possible by changing cytokinins (YANG Wei-jun,2001) and GA (ALVAREZ R,2003) thus contributing to some plant cotyledon expansion and seed germination. Relatively low molecular weight fulvic acid (FA), and contains more oxygen-containing aromatic ring structure, less fat structure, polar, strong liquidity, compared with high affinity and polar compounds containing metal ions or compounds of metal ions; larger relative molecular mass of brown humic acid, fulvic acid black, and oxygen-containing aromatic ring structures containing fewer, more fat structure, polarity small, weak liquidity, and at a lower resistance than the pro-non-polar compounds. So, because of its high content of fulvic acid reactive groups, strong physiological activity (Jun-Ichiro H,1999), to promote germination and growth of various types of plants and plant damage mitigation of harmful factors of strong acids and black rot on brown rot acid.The preliminary experiments indicated that the effect of promoting plant growth and alleviating the armful influence come from salt BCD is better than fulvic acid, may be due to the molecules spatial conformation in solution have more obvious influence on biological activity. Preliminary has carried on the essence of lignite (Brown Coal Distillate, BCD) material basic research, found that contain at least seven material in the lignite essence, most of the compounds of plant seed germination and salt resistance did not see the influence of the literature, but their structure contains the active groups such as hydroxyl, carboxyl, carbonyl, plant absorption and accumulation of these small molecule organic matter to reduce cell osmotic potential, enhances the salt resistance ability of the plant.Among them, compound acetic acid and propionic acid can inhibit the growth of bacteria and fungi, which is conducive to the establishment of the plant growth and good environment.Urea can provide source of nitrogen for plant growth, promote cell division and growth, improve resistance of plants.Analysis showed that these compounds are potentially salt resistance.BCD to study the influence of wheat seed germination, deal with wheat seeds with different concentrations of BCD yannong19and luyuan301, in the absence of salt stress and low concentration of salt (25mmol/L Na2CO3,50mmol/L NaCl,25mmol/L NaaSO4), the concentration of salt (50mmol/L Na2CO3,100mmol/L NaCl,125mmol/L NaCl,25mmol/L Na2SO4), high concentration of salt (25mmol/L Na2SO4) three days after cultivation of wheat under the condition of stress determination of seed germination rate, relative coleoptile elongation rate, coleoptile fresh dry weight of radicle, osmotic regulation ability, quality of malondialdehyde content and radicle., according to the results of BCD can promote the germination of wheat seed, fresh dry weight increase of coleoptile and radicle, improve the osmotic regulation ability germinated seeds under salt stress, reduce the increase of membrane lipid peroxidation product in coleoptile.It follows that BCD can promote the germination of wheat seed, salt damage to wheat germination stage. |
PDF Full Text Request