| Soil salinization is a widely concerned environmental problem at present.As a kind of saline-alkali soil which is difficult to be improved,soda saline-alkali soil has serious harm to plant growth and development.The hydrocharization of agricultural and forestry wastes is acidic with developed pore structure and abundant oxygen-containing functional groups,which has a good retention effect on soil nutrients and promotes the formation of large soil aggregates,and may have great application potential in improving soda saline-alkali soil.But few are studied by using water burning charcoal modified soda saline-alkali soil,based on this,in this paper,the soda saline-alkali soil as the research object,research on hydrochar of soda saline-alkali soil physical and chemical properties,soil fertility improvement potential,and by the growth of rice seedlings,validation of burning charcoal to soda saline-alkali soil and water burning charcoal modified soda saline-alkali soil influence on rice seedling growth,so as to provide scientific basis for improvement of soda saline-alkali soil and technical support,in this paper,the main research results are as follows:1)Using corn stalk,corn stalk leaf,corn stalk core and fungus chaff as raw materials,hydrochar was prepared under the conditions of 180?,240 min and solid-liquid ratio of 1:10.Compared with the hydrochar prepared from the other three raw materials,the surface of the hydrochar from Auricularia fungus chaff is rougher,the structure is looser,and the pH value is lower,and the content of Na+is lower.The hydrochar prepared from Auricularia fungus chaff has the best improvement potential of soda saline-alkali soil.2)Hydrochar can not only reduce the pH,conductivity and alkalinity of soda saline-alkali soil,but also improve the physical and chemical properties,organic matter and nutrients of soda saline-alkali soil.In the soil with pH of 9.78 and 9.03,the pH decreased to 9.52 and 8.87,respectively,when the addition ratio of water-thermal carbon was 4%.When the addition amount of hydrochar was 6%,the soil electrical conductivity at pH 9.78 and 9.03 decreased from 645?S·cm-1 and 573?S·cm-1 to 608?S·cm-1and 540?S·cm-1,which decreased by 37?S·cm-1 and 33?S·cm-1.Soil alkalinity at pH 9.03 was significantly decreased by 7.3%,14.3%and 18.5%,respectively,at the addition ratios of 2%,4%and 6%hydrochar.The increment of cation exchange capacity of the three groups was 2.28 cmol·kg-1,3.04 cmol·kg-1 and 3.40 cmol·kg-1,respectively,when the addition ratio of water-thermal carbon was 6%,which also greatly reduced the alkalization degree of the soda-saline-alkali soil.The proportion of>1mm aggregates in soda-saline-alkali soil increased significantly with the increase of the proportion of hydrochar.However,the ratio of particle size between 1-0.25 mm and 0.25-0.053 mm decreased significantly,which increased the soil porosity.The comprehensive analysis shows that hydrochar has better improvement potential for soda saline-alkali soil.3)First,the soil properties were improved after the water and heat carbon was improved by the cultivation of rice in soda alkali soil.When the proportion of hydrochar was 4%,pH decreased by 2.8%,and when the ratio of adding reached 6%,the conductivity decreased by 5.7%;Compared with the former,the alkalinity of rice decreased by 6.5%;When the proportion of hydrochar is 6%,the proportion of aggregate size is more than 1 mm increases 79.6%.In addition,the proportion of the particle size of salt alkali soil can be significantly reduced by 1-0.25 mm,which is much lower than before rice planting.Secondly,the improvement of the soil by hydrochar can promote the growth of rice seedlings.After the water heat carbon was improved to grow rice in soda saline-alkali soil,the content of superoxide dismutase and malondialdehyde was significantly reduced.When the proportion of hydrochar was 2%,the content of SOD and MDA decreased by 4.87 U/g and 0.718?mol/g respectively;With the increase of the proportion of hydrochar,proline content was 513.37?g/g·FW decreased to 37.31?g/g·FW significantly.Through the comparative analysis of various indexes of rice rhizosphere soil and physiological indexes of rice seedlings,the results showed that the addition of hydrotchar could significantly reduce the degree of saline-alkali stress of soda saline-alkali soil on rice seedlings and promote the growth of rice seedlings.The research results show that the use of agriculture,forestry and preparation of water waste edible Auricularia fungus chaff burning charcoal has a good application potential of soda saline-alkali soil improvement,water and burning charcoal modified soda saline-alkali soil after planting rice further enhance the physical and chemical properties of soil,so as to promote the growth of rice seedlings,reduced the soda saline-alkali soil salinity-alkalinity stress on the rice seedlings,in the aspect of water burning charcoal modified soda saline-alkali soil has important application value... |
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