| Peats are the main material of seedling matrix.However,the peat reserves are limited,the consumption is increasing,and mining peats could cause environmental problems.Therefore there is an urgent need for resource replacement in peats.Coal gangue is one of the largest industrial solid residues in China.The physicochemical properties of coal gangue have the possibility of application in agriculture,but few studies have been made on the utilization of coal gangue for agricultural resources,especially as nursery matrix.This paper mainly explored the feasibility of using coal gangue to produce rice seedling matrix,and assessed the different ratios of nursery substrates.In order to obtain the suitable production process for rice nursery matrix using coal gangue.Meanwhile,It will provide technical support for the utilization of coal gangue agricultural resources.The main results are listed as follows.1.The compound matrix seedling experiment using SA?sodium alginate?to treat coal gangue.That by measuring and analyzing the basic physicochemical properties of coal gangue and peat,and the bulk density(0.5,0.6,0.7 g·cm-3)was used as a variables.The compound matrix were evaluated from two aspects:the basic physicochemical properties of matrix and the growth quality of rice seedlings.The results show:The coal gangue treated with SA that can be used as material for rice seedling matrix.The matrixs can meet the requirements of the rice seedling matrix,that coal gangue compounded with peats and adjusted the pH and adding fertilizer.When the bulk density of the compound matrix was 0.6 g·cm-3?the volume of the coal gangue added is 38%?,rice seedlings had the best growth quality.There were no significant difference in height of plants,dry weight of roots,mechanical capacity of roots compared with commercial peat matrixs.But the stem diameter,dry weight of whole plant and dry weight of ground were better than commercial matrix?P<0.05?;When the bulk density of compound matrix was 0.5 g·cm-3?the volume of coal gangue added is 25%?,there were no significant difference in height of plant,stem diameter,fresh weight of roots,dry weight of roots and mechanical capacity of roots compared with the matrix with a bulk density of 0.6 g·cm-3.But the fresh weight of whole plant,fresh weight on ground,dry weight of whole plant and dry weight on ground were smaller?P<0.05?;When the matrix with a bulk density of 0.7 g·cm-3?the volume of coal gangue added is 50%?,the height of seedling,fresh weight of the whole plant,dry weight on the ground and dry weight of the ground were significantly lower than the matrix breeding seedlings with the bulk density of 0.6g·cm-3?P<0.05?,and the seedlings were yellowish and shortaged fertilizer in late growth stage.2.The coal gangue has the best effect on the improvement that treated with the combination of SA and calcination.After modification,when the matrix of bulk density was 0.6 g·cm-3,the volume of coal gangue increased from 38%to 60%.The seedling quality of seedlings height was lower than that of the commercial matrix?P<0.05?.There were no significant difference in roots weight,dry weight of the whole plant,roots dry weight,roots diameter,roots number and rootsing ability.While the stem diameter,fresh weight of the whole plant,dry ground weight,fresh ground weight and roots length were better than that of the commercial seedlings?P<0.05?;When the matrix bulk density was 0.7 g·cm-3?the volume of coal gangue was 80%?,there were no significant difference in other quality indicators between the cultivated seedlings with matrix of bulk density was 0.6 g·cm-3.In addition to,the low emergence rate and the shortaged fertilizer in the late growth stage of the seedlings;However,when the matrix bulk density was 0.5 g·cm-3?the volume of coal gangue was 40%?,the whole plant fresh weight,ground fresh weight,ground dry weight,roots length,roots stem and rooting ability of the seedlings were lower than the matrix bulk density was 0.6 g·cm-3?P<0.05?.3.Using vermiculite as a replacement that conduct a complete replacement experiment for peat.The results show:Vermiculite can be used in coal gangue and can completely replace peat because of its characteristics similar to that of peat,stable properties,strong cation exchange capacity and good adsorption.The optimal matrix ratio was 25%of the volume of coal gangue treated by SA,and the amount of vermiculite volume is 75%(0.5 g·cm-3 of compound matrix weight).The stem diameter and roots length of the seedling quality index are better than the commercial matrix cultivated seedlings?P<0.05?.There were no significant differences between other quality indicators and commercial matrix cultivated seedlings.But dry matter accumulation in roots unit length was less,and the growth quality of rice seedlings decreased with the increase of coal gangue addition.4.Comprehensive coal gangue improvement measures and seedling growth requirements getting that the preparation process of compound bases is as follows:Coal gangue over 2 mm sieves,coal gangue tread with SA or coal gangue were calcined and tread with SA?calcined coal gangue can improve usage,thereby reducing the amount of peat?,With peat and vermiculite?2 mm screen?to the target volume mixture density,adding fertilizer 2 g·kg-1 matrix?N:P:K=2:1:1?,adjust the pH to 4-5 with 1%sulfuric acid,and the humidity is adjusted to make the moisture content of the matrix up to 40%. |
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