| With the rapid development of organic agriculture in China,the area of organic rice production and the area of certification are expanding,but the research on the production technology of organic rice has not been further developed.According to the national standards for the production of organic products,chemical fertilizers and pesticides are not allowed to be used in the process of organic rice production.At present,most of the production is the use of pastoral soil and farm manure mixed or marketed nutritious soil to rice seedling cultivation.The former has the problems of poor quality and high incidence of disease.The latter does not meet the production standard of organic rice,which seriously restricts the large-scale development of organic rice production.Therefore,it is of great practical significance to carry out research on organic rice seedling technology.Therefore,this paper combined indoor analysis with greenhouse seedlings,taking mushroom residue,sheep dung,oyster powder,vermiculite and soil as the main raw materials,and setting up the T1（30%mushroom residue）,T2（40%mushroom residue）,T3（50%mushroom residue）and T4（60%mushroom residue）,with the nutritional soil sold as the control（CK）,The effects of different rice seedling substrates on seedling growth,physiological characteristics,nitrogen,phosphorus and potassium content and the physical and chemical properties of different rice seedling substrates were studied,so as to select the best matrix formula,in order to provide technical reference for the cultivation of organic rice.The main conclusions are as follows:1.The suitable ratio of organic rice seedling substrate has better physical and chemical properties,and is the basis for cultivating strong seedlings.The organic matter content of the organic seedling substrate was significantly higher than that of CK（P<0.05）,and the pH value of the organic rice seedling substrate was maintained between 4.5 and 5.5 during the seedling period.Compared with CK,the bulk density of the organic rice seedling matrix was smaller than the T4 treatment,and the bulk density was 0.5 g·cm-33 to 0.8 g·cm-3;compared with CK,the organic rice seedling matrix was the largest.The water holding capacity was high and the water loss rate was low.The maximum water holding capacity of T2 and T3 was over 90%,and the water holding capacity was good.2.The suitable proportion of organic rice seedling substrate can improve the emergence rate and uniformity of seedlings,and promote the formation of strong seedlings.The seedling emergence rate of different treatment seedlings reached 85%.The seedling emergence rate of different organic rice seedlings was greater than that of CK,and the highest seedling emergence rate of T3 treated seedlings was 96.7%,which was 10%higher than that of CK,and the seedling density of each treatment was 2.5 above/cm2,of which the density of T3treated seedlings was the largest,which was 24%.Compared with CK,the seedling density of T4 treated seedlings was the least,and the height of the seedlings was less than that of the CK,but the height difference of the seedlings was smaller than that of the CK.Among them,the seedling emergence was the most homogeneous,the height difference of the seedlings was 4.3,the next was the T3 treatment,and the stem diameter of the seedlings of different organic seedling substrates were all in 2mm.There was no significant difference compared with CK.The leaf width and leaf age of the seedling raised by organic rice seedlings were larger.The seedling index of T2 and T3 seedlings had no significant difference compared with that of CK;the root length and root number of the seedling raised by different organic seedling substrates were significantly higher than that of CK（P<0.05）,and the T3 treatment in the seedling was the best.3.The suitable proportion of organic rice seedling substrate is beneficial to improve seedling root activity and seedling physiological activity.The root vigor of the seedlings of different seedlings is strong.Compared with CK,the root activity of the seedlings was significantly enhanced by the organic seedling matrix T3 and T4（P<0.05）,and the content of soluble sugar in the seedlings of different treatments was not significant.The content of proline and MDA,the activity of SOD and the activity of POD of the seedlings treated with T3 and T4 were in phase of CK.There was no significant difference between the two treatments.The physiological activity of the seedlings treated with T1 and T2 was lower than that of CK.4.The suitable proportion of organic rice seedling substrate can significantly increase the content of phosphorus and potassium in the seedlings,and the nutrient accumulation of the seedlings is high.The nitrogen content of the seedlings treated with organic seedlings was lower than that of CK,in which the nitrogen content of T3 treated seedlings was higher,and the nitrogen content of the seedlings was normal,the nitrogen content was lowest in T1treatment and the seedling quality was poor.The phosphorus content in the seedling raised by the organic seedling substrate was higher than that of the CK,and the phosphorus content in the T3 treated seedlings was significantly higher than that of the CK（P<0.05）.The content of potassium in the seedlings of different organic seedlings was significantly higher than that of CK（P<0.05）,and the content of N,P and K in the seedlings treated with organic seedling matrix T3 was more optimal.To sum up,T3 treatment（50%mushroom residue+10%sheep dung+20%soil+5%oysters+15%vermiculite）can provide a better growth environment for seedlings,and the cultivated seedlings have good growth condition,which is the best matrix formula in this experiment. |
