Feasibility Of Mixing Spent Mushroom Substrate With Garbage Soil As Rice Seedling Substrate

In recent years,more rice is demanded by people,but the cultivated land was reduced,especially high quality soil used for rice seedling became more scarce.Spent mushroom substrates contains nutrients,which could be considered as a kind of high quality fertilizer and soil conditioner.In this experiment,ammoniated garbage soil was mixed with spent mushroom substrates by 0 %(treatment 1),20 %(treatment 2),40 %(treatment 3),60 %(treatment 4),80 %(treatment 5)and 100 %(treatment 6)to study the feasibility of mixing spent mushroom substrate with garbage soil as rice seedling substrates.Rice seed Daohuaxiang No.2 was used as the study materials.After the 1st day,10 th day,20 th day and 30 th day.The physical property,microbial quantity,biomass carbon,biomass nitrogen,enzyme activity,seedling height,leaf number,stem width,root number,length of the longest root,root activity,the aboveground fresh and dry biomass,and belowground fresh and dry biomass were measured on 1st,10 th 20th and30 th day after seedling.It was expected to find a suitable rice seedling substrates to alleviate the shortage of rice seedling substrate in rice production area.The main results were as follows:Spent mushroom substrates reduced the mixer's bulk density and improve some other physical properties.The number of bacterium and fungus were large in the spent mushroom substrates,but it had a strong inhibitory effect on the propagation of actinomycetes.The biomass carbon was higher,but the biomass nitrogen had little change during the seedling growing period under all treatments.The urease activity under treatment 5 and treatment 6 was the highest in the whole seedling period,which was significantly different from other treatments.In the first 20 days,the higher the content of spent mushroom substrates was,the higher the sucrase activity was.After the thirtieth days,the urease activity under treatment 3 was the highest,and the sucrase activity in the substrate was increased by 72.87 % compared with that on the first day.There was no significant difference for the acid phosphatase activity under all the treatments.In the early seedling stage,the acid phosphatase activity was increased with the content of spent mushroom substrates increased,but after 20 days,the acid phosphatase activity under treatment 3 was the strongest.During the seedling period,there were no significant difference in the content of alkali-hydrolyzed nitrogen and available phosphorus under each treatment.There was no difference in available potassium in spent substrates under treatments at the later rice seedling stage.After sowing,the growth of seedlings under treatment 1 was mainly in the first 20 days.Howerver the growth of rice seedlings under the treatments mixed with spent mushroom substrates was mainly in the middle and later stages.Leaf age had the similar trend with plant height.The stem width under treatment 1 was the highest in the early seedling stage,but there was no significant difference among treatments at the middle stage.In the early seedling stage,when the spent mushroom substrate was increased,the number of roots per rice were decreased.The content of spent mushroom substrates 60 % and above could reduce the rooting rate in the substrates.The inhibitory effect was weakened in the middle seedling stage.Keeping the content of spent mushroom substrates 40 % and above in the substrates could speed up seedling root elongation rate significantly.The roots under treatments with high content of garbage soil and the high spent mushroom substrates were stronger in the early seedling stage.The root ability and root activity level under treatment 3 were the highest at the transplanting period and the difference was significant compared with other treatments.Under the conditions of this experiment,the aboveground fresh mass of the seedlings under all the treatment was 7.201 g to 7.790 g.The maximum dry mass was under treatment 3.The effect of spent mushroom substrates on belowground fresh plant mass and dry mass plant weight was significant.By comprehensive consideration,seedling growth and quality of the substrate in this study,mixing spent mushroom substrate with garbage soil as rice seedling substrate was feasible.2:3(spent mushroom substrate with garbage soil)was recommended as the optimal ratio in the rice seedling substrate.