The Effect Of Different Ways Of Rice Straws Incorporated Into Soil On The Change Of Soil Temperature And Microorganism Groups

There are abundant crops straw resoxurces in China,and in some areas straws are even oversupply.With the development of mechanical and intelligent manufacturing in the future,straws will be usually oversupply in China.So it is urgent to find a way to utilize the straws rationally.In recent years,there were a lot of ways to utilize the straws,but in general the industrialization of using straw was still in the early stage.That straws are incorporated into soil directly is the most realistic and effective way to ease the problem of burning straws.In this study,the soil temperature was monitored to test the effect of buried depth,rotten bacteria agent and the organic fertilizer on the decomposition of straws;and the microbial biomass in different treatments was also measured to find a better way to alter the soil microorganism groups,especially to decrease the amount of soil-bome disease pathogen.Using the sunlight greenhouse cultivation and nylon bag method,nine levels were set:buried deeply with rotten bacteria agent and fertilizer(DS),buried uniformly with rotten bacteria agent and fertilizer(S),buried deeply with rotten bacteria agent and without fertilizer(DC),buried uniformly with rotten bacteria agent and without fertilizer(C),buried deeply with fertilizer and without rotten bacteria agent(DS-),buried uniformly with fertilizer and without rotten bacteria agent(S-),buried deeply without rotten bacteria agent and fertilizer(DC-),buried uniformly without rotten bacteria agent and fertilizer(C-),no straw with rotten bacteria agent and fertilizer(CK).A multi-point system was designed to obtain temperature data from different treatments simultaneously.The temperatures of soil in 22.5 cm depth were measured.The decomposed rice straw and surrounding soil were sampled to explore the decomposition characteristics of rice straw and soil microbial population variation.The results were showed as follows.1.A multi-point system was designed to obtain temperature data from different treatments simultaneously.This system was designed based on STM32 and DS18B20 temperature sensor and had the following advantages:simple structure,stable operation,minor temperature variation within groups and long-time run in greenhouse.The temperature data were stored in SD card,which benefited data analysis.2.The ways of rice straw returning to field had the effect on soil temperature changing pattern.Straw buried deeply or with fertilizer or with microbial agents can increase soil temperature.Straw buried deeply with fertilizer and with microbial agents had obvious effect on rising soil temperature,while straw without rotten bacteria agent and fertilizer had little effect on rising soil temperature,which had significant difference in the improvement of the soil temperature compared with other treatment.The buried depth had the most significant effect on soil temperature,then rotten bacteria agent,while the organic fertilizer had minor effect among the three factors.The data also indicated that DS treatment had the most excellent performance and was 0.5?higher than S-treatment.3.Experimental treatments affected the chemical composition of rice straw decomposition process.The contents of cellulose and hemicellulose were decreased while the content of ash was increased in the treatments of rice straw incorporated into soil deeply or incorporated with rotten bacteria agent.The rotten bacteria agent added could accelerate the decomposition speed of rice straw uniformly without rotten bacteria agent and fertilizer4.The microorganism composition in soil could be altered by ways of rice straw incorporation.The quantity of bacteria in treatments of straw buried deeply were boosted obviously due to the increased nutrient level in soil,while there was no obvious change for the content of bacteria in treatments of straw incorporated with organic fertilizer.Results in this study would benefit us to find a better way of straw incorporation.Furthermore they would also provide scientific reference for the development of key techniques in organic material incorporation and the inhibition of the soil borne disease.