Effects Of Straw Returning On Soil Microenvironment And The Quality Of Tobacco

In this test, with the study of effects of high temperature composting and ploughing back straw on soil microorganisms, enzymes organic content and the quality of tobacco reveal the status and trends of rice, maize straw returning to the field with High temperature composting and ploughing back treatment on soil microenvironment and the quality of tobacco,aims to provide the theoretical basis for the application of straw returning technology.The test results are as follows:1. The changes of urease, sucrase, catalase, nitrate reductase activity were analysed after returning whole corn stalk into soil and cutting stalk into pieces in rosette stage,every stage, topping stage,the result shows:The urease activity was the lowest without NPK fertilizer,only 28.01(NH+4-N?g/(g/h)) the urease activity of the sample treated by NPK fertilizer was higher than the sample without NPK fertilizer. The soil sucrose enzyme activity displays a change which elevates first and reduces later, the soil sucrose enzyme activity of all the samples treated were higher than the match group except the group with CK treatment. No-returning whole corn stalk into soil with high temperature and added fertilizer. The catalase activity drops gradually except the group with CK and CK-F treatment, the nitrate reductase activity achieves 35.62mg/g after returning whole corn stalk into soil; It showed differences of nitrate reductase activity,that returning whole corn stalk into soil two months-F> returning whole corn stalk into soil two months> returning whole corn stalk into soil one month-F> returning whole corn stalk into soil one month> returning whole com stalk into soil three months-F> returning whole corn stalk into soil two three months> CK-F> CF,the tendency was:it increases first and decreases later of time.The activity of urease, sucrase, nitrate reductase activity increased with cutting stalk into pieces treatment, when the nitrate reductase activity has a difference between different treatments.2.The Straw after different treatment,the soil organic matter content is varied differently,at every growth stage have show:retting two months-F treatment of soil organic matter content compared with other treatment was the highest.The straw returned and cooperate with application of NPK fertilizer had evident effect in improving the soil organic matter content.CK,Straw crushing and returning into field without NPK fertilizer,soil organic matter content is the lowest.Farmland soil organic matter content in Straw crushing and returning into field combined with NPK fertilize treatment is significantly higher than control (CK-F),Among in all treatment, rice, maize straw crushing and returning into field combined with NPK fertilize soil organic matter content is the highest.but two kinds of crop straw returning to the field alone the soil organic matter content is not affected obviously.3.The study found that:Under different growth period and different test approach,Straw retting in high-temperature and returning into field compared with the control(CK),applying fertilizer can increase the quantity of actinomycetes,but not increase the number of fungi in the soil,the quantity of bacteria, actinomyces and fungi in soil on straw retting in high-temperature and returning into field combined with NPK fertilize treatment is significantly higher than CK,among the three kinds of microorganism,the differences of the quantity of germs is the largest.In the straw crushing and returning into field treatment,fertilization have some degree of impact on the quantity of bacteria,all treatment combined with NPK fertilization the quantity of the germs were decreased.And separate straw returned with fertilizer treatment the increase in the number of bacteria is not obvious,but after the two straw crushing and returning into field treatment,an increase in the number of bacteria was significantly compared with other treatments,This illustrates that the straw returned are the main factors influencing the number of bacteria in the soil.4.Effects of different treatments of straw on tobacco growth, yield and quality of tobacco leaves is different,crushing and returning into field treatment plant height than the straw returning with high-temperature heap retting is generally higher 1-3 cm,difference between stem circumference maximum 8.8%,crushing and returning into field treatment highest yield 2356kg/hm2,,compared to straw returning with high-temperature heap retting highest yield 2004kg/hm2 highter than 17.56%.NPK fertilizer control group urease activity in soil higher than that of no fertilizer control group 15.17 (NH+4-N (including g/(g/h)) at the same period.although rice, maize straw returning with high-temperature heap retting have some kind of impact on tobacco yield and quality,but crushing and returning into field treatment is more suitable for the growth of tobacco.