| In the middle and lower reaches of the Yangtze River in the two cropping areas of rice and wheat rotation,the ultra high yield of crops leads to the excessive amount of straw and uses straw as a way of ditching and stalk-disposing to the field.The harvest ditch and stalk-disposing machine(hereinafter referred to as multi-function machine)developed by our research team has solved the combined operation such as combined harvesting,ditch digging and straw filling.But the practice shows that the stability of the walking and the comprehensive performance of the whole machine are poor in the operation of the multi-function machine.In addition,straw placed in the trench is difficult to decay in a short time,and it has a negative impact on the emergence and growth of crops under no tillage direct seeding mode.In view of the above problems,this research takes the multi-function machine as a platform,straw of ditching and stalk-disposing as a study object and biological characteristics of microbial straw decomposing bacteria as a research method.First of all,according to the the lateral cylinder of transfer guide function and two times removal function,it changes the position of the grass to move the ditcher,Improve the walking performance and threshing quality of grain by adding auxiliary threshing cylinder;Then the overall performance of the machine can be raised by improving the auxiliary threshing cylinder and other parts of the machine;At last,it designs spraying device integrated with the improved multi-function machine to investigate the effect of microorganism on the decay of straw in ditch through field trials in many seasons.The main results are as follows.(1)Design and improvement of the harvest ditch and stalk-disposing machine’s assisted guide cylinderAim at poor straight walking performance and running deviation for this machine.An assisted threshing cylinder that making the ditching device located in the middle surface of the track to eliminate deflecting force,The performance test showed that the walking position deflections of modified machine under 3 different working speeds(low speed 0.38 m/s,medium speed 0.56 m/s and high speed 0.74 m/s)were reduced by 93.9%,94.4%and 93.3%,respectively.Furthermore,the straight walking stability and control performance were significantly improved.In the harvest process,improved the threshing quality of the multifunctional machine.Aiming at the problem of high blocking rate assisted cylinder The original nail tooth on assisted cylinder was too dense.Machine mentioned in this study reduced the number of nail tooth according to the spiral distribution principle.The number of nail teeth of a single toothed bar is 7,and interval between the nail teeth and the concave plate is adjusted to 25 mm,the diversion angle is calculated to be 24 degrees.After the improvement,the Adams software is used to simulate the dynamic balance and stability of the assisted cylinder,the relationship between different rotation speed and feeding weight of the cylinder was studied through the experiment.The field experiment showed that the wheat straw discharging performance was good,and the rice straw assisted cylinder Block hasty rate was decreased by 75%.(2)Improvement and field test of other parts of the harvest ditch and stalk-disposing machineAim at the problem of poor integrated performance for the multifunctional machine,on the basis of the improvement of the auxiliary roller,the other parts of the multifunctional machine are improved.Analysis and improvement on the theory of straw guide groove,the reserved height H was designed in 34 cm,And verified by EDEM software,the smoothness of straw removal in improved straw guide groove was analyzed,which is not affected by the movement of straw.The ditcher was improved,by means of increased strength and stiffness for improve the adaptability in the soil hardness.On board was improved,the trajectory control throws..The field experiment shows that the performance of the improved multifunctional machine is improved obviously.(3)Microbiology spraying device designing based on the multifunctional machineAccording to the structural characteristics and the working requirement of the multifunctional machine,the microbiology spraying device was designed in the rear part of the whole machine.The liquid tank was placed in the back of the main threshing and the side of auxiliary threshing.The nozzle is arranged on the port of the guiding grass slot,and the contact time and the mixing time between the liquid and the straw in the guide trough are prolonged.In the 4 spraying methods(A、B、C、D),the surface coverage rate of straw was 70%,and the difference was not significant(p>0.05).But the bottom coverage rate,tilted spray(B)and overhead spray(C)are 52.26%and 73.75%,much higher than 20.66%of vertical spray(A)and 23.67%of ditch spray(D).It is suggested that the installation of tilted spraying(B)and overhead spraying(C)should be adopted.Combined with the operation speed and the flow rate of the multifunctional machine,the volume of the bacterial tank is 80 L according to the frequency of 2 mu/times,and the structure of the bacterial tank is adapted to the installation position.The practice shows that spraying droplets continuously does not affect the normal discharge of straw.Through the simulation of tracking Panacea stain,when the machine operating speed is 0.30 m·s-1,compared with the same speed of ordinary knapsack spraying,spraying device in different straw layer(0,5,10,15,20 cm)coverage rate were 41.5%,27.4%,29.4%,24.2%,23.6%that is better than the knapsack sprayer 38.6%,4.8%,5.9%,4%,3.8%.The distribution of droplet on straw is more uniform,which can meet the requirements of spraying bacteria.(4)Experiment on promoting decomposing of microbial strain on strawWheat and rice straw returning into the ditch by spraying device for spraying bacteria,through field test consecutive quarter,effects of different regions,different types of microbial conditions on the ditch straw decomposition effect comparison.Research shows that bacteria can promote rapid decomposing of straw.In terms of wheat straw,in 2013 to 2016 each year,with improved year by year test method,straw decomposition degree is also significantly improved,from 32.27%in 2013 to 60.33%in 2016,increased by nearly thirty percentage points.Different types of microbial decomposition conditions have obvious difference,the powder microbial(PM)with liquid microbial(LM)low decomposition degree under the same conditions,and the soaking water treatment(JPS)due to its inherent natural adaptability,relatively the best role in promoting decomposition.The nitrogen application had obvious effect on the decomposition of straw.Although the overall decomposition degree was still limited,but the test results show that in the condition of suitable control mode is feasible;the rice straw,from 20.60%in 2013 to 29.25%in 2015,the growth rate is relatively limited,although Trichoderma(TD),the soaking water(JPS)such as different types of bacteria on rice straw decomposition has certain effect,but the effect was limited,should be considered more suitable for microbial life activities under the condition of low temperature measures.In general,microbial decay of wheat straw effect is better than rice straw,This may have something to do with temperature,low temperature inhibits microbial life activities Compared with huanghai farm and hongchang farm,the same treatment of straw decomposing also differ,decomposing degree of the overall hongchang farm slightly higher than huanghai farm,this may be related to the temperature soil environment have certain relations.To sum up,microbial promote decomposition of the straw is under the influence of many factors to participate in and completed. |
PDF Full Text Request