Influences of wide-narrow seeding on soil properties and winter wheat yields under conservation tillage in North China Plain

In order to promote the winter wheat yield and guarantee seeding quality in double-cropping system,no-tillage or reduced tillage planting modes with different row spacing have been implemented to result in different levels of yield.A three-year(2012-2015)field experiment was conducted on the experimental farm at Zhuozhou of Hebei Province in North China Plain to compare winter wheat yield from the two planting modes:wide-narrow row space planting mode(WN)and uniform row space planting mode(UR)Both planting modes were performed under reduced tillage conditions with straw mulching.The results showed that in North China Plain WN had positive impacts on crop yield,yield components,leaf area index(LAI)and intercepted photosynthetically active radiation(IPAR)index.Comparing with the UR,IPAR and LAI index for WN were enhanced by 4.8%and 5.2%,respectively.The average yield for WN was 7.2%,significantly greater than that of UR under the same quantity and density.In addition,for WN mode,machinery could pass through with less blocking under large amount of straw mulching,which largely improved tillage efficiency and potentially popularized the conservation tillage technology in North China plain.It is therefore recommended that wide-narrow row space planting mode(WN)combined with reduced tillage and straw mulching be more suitable for conservation tillage in double-cropping pattern areas in North China Plain.

Design and experiment of the pneumatic pressure control device for no-till planter

An adequate and uniform press wheel pressure is crucial for the homogeneous development of a crop,as it affects actual seeding depth and germination rate.The problems of uneven compaction of seed furrow and consistency of seeding depth can be caused by the pressure fluctuation of the coil-spring pressure control device(CPCD)when the no-till planter is working on the unplowed ground.In this study,a pneumatic pressure control device(PPCD)was designed for the no-till planter,the key structural parameters of air spring for press wheel pressure(PWP)stability were determined by theoretical analysis and parameter calculation.Using the gas-structure coupling finite element simulation method(FESM),the piston radius,piston angle,and cord angle of the air spring are selected as the test factors,and the vertical stiffness was used as the test index to carry out the quadratic rotation orthogonal combination test to establish the regression model of test index and factor.The bench test of the PPCD was carried out under the optimal parameter combination,piston radius of 27.2 mm,piston angle of 11.7°,and cord angle of 30.0°.The vertical stiffness verification test showed that the simulation test was consistent with the bench test result,the vertical stiffness simulation error was 7.1%,and the internal air pressure simulation error was 3.0%;The control response test showed that the average response time of the air spring inflating and deflating was 0.80 s,the maximum overshoot was 4.33%during inflation,and no pressure overshoot during deflation;Under the condition of-40-40 mm surface relief height,the PPCD could effectively reduce the pressure fluctuation compared with the CPCD,and the average reduction of the pressure fluctuation was about 25.1%.

Design and experiment of anti-vibrating and anti-wrapping rotary components for subsoiler cum rotary tiller

The commonly used subsoiling cum rotary tiller machine(SRT)in Northern China is a combination of subsoiler and horizontal rotary tiller,however backfilling of the subsoiling slot,excessive vibration and plant residue wrapping on rotary components has been rarely considered.Therefore,the rotary components and assembly were redesigned to address these issues and to an SRT fitted with IT225 short curve rotary blades behind the V-shape subsoiling slots and IIT245 long curve rotary blades between the tines.Long and short blades were fitted on a rotor in a double helix,with optimal spiral angles of 65° and 90°,and phase angle of 147°and 180°,respectively.Compared with the commonly used SRT(CSRT),the additional anti-wrapping cutting blades in the circumferential and axial direction of ASRT could remove hanging residue on the blade holders,wrapping on the rotor and formation of an isolation layer.Moreover,the cutting edge curve of anti-wrapping cutting blades was an exponential curve.Field tests demonstrated that the redesigned SRT with anti-vibrating and anti-wrapping rotary components(ASRT)had was a significant advancement over the CSRT.Moreover,the working depth of rotary tillage was more stable,while other observations confirmed that backfilling of the subsoiling slot was also improved.

Preliminary bench experiment study on working parameters of pneumatic seeding mechanism for wheat in rice-wheat rotation areas

In order to solve the serious problems of soil adhesion and blockage as well as high operating resistance for wheat seeders under the condition of sticky heavy loam clay in rice-wheat rotation area,a new concept of non-contact pneumatic seeding technology that could rip wheat seed into the soil by high pressure accelerating airflow was proposed in this paper.A preliminary bench experiment was conducted and high-speed photography technology was used to study the parameters of wheat pneumatic seeding under five levels(30%,35%,40%,45%and 50%)of soil moisture content for loam clay.Experimental results showed that:wheat seeds could be ripped into soil without damage and acquired varying degrees of germination by way of pneumatic seeding;shooting depth shown a deepening tendency with the increase in shooting velocity,and the value of seeding depth and seeding velocity are closely related to the soil moisture level,which wheat seeds can achieve higher shooting depth with relative lower shooting velocity when the soil moisture content increases continuously;none of wheat seeds could be ripped into the soil with about 2.93 m/s shooting velocity that accelerated in the form of free fall,while the shooting velocity that wheat seeds needed in order to be completely ripped into soil with 3 mm shooting depth were 40-50 m/s(30%soil moisture content),30-40 m/s(35%soil moisture content),20-30 m/s(40%soil moisture content),10-20 m/s(45%soil moisture content)and 2.93-10 m/s(20%soil moisture content),respectively.The experimental results can provide basic data and technical support for the development of non-contact wheat seeding equipment in rice-wheat rotation area.

Anti-blocking performance of ultrahigh-pressure waterjet assisted furrow opener for no-till seeder

No-till planting method is widely used for maize-wheat two-crops-a-year area in the North China Plain.However,cruel soil conditions,especially the large number of maize stalks which are hard to cutoff covering,often cause an unsatisfying planting quality.Based on the authors’previous investigation,ultrahigh-pressure(UHP)waterjet is capable to solve this problem and obtain qualified seedbeds.Thus,a UHP waterjet assisted furrow opener for no-till seeder was designed.Field tests showed that double-disc furrow openers worked well with UHP waterjet,since the sharpened disc blades could help to cut soil and residue,meanwhile,minimize soil disturbance.Response surface method(RSM)was used to investigate the relationship among forward speed,waterjet pressure,jet impingement angle and anti-blocking performance(stalks cutoff ratio and depth of soil cutting),and a Box-Behnken three-factor design was used to identify the optional operation parameters.A total of 17 combinations were conducted,and the results showed all three operation parameters significantly affected anti-blocking performance.Stalks cutoff ratio and depth of soil cutting increased with the increase of waterjet pressure,jet impingement angle,and decreased with the increase of forward speed.The optimization analysis indicated that when waterjet pressure was 267-280 MPa,jet impingement angle was 80.2°to 90.0°and forward speed was 4.00-4.42 km/h,the overall performance of UHP waterjet assisted double-disc furrow opener for no-till seeder was maximized.Stalks cutoff ratio could be above 95%and no blockage occurred.This study may provide a new approach and reference for the anti-blocking technology of no-tillage seeding.

Performance of waterjet on cutting maize stalks: A preliminary investigation

Large amounts of crop stalks left in the field as a result of conservation agriculture cause blockage during no-till planting.To solve this issue,pure waterjet was used to cut off the maize stalks so that the rear furrow opener could pass through without blockage.In this investigation,an experimental study on depth of cut,which was the main performance indicator of pure waterjet on cutting maize stalks,was presented.A full factorial design with 200 tests was implemented with respect to three operation parameters,that is traverse speed,waterjet pressure,and standoff distance were considered as variables.An analysis of variance(ANOVA)was carried out in order to determine the statistical significance of individual operation parameters.Using multilinear stepwise regression analysis,a model to predict the cut of depth from the predicted pure waterjet operation to cut maize stalks was then developed.All three operation parameters significantly influenced the cutting performance.Moreover,the results indicated that depth of cut increased with the increase of waterjet pressure,the decrease of traverse speed,and decrease in standoff distance.Waterjet pressure provided major contribution to depth of cut,followed by traverse speed,then standoff distance,which was demonstrated by both ANOVA and regression analysis.The experimental results showed that when the standoff distance was closer than 10 mm and waterjet pressure was 280 MPa,all maize stalks specimen could be cutoff thoroughly.With the consideration of field operating conditions,waterjet pressure of 280 MPa or higher and 10 mm to 15 mm standoff distance were recommended for maize stalks cutting.This analysis provided a realistic approach for the optimization of the ultra-high pressure pure waterjet parameters in maize stalks cutting,which could be used to relieve the occurrence of straw blockage in no-till planting.

Design and experiment of seed furrow cleaning device based on throwing and sliding for no-till maize seeding

In order to solve the serious problems of seeds are covered by residual film and overhead by straw during no-till seeding,a seed furrow cleaning device for no-till maize seeding was developed,which adopted a collaborative cleaning method of rotating spring teeth and curved sliding shovel.The movement process and motion trajectory of throwing residual film and straw were constructed.The maximum distance of throwing to one side in horizontal and maximum height in vertical were obtained.The motion trajectory of adjacent spring teeth was analyzed by Matlab,the motion trajectories of adjacent spring teeth at different speeds of 120 r/min,150 r/min and 180 r/min were achieved,the theoretical analysis results showed that the area of omitted area decreased with the increase of rotation speed.Based on theoretical and simulation analysis of critical parameters,the forward speed of machine,rotation speed of spring teeth,and dip angle between spring teeth and rotary disc were selected as the influencing factor.Straw cleaning rate(SCR)and residual film cleaning rate(RFCR)were selected as the response values for three factors and three levels of orthogonal experiment design.The optimal combination of the selected parameters was obtained,and the field test verification was also conducted.The results showed that the rotation speed of spring teeth,forward speed and dip angle of spring teeth significantly affect SCR and RFCR were in decreasing order.The field test results indicated that when forward speed was 6 km/h,rotation speed of spring teeth was 180 r/min and dip angle of spring teeth was 40°,SCR and RFCR were 88.27%and 84.31%,respectively.This study provides a reference for the development of no-till seeder in Xinjiang and the northwestern regions of China.

Optimization of operating parameters of seeding device in plot drill with seeding control system

Plot drill has a significant impact on field breeding by replacing manual seeding.However,the seeding performance of plot drill needs to be further improved as the mechanical transmission method cannot work under the optimal combination of operating parameters.In this study,a cone compartment tray of sowing device was evaluated under the laboratory conditions,using a self-designed seeding control system to adjust the operating parameters.Among them,a plot seeding control system was involved that could set operating parameters through an Android terminal,which effectively reduced the difficulty of parameters adjustment.The method of central composite experiment design was employed to conduct experiments and explore the effects of experiment factors such as lifting height of storage tube(LHST),rotation speed of cone compartment tray(RSCCT),and rotation speed seed distributor(RSSD)on the seeding uniformity coefficient of variation among rows(SUCVR)and the rate of damaged seeds(RDS).For SUCVR of wheat,the results showed that the importance order of main factors from high to low was RSSD,RSCCT and LHST.And for SUCVR of buckwheat,RSCCT had the largest influence,followed by RSSD,and LHST had the smallest influence.For RDS of wheat and buckwheat,only RSSD had a very significant effect among the main factors.The experiments data of wheat indicated that when operated at 27.2 mm for LHST,4.5 r/min for RSCCT and 1169 r/min for RSSD,the sowing performance of wheat was optimal,with SUCVR and RDS values of 5.02%and 0.117%,respectively.The buckwheat seeding performance was found to be optimal when the LHST,RSCCT and RSSD were 26.5 mm,3.9 r/min and 711 r/min,and SUCVR and RDS were 4.74%and 0.113%.The seeding control system realized the electromechanical control of the seeding equipment,was convenient for parameter setting and stepless adjustment,and could be operated under an optimized combination of operating parameters.The research results could provide a reference for the performance improvement and application of plot drill.