Study On Ridge Cultivation And Matching Combined Minimum Tillage Implements For Soil Water Storage And Preservation In Northeastern China

The tillage technology for soil water storage and preservation in dryland farming and itsmatching combined and minimum tillage implements are the problems needing to be solved fora long period of time in the dryland area of northern China particularly in the ridge culture areaof northeastern China. It is the requirement for sustainable development in agriculture to recoverand improve the soil fertility, to increase the preservation and storage rate of natural rainfall, totake advantage of the disposition of natural resources with water and soil as the core, and to formthe production capacity that can meet the demand of people's living and social developmentunder the actual conditions in the ridge culture area of northeastern China. It was an importanttask for dryland and water-saving farming during the period of the country's 10th Five-year Planto develop a whole set of technologies and equipment with advanced levels in the country oreven in the world on the basis of the optimized combination of various advanced technologiesfor soil water storage and preservation..During his doctoral dissertation research, the author undertook the National Hi-TechResearch and Development Program (863 Program) which included the projects for the nationaldevelopment and industrialization, "the multi-functional tillage implements and completeequipment for soil water storage and preservation (project no. 2002AA2Z4121)"and "themulti-functional tillage implements for soil water storage and preservation and movableirrigation machines (project no. 2004AA2Z4120)". This dissertation contains the theoreticalresults of the projects and the main part of the research contents of the projects.A design theory and method with computer program were proposed, by applying analysis,mathematical statistics, orthogonal test, and mathematical and mechanical models. Throughexperiments with the mechanized farming for soil water storage and preservation in the ridgeculture area of northeastern China, the stalk-stubble breaking and mulching combine, seriestillage-rototilling combine and tillage-planting combine were developed. Based on the relatednational and industrial standards and combined with the specific conditions of these researchprojects, the testing methods for these machines were established. Then the performance testsand production tests were conducted. The main findings of the research are as followings: 1. The current situation of dryland farming in northern China and the problems in theexisting farming modes were analysed. A three-year mechanized rotation tillage method for soilwater storage and preservation in the northeastern ridge culture area and a periodic cyclediagram were created on the basis of the optimized combination of various advancedmechanized farming technologies for soil water storage and preservation. Each crop year beginswith soil preparation after autumn harvest and ends with autumn harvest next year in theresearched cycle. In each crop year, the stalk and stubble are treated in different ways and thepreliminary test was conducted. The characteristics and positive role of the new farming methodis described in details: The substantial contents of the new farming method include stalkmulching once every three years, stubble breaking and mulching thrice every three years, furrowand ridge alternation once every three years, subsoiling before the first period of the hot season,crop row strip tillage, precision seeding and chemical weeding. The tillage method has been filedfor patent application. 2. The systematic theoretical research on the direct-throw, curved-surface, straight-edgecutting knife, and the cutting throwing unit was conducted. The differential equation of the cutstalk moving along the knife was established. Then the conditions to determine the position ofthe cut stalk throwing spout was were given. A model was established to describe the effect ofthe rotation of the knife on the length of the cut stalks, throwing distance, and powerconsumption. The structural and motional parameters of the stalk cutting knife and the cuttingthrowing unit were optimized. The actual application of the three regression equations wasanalyzed. A new type of knife and unit that can simultaneously perform the cutting and throwingoperations were successfully developed. A separated structure with the universal symmetrical gearbox and both-side balancedtransmission was adopted in the stalk-stubble breaking and mulching combine, which not onlymeets the requirements of combined operations, but also can be a separate stalk mulcher or astubble breaker, i.e. one machine can be used for three purposes. A design theory and method forthe whole machine were established and the formula of the relative position of thestalk-mulching knife roller and the stubble-breaking knife roller was also established. Thestalk-stubble breaking and mulching combine was successfully developed. The test methods were established for the stalk-stubble breaking and mulching combine,according to the Standard for the Smashed Straw Machine (JB/T6678-2001), the Standard for theSmashed Root-stubble Machine (JB/T8401.3-2001) and other related national and industrialstandards, as well as in combination with the production practice. The performance tests andproduction tests were conducted. The test results and the basic conclusions of the research on thestalk-stubble breaking and mulching combine were obtained. The established test methods forthe stalk-stubble breaking and mulching combine have been proposed as the industrial standard. 3. The theoretical analysis and experimental study of the core working parts of the seriesmulti-functional rototilling-tillage combine, including the universal blade rotor, blade disc anduniversal blade, were conducted. The systematic design theory and method were established.The design idea of the universal blade rotor and blade disc for rototilling and stubble breakingwas proposed, which combines the functions of the two rotatory parts into one blade rotor. Amathematical model for optimization design of the blade rotor and a method of compoundmulti-spiral arrangement of the rototilling blade and stubble-breaking blade were established.Through optimization design, the problem of mutual interference between the two blades in thesame blade disk in different spiral arrangements was solved. A computer program was coded formulti-spiral arrangement of the blades, and the five principles of blade arrangement wereproposed. A set of curve equations was established for the cutting edge of the universal blade.The appropriate structural parameters were selected through the orthogonal test. A unique bionicresistance-reducing subsoiler was used. The series multi-functional rototilling-tillage combinewas developed, achieving the combination of many different operations such as stubble breaking,rototilling, fertilizing, subsoiling, ridging, and pressing. The test methods were established for the series multi-functional rototilling-tillage combine,according to the Standards for Rotary Tiller—Testing Method, Rotary Tiller Combine,Combined Implement for Subsoiler and Cultivating and Smashed Straw Machine and otherrelated national and industrial standards, as well as in combination with the production practice.The performance test and production test were conducted. The basic conclusions of the researchon the series multi-functional rototilling-tillage combine were obtained. 4. The theoretical analysis and experimental study of the complete-machine connectionmechanism and the main working parts of the series rototilling-planting combine wereconducted. The design theory and method were established for the whole machine and the keyparts. A combined structure was used to join an independent rototilling-tillage combine with aplanting machine. It is capable of performing a combined rototilling and planting operation.Both rototilling-tillage combine and the planter can operate with the tractor independently. It isconvenient, reliable and easy to assemble and or disassemble. A compensation three-point hitchlinkage mechanism was developed, and the mechanical analyses of the mechanism wereconducted. A three-in-one structural design of the contour wheel, depth wheel and press wheelwas adopted in the planter. After large quantities of experiments and improvements, a new typeof cell wheel seedmeter with the floating seed scraping and retaining structure were successfullydeveloped. A patented precision seedmeter with concave metering inner-cell and bionic flexiblepress roller were adopted. The series rototilling-planting combine was successfully developed. Based on the Standards for the Rotary Tiller Combine, Single Seed (Precision)Planter—Technical Requirements, Grain Seeder—Technical Requirements, BoomSprayer—Testing Methods, Smashed Root-stubble Machine, and other related national andindustrial standards, and combined with the production practice, the performance tests andproduction tests were conducted, test results and conclusions for the comprehensive research onthe series rototilling-planting combine were obtained. In this dissertation, creative research was conducted based on various advancedtechnologies for soil water storage and preservation. A series of components and devices weredesigned and manufactured, such as the direct-throw, curved-surface, straight-edge cutting knife,separated structure with the universal symmetrical gearbox and both-side balanced transmission,universal blade rotor and blade disc and universal blade, compensation three-point hitch linkagemechanism, new-type cell wheel seedmeter with the floating seed scraping and retainingstructure, the complete machine connecting mechanism and many other structurally novel keyparts. A three-year mechanized rotation tillage method was successfully developed. Theoretically,the author established the dynamical equations of the cut stalk motions, the relational modelsand regression equations for the effect of the rotation of the knife on the length of the cut stalks,throwing distance and power consumption. Design theory, design method and optimum designmathematical model were established for the universal blade rotor, universal blade disc anduniversal blade. Basic principles and computer programs of multi-spiral arrangement of therototilling blade were also established; the mechanical analysis method of the compensationthree-point hitch linkage mechanism was proposed. These theoretical achievements not onlyhave increased the study level of the agriculture technologies and the machines but also have acertain guiding significance to the development and design of agricultural machines. A close combination of agricultural machines and agricultural techniques can both ensureadvanced agricultural techniques and achieve the feasibility of agricultural machines. Thismethod is also capable of meeting the requirements of different soil and agrotechnical conditions.Years of application and promotion have confirmed that all the performance of the developed...