Lesson Plan - New Mexico State University
Contents
1. pAb AA iuno5 SON eee ba E Er 15 4 4 4 d 4 ee e eeez 0 e s o A4 AT ATA 919 4100 1 bs Ds u1001L L sjenby 01 01 9 lt 545501 NHOO ONIYNSVSIN New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 18 TM A7 7G DETERMINING SMALL GRAIN LOSSES Source of Loss Kernels of grain 1 sq ft No of grains sq ft to bu A Loss bu A Accept able loss acre Grain loss behind combine Area D 2 Pre harvest loss Area A 3 Total machine loss 4 Header and pre harvest loss Area B 5 Header loss 6 Cylinder and separation loss Wheat 20 grains Barley I5 grains Oats I2 grains Rye 24 grains 10 sq ft 10 sq ft WHEAT HARVEST A 275 loose grains or loose heads B 400 loose grains or loose heads C 224 loose grains or loose heads D 625 loose grains or loose heads 10 sq ft Note These counts must be divided by 10 to get 1 sq ft for first column New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 19 TM A7 7H COMBINE SERVICING BELTS CHAINS Check sprocket alignment with a straight edge or string Misalignment will cause rapid2. The parts involve include the grates straw walkers beater or rotary deflector The cleaning function removes the grain from the trash Parts involved include the cleaning shoe sieves chaffer and fan Moving the grain throughout the machine is the handling function Parts involved include the clean grain augers elevators and grain tank tailings augurs and ele vators grain holding grain tank and unloading augers Use TM A7 7A A7 7B and A7 7C to illustrate various harvesting equipment An alternative approach is to transfer the information from the transparency masters to a multimedia presentation Use LS A7 7A to strengthen student understanding of concepts Use text material to strengthen student understanding of concepts Chapter 1 and 2 in Combine Harvesting and Introduction to Combines VAS 3047 are recommended Objective 2 Explain the calibration of grain harvesting equipment Anticipated Problem How is grain harvesting equipment calibrated II Unless the operator knows the source of grain losses he or she cannot calibrate the machine to reduce the losses Some losses are due to improper operation and others are caused by improper adjustment A Harvesting losses occur in different areas of the harvesting process 1 Pre harvest losses are those which occur in the field before combining Such losses show up as grain on the ground the result of wind shatter lodging down crop or weather conditions The
3. 10 Sample Test Name Test Lesson A7 7 Operating Calibrating and Maintaining Grain Harvesting and Handling Systems Part One Matching Instructions Match the term with the correct response Write the letter of the term by the defini tion tailings e drying zone i allowable storage time cleaning f threshing j equilibrium moisture content cutting g feeding drying front h lodging 10 ee OL Cutting or gathering the crop Length of time grain can be stored at a given moisture content and temperature Material that is not completely threshed or separated Removing the grain from the trash Layer of grain being dried Removal of the grain from the head seedpod or cob Inability of the crop to stand Point when continued contact with the drying air results in no further moisture re duction Delivering the crop material to the threshing unit in a steady uniform flow Leading edge of the drying zone Part Two Completion Instructions Provide the word or words to complete the following statements 1 Moving the grain throughout the combine is referred to as the function 2 Grade quality measurements categorized as grades 3 A chain in correct tension would have inch of sag per foot between shaft cen ters New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 11 4 The Grain Grading Stand
4. Line 5 Line 6 New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 25 LS A7 7C Lab Sheet Calculating Harvest Loss Soybeans Name COMBINES REDUCING HARVESTING LOSSES Figure the soybean loss using the data on the attached page Column A Number Beans Found of Beans in 1 Sq Ft to 1 Bean Loss Sources of Loss Area Bu Acre Total 1 Total Crop Loss 4 2 Pre Harvest Loss 4 3 Machine Loss Line 1 minus Line 2 4 Gathering Unit Loss Total of From Area B a Shatter Loose beans pre harvest pod 4 b Loose pod Loose pod pre harvest pod 4 c Loose stalk Not attached to plant 4 d Lodged stalk Not attached to plant 4 e Stubble Pods attached to stubble 4 Total gathering unit loss To tal line a through line e 5 Cylinder and Separation Loss Machine loss line 3 minus Header loss line 4f New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 26 A 62 beans B Loose stalk 29 beans Shatter 142 beans Stubble 22 pods 3 beans per pod 66 beans Lodged stalk 0 Pods O 194 8 beans 432 beans The soybean yield for this field is 45 bu per acre How efficient is this combine 65 5 75 79 4 83 2 10 sq ft 10 sq ft Note These counts must be divided by 10 to get 1 sq ft for Column A New Mexico Agricultural
5. Maximum Moisture Content Grain Type and Storage Time For Harvesting For Safe Storage Shelled corn and sorghum Sold as grain by spring 30 Stored 6 12 months 30 Stored more than year Soybeans Sold by spring Stored up to I year Stored more than year eat oats barley Stored up to 6 months Stored more than 6 months Sunflower Stored up to 6 months Stored more than 6 months Stored up to 6 months Stored more than 6 months Edible beans Stored up to 6 months Stored more than 6 months New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 23 LS A7 7A Name Lab Sheet Combine Data Sheet Directions Complete this data sheet for a combine in your area 14 15 16 17 18 19 20 Make Model Type of head Width Does this combine have a floating cutter bar How can you tell if a head has a floating cutter bar How is the reel or corn snap roller turned Is the reel a slat type or pickup type Is the reel fore and aft adjustment mechanical or remote controlled How many row cornhead is used or can be used on this combine How many feeder chain sections are across the feeder throat Cylinder type Type of beater How many sections of straw walkers How many holes across one section of straw walker Does the machine have an auger or return pan at the end of the straw walker Where is
6. Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 27 LS A7 7D Name Lab Sheet Calculating Harvest Loss Small Grain No of Kernels of Grains Sq Grain Ft to 1 Acceptable Source of Loss 1 Sq Ft Bu A Loss Bu A Loss Acre 1 Grain loss behind combine Area D T 2 Pre harvest loss Area A B 3 Total machine loss 4 Header and pre harvest loss Area B 5 Header loss B A 6 Cylinder and separation loss Wheat 20 grains Barley 15 grains Oats 12 grains Rye 24 grains D 10 sq ft WHEAT HARVEST A 200 loose grains or loose heads B 300 loose grains or loose heads C 100 loose grains or loose heads D 400 loose grains or loose heads Note These counts must be divided by 10 to get 1 sq ft for first column New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 28
7. etc Moisture tester Terms The following terms are presented in this lesson shown in bold italics Allowable storage time Cleaning Drying front Drying zone New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 2 Equilibrium moisture content Feeding Handling Lodging Tailings Threshing Interest Approach Use an interest approach that will prepare the students for the les son Teachers often develop approaches for their unique class and student situations A possible approach is included here Display to the class the parts from different combines snapping rolls cutter bar knives guards rasp bars etc Ask students to identify what the parts are used for on a combine On the floor mark out ten square feet Tell students this represents an area behind a combine Place crop seed corn soybean etc in the area Based on the number of seeds used ask the students how efficient the combine was Summary of Content and Teaching Strategies Objective I Explain the operating principles of grain harvesting equipment Anticipated Problem What are the operating principles of grain harvesting equipment I Early combines were known as harvester threshers machines that were pulled through the fields by teams of horses or mules Some machines were known only as threshers since the grain was first cut and then brought to a thresher for threshing and separating th
8. of stored grain are insects rodents and bacte ria New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 7 Use A7 7I to illustrate the principles of grain drying TM 7 7 and TM 7 7 will be helpful in reinforcing the concepts of storage life and moisture content in grains An alternative approach is to transfer the information from the transparency masters to a multimedia presentation Use text material to strengthen student understanding of concepts Grain Drying Handling and Storage Handbook MWPS 13 and FS Grain Drying Guide are recommended Objective 5 Explain the calibration of grain drying and handling equipment Anticipated Problem How is grain drying and handling equipment calibrated V Calibration of grain drying equipment is important to attain the proper moisture content for stored grain There are several factors that are taken into consideration when calibrating grain drying equipment They include A Initial moisture content of the grain B Temperature of the grain C Relative humidity of the outside air D Desired final moisture content of the grain which is affected by the use of the grain Again TM A7 7 and A7 7K will help students in understanding this objective An alternative approach is to transfer the information from the transparency masters to a multimedia presentation Use text material to strengthen student understanding of conc
9. 11 Keep up to date maintenance records A simple chart showing when lubrication and service adjustments were performed can help to insure that all needed maintenance has been performed Inspect the equipment every day A brief inspection of all areas can help you spot potential machine failures and safety hazards Check all fluid levels daily Lubricate bearings and chains as called for in the operator s service manual Check belts frequently for correct tension excessive wear tearing cracking swell ing and unraveling Maintain correct chain tension 1 4 inch of sag per foot between shaft centers Check all electrical equipment prior to use Insure that all fire extinguishers are properly charged and in working order Use text material to strengthen student understanding of concepts Grain Drying Handling and Storage Handbook MWPS 13 and FS Grain Drying Guide are recommended Reinforce the major concepts of this objective through classroom discussion Objective 7 Identify the grain quality standards associated with a given crop Anticipated Problem What are the grain quality standards VII A set of standards established by the United States Department of Agriculture USDA known as the Grain Grading Standards USDA 1995 serve as a general guideline for char acterizing physical grain quality A This system was developed in 1916 to enable grain merchants to trade grain using con sistent measurable quality cr
10. Determining losses varies with the type of grain har vested 1 The most difficult problem in harvesting soybeans is getting all the beans into the header The combine must be operated accurately and gently to allow the most beans possible to enter the machine After soybeans reach maturity they tend to shatter and fall on the ground The loss at the header can account for 90 percent of the total loss 2 Corn harvesting losses can occur as ear losses and kernel loss The largest corn loss usually is in ears left in the field C Precision agriculture equipment global positioning systems and yield and moisture monitors are calibrated by following the directions in the owner operator manual Vibra tion load weights and temperature are some of the calibrations that need to be made in order for the equipment to be accurate Use TM A7 7D 7 7 7 7 and A7 7G to reinforce the concepts of header loss and how it is calculated An alternative approach is to transfer the information from the transparency masters to a mul timedia presentation Use LS 7 78 7 7 and A7 7D to strengthen student understanding of con cepts Use text material to strengthen student understanding of concepts Chapter 5 in Combine Har vesting and Combines Reducing Harvesting Losses VAS 3049 are recommended Objective 3 Identify proper maintenance procedures for grain harvesting equipment Anticipated Problem What maintenance procedures should be
11. Lesson A7 7 Operating Calibrating and Maintaining Grain Harvesting and Handling Systems Unit A Mechanical Systems and Technology Problem Area 7 Agricultural Equipment Systems Lesson 7 Operating Calibrating and Maintaining Grain Harvesting and Handling Systems New Mexico Content Standard Pathway Strand Power Structural and Technical Systems Standard II Apply principles of operation and maintenance to mechanical equipment structures biological systems land treatment power utilization and technology Benchmark Perform scheduled services routines to maintain machinery and equip ment Performance Standard 7 Maintain vehicle machinery and equipment cleanliness and appearance 9 Design a preventative maintenance schedule 11 Calibrate metering monitoring and sensing equipment Student Learning Objectives Instruction in this lesson should result in students achieving the following objectives Explain the operating principles of grain harvesting equipment Explain the calibration of grain harvesting equipment Identify proper maintenance procedures for grain harvesting equipment Explain the principles of operating grain drying and handling equipment Explain the calibration of grain drying and handling equipment Identify proper maintenance procedures for grain drying and handling equipment DX OA SAX BS o ps ds Identify the grain quality standards associated with a given crop New
12. Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page List of Resources The following resources may be useful in teaching this lesson Recommended Resources One of the following resources should be selected to accompany the lesson Combines Reducing Harvesting Losses VAS 3049 University of Illinois Urbana Illinois ITCS Instructional Materials Combines Selecting and Servicing V AS 3048 University of Illinois Urbana Illi nois ITCS Instructional Materials Grain Drying Handling and Storage Handbook MWPS 13 Iowa State University Ames Iowa 1988 Griffin George A Combine Harvesting Moline Illinois Deere amp Company 1991 GROWMARK FS Grain Drying Guide FS Supplies Division Bloomington Illi nois Introduction to Combines V AS 3047 University of Illinois Urbana Illinois ITCS Instructional Materials USDA Official United States Standards for Grain Federal Grain Inspection Service USDA Washington DC 1995 Other Resources The following resources will be useful to students and teachers Farm equipment manufacturers Case IH Gleaner John Deere New Holland lit erature on their line of harvesting equipment List of Equipment Tools Supplies and Facilities Writing surface Overhead projector Transparencies from attached masters Copies of student lab sheets Combine parts Rope to make 10 square feet Crop seeds corn soybeans
13. ards were developed in 1916 to enable grain merchants to trade grain using consistent measurable criteria 5 Grain is harvested at high moisture contents to minimize 6 If the drying and handling system is properly maintained and adjusted costly premature loss of harvesting and can be reduced 7 The name combine developed when the and operations were combined into one complete machine 8 Drying and storage systems are designed around the 9 Factors that affect the condition of stored grain Part Three Short Answer Instructions Provide information to answer the following questions 1 What are the five goals of a well designed drying system 2 What are the six basic functions that a combine performs New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 12 AT TA TM COMBINE WITH CORN HEAD Courtesy John Deere New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 13 TM A7 7B COMBINE WITH SOYBEAN HEAD A ud 9877 1 Courtesy John Deere New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 14 TM A7 7C T P OIDs WI PP Sa uem SAN xs Ns 3iNISINOD SMON MOH New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem A
14. as it enters and leaves the sprocket d Check alignment of all sprockets in drive and correct misalignment when neces sary e Do not put a new chain on worn sprockets as its life will be shortened Use TM A7 7H provide examples of the servicing of combine belts and chains An alternative approach is to transfer the information from the transparency masters to a multimedia presentation Use text mate rial to strengthen student understanding of concepts Chapter 5 and 6 in Combine Harvesting and Com bines Selecting and Servicing VAS 3048 are recommended New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 6 Objective 4 Explain the principles of operating grain drying and handling equipment Anticipated Problem What are the principles for operating grain drying and handling equip ment IV The principles involved in the operation of grain drying and handling equipment involve factors relating to system design and the removal of moisture A Goals of a well designed drying system include 1 di a Timely harvest of top quality grain Safe and pleasant working conditions Ability to do important drying jobs efficiently such as a Holding wet grain to be dried b Drying wet grain c Cooling dried grain Capacity to handle grain at the harvesting rate Provisions for easy expansion in the future due to increased volume and harvesting rate B Grain dries due
15. e grain from the straw A Today the combine is a complex machine used to harvest and thresh all kinds of grain in a variety of crop and field conditions The name combine developed when the harvest ing and threshing operations were combined into one complete machine B To understand the operation of a combine look closely at each function of the machine Once the operation of each of these components is understood it becomes easier to un derstand how they relate to each other and to the operation of the entire machine C All combines perform six basic functions 1 The gathering of the standing crop is referred to as the cutting function Parts of the combine involved include the platform cutter bar and reel corn head snapping unit gathering chains snapping rolls and stripper plates 2 Delivering the cut crop material to the threshing unit in a steady uniform flow is called the feeding function Parts involved include the header or platform auger table auger feeder house feeder conveyor paddle conveyor or feeder chain New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 3 The threshing function involves the removal of grain from the head seedpod or cob by either a flailing or a rubbing action or a combination of both Parts involved include the cylinder or rotor and concave Separating the loose grain from the straw is referred to as the separation function
16. epts Grain Drying Handling and Storage Handbook MWPS 13 and FS Grain Drying Guide are recommended Objective 6 Identify proper maintenance procedures for grain drying and handling equip ment Anticipated Problem What maintenance procedures should be followed for grain drying and handling equipment VI Proper maintenance and service adjustments are necessary to assure efficient safe operation of the drying and handling equipment A Costly repairs premature wear loss of harvesting time and accidents can be reduced if the drying and handling systems are properly maintained and adjusted The operator s manual for the equipment should be used in reference to specific maintenance intervals location of service points and instructions for the performance of maintenance and ser vice adjustments B There are general maintenance practices to follow in order to make operating and main taining the drying and handling systems much easier and safer 1 Thoroughly clean all grain drying and handling equipment prior to use Always keep machinery and equipment clean Excessive build up of trash debris and fine dirt can cause heat build up part fatigue and failure and or fires 2 Inspect all bearing and friction surfaces for excessive wear Make sure that shields and other safety equipment are in place at all times New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 8 9 10
17. followed for grain harvesting equipment III Proper maintenance and service adjustments are necessary to assure efficient safe operation of the combine Costly repairs premature wear loss of field time and accidents can be reduced if the combine is properly maintained and adjusted A The operator s manual for the machine should be used in reference to specific mainte nance intervals location of service points and instructions for the performance of main tenance and service adjustments B The following are general maintenance practices that a good machine operator should always follow in order to make operating and maintaining the combine much easier and safer 1 Before starting the harvest season preliminary inspections and adjustments should be made following the guidelines in the operators owners manual 2 Always keep the machine clean Before starting the combine clean all field trash mud and excess grease and oil from the machine New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 5 3 Make sure that nuts cap screws shields and sheet metal parts are tight A loose shield can vibrate produce excess heat produce irritating noise and cause a machine to fail if it falls in the way of moving parts 4 Inspect the combine every day before starting A brief look at all areas of the com bine can help you spot potential machine failures and safety hazards 5 Kee
18. inability of the crop to stand is known as lodging Header losses occur when the header is operated improperly or when the crop tends to shatter easily Each type of header cutting platforms corn heads and windrow pickup units has operating characteristics which can cause losses Threshing losses are caused by unthreshed grain carried over straw walkers cracked grain due to overthreshing or cracked grain due to excessive tailings Material that is not completely threshed or separated is called tailings Straw walkers or separator losses are usually caused by feeding too much material over them at slow cylinder speeds and wide concave spacing when the combine is operating at excessive ground speeds Too much material prevents the grain from falling through the walkers and onto the cleaning shoe Cleaning shoe losses may be caused by too much air from the fan too much material on the chaffer or improperly adjusted chaffer and sieve Leakage losses can occur almost anywhere on the combine To guard against leak age inspect the combine to see that all inspection doors cleaning doors and drain New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 4 age doors are in the proper position and closed securely Also check for torn seals damaged sheet metal or holes B The areas of combine cutting feeding threshing separating and cleaning may be responsible for harvesting loss
19. iteria B Since 1916 numerous changes in the grading standards have occurred to reflect changes in technology the ability to measure quality and customer demands C Grade quality measurements are categorized as non grade determining factors grade determining factors and special grades 1 Non grade determining factors include moisture and possibly dockage depending on the grain Grade determining factors include test weight damaged kernels foreign material broken kernels odor and heating Grades are assigned based on the lowest factor Sample grade is the lowest possible category in the grading system Special grades depending on the grain include infested ergoty garlicky and smutty These words are added to the grade designation but do not determine the numerical grade Use text material to strengthen student understanding of concepts The Official United States Standards for Grain are recommended Have students research the Standards on the Internet Assign different crop standards to various groups of students Refer the class to www access gpo gov nara cfr waisidx_01 7cfr810_01 html This New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 9 is the Government Printing Office Web site It contains the Code of Federal Regulations and includes the Official Grain Standards Review Summary Use the student learning objectives to summarize the lesson Have studen
20. p maintenance records A simple chart showing when lubrication and service adjustments were made can help insure that all needed maintenance has been per formed 6 Do not abuse the machine Proper lubrication and adjustment is of little help if the operator abuses the machine Check all fluid levels daily prior to starting Lubricate bearings and chains as called for in the operator s service manual Check tire air pressures periodically throughout the harvesting season 10 Check belts frequently for correct tension excessive wear tearing cracking swell ing and unraveling a When replacing a belt never pry it over the rim of a sheave b Wipe off oil and grease as soon as they are spilled and then clean the belt with suitable cleaner that will not soak into it c Clean belts periodically in mild soap and water do not use strong detergents Use of belt dressings is not recommended because they may deteriorate the belt Check pulleys for misalignment excessive wear damage distortion and accu mulation of dirt and debris in the bottom of grooves 11 Maintain correct chain tension 1 4 inch of sag per foot between shaft centers a Chains should be removed from the combine for cleaning and lubrication at the end of every season b Add or remove offset links half links to ensure correct length and tension c Do not add new links to an old chain or old links to a new chain this will change the bite of the chain
21. rea 7 Lesson 7 Page 15 TM A7 7D TYPES OF HEADER LOSS SOYBEANS Shatter Stubble MT Stalk Lodged New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 16 TM A7 7E CALCULATING SOYBEAN LOSS 1 Total Crop Loss 2 Gathering 3 Pre harvest Unit Loss NT we 1977 Cut Standing 49 7 gos Beans Beans OTN wv LOSS DATA WORKSHEET Column C Column A Column B Acceptable Beans Found Number of Your Bean Loss Level in in 10 sq ft Beans to Loss in 40 bu acre Source of Loss area I bu acre bu acre yield Total Crop Loss 2 Pre Harvest Loss 3 Machine Loss 4 Gathering Unit Loss Totals of a Shatter b Loose Stalk c Lodged Stalk d Stubble Cylinder and Separation Loss New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 17 SSO 5501 peau 550 sqoo 5 5501 JapuljAD 5501 pue 5 SSO peau ulo 550 550 O9UJ9 peau UJO2 5501 5501 61104 550 129 SSO GUJ9Y SSO 129 pue 2 15 peusegunAuo
22. the clean grain fan located on the combine You are in the driver s seat How many augers in the grain tank What drives the cylinder Where are the concaves adjusted Size of the front tires rear tires Does this combine have a straw spreader Why is leasing a combine more of an advantage to some people than buying How many steps are on the entrance ladder New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 24 LS A7 7B Name Lab Sheet Calculating Harvest Loss Corn 1 100th Acre 1 100th Acre v 471 Area A Area B 2 3 4 Ib ears 4 3 4 Ib ears 6 1 2 Ib ears 6 1 2 Ib ears No broken ears No broken ears Harvesting Losses 1 Total Ear Loss behind machine Bu Acre 2 Pre harvest loss Bu Acre 3 Corn head loss Bu Acre A are 10 square feet B 200 loose kernels 600 loose kernels 100 kernels on partially shelled cobs Determining Total Kernel Loss No of No of Kernels Sq Ft Kernels Sq Ft Record Kernel Losses Counted 1 Bu A Loss Bu A Loose kernel loss behind combine 2 Loose kernel loss Snapping rolls 2 Separator and shoe loss No 1 minus No 2 2 Cylinder loss Kernels on partially shelled cobs 7 Total loss acre Add lines 2 3 and 4 Total ear loss acre Line 3 Harvesting Losses 0 Un DB Total corn harvesting loss
23. to the removal of water leaving dry matter 1 2 4 Grain is harvested at high moisture contents to minimize field losses Grain that is harvested as too wet for safe storage is usually dried for maximum mar keting potential and storage flexibility Grain must be artificially dried to reduce the moisture content to a safe storage level to prevent spoilage a A fan picks up air carries it over an energy source gas electric solar etc to improve its moisture holding capability pushes the air through the grain mass to absorb the moisture from the grain and then carries it outside the system b The layer being dried is referred to as the drying zone only the grain in this zone is drying The grain above this zone remains wet while the layer below is dry c The leading edge of the drying zone is called the drying front Equilibrium moisture content is the point when continued contact with the drying air results in no further moisture reduction Drying system capacity should be suffi cient to receive and handle the daily harvest rate and allow for increasing capacity in the future Length of time grain can be stored at a given moisture content and temperature is known as allowable storage time AST a Drying and storage systems are designed around the allowable storage time b A combination of high moisture content and high temperature leads to fast mold growth and rapid spoilage c Factors that affect the condition
24. ts explain the content associated with each objective Student responses can be used in determining which objectives need to be reviewed or taught from a different angle Application Use the accompanying lab sheets to help students in applying the lesson s con tent LS A7 7A Combine Data Sheet LS A7 7B Calculating Harvest Loss Corn LS A7 7C Calculating Harvest Loss Soybeans LS A7 7D Calculating Harvest Loss Small Grain Evaluation Evaluation should focus on student achievement of the objectives for the les son Various techniques can be used such as student performance on the application activity A sample written test is attached Answers to Sample Test Part One Matching 2 1 3 4 5 7 8 9 10 Part Two Completion 1 handling 2 non grade grade special 3 4 quality 5 field losses 6 repairs wear time accidents 7 harvesting threshing 8 allowable storage time 9 insects rodents bacteria Part Three Short Answer 1 Timely harvest of top quality grain safer and pleasant working conditions ability to do important drying jobs efficiently capacity to handle grain at the harvesting rate provi sions for easy expansion to future due to increased volume and harvesting rate 2 Cutting feeding threshing separating cleaning handling New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page
25. wear of sprockets and chains Never pry a belt over a pulley This breaks the cords in the belt and will result in belt roll over and early belt failure Check pulley alignment Pulley misalignment will result in distortion of belts which results in excessive wear and damage Keep chains adjusted to 1 4 sag per foot between shaft centers Over tightening produces rapid chain and sprocket wear Loose chains whip and can cause chain and sprocket damage New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 20 TM A7 71 GRAIN DRYING PRINCIPLES r NS 2 Wet grain Drying zone Dry grain The drying zone starts at the bottom When it reaches the top drying is completed Spoilage will occur if the drying zone doesn t reach the top within the allowable storage time New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 21 TM 7 7 MAXIMUM STORAGE LIFE FOR SHELLED CORN Grain Moisture Content wet basis Temperature CF New Mexico Agricultural Mechanics and Technology Lesson Plan Library Unit A Problem Area 7 Lesson 7 Page 22 TM A7 7K STORAGE MOISTURE CONTENTS Grain Drying Tables Equilibrium Moisture Contents Relative Humidity 30 Corn 96 Maximum Moisture Contents for Grain Harvest and Safe Storage
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