11. Harvesting Practices

By John A. Smith, Mark D. Schrock, Randal K. Taylor, and Randy R. Price

The productivity of wheat harvest and the role of wheat harvest within the larger picture of multi-year cropping systems are being improved through new technologies. Refinements such as header height control, automated threshing and cleaning adjustments, auto-steer, uniform spreading of straw and chaff, and yield mapping have increased machine capacity, increased operator efficiency, reduced grain damage, and improved productivity of the overall cropping system. The following sections describe some of these technologies available with today’s combine harvesters.

General Combine Types and Selection

The two basic types of combines are “conventional cylinder” and “rotary.” Conventional cylinder combines use a cylinder-concave threshing mechanism located near
the front of the combine, with its axis perpendicular to the direction of material flow and combine travel. Because the cylinder is positioned transversely within the combine, the cylinder can only be as wide as the inflow of material. This cylinder-concave combination threshes the crop using an impact and rubbing type action. The concaves and grates located at the bottom of the cylinder drum allow seed and chaff to exit the cylinder area and drop into the grain cleaning system, which consists of a set of sieves where the seed is cleaned with air. A tailings auger is used to catch any remaining unthreshed heads and return them to the cylinder for rethreshing. Straw exits at the top, rear of the cylinder onto straw walkers, which use a vibrating action to move the straw through the combine and to separate out any remaining seed or chaff. Rotational speed of the cylinder is an important factor in breaking of kernels and threshing efficiency.

Figure 11.1 Combine with rigid header harvesting winter wheat.

The rotary combine uses a rotating, threshing, separating mechanism with its axis parallel to the direction of combine travel. Because of this orientation, the threshing mechanism can be much longer than that of the conventional combine. Material moves through the combine in a helical, spiraling type path, first through the threshing section and then through the separation section. A fan and sieve combination is used to separate the chaff from the seed. The rotary separation mechanism eliminates the need for straw walkers.

Rotary combines tend to be gentler to the seed because they contain fewer moving parts and have higher throughputs than conventional cylinder machines. However, rotary combines also tend to require more engine power and break straw into shorter lengths so that baling the straw is more difficult. A conventional combine is recommended if baling is desired (for haying or bedding).

Combine size and capacity have increased dramatically through the years. There is not currently a consistent criterion available for designating or comparing combine capacity. Before rotary combines became popular, conventional combines were according to the number of individual sections of the straw walker. Engine power, grain tank size, and grain tank unloading rate were added as additional descriptive measures of combine ‘size.’ Today, this classification is used only to report combine sales and is based solely on advertised engine power. Current reporting classes include:

• Class 5 under 200 kw (268 hp)

• Class 6 200 kw (268 hp) to under 240 kw (322 hp)

• Class 7 240 kw (322 hp) to under 280 kw (375 hp)

• Classes 8 & 9 over 280 kw (375 hp)

The size and capacity of combines continues to increase as evidenced by the recent introduction of a nearly 500 horsepower class 9 machine. Increases in size of combines and associated headers offers increased field capacity but also necessitates an increase in the level of system management.

Header Types

For decades, rigid headers (Figure 11.1) using an auger to convey the crop to the feeder house have been the standard of wheat harvest. Recently, however, two new wheat header concepts have gained popularity.

Stripper Headers

The stripper concept of harvesting wheat offers many advantages (Figure 11.2).

The stripper header does not cut the wheat stalk but rather engages wheat spikes with plastic-backed stainless steel combs attached to a transverse rotor. The rotor rotates in the opposite direction of the combine wheels, so the spikes are combed with a forward and upward motion. Most of the kernels are threshed from the spike and enter the combine as loose grain. Depending on crop conditions, part of the grain may enter as unthreshed spikes and spike fragments.

The stripper header reduces the amount of material other than grain (MOG) entering the combine by 80 to 90 percent. Because the stem is not cut, straw remains in the field, and the combine processes very little MOG when compared to conventional rigid headers. The low amount of MOG eases the separation and cleaning processes and increases the capacity of conventional cylinder combines by 30 to 100 percent. Rotary combine capacity is more limited by factors affecting ground speed, such as terrain roughness, than by separation capacity (with either type of header). Wheat separation and cleaning losses from a combine equipped with a stripper header are usually quite low.

Stripper heads also improve crop residue management. Because the straw is never gathered into the combine, the combine straw discharge does not have to be chopped and spread as with a conventional header. This reduces combine power requirements and eliminates the need for optional equipment to handle the residue, although chaff and fines may still need to be spread. Furthermore, the tall, stripped stubble has positive implications for subsequent no-till planting, as well as favorable evaporation and snow catch characteristics for fallow cropping systems.

Stripper headers work best in a high yielding crop. In thick wheat, the incoming crop retards movement of loose grain and gives the rotor a second chance to deliver it into the header. Percentage of grain losses are higher in short, thin, droughty wheat. At four miles per hour ground speed, increasing wheat yield from 30 to 90 bushels per acre can reduce losses from about 5.5 percent to just under 3 percent. The greater header loss from stripper headers, relative to conventional headers, is offset by lower separation and cleaning losses and larger combine capacity.

Losses from a stripper header are usually reduced by increasing the ground speed. Increasing ground speed from 2.3 to 5.4 miles per hour can reduce losses from about 7 percent to just over 4 percent. Most new operators of stripper headers require a day or two of experience to accept this counterintuitive trend (higher speeds producing less grain loss).

Draper Headers

Draper swathers have always been popular in the northern plains because they gently swath wheat, but more recently they have become popular for combines. There are several advantages of draper headers over auger headers in wheat.

Figure 11.2 Stripper header on wheat combine.

stripper header on wheat combine

First of all, wider models are available in draper configuration. Auger headers over 30 feet wide are rare due to problems with auger runout and thermal warping. Because draper headers eliminate the table auger, they can be substantially wider than flex or rigid headers. This is important because the 30 foot header size limit has become a limiting factor, given the recent increase in combine threshing, separation, and cleaning capacities. Unacceptably high ground speeds may be needed to compensate for the limitations of a 30 foot header on a large combine in typical Great Plains wheat.

Draper headers feed the crop more uniformly than auger headers. With an auger header, there is a space just behind the cutterbar and in front of the auger where the crop is not in contact with either the reel or the auger. Also, the orientation of the crop entering the feeder house is random. In contrast, a draper header reel delivers the cut crop directly onto the draper which moves it laterally onto a center draper. The center draper then moves rearward into the feeder house. Draper headers tend to feed the wheat plant head first into the threshing element of the combine, resulting in smooth feeding that increases the degree of capacity 20 to 30 percent.

The wider models of draper headers commonly incorporate suspended outrigger wheels and an integral means of transport. In some cases, the conversion to transport mode involves changing the wheels from field position to transport position and repositioning a hitch tongue. The rapid, easy conversion from field to transport is an important feature for custom harvesters.

Combine Sensors and Control Systems

Today’s combines are more complex than those from just a few years ago. Although general combine design and processes have changed little, there have been many recent advances in sensors and control systems. Steering and speed control systems are relatively new. Yield monitors and protein sensors to gather data regarding crop production are also newly available. The industry will continue to see such advances as we attempt to automate repetitive harvest tasks.

Header Control

Some of the earliest control systems for grain combines were developed for the header. Automatic reel speed control systems adjust reel speed relative to ground speed to maintain uniform crop flow into the header. Proper reel speed adjustment will reduce potential shattering of grain and header loss. These automated systems maintain the reel speed to ground speed ratio as the combine operator makes ground speed adjustments.

Header height control systems are common in soybean production and are gaining popularity in wheat as grain platforms have become wider. These systems maintain the header at constant height from the ground. In severely sloped terrain, the stan- dard system may keep one end of the header from hitting the ground while raising the opposite end out of the wheat crop. In combines equipped with a tilting feeder house, the operator also can control header tilt, which maintains the entire header at the desired height across rolling terrain.

Automatic Steering Systems

Guidance systems for tractors and sprayers that use Differential Global Positioning

System (DGPS) receivers to reduce skips and overlaps are becoming more common in the Great Plains. Reducing operator fatigue is the primary benefit of these systems on combines. Removing the need to steer reduces stress and frees the operator for other tasks. Generally, DGPS guidance systems are limited to straight lines, but recent advances in laser scanning guidance may be applicable in wheat harvesting. A laser scanner would examine the crop ahead of the combine and make steering adjustments to keep the header full even if this requires an irregular path. This should result in increased productivity and reduced operator fatigue in solid seeded crops like wheat.

Speed Control Systems

Similar to cruise control on cars, combine speed control systems adjust ground speed to maintain the desired material flow through the combine. Good combine operators do this intuitively, but it can be challenging to adjust speed in response to subtle changes in crop density. A speed control system uses sensors in the combine to measure capacity or load. When engaged, it will control ground speed to keep the combine fully loaded, increasing potential capacity by 5 to 15 percent.

Yield Monitors

Yield monitors are common in the Corn Belt but are used less in wheat producing areas. Basic yield monitor components are flow, moisture and field speed sensors, a DGPS receiver, a processor, and a display. Flow sensors measure the mass or volume of grain flowing through the clean grain system. The most common design in wheat producing regions is an impact flow sensor mounted in the clean grain elevator. An initial calibration for wheat is required in the first season, but then can be simply checked in following seasons. To calibrate, compare the yield monitor reading for one load to the measured mass from a reference scale, which can be a weigh wagon or the scale at a local elevator. Some yield monitors may require multiple loads for accurate calibration, which should be at different flow rates. The yield monitor also will require separate calibrations for other crops.

The moisture sensor, a popular yield monitor component, also requires initial calibration. Compare the sensor moisture reading to that from a reliable moisture meter, and apply an offset so that they match. The combine operator can now assess grain moisture instantaneously. This facilitates decisions such as whether to keep harvesting and whether the grain needs more time to dry.

Sensor data are used to calculate yield, which the DGPS receiver allows us to map. Major uses for yield maps include diagnosing crop production problems, conducting on-farm research, and determining spatial yield potential. Most producers know where the good and bad spots are in their fields, but the yield monitor allows them to measure and map problem areas. The producer who uses custom harvesters does not get to ride the combine and see the yield variation, so the yield map may be the only available feedback on production problems.

Most farmers have conducted some type of on-farm research by measuring yields with a weigh wagon or by sending partially loaded trucks to the elevator, which can seem overwhelming in the rush of harvest. Yield monitors allow seamless yield data collection without impeding harvest. Farmers can develop yield potential maps from multiple years of yield monitor data, which can be used to guide input decisions for future crops.

Data from the yield monitor, moisture sensor, and DGPS receiver can be integrated into maps, showing specific yield and grain moisture performance of different sections of the field. These maps can be combined with soil type maps and fertilizer application maps to improve management of the crop. In addition, most field mapping systems allow the combine operator to insert notes (map ‘flags’) in the map, which can be used to locate particular weed infestations, broken terraces, drainage problems, or other visible areas of interest.

Protein Sensors

The development of accurate combine mounted protein sensors, used to create grain protein maps, is ongoing. Protein sensors could be used to segregate grain based on protein content or to establish nitrogen management zones. While protein measured with combine mounted sensors is correlated with laboratory measurements, sometimes the correlation is not strong enough to allow grain segregation. However, there was sufficient correlation to delineate nitrogen management zones. As with any sensor, calibration is a necessity.
Sensor and control system technology for combines continues to advance. More sophisticated control systems will evolve as more sensors are developed and improved. These systems will ease the workload on combine operators but will likely alter, if not increase, the skill required to operate a wheat combine.

Straw and Chaff Spreading and Chopping

The question of whether to windrow or spread the straw and chaff that is discharged from the combine is answered by the goals of the overall cropping system. In some systems, the straw is simply a nuisance in the field and provides income if packaged and removed from the field. In other systems, the residue provides soil surface cover, reducing soil erosion and improving conservation of soil water. In either case, the success of the overall system often depends on how uniformly the straw and chaff are distributed behind the combine or how well the windrows are made to accommodate complete pickup by a baler or other pickup equipment.

Most experienced no-till or conservation tillage producers will say that their production system begins with uniform distribution of both the straw and chaffbehind the combine Problems associated with uneven residue distribution can include:

• Plugging of tillage equipment and bunching of residue (if tillage is used).

• Plugging of planting equipment.

• "Hair pinning" of residue into the seed furrow and inadequate seed-soil contact.

• Too much residue in one area shielding soil from the sun, or too little residue in another area exposing the soil to water evaporation and erosion.

• Concentrations of residue shielding the soil and weeds from herbicide application.

• Weed and volunteer wheat control difficulties in concentrated windrows.

Generally, chaff and fines are more of a problem to spread uniformly than the long straw. Straw tends to be "heavier" and is easier to move mechanically or with air. The quantity of chaff and fines can be significant and pose a large problem if not spread.

Approximately 10 bushels per acre of wheat is associated with about 1000 pounds per acre of above ground residue. Of this residue, approximately half is cut by and taken into the combine. Of the material that passes through the combine, 30 to 70 percent drops from the sieves as "chaff" and never reaches the straw spreader. For example, if we assume a 40 bushels per acre grain yield and 50 percent of the material passing through the combine is chaff, then there will be approximately 1000 pounds per acre of chaff discharged by the combine. If that is distributed over half the combine header width, there would be 2000 pounds per acre chaff cover where the chaff lands. If the chaff is only distributed over 1;4 the width of the header (8 ft. windrow behind 35 ft. head), then the concentration of chaff would be 4000 pounds per acre. This is an excessive residue concentration.

Roughly 2000 pounds per acre of residue can provide significant benefits in reducing soil erosion and soil water evaporation. However, if this residue amount covers the planted row of an emerging crop it can have negative effects, such as reducing soil temperature or causing an allelopathic effect that hinders normal development of the crop seedling. Uniform distribution of the residue behind the combine can contribute significantly to the success of no-till and conservation tillage systems.

Complete, uniform distribution of straw and chaff behind the combine can be very difficult to achieve, but perfect distribution is not necessary. Several practices can help:

• Leave stubble as tall as possible. Less material going through the combine means less material to spread uniformly.
• Avoid stopping the combine in one spot. If you need to stop the forward motion of the combine, keep the combine moving in reverse or in a circle over the harvested stubble until it cleans out. This will avoid a large pile of residue.
• If wind prevents good side-to-side distribution, change combine directions if possible.
• Experiment with any adjustments, such as to deflectors, to the side and to the rear that might help residue distribution, particularly in windy situations.
• Examine the spreader mechanism for wear (including bats, spinning disks, and flails).
• Try any options for speed of rotation of the spreader mechanism.
• Consider a stripper header which will leave all the straw attached to the soil and will reduce the amount of chaff and fines that need to be distributed.

If removing the wheat straw from the field is the goal of the cropping system, then attention must be given to making a windrow that will best accommodate the baling or packaging equipment. Avoid aggressive threshing to minimize breaking the straw into short pieces, which do not maintain good bale shape. Rotary combines generally break the straw into much shorter pieces than conventional cylinder machines. Some producers who focus on baling wheat straw choose custom combiners with conventional cylinder machines. Certain adjustments, particularly close concave settings, tend to break straw into small pieces in combines with rotary threshing systems. Rotor cage vanes can be adjusted in some machines to move the straw through the rotor more quickly to increase straw length, but at the risk of increased rotor grain loss.

Keep windrows as narrow as possible to match the pickup headers on balers. Some of the fines and chaff from the sieves will be picked up by the baler but much will often be too fine to be picked up. What is left may create a dense residue that can create problems in the following crop. To avoid this problem, producers may need to windrow the straw but spread the chaff and fines.

Some producers do not want windrow or distributed long straw left behind the combine, and it is preferred to chop the straw into fine pieces and spread over a wide area. Straw choppers are now available that can chop the straw into very fine pieces and spread this material uniformly over a 30 foot width (in the absence of wind) to allow the straw to break down rapidly.

Estimating Wheat Harvest Losses

Check the combine frequently to ensure efficient harvesting. During a single after­ noon, conditions can change enough to require resetting some of the machine's com­ ponents. Ground counts are based on the general rule that it takes about 20 kernels of wheat per square foot to equal one bushel per acre when spread evenly across the field.

Although ground counts are a simple concept, finding all the loose kernels lying in stubble can be tedious, particularly if heavy residues remain from the previous crop. Many producers train a truck or cart driver to perform initial ground counts, so the combine can keep harvesting during the count. The only equipment needed to check losses is a one square foot frame. Follow these steps to determine losses:

1. Cut through a typical area at the usual speed, then stop the combine and back up about 20 feet.

2. In the area behind the separator discharge, lay the one foot square frame down three times and take ground counts, including both loose and unthreshed kernels. Average the three counts to get the separator count.

3. In the area between the cutter bar and the standing wheat, take three more ground counts and average them. Do not forget to look for heads. This is the header count.

4. Take a final three ground counts in the standing wheat and average them. This is the preharvest count.

5. Calculate header loss in bushels per acre.

header loss

6. Calculate the separator loss in bushels per acre.

separator loss

Since header width for most combines is about four times as wide as the separator, it takes about 80 kernels per square foot behind the separator discharge to equal one bushel per acre if no spreading devices are being used. If your combine has a bat type spreader, use 65 kernels per square foot instead of 80. If you have a straw chopper, use 50 and if you also have a chaff spreader, use 25.

What are acceptable losses? This depends on the operator and the condition of the crop. However, for standing wheat under good harvesting conditions, machine losses can usually be held to two percent of the total yield. Higher losses will have to be tolerated in downed or damaged wheat.

Combine Settings

The best source of information on combine adjustment is the operator’s manual for the specific combine model being used. With the intent of reinforcing and supplementing the manual, the following adjustment principals and guidelines are offered.

Header Height

Height of cut is a frequent adjustment during wheat harvest and has a substantial impact on harvest loss, combine capacity, operating cost, and even subsequent crop yields. In general, the cutter bar height should be set as high as possible without missing more than a few of the lowest heads. Uniformity of head height varies with variety and growing conditions, but a three year study of nine varieties in Fort Collins, Colorado suggested that a cutting height of 2/ the average head height would result in a loss of less than 0.5 percent. Low heads usually contain less grain than average.

In wheat, material other than grain (MOG) usually drives separator loss, so taller stubble will increase combine capacity and reduce fuel consumption per acre. Fuel savings of up to 30 percent can result from higher height of cut, while staying within permissible loss limits. In addition, taller stubble reduces straw-handling problems for subsequent cropping systems, particularly if a double crop is planted immediately after wheat harvest.

Taller stubble reduces evaporation. Increasing stubble height from 4 to 20 inches can reduce potential evaporation by about 40 percent, at a stem density of 170 stems per square yard. Increasing wheat stubble height from 4 inches to 10 inches can increase subsequent no-till corn yield from 40 bushels per acre to nearly 65 bushels per acre. Corn and grain sorghum can yield five bushels per acre more following stripped wheat. Taller stubble improves wildlife habitat. Increasing the stubble height from 9 inch- es to 18 inches produced a nearly nine-fold increase in winter pheasant populations in western High Plains wheat.

Combine Speed

Travel speed is another frequent operator adjustment. With conventional cylinder combines, the straw walkers are usually the first component of the separator to over-load. This becomes evident only if a loss monitor is used correctly. Grain yields have large spatial variations, so frequent changes in combine travel speed are needed for best performance. Generally, rotary combines are less susceptible to separator over-load caused by excessive speed or MOG input.

Combine Adjustments

Adjust table auger finger timing to achieve smooth feeding into the feeder house. Fingers should be adjusted to extend later when harvesting light droughty wheat. Finger timing is usually adjusted by rotating a plate on the undriven end of the table auger (see owner’s manual).

Adjust table auger strippers as close as practical to the auger flighting. Care must be taken to allow clearance for auger run out, including the transient thermal warping that can be caused by direct sunlight. Wider headers require more clearance between auger and strippers. Floor strippers are recommended when available.

Set cylinder or rotor speed and clearance to thresh the crop no more than needed to dislodge the grain and separate it efficiently. Overthreshing wastes power and can crack grain, overload the cleaning shoe, impede baling the combine discharge, and lead to rapid wear of concaves, bars, and drive systems. Cracked grain usually is caused by excessive cylinder speed rather than insufficient cylinder-concave clearance.

Most combines sold in the Great Plains are "corn-soybean" models, because the penalty for using such a combine in wheat is less than the penalty of using a wheat combine in corn and beans. However, wheat growers may find it advantageous to exchange the 1% inch louvered corn-bean chaffer for a 1 1/8 inch wheat chaffer. Fixed air­foil and adjustable Peterson chaffers are also available for most machines and should be considered, especially if the combine is also used in canola.

Harvesting Infested Crops

Winter annual grasses are best managed by herbicides and crop rotations, but to harvest an infested crop, the following practices are suggested:

1. Harvest heavily infested wheat fields last to give the weedy grasses time to dry.

2. Set the chaffer toward the open end of the recommended range.

3. Set the cleaning sieve toward the closed end of the recommended range.

4. Set the fan toward the high end of its recommended range.

5. Be watchful for excessive return and make adjustments as needed.

6. Manage combine traffic patterns. The combine can carry weed seed for over a minute, potentially spreading seed from an isolated infestation over a wide area.

Moisture Docks

Be prepared to take a modest moisture dock at the beginning of harvest. Many farmers wait until wheat dries to the point that it is accepted into commercial channels with zero moisture dockage before beginning harvest. If the wheat harvest is long, this can result in very dry (less than 10 percent) wheat during the last days of harvest. Over dry wheat represents lost income as surely as the moisture dockage that would have occurred with an earlier start date. A balanced approach, accepting a modest moisture dock at the start of harvest, results in earlier harvest completion, less weather exposure, and improved double-cropping potential.

Soil Compaction from Combines and Grain Carts

Combines and grain carts are usually the heaviest equipment items on a field. Large combines with wide headers and 300 plus bushel grain tanks can have total loaded weights approaching 60,000 pounds. Grain carts are now as large as 1400 bushels and can have loaded weights of nearly 100,000 pounds. If not equipped with properly designed tire or track systems, these high loads can potentially cause serious soil compaction, which will negatively affect future crops.

Combine or grain cart weights as high as 60,000 pounds or even 100,000 pounds do not necessarily cause soil compaction. There are several factors which will determine whether these, or even much lower implement weights, will cause soil compaction.

Soil moisture content

As soil moisture content increases, the ability of the soil to resist mechanical deformation or alteration in structural integrity decreases, making soil compaction more likely. When the soil is “too wet,” it is best to simply stay out of the field.

Repeat traffic

Soil compaction can accumulate with repeat passes of a tractor or implement. One pass might be sufficient to create only a low or moderate level of soil compaction. Repeated traffic by the same implement over the same path will increase the level of soil compaction. Avoid repeat traffic where possible, or intentionally designate a driveway to limit the area of soil compaction. Generally, most soil compaction below the soil surface will occur on the first pass.

Soil-to-tire or soil-to-track pressure

It is not necessarily the total weight of an implement or the axle load that can cause soil compaction. Instead, it is the pressure of the tire or track surface to the soil. This soil contact pressure can be managed to avoid soil compaction by using “enough” tire or track to support the axle or implement load.

Avoiding Soil Compaction

Contact pressures between the tire or track and the soil of less than about 10 or 12 pounds per square inch (psi) rarely will cause soil compaction in most field conditions, unless the soil is very wet or very loose. In contrast, contact pressures above 30 or 40 psi will often cause some level of soil compaction, again depending on several factors. Whether soil compaction will be caused by contact pressures between these two general pressure levels will depend on many factors, primarily soil water content and tillage condition.

We can address the soil pressure problem by having enough supported, rubber track on the implement or by having "enough tire" on the implement. For example, a 36 inch wide rubber track with appropriate support idlers and 12 feet of contact length has 36 square feet (5,184 square inches) of contact surface. One track of this size could support 40,000 pounds with an average soil contact pressure of 7.7 psi, which should be acceptable to avoid soil compaction in most cases. The effective soil-to-tire contact pressure of a correctly inflated radial tire will be approximately 2 psi higher than the inflation pressure. Most modern radial tractor and combine drive tires, and some implement load bearing tires, are designed to operate as low as 6 psi with a designated maximum axle load. To apply this rule, we must consult a tire handbook (available at tire dealers or on the tire manufacturers' websites) and specify enough tires and large enough tires to maintain a recommended inflation pressure below 8 or 10 psi (or at least as low as practical) for the actual axle load. In reality, with very high axle loads possible with the largest combines and grain carts, it is difficult to specify enough large tires to achieve the desired low inflation pressures. Large belted track systems may offer better floatation.

Avoiding soil compaction with very large combines and grain carts is a real issue with wheat harvest. A combination of management tools can prevent soil compaction in almost all cases:

• Stay off very wet fields when possible-allow a day or so to dry.

• Avoid repeat traffic, or create a small area for designated traffic.

• Keep tire or track-to-soil contact pressure below 10 psi or at least below 15 psi.

• Use wide belted tracks or large radial tires with low inflation pressure to achieve needed floatation.

• If the soil is too wet or other conditions suggest soil compaction may be occurring, only load the combine grain tank or grain cart half full to reduce axle weight and track or tire-to-soil contact pressure.

• Judicious 'spotting' of trucks, providing multiple field access points and unloading prematurely when the combine is close to the truck, can often reduce combine and cart travel.

• Local band radios enhance management of grain carts to avoid unnecessary travel of both grain carts and combines for unloading.

New technologies in the various forms of machine design, sensors, controls, and management techniques allow the wheat producer to maximize wheat yield, reduce input costs, and conserve natural resources as the wheat crop is harvested. These new harvest technologies will continue to evolve and allow the wheat producer to maximize productivity, profitability, and sustainability.