Reducing Losses at Harvest Time
Sep 04, 2019
by Braden Olsen
Each year farmers devote countless time, effort and money towards their crops in hopes of producing big bushels and profits. After spending the fall and winter planning for the growing season ahead, the spring planting season kicks off by properly setting seeding equipment so the crop has the best possible chance to get established. Monitoring the crop throughout the growing season helps to minimize losses from weeds, insects and diseases. The possibility for losses continues at harvest time, so great care should be taken to minimize them until every kernel of grain is shipped to its buyer. These losses can occur due to improper combine settings, untimely crop desiccation, or other physical characteristics, such as lodging, that make harvesting difficult.
Setting your combine and measuring losses
The first step in reducing harvest losses is to ensure your combine is properly set. Even though technology has allowed farmers to monitor losses from the operator’s seat, it is still important to get off machine the and check. Loss monitors indicate whether losses are going up or down, but do not measure how many bushels are actually being thrown over. To accurately measure how many bushels per acre are being lost, a drop pan is required to catch the material exiting the back of the combine. Calculations can then be made based on the number of seeds that are collected in the pan.
The Canola Council of Canada and Prairie Agricultural Machine Institute (PAMI) have worked together to determine a way to accurately measure combine threshing losses.
1. Disengage the straw chopper/spreader so that all of the straw and chaff is dropped into a swath behind the combine.
2. Drop a pan, 1 ft2 in size, underneath the combine after the header has passed over. This will ensure that the pan does not collect header losses.
3. Weigh the seeds collected in the pan after all the straw and chaff has been removed.
4. Determine a concentration factor for your combine by dividing the width of the header by the width of discharge behind the combine.
5. Determine your combine loss in lbs per acre by plugging in the concentration factor and weight of seeds lost into Figure 1
Figure 1. Concentration factors to determine combine yield loss (Canola Council of Canada and PAMI, 2015)
Once you have calculated your combine losses, you can decide if they are acceptable or if the combine settings need to be adjusted to lower the amount grain being thrown over. The Canola Council of Canada recommends combine losses of about 0.5 bu ac-1 and that they should be less than 1.0 bu ac-1. Their priority recommendation for reducing combine losses is to reduce travel speed. Combine losses generally remain low at travel speeds below the point where the combine has reached its maximum threshing capacity. Travel speeds as little as 0.2-0.3 mph faster than the combine’s maximum capacity can cause significant yield loss and losses continue to rise steeply as you go faster. If the threshing speed, fan speed, sieve or chaffer must be adjusted to improve the sample or reduce losses, ensure that you only adjust one device at a time and recheck your losses.
Proper Harvest Timing
Improper harvest timing is another factor that can cause significant yield loss. Desiccation and swath timings differ for each crop and product but, at minimum, seeds must reach physiological maturity. If the crop is desiccated or swathed too early there is a possibility for yield loss from seeds that will not properly fill out. This can also reduce the crop quality due to reduced seed size or seed discoloration. On the other hand, leaving the crop stand mature for too long before harvest can also result in yield and quality losses. Shelling, as a result of wind or other extreme weather events, wreaks havoc on ripened crops. Quality losses such as bleaching, decreases in protein, and sprouting, can also limit grade potential when ripe crops are left to weather. It is ideal to have crops ripen in succession throughout harvest as the combine becomes available. Staggering spraying and/or swathing timing or seeding crops and varieties with different days to maturity will help spread out harvest. Seeding crops and varieties with different days to maturing will also help with harvest management. For example, growers with a large number of canola acres have had success with planting multiple canola varieties with a range in maturity. Seeding the earlier maturing varieties first and the later maturing varieties last allows for the canola crops to naturally mature at different dates during harvest.
Dealing with Lodged Crops
Lodged crops, as a result of recent rains, strong winds, and a heavy canopy, is a common occurrence this harvest. Although lodged crops can make harvest more difficult, there are a few things that can be done to help capture as much yield as possible. Because conditions under the mat of lodged crop create a perfect climate for diseases and, as the seeds mature, sprouting, the crop may need to be swathed or desiccated earlier than normal to allow for the crop to be harvested before these issues significantly reduce quality. Picking up lodged crops is also of concern and crop lifters, pick-up reels and air-reels are all tools that can help. Lifters make it possible for the header to cut all the crop, while not having to shave the ground. This will make for easier and faster harvesting because less material is travelling through the combine. Also, more straw will be left behind to catch snow over the winter. Regardless of your header options, combine travel speeds will ultimately have to be reduced. A reduction in speed will help ensure the header is picking up as much crop as possible and also that the combine has a chance to properly thrash. Lodged crop leads to uneven feeding of the combine, which reduces its threshing efficiency. Thus, more time is needed for the combine to properly thrash the grain, so that is not lost out the back end of the combine.
Every decision made on the farm throughout the season is motivated by putting as much high quality grain into the bin at harvest as possible. Once the combines hit the field, it is more important than ever not to lose sight of this goal as the potential for yield and quality loss is at its peak. With lots of acres and only a short harvest window, it can be tempting to push your harvest timing and equipment to its limits. However, by slowing down and understanding where your harvest losses are coming from you can maximize the number of bushels in the bin at the end of the day
Each year farmers devote countless time, effort and money towards their crops in hopes of producing big bushels and profits. After spending the fall and winter planning for the growing season ahead, the spring planting season kicks off by properly setting seeding equipment so the crop has the best possible chance to get established. Monitoring the crop throughout the growing season helps to minimize losses from weeds, insects and diseases. The possibility for losses continues at harvest time, so great care should be taken to minimize them until every kernel of grain is shipped to its buyer. These losses can occur due to improper combine settings, untimely crop desiccation, or other physical characteristics, such as lodging, that make harvesting difficult.
Setting your combine and measuring losses
The first step in reducing harvest losses is to ensure your combine is properly set. Even though technology has allowed farmers to monitor losses from the operator’s seat, it is still important to get off machine the and check. Loss monitors indicate whether losses are going up or down, but do not measure how many bushels are actually being thrown over. To accurately measure how many bushels per acre are being lost, a drop pan is required to catch the material exiting the back of the combine. Calculations can then be made based on the number of seeds that are collected in the pan.
The Canola Council of Canada and Prairie Agricultural Machine Institute (PAMI) have worked together to determine a way to accurately measure combine threshing losses.
1. Disengage the straw chopper/spreader so that all of the straw and chaff is dropped into a swath behind the combine.
2. Drop a pan, 1 ft2 in size, underneath the combine after the header has passed over. This will ensure that the pan does not collect header losses.
3. Weigh the seeds collected in the pan after all the straw and chaff has been removed.
4. Determine a concentration factor for your combine by dividing the width of the header by the width of discharge behind the combine.
5. Determine your combine loss in lbs per acre by plugging in the concentration factor and weight of seeds lost into Figure 1
Figure 1. Concentration factors to determine combine yield loss (Canola Council of Canada and PAMI, 2015)
Once you have calculated your combine losses, you can decide if they are acceptable or if the combine settings need to be adjusted to lower the amount grain being thrown over. The Canola Council of Canada recommends combine losses of about 0.5 bu ac-1 and that they should be less than 1.0 bu ac-1. Their priority recommendation for reducing combine losses is to reduce travel speed. Combine losses generally remain low at travel speeds below the point where the combine has reached its maximum threshing capacity. Travel speeds as little as 0.2-0.3 mph faster than the combine’s maximum capacity can cause significant yield loss and losses continue to rise steeply as you go faster. If the threshing speed, fan speed, sieve or chaffer must be adjusted to improve the sample or reduce losses, ensure that you only adjust one device at a time and recheck your losses.
Proper Harvest Timing
Improper harvest timing is another factor that can cause significant yield loss. Desiccation and swath timings differ for each crop and product but, at minimum, seeds must reach physiological maturity. If the crop is desiccated or swathed too early there is a possibility for yield loss from seeds that will not properly fill out. This can also reduce the crop quality due to reduced seed size or seed discoloration. On the other hand, leaving the crop stand mature for too long before harvest can also result in yield and quality losses. Shelling, as a result of wind or other extreme weather events, wreaks havoc on ripened crops. Quality losses such as bleaching, decreases in protein, and sprouting, can also limit grade potential when ripe crops are left to weather. It is ideal to have crops ripen in succession throughout harvest as the combine becomes available. Staggering spraying and/or swathing timing or seeding crops and varieties with different days to maturity will help spread out harvest. Seeding crops and varieties with different days to maturing will also help with harvest management. For example, growers with a large number of canola acres have had success with planting multiple canola varieties with a range in maturity. Seeding the earlier maturing varieties first and the later maturing varieties last allows for the canola crops to naturally mature at different dates during harvest.
Dealing with Lodged Crops
Lodged crops, as a result of recent rains, strong winds, and a heavy canopy, is a common occurrence this harvest. Although lodged crops can make harvest more difficult, there are a few things that can be done to help capture as much yield as possible. Because conditions under the mat of lodged crop create a perfect climate for diseases and, as the seeds mature, sprouting, the crop may need to be swathed or desiccated earlier than normal to allow for the crop to be harvested before these issues significantly reduce quality. Picking up lodged crops is also of concern and crop lifters, pick-up reels and air-reels are all tools that can help. Lifters make it possible for the header to cut all the crop, while not having to shave the ground. This will make for easier and faster harvesting because less material is travelling through the combine. Also, more straw will be left behind to catch snow over the winter. Regardless of your header options, combine travel speeds will ultimately have to be reduced. A reduction in speed will help ensure the header is picking up as much crop as possible and also that the combine has a chance to properly thrash. Lodged crop leads to uneven feeding of the combine, which reduces its threshing efficiency. Thus, more time is needed for the combine to properly thrash the grain, so that is not lost out the back end of the combine.
Every decision made on the farm throughout the season is motivated by putting as much high quality grain into the bin at harvest as possible. Once the combines hit the field, it is more important than ever not to lose sight of this goal as the potential for yield and quality loss is at its peak. With lots of acres and only a short harvest window, it can be tempting to push your harvest timing and equipment to its limits. However, by slowing down and understanding where your harvest losses are coming from you can maximize the number of bushels in the bin at the end of the day