by Andrew Wilkinson, staff writer, Milling and Grain Magazine
ats are a hardy cereal grain able to withstand poor soil conditions in which other crops are unable to thrive. Although oats, or Aveena Sativa to give the Latin name, are more commonly eaten in the form of oatmeal or rolled oats, they also offer a vast array of other uses; from use as an ingredient in baked goods to use as a treatment for skin complaints. Oats have also found fame in recent years as a health food and are widely believed to be able to help combat a whole raft of serious ailments such as heart disease and diabetes. Although the crop is considered to be very resilient, a great deal of thought and planning is still required to ensure that the best quality product is delivered from seed to spoon. The very first stage of this journey involves the tending of the soil and seed planting.
When planting oats, the ground is prepared immediately after the previous crop has been harvested, which is usually during the late summer months time. The soil is then ploughed, a process which vastly reduces the risk of cross contamination of seed from the previous crop. Once the soil has been prepared, the seed is then sown. Once the seeds have been fully planted, the crop will then need to be tended right up until maturity.
The biggest problem when tending oats is weeds. To prevent the spread of weeds, a pre-emergent herbicide is applied within a week of sowing the field. The crop is then continually monitored for any pests and diseases. The soil is also tested every four to five years to ascertain the nutrient level. The results of the tests are then used to apply fertiliser, which provides the right amount of nutrients that the oats require. This stage is facilitated on some farms with the use of satellite navigation technology that steers the tractor in a perfectly straight line, thus saving time and ensuring even coverage. When spring arrives, nitrogen is then applied to the crop with the help of a nitrogen sensor mounted on a tractor, which can calculate how much nitrogen the crop needs. It then adjusts the application rates accordingly, in real time, as the tractor and spreader is moving through the crop. This new technology improves the efficiency of nitrogen application; so only what is needed is used. Once the crop has fully matured, it is then ready to be harvested.
The method that is usually used for harvesting oats is â€œdirect
60 | December 2015 - Milling and Grain
headingâ€?. This process involves the cutting of standing grain as soon as the crop has fully ripened. If the grain moisture is consistent throughout the crop and is less than 12 percent; then this is considered to be the method most likely to avoid mass shedding of grains. Whilst direct heading is the least expensive method of harvesting oats, the danger is that there may be long periods of high relative humidity in which the harvesting dry grain is not possible. This problem can cause considerable delays to the harvesting operation and increase the risk of head loss or grain washed out by rain. Once the matured crop has been cut, the crop is then gathered up into swathes.
Swathing is a term used to describe the process of cutting the oat crop and placing it in rows held together by interlaced straws that are supported above the ground by the remaining stubble. Swathing is considered best practice where the crop is uneven in maturity; or the climate does not allow for rapid drying of the grain naturally. Swathing is also ideal for where there is a risk of crop losses from shedding and lodging. High yielding crops may gain more from swathing than low yielding crops. Generally, crops expected to yield less than two tonnes per hectare should not be swathed. Picking up swathed oats is significantly slower than direct heading because of the large volume of material. However, if the crop is either too thin or the stubble is too short to support the swath above the ground, then the crop should not be swathed. The main problem with swathing in these circumstances is that the heads on the ground may sprout and when attempts to pick up heads that are lying close to the soil surface are made, the crop may become contaminated with soil. Although it is better to swath early to prevent losses from shedding and lodging, one should not do so when the ground is wet after rain. Although it may be easier to swath later, the swaths of a ripe crop may not interlock well enough to withstand disturbance from strong wind.
Harvesting the swath
Once the crop has been swathed, the harvesting must be carried out as soon as possible, ideally within 10 days of swathing. If the crop is left exposed to the elements for too long too long and subjected to long periods of wetting, the grain may sprout and become stained. In more extreme cases the swath could also become contaminated with bronze field beetle. The stubble being torn out of the field during the swathing operation is one of the major sources of contamination in swathed oats. This usually occurs when the swather is operated at too high a ground speed or when trying to swath when the straw is tough due to it being cool or damp. As well as stubble contamination, another issue that can hinder farmers when harvesting oats is