Agronomy II - Grains

Learn to Grow Grain Crops

WHY STUDY GRAINS?

This course discusses cereals, pulses (e.g. beans), and pseudo grains (e.g. quinoa).

• Learn about a wide variety of different grains
• Make better choices about what species and cultivars to grow
• Grow better crops using better techniques for better harvests

This course discusses cereals, pulses (e.g. beans), and pseudo grains (e.g. quinoa).

Grains are a major part of farming world wide – and a very significant food for both human and animal consumption. This is a very large industry, that encompasses not only the most common grains (e.g. wheat and rice), but also many dozens of other grain crops (e.g. amaranth and soybeans). 

Large scale production of grains is carried out around the world on very large farms, with a high degree of mechanisation. Much of the world's staple foods are produced this way. This is by no means the only way grains can be grown though.

Whether you grow grains on a small or large scale success always depends on the following requirements:

• Good quality seed, with high germination rate
• Protect seeds against pests and disease
• Prepare seedbed well
• Adequate nutrition in soil
• Timely sowing – temperature, moisture and climatic conditions suitable

Lesson Structure

There are 9 lessons in this course:

1. Introduction to grains
2. Cereal/grain infrastructure and machinery requirements
3. Wheat, triticale, spelt, barley, oats, rye.
4. Maize, Sorghum, millet
5. Rice
6. Pulse crops
7. Pseudo cereals
8. Processing grains for human consumption
9. Grains for livestock consumption

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Aims

• Classify important existing and emerging grains or cereals grown around the world and explain the production systems both large and small scale, used for growing, harvesting and storing grains in different countries.
• Describe important farm structures, equipment, vehicles, supplies and natural resources required for successful production of cereal/grain crops
• Describe and compare the properties and production systems of the major ‘cool season’ cereals, namely: wheat, triticale, spelt, barley, oats and rye.
• Describe and compare the properties and production systems of the major ‘warm season’ cereals, namely: maize, sorghum and millet
• Describe the four main broad habitats where rice is grown and explain the variety of production systems used within these different habitats.
• Explain and compare the production systems and uses of important cool and warm season pulse crops grown around the world.
• Describe production of ‘non-grasses’ that are existing or emerging as important‘cereals’, such as chia, quinoa, amaranth and buckwheat.
• Explain post harvest storage and processing methods used for cereals for human consumption and examine the various sales procedures used.
• Describe the production of important warm and cool season grasses used for forage and stock feed
• Describe the storage, processing and sale of cereals used for livestock and demonstrate the calculation of some sample stock rations

Harvest

Grains need to be harvested at the right time in their growth cycle, in order to obtain the best quantity and quality in the harvest. Subsistence farmers have harvested grain crops manually for thousands of years, and some still do. Most commercial grain crops though, will be harvested with machines. Machine harvesters may be owned by large farming operations; but for smaller operations, the harvesting may be contracted to someone with the machinery to do the job.

One of the first issues is to harvest the crop while it is at its best. That is while the moisture content is at the maximum acceptable level but not too wet to cause storage or quality issues. 

Another issue that approaches at harvest is weather damage. Crops are quite susceptible to loss of quality if rain falls on a ripe crop, wind, hail or heavy rain can cause crops to shed grain, or shatter pods.  

As a general rule of thumb, pulse crops such as chickpeas weather quite well for a short period of time as the grain is protected inside a pod, however with canola the pods become very brittle when ripe and can shatter very easily which is why a windrower is often used to lay the crop on the ground to reduce the chance of pods shatter from adverse weather.  

Some cereal crops weather better than others, some wheat varieties can weather quite well whereas barley has a fairly soft straw and can lodge (fall over) if too much rain falls onto a ripening crop. For this reason, farmers often have some form of grain storage. Grain storage can open up a range of marketing options as well.  If crop prices are not particularly attractive during harvest (which often happens) farmers can then store their crops and sell them at a time when markets are priced more favourably. So with this in mind, we will look at some basic storage options for a grain farmer.

Silos
Silos are the most permanent form of grain storage. They are usually large steel cylinder structures with a cone base; however some silos have flat bottoms.  The cone base helps the grain to flow down to the bottom of the silo into a hopper where an auger can pump the grain into a truck.  Most large grain farms have a silo complex (a number of silos for seed storage as well as grain storage during harvest).  Silos complexes usually are attached to power so that grain dryers can be used.  
Grain dryers are used to bring the moisture content down to a level that is acceptable to the grain receiver and this is particularly useful if a farmer has to harvest grain at a higher moisture content just to get the crop out of the field, whether that is because adverse weather conditions are forecast, or large areas of crop need to be harvested so the farmer just has to get on with it.  
Most modern silos are fitted with aerators.  These are small fans fitted into the base of the silo that forces air up through the silo. They help keep the grain at a constant temperature which maintains the quality of the grain. It is a good idea to think of grain as a living thing, as adverse temperatures or moisture in storage will ruin the viability of any grain kept for seed.  Grain dryers are also particularly good at keeping grain insect free, so are a good investment if planning on constructing new silos.  

Silo Bags
Silo bags are large heavy plastic sausage-like bags that can hold up to 220 tonnes of wheat.  They have a life of up to 18months out in the open.  They are very useful for storing grain on the sides of fields during harvest, however, the grain must be of the right moisture content otherwise the grain will sweat in the bag and go mouldy. They are quick to use and quite good for temporary storage however you may have issues with access when the time comes to unload them if they are out on the edge of a field (as opposed to permanent silos that usually have a heavy gravel pad around them allowing for all weather access). They also require a specialise bag unloader and if you are planning on leaving them in the field for a period of time they will require an electric fence constructed around them as pigs and other animals can puncture them and they have been known to tear open like a ladder in a stocking which is can cause quite a bit of grain loss.

Bunkers
Bunkers describe where grain is dumped in a large pile on the ground, or a cement slab, sometimes bunkers are covered with a plastic tarp (which is most desirable to reduce weather damage).  These are a very temporary form of storage and grain is usually moved as quickly as possible out of a bunker.  An ideal bunker site should be raised to allow water to drain away from the grain.  Most farmers would have this area known as the pad, to be built up by a grader and have the floor packed hard.
Insect pest control in grain storage  

Grain insects develop quickly in stored grain if the right conditions are prevalent. Most grain pests reproduce rapidly at temperatures of around 30°C, so cool storage conditions are best if possible at around 20°C or less, this could be quite difficult to achieve in some countries but aeration of silos will help.  Grain insects in some countries have already developed resistance to some grain protectant chemicals, so often a combination of protectants is necessary. 

The use of protectants hinges on the withholding period of the product so in some situations will not be suitable if grain needs to be sold within the withholding period. Protectants are not designed to be applied to grain with a visible insect infestation, they are meant to be applied to grain as it enters storage. We encourage you to familiarise yourself with the resistant grain insects. We also recommend that you investigate the main grain pests to your region or country.

Milling
Sometimes known as grist milling, milling is the process by which grain is flattened or ground. In the past, water and wind have been used to powered mills; today's mills are usually electric steel roll mills. This means that the grains are rolled between two steel rollers with roughened edges or teeth to break the grains. After this, grains are sieved, such that the endosperm (white flour) is separated from bran layers and germ. The endosperm is then milled again until the desired level of refinement is reached. In some cases, bran layers and germ are also ground finer, and added back into the endosperm grounds to produce brown and wholemeal flours. 

WHO CAN BENEFIT FROM THIS COURSE?

• Farmers and farm workers
• Farm equipment and service suppliers
• Agriculture students and professionals
• Small farm or hobby farm owners considering new "niche" crops
• Livestock owners/managers, wanting to produce animal feeds

MORE AGRONOMY COURSES

Other Agronomy courses are planned to follow this course; tentatively:

    Agronomy -Fibre Crops
    Agronomy - Oil Crops
    Agronomy -Pulses (legumes)
    Agronomy -Biofuels
    Agronomy - Root Crops