We are at the beginning of February and, while in South America they are almost ready for the quinoa harvest, in the Mediterranean area it is time to start thinking about sowing that, in Europe, under normal conditions, takes place between early March and late April (In the extreme south of Europe, Like south of Spain or Sicily, it is possible to sow from the end of January). In this article I will talk about growing Quinoa and the operations to be carried out from sowing to harvest.
First, I would like to make a premise: as far as Quinoa is concerned, to date in Europe, there are no registered pesticides that can be used on this crop. Therefore, I will not distinguish between organic and conventional cultivation. The only difference can be represented by the fertilisations that can be organic or chemical.
As I have already said in other posts, Quinoa is a plant that adapts to situations of drought, temperature and soil salinity. Therefore, the factors that make a land “unsuitable” for the cultivation of Quinoa are mainly: water stagnation (the areas where stagnation occurs are categorically excluded), crusty soils (they would bring out difficult soils), very sandy soils (unless you have the possibility to irrigate in summer).
Once the plot on which to sow Quinoa has been chosen, it is important to proceed with the preparation of the soil and the seedbed. Particularly deep tillage is not necessary for Quinoa, in more compact soils a more thorough tillage may be useful, preferably with ripper to facilitate drainage. The size of the seed requires a good refinement of the soil at the time of sowing. It is important to carry out adequate fertilisation in pre-sowing, as is done with cereals.
Sowing, as already mentioned, takes place in spring or late winter (obviously in the south it will take place earlier than in the north) and can be carried out with different methods based on the type of soil, the variety of Quinoa we are going to sow and the machinery that will be available. If our aim is to carry out a plot test (which in the experimental phase is a more than advisable option), the advice is to proceed with the sowing manually; for larger extensions, instead, a precision seeder (recommended technique) can be used or a pneumatic grain seeder. The soil can be prepared by carrying out the same operations as for wheat, trying to carefully refine the soil to create an ideal seedbed.
Sowing can be done with different techniques depending on the equipment available. It is possible to carry out precision sowing or broadcast sowing; the latter does not consider weeding, but ensures that the plants can be evenly distributed on the ground and can compete with weeds. The quantity of seed per hectare is about 10 kg with broadcast sowing, with precision sowing it is possible to reduce the amount of seeds by 20-30% (using the micro-granulator). If you have a precision pneumatic seeder for vegetables, with pneumatic ejection of the seed, the quantity of seed required can drop below 5 kg/ha. Some farmers use the continuous row technique using a grain seeder (distance between rows 11-15 cm).
Precision sowing: The recommended row spacing is 45/50 cm (if you have weeders capable of working at shorter distances, you can reduce the distance between the rows), while on the row it is also possible to sow with very high densities (the use of the micro-granulator is recommended because quinoa seeds release a dust that tends to clog the holes of the discs of the seeder, unless you have a precision pneumatic seeder for vegetables). Precision sowing will facilitate mechanical weed control. If you only have equipment for growing sunflower or corn (seeder and weeder in rows spaced 75 cm), you can use them by slightly reducing the amount of seed per hectare.
Broadcast sowing: In my opinion, broadcast sowing is one of the techniques that can be used on land that does not present complexity in terms of weeds. Broadcasting means sowing with a grain seeder, by detaching the tubes that carry the seed to the disc, so that it falls out without going on the row. This ensures that the plants cover the ground evenly, avoiding the space between rows (which is where weeds would grow). It is advisable to pass with a roller before sowing (I recommend it for all sowing techniques, especially if the soil is particularly soft) to prevent the seed from going too deep. Obviously with this technique the sowing depth will not be homogeneous.
With good soil management and rotation, weed control will be relatively simple and can be accomplished with mechanical weeding. If the presence of weeds is particularly consistent, more steps will certainly be required. This aspect must be evaluated from time to time. The important thing is that weeds are kept under control until the plants manage to close the row.
One of the most interesting aspects of this plant is its resistance to drought. Obviously, if water is available, irrigation immediately after sowing (to facilitate emergencies in drought situations) or before flowering can be an important aid in particularly dry years.
As far as plant diseases are concerned, Quinoa is not affected by specific problems even if some varieties can be particularly subject to downy mildew, which normally does not go beyond the basal leaves and freezes with the arrival of high temperatures. It can delay plant growth and encourage weeds. So far, among the tests carried out in the Mediterranean area, this problem has occurred only in sporadic cases coinciding with particularly rainy springs. Presently, in Europe, no problems related to particular insects, spiders or other microorganisms have been recorded, with the exception of aphids and, in some areas, bedbugs. Wild boars are not attracted to Quinoa, which is very important, given the high presence of ungulates, especially in Italy.
The vegetative cycle of Quinoa can vary from 120 days up to 210 days depending on the variety. In Italy, and in most of Europe, short cycle varieties are preferred (120-140 days), the southernmost areas of Europe can offer the possibility of using longer cycle varieties, even up to 180 days.
Quinoa can be harvested with a regular combine harvester for wheat, paying particular attention to the moisture level. It is normally harvested with a humidity rate of 14/15% and then undergoes a drying process to bring the humidity below 12%. It is possible to wait for the humidity rate to drop below 12% before harvesting, especially in particularly dry climates, but this entails a high risk of seed loss.
Obviously, this is not a standard protocol for growing Quinoa, as we know that the variables are infinite and that every place, every type of soil and every environment has its own peculiarities.
Therefore, the advice I want to give to anyone who is intrigued and teased by this type of cultivation which, in my opinion, represents a valid alternative in the medium-term, is to carry out tests on small plots using the machinery present in the farm, perhaps using different varieties, to evaluate the results and potential of Quinoa.