Sowing Quinoa, How and When? Here are our tips

About ten years ago, quinoa began to be introduced in Europe and what was then a crop to be discovered, is now gradually entering the cultivation plans of many farmers and, thanks to the experience acquired over the years on this crop, today we have information and knowledge that are allowing farmers to make it a valid alternative for income.
At that time, information on quinoa was based on experiences from cultivation in other geographical areas, at other latitudes, with other soils and climate conditions. Today our expertise has allowed us to optimize cultivation techniques. In this article we will focus on the most important and delicate phases of the quinoa production process: sowing. The main aspects to consider are three:
• Sowing time
• Sowing technique
• Fertilization

Initially, the sowing period indicated as the “ideal” period was generally from the end of March to the end of April. Over the years we have noticed that early sowing offers numerous and important advantages:
• Better rooting of plants
• Reduction of downy mildew attacks in the early life stage
• Less damage from Altica’s attacks
• Reduce the risk of high temperature in flowering stage

But what is the right time to sow quinoa? If we say from mid-February, we would be giving a correct indication for the entire Mediterranean area, but we would probably not be giving an optimal indication. In fact, we have observed that in the southernmost areas, the geographical band corresponding to Sicily, Andalusia or southern Greece (Band 1 of the map), you can sow starting from mid-January (even earlier in some areas), the same sowing period can also be valid for coastal locations located further north (Band 2 of the map). Therefore, in these areas we could indicate as the optimal period that goes from the beginning of January to the end of February.

In the northernmost band (Band 2), corresponding to the centre-south of the Italian peninsula, central Spain or the north of Greece, but in which we could also include the coastal area of ​​southern France, sowing can be carried out from the end of January/beginning of February (coastal areas) until the end of March (in the more internal areas).
Moving further north (Band 3), therefore the entire area of ​​the Po Valley in Italy, the areas of central-southern France, the Balkan area, starting from mid-February, until the end of March/beginning of April.

In Central Europe (Belt 4), the band that includes central-northern France and central-southern Germany, sowing can take place from mid-March until the end of April.

In Northern Europe (Band 5), the most suitable time for sowing is the month of April, until the beginning of May, taking care to use medium-short cycle varieties, to allow the plant to reach maturity by the end of summer. In the northernmost areas, growing quinoa is very complex due to photoperiod and climatology issues.

We remind you that in Europe quinoa is mainly grown in the plains or low hills, therefore the indications provided regarding the sowing period and cultivation in general refer only to these territories. The division into bands that considers only the latitude is intended to give only a general indication, it is then important to consider many other aspects such as the position with respect to the coast, the altitude, the exposure, the type of soil etc… These are considerations to be made in a much more precise manner, based on the real soil and climate conditions of each environment or micro-area.

At this point it is legitimate to ask whether anticipating sowing offers only advantages or also causes disadvantages or difficulties. Like everything in this world, in addition to the pros there are also cons, and in this case the main disadvantage in anticipating sowing is represented by the greater difficulty in controlling weeds. We remember that even in conventional agriculture there are no registered herbicides for quinoa, therefore the removal of weeds must be done mechanically. Anticipating sowing obviously means losing at least one false sowing intervention, therefore managing to eliminate a smaller number of weeds in pre-sowing.

There are different techniques for sowing quinoa and we will try to illustrate the main ones in this article, but from experience we believe that the techniques that guarantee the best results both in terms of production and in terms of cost reduction are those that provide a distance between the rows that makes possible mechanical weeding. The sowing density, which is a fundamental aspect for many crops, does not appear to be so binding for quinoa. After numerous observations in the field, and based on the results of some studies, we can affirm that quinoa, thanks to its plasticity, regardless of the density of plants that reach maturity (in a range that goes from 20 to 60 plants/m2 at maturity), does not record noteworthy variations in terms of overall production. At the time of sowing, different sowing densities are considered based on the technique used and significantly higher than 20-60 plants per m2, but this is mainly due, as we will see later, to the need to control weeds. We must also take into account that many plants are lost due to biotic and abiotic agents against which it is not possible to intervene with pesticides, as there are no registered products to date in Europe. Therefore, it is necessary to have many plants to ensure that enough of them reach maturity. The optimal density at the time of maturation for a quinoa field is between 20 and 45 plants/m2, in a few cases 50-60 plants per m2 are reached, but normally the greater the number of plants, the lower the unit production per plant.
Returning to the sowing techniques, for quinoa it is essential to use a technique that allows you to achieve three objectives:
• Carry out inter-row weeding
• Being able to sow the seed on the surface (maximum depth 2 cm)
• Reduce the amount of seed used (to reduce production costs)

That said, let’s look at the main techniques in detail:
• Row sowing with cereal seeder: It was the first technique used in Italy and in some cases it can give good results, especially on soils with a low presence of weeds. In fact, it is not possible to carry out hoeing. This technique is now adopted on non-flat soils, with slopes that would not allow hoeing anyway. In addition to making mechanical control of weeds impossible, this technique requires a greater investment in seed (double or triple compared to sowing with a single-germ seeder), thus increasing production costs. Among the techniques used, this is the one we consider the least suitable and therefore we do not recommend. With this technique the seed requirement is approximately 10 kg/ha, equivalent to approximately 270 germinable seeds/m2. On well-prepared and refined soils, it can go down to 8 kg/ha.
• Broadcast sowing with cereal seeder: The only difference between this technique and the previous one is that the seeds do not fall on the row, but scattered on the ground, therefore they are able to have greater competition with the weeds. To do this it is necessary to detach the tubes that carry the seed to the seeder discs. This technique has the same disadvantages as the previous one in terms of costs, furthermore the sowing depth is less uniform, however weeds can be contained in a slightly more effective way. Between this technique and the previous one we prefer this one, but only if there are no other alternatives. The sowing density can be the same as indicated for the previous technique, on coarse soils it is advisable to increase the dose by 10-20%.

• Sowing with inter-row spacing of 45-50cm (single-germ seeder): This sowing technique is undoubtedly the most complicated for quinoa as not all types of single-germ seed drills can give good results on quinoa. At the same time, this technique is also the one that allows you to reduce the quantity of seed to the minimum and therefore reduce costs. For a good result, you need to have discs with very small holes (between 1 and 1.2 mm) with a very high number of holes (170-180 holes) and be able to sow at a distance of 1.6 cm to 2 cm on the row. You need to be very careful (this is where the complexity of this technique lies) with the dust that the quinoa seed releases when rubbing, it could block the holes of some seed drills and prevent the seed from being deposited in the soil. With this technique, on well-prepared soil, you use 3.5 to 4.5 kg of seed per hectare, for a density of about 90-110 germinable seeds per m2.
• Sowing with inter-row spacing of 45-50cm (microgranulator): This is probably the most used technique because it offers the best compromise between effectiveness and costs. Seeds are inserted into the microgranulator, and is sown on the row by falling. In this way, the problems deriving from the search for suitable discs (which are not normally accessories supplied with seed drills) and the difficulties deriving from their blocking are avoided. It will be necessary to slightly increase the sowing dose because the same precision will not be achieved, especially due to the depth of the seed. With this technique, we should therefore calculate a distance on the row of between 1.5 and 1.8 cm. On well-prepared soil, 4.5 to 5 kg of seed per hectare are used, for a density of approximately 100-120 germinable seeds per m2. This technique, unlike single-germ sowing, can also be used on soil that is not perfectly prepared. In that case, it will be necessary to increase the quantity of seed to 5.5 – 6 kg.
• Sowing with 70-75cm inter-row spacing: Using corn or sunflower seeders, with a row spacing of 70-75 cm, it is possible to adopt the same techniques seen for a row spacing of 45-50 cm, maintaining the same distances on the row, because it would not make sense to increase them further. Obviously, the need for seed per hectare decreases significantly, and also decreases the ability of the plants to compete with weeds since they will take a long time to close the row.

Even though the topic of this article is sowing, we believe it is essential to open a parenthesis on fertilization, being a very important aspect and, very often, due to erroneous information and urban legends about that, it is the cause of failures in many fields.
Quinoa, since the first cultivation tests in Europe, has been presented as a rustic plant, simple to grow and not very demanding in terms of nutrients, often being indicated as a renewal crop. With experience we have seen that there is very little truth in this. Quinoa is a plant that needs attention, especially in the early stages, the most delicate ones, and is very sensitive to fertilization, in particular to nitrogen and phosphorus. Potassium also has its importance, a potassium deficiency can in fact facilitate lodging, especially if the crop has received a lot of nitrogen. Fertilization is essential in the first phase, the ideal is to fertilize in 2 or 3 phases. Before sowing, fertilization with phosphorus is essential, in quantities similar to those used for wheat, a diammonium can be used in conventional agriculture or organic fertilizers with a high content of phosphorus and organic matter in organic. A second nitrogen fertilization should be done when the plant reaches 6-8 leaves, with at least 80-100 units of nitrogen. The second fertilization can be divided into 2 phases, with a third intervention before flowering. In organic farming it is recommended to use foliar fertilizers.

“The information provided in this article is of a general nature, without any purpose of determining technical or production choices, for which we recommend using targeted and personalized advice.”