Dutch potato growing technology has one feature. Food, as well as seed potatoes are grown in different ways, on separate fields, by different farms. Dutch farmers pay special attention to soil preparation. It should be loose, small-sized. Tubers are planted with well-sprouted eyes, short sturdy sprouts.
Dutch potato planting technology
Features of planting potatoes according to Dutch technology are as follows: the upper part of the potato tuber is at the level of the soil surface. Such a shallow landing facilitates, greatly accelerates the emergence of seedlings. After planting over the tubers, ridges are formed 25 cm high, 75 cm wide at the base with a wide rounded top. Tubers form and develop inside a wide ridge, do not flood with heavy rain, do not rot.
Dutch technology potato harvesting
Different approaches to the harvesting and storage of food and seed potatoes are different in Dutch growing technology. If the first is removed in late August - early September, then the second - much earlier (in July, rarely - at the very beginning of August).
Moreover, 5-7 days before harvesting, the tops, still completely green, must be removed. It is cut off with special machines and crushed to obtain silage, sometimes chemicals are used.
The tops are removed so that the seed tubers are not infected by viral diseases carried by aphids. In addition, when the tops are removed, the tubers ripen faster, since the influx of assimilants from the leaves ceases, they previously formed a strong peel that protects against mechanical damage and diseases.
Farmers growing seed potatoes believe that the tops should be removed when the tubers have an optimal size (diameter not more than 28–55 mm). This protects them from infection with rhizoctoniosis, the so-called black dandruff.
Cutting tops and digging is carried out by machines. From the field to the storage, potatoes are usually transported on trailers with tippers. Here the tubers are cleaned, sorted, laid for long-term storage.
Features of storing potatoes in the Netherlands
After harvesting the tubers of most Dutch varieties do not germinate for 2-3 months. The duration of this dormant period depends on the biological characteristics of the variety, the degree of tuber maturity, temperature, humidity in the storage, damage, etc. Tubers harvested before full maturity or after a warm summer have a longer dormant period.
At a temperature of 3-5 degrees, relative humidity of 92-95%, potatoes intended for food purposes or processing are well preserved without significant loss of food quality for 8–9 months, especially reliable, since the storage mode is controlled by automation.
If the air humidity drops below 92%, the potato tubers lose a lot of moisture, become porous, wrinkled. And at a moisture content of more than 95%, the buds begin to sprout, the tubers become ill.
However, with such storage (+ 4-5 ° C), the content of sugars in the tubers increases significantly. This is the main reason for the appearance of a brown tint, for example, in chips. Therefore, in the Netherlands, tubers for processing are stored separately at a higher temperature.
Since in the country many large tubers are spent on the preparation of fried potatoes, most of the crop is stored at t + 6-7 degrees. And the tubers used to make chips are at + 8-10 degrees. Substances that inhibit the germination of tubers are also used.
Seed tubers are stored at a temperature of 3-4 degrees, at which it lies well until March.
Seed and industrial potatoes are kept in special storage facilities with modern ventilation systems. A powerful fan (100 cubic meters of air per 1 cubic meter of potato mass with a static pressure of 15 mm water sensor) takes fresh air from the outside and drives it through the entire mass of products. Exhaust air comes out through automatic shutters.
And the system of the external pipeline (or laid under the storage) ensures even distribution of air. The temperature regime of storage is constant, because all the walls of the storehouse are quite well insulated.
Tubers brought from the field are always slightly moist, therefore, in order to avoid the development of diseases, they are first dried for several days with the help of fans. And they stand it for another 7-14 days at a temperature of 12 degrees, so that black spots (late blight) appear.
According to Dutch technology, before laying the tubers for long-term storage, they are thoroughly cleaned from the ground, roots, and the remains of the tops, sorted by size, separating all damaged, diseased or very small ones. The tubers, passing along the conveyor, rotate around the axis, which allows operators to inspect them from all sides.
Improving sorting in the Netherlands is of great importance. The cost of sorting is about a quarter of the cost of producing potatoes sold. Some farmers carry out these works on their own, others transfer products to specialized cooperative centers or organizations that are engaged in marketing. The production facilities for centralized machine sorting are large here.
In Flevoland, on the land "rising from the sea", the conditions are especially favorable, there are many relatively large potato farms.
At the New Polder, the storage consists of cells with a capacity of 300 tons each - this is a huge, two-story sorting center. Workers, sitting in comfortable mobile chairs, pack 2, 2.5, and 5 kg tubers in plastic bags that are left over from last year’s harvest, cleanly washed, conveyed from the storehouse, and also young medium-sized tubers that have just been brought from farms.
The packages indicate not only the weight, but also the variety, as well as the preferred use of the products — for boiling, stewing, making mashed potatoes, frying, starch, protein, total calorie content and other varietal indicators are indicated.
The so-called environmentally friendly potatoes, that is, grown without the use of any chemicals, are more expensive, as well as young compared to last year, although after almost 9 months of storage the weight loss of the latter does not exceed 1%.
Near Rotterdam, in Maasdijk, is the company “Vanders agro V.F.”, which is engaged in the construction of such potato storages, producing equipment for them. The ordering company develops storage projects for specific local conditions, comprehensively examining their features. In addition, it implements its projects in other countries.
I suggest watching a few videos about planting and harvesting potatoes in the Netherlands. Very interesting!