Nitrates are distributed unevenly in different plants, accumulating in certain areas. For example, cabbage accumulates nitrates in the stalk and upper leaves, cucumbers and squash - in the peel, zucchini, beets, carrots - in the lower part of the fruit, potatoes - in the middle. Experts recommend removing the nitrate “zones” and soaking the potatoes beforehand.
To evaluate the suitability of vegetables for food, reference points were required. A large group of specialists created standards approved by the Ministry of Health. Here are these numbers: the allowable nitrate content (in mg per kg per nitration) in potatoes - 80, carrots - 300, cabbage - 300, onions - 60, tomatoes - 60. For early vegetables and grown in greenhouses, these standard figures doubled. What to do if the permitted nitrate content in plants is significantly exceeded or persistent suspicion arises on this point? When the standard is exceeded to twice, the vegetables are used in dispersal conditions, i.e. as part of dishes like salads. Or after boiling: up to 50% of the initial amount of nitrates and more is transferred to the broth, especially if the vegetables were cut before cooking. Of course, the combination of these methods - dispersion and cooking - is quite acceptable and even useful, and not only in catering, which recommendations are mainly intended for, but also in domestic situations.
How to get rid of nitrates in products? Nitrates dissolve well. That is why vegetables should be cooked. The broth will leave most of the harmful compounds. When cooking potatoes and carrots in water will be up to 60, in beets up to 40, and in cabbage up to 70% of the nitrates contained in these products. In addition, it must be remembered that the roots and stems are more “rich” in nitrates, so it is better to cut or cook them longer than usual and also in high water.
© Rick Heath
There is another way to get rid of nitrates. When salting, pickling or pickling, their number significantly decreases (up to 60% goes to brine). For example, sauerkraut contains much less nitrates than raw.
How does the content of nitrates in vegetables during storage? In the literature, the data is contradictory, but, in any case, a tangible decrease in the level of nitrates can be expected only in a few months. And if so, then the main thing in controlling nitrates is time before cleaning. According to the established procedure, for a week and a half before harvesting, in the fields and plantations, samples of vegetables are taken according to a specific scheme for research in specialized laboratories of regional and regional chemicalization plants for agriculture.
An effective method of increasing the efficiency of farming and improving the use of fertilizers by plants is the use of irrigated and semi-planted crops, which make good use of mobile residues of nitrate fertilizers.
Stable control over environmental pollution by chemicals used in agriculture has been established. Such control is entrusted to special agricultural departments existing in agrochemical laboratories and chemicalization stations.
It is indispensable to completely exclude mineral fertilizers from agriculture and, in general, chemicalization cannot be. It is important to learn how to correctly use its achievements. If somewhere a careless owner did not correctly dispose of the mineral fertilizers at his disposal, this should not mean that it is necessary to prohibit their use altogether. It's like talking about banning the use of fire, as there are fires.
Many farms use biological methods of soil enrichment with nitrogen due to perennial grasses. In a number of districts of Chuvashia, the structure of crops has been changed: large areas are occupied by herbs. In the grass-seed farms there have been changes: the wedge of perennial grasses has been increased. This is the link that will extend the whole chain: improve the structure, increase fertility, create the conditions for a full transition to the production of biologically pure products. Many herbs well protect the soil from erosion, and at the same time improve, enrich it with organic substances, especially clover, alfalfa, sweet clover. Clover on each hectare produces 150-200 kg of nitrogen, and if we take into account the dry matter of root and crop residues, it replaces 30-40 tons of high-quality manure. This makes it possible to dramatically reduce the introduction of nitrogen fertilizers.