Video: Accumulation Of Nitrates In Plants
Nitrates are unevenly distributed in different plants, accumulating in certain zones. 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 pre-soaking the potatoes.
Benchmarks were required to assess the suitability of vegetables for food. A large group of specialists created standards approved by the Ministry of Health. These are the figures: the permissible content of nitrates (in mg per kg for nitration) in potatoes is 80, carrots - 300, cabbage - 300, onions - 60, tomatoes - 60. For early vegetables and grown in greenhouses, these normative figures are doubled. And what to do if the permitted content of nitrates in plants is significantly exceeded or there is a persistent suspicion about this? If the standard is exceeded up to two times, vegetables are used in conditions of dispersal, that is, in dishes like salads. Or after boiling: up to 50% of the starting amount of nitrates and more are transferred to the broth, especially if the vegetables were cut before cooking. Sure,and the combination of these methods - dispersing and cooking - is quite acceptable and even useful, and not only in public catering, for which the recommendations are mainly designed, but also in home situations.
How to get rid of nitrates in foods? Nitrates dissolve well. This is why vegetables should be boiled. Most of the harmful compounds will go into the broth. When boiling potatoes and carrots, it will be up to 60% in water, up to 40% in beets, and up to 70% of the nitrates in cabbage 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 them off or cook them longer than usual and also in large water.
© Rick Heath
There is another way to get rid of nitrates. When salting, pickling or pickling, their number is significantly reduced (up to 60% goes into the brine). For example, sauerkraut contains much less nitrates than raw cabbage.
How does the nitrate content of vegetables change during storage? In the literature, the data are contradictory, but, in any case, a tangible decrease in the level of nitrates can be expected only after a few months. And if so, then the main thing in nitrate control is the time before harvest. According to the established procedure, a week and a half before harvesting on the fields and plantations, according to a certain scheme, samples of vegetables are taken for research in specialized laboratories of regional and regional stations for chemicalization of agriculture.
An effective method of increasing the efficiency of agriculture and improving the use of fertilizers by plants is the use of irrigated and semi-cut crops, which make good use of mobile residues of nitrate fertilizers.
Established stable control over environmental pollution by chemicals used in agriculture. Such control is entrusted to special agricultural departments existing in agrochemical laboratories and chemicalization stations.
It is indiscriminate to completely exclude mineral fertilizers from agriculture and, in general, chemicalization is impossible. It is important to learn how to use her achievements competently. If somewhere a careless owner mismanaged the mineral fertilizers at his disposal, this should not mean that their use should be banned altogether. This is like talking about prohibiting the use of fire, because fires happen.
Many farms use biological methods for enriching the soil with nitrogen from perennial grasses. In a number of regions of Chuvashia, the structure of crops has been changed: large areas are occupied by herbs. Changes have taken place in the herb seed farms: the wedge of perennial grasses has been increased. This is the link that will stretch the entire chain: improve the structure, increase fertility, create conditions for a complete transition to the production of biologically pure products. Many herbs protect the soil well from erosion, and at the same time improve and enrich it with organic substances, especially clover, alfalfa, sweet clover. Clover produces 150-200 kg of nitrogen per hectare, 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 application of nitrogen fertilizers.