Thus, accumulation of nitrates in general of a plant and in separate parts it happens extremely unevenly. One of the reasons of it is unequal activity of a nitratreduktaza, that is the enzyme participating and assimilations of nitrates. Nature of distribution of nitrates is defined by biological feature of plants and a structure of body.
Researches showed: excess accumulation of nitrates is noted in production of the protected soil. Especially much they are revealed in hothouse salad, a garden radish and green onions, and in some cases – and in cucumbers. It is connected with cultivation of plants on soil rich with organic chemistry and nitric food, and adverse, especially during the winter period, conditions of synthesis of nitrates.
Salad of various grades differs on length and diameter of the socket, size and character of a surface of leaves, thickness of veins, etc. Usually in the salad having rough, bubbly leaves contains nitrates more, than in salad with smooth leaves.
The plants which are insufficiently provided with nitrogen poorly grow, have light green or even yellowish coloring. Vegetative development comes to an end before usual and plants look physiologically older. Normal supply of plants with nitrogen raises the maintenance of a chlorophyll and intensity of photosynthesis, increases an assimilatory surface of leaves and term of their life. This element and influences processes of water exchange in plants. Therefore vegetable plants need, first of all, nitric fertilizers as the soil is better provided with phosphorus and potassium, than nitrogen. Excess unbalanced food by nitrogen promotes accumulation in vegetables of unhealthy people of nitrates and nitrites.
During growth and development of plants there is a big consumption of nitrogen which shortcoming strongly oppresses them. The exclusive role of nitrogen for plants and all live on the earth is defined first of all by that it is a part of proteins (16-18%) and a chlorophyll without which the most important function of a green plant – photosynthesis is impossible. Its role in formation of many vitamins is not less important.
In the nature there are no absolutely pure food. Nitrates in environment were and will be. It is all about that, how many collects them in products. Such level of nitrates which does not constitute health hazard of the person is necessary for us.
Fertilizers unequally influence accumulation of nitrates in various bodies of plants. Example: with increase in doses of nitrogen the amount of nitrates at a cauliflower more increases in stalks, than in heads.
Nitric fertilizers: The problem of the raised content of nitrates in some types of vegetables and food sometimes becomes simpler use of nitric fertilizers. Very often as responsible everything the worsening conditions of environment consider chemistry. It is promoted in no small measure by emergence of numerous messages in mass media which sometimes have subjective character and are insufficiently evidence-based. Really, products of chemical production of any kind are alien to the nature. However it must be kept in mind that further development of human society without chemistry is impossible. All problem consists in that correctly to use it for needs of mankind.
The negative phenomena take place in case plants absorb excess amount of nitrogen which they owing to the genetic features or other reasons are not able to use in the usual physiological way. Due to these it is necessary to control systematically the content of nitrogen in the soil and to support him up to standard by the correct application of receptions of technology. It is one of the most important criteria of further development of agriculture and production.
Development of the system of control of foreign substances in raw materials and finished goods – one of the major tasks having huge value for improvement of quality of production and the main thing - safety for human health. The solution of this very important task possibly, in particular, by adoption of the relevant resolutions concerning restrictions in the content of certain substances in vegetable production.