Nutritional requirements for roses. We already know from the considerations so far, that roses do not have high soil requirements, content with average conditions; we also know, że takie przeciętne gleby muszą być jednak prawidłowo uprawiane i obficie nawożone. There is a simple conclusion from this, that roses have high nutritional requirements. These requirements, compared to plants commonly cultivated in agriculture, can be defined as o 100% higher.
In the period when we did not have any chemical and agricultural stations, we were forced to base the fertilization of the soil on completely unmeasurable elements, because mainly on observations regarding cultivation on a given piece of land. Currently, in the field of fertilization, we rely on completely specific and measurable values, regarding soil fertility, which data can be obtained from the appropriate chemical and agricultural station. When starting the cultivation of roses, we must first carry out chemical analyzes of the soil intended for these plants and only on this basis develop a fertilization program.
Today, chemical and agricultural stations are represented in the departments of agriculture and forestry in the presidencies of national councils. It is therefore necessary to communicate in the appropriate presidium with a representative of the chemical and agricultural station, who will take soil samples and help to complete the related procedure.
The so-called soils. agricultural, and thus used for the cultivation of basic agricultural crops, as a rule, they have a lower content of nutrients than so-called soils. gardening; the differences can be surprisingly high in favor of the soils used for horticultural crops, if, of course, these soils were properly cultivated and fertilized. Horticultural plants require more careful cultivation and much more fertilization due to their high nutritional requirements. Moreover, the soil under such plants is used very intensively by the use of forecrops, catch crops and catch crops, which also requires careful cultivation and abundant fertilization.
For a better understanding of the criteria for evaluating agricultural and horticultural soils and the huge differences in this area, I am giving some figures: phosphorus content of 12 mg w 100 g of soil in agriculture is considered high, in horticulture, the high content is only considered 81 mg of this component w 100 g of soil. The same is with potassium. For agriculture it is enough 22 mg of potassium, To define, that its content is high, for horticulture - over 80 mg.
Assessing soil under agricultural crops in general, we have to conclude, that they show remarkably low potassium content, insufficient - phosphorus and the vast majority of them are acidified. Materials provided to me by the Chemical and Agricultural Station in Łódź, referring to the soils of the former Łódź Province, they clearly confirm it. For example, low phosphorus content (below 6 mg) ma 53,8% soils, average (6 —10 mg) - ma 34,2%, high - just 12,0% Low potassium content (light soil to 7 mg, medium to 9 mg, heavy to 14 mg) - ma 89,2% soils; average (light 8-12 mg, average 10-15 mg, heavy 15-20 mg) — 8,7%; tall (light from 13 mg, average from 16 mg, heavy since 21 mg).just 2,1%.
Soil's reaction is also terrible 80,4% agricultural soils of the former Łódź Province show a very acidic reaction (below 4,5 pH) and sour (4,6—5,5 pH), 11,8% slightly acidic (5,6—6,5 pH), 7,8% has a neutral reaction (6,6 do 7,2 pH) and alkaline (more than 7,2 pH).