The need of various species of trees and shrubs for basic nutrients (N — nitrogen, P — phosphorus, K - potassium) is different. Approximately the proportions of these components are as 1,0 : 0,8 : 0,6. It is most expedient to use multi-component fertilizers, in which the percentage of nitrogen content, phosphorus and potassium are present in or near these proportions. The compound fertilizers produced by us have different proportions, because they are adapted to other crops. Therefore, the use of these fertilizers is more difficult, but possible, especially if the ratio is changed by adding an appropriate single component fertilizer. The table shows the percentage of basic nutrients in our multi-component fertilizers and the microelements that are present there..
Percentage and proportion of basic nutrients and microelements in several compound fertilizers produced in Poland.
| Fertilizer | N | p2o5 | k2o | Proportion
N:P205:K20 |
Microelements |
| Azofoska | 13,6 | 6,4 | 19,1 | 1:0,5:1,4 | Mg Fe Cu Mn Zn B Mo |
| Flora | 8,2 | 12,3 | 23 | 1:1,5:2,8 | Mg Fe Cu Mn Zn B Mo |
| Fruit 1 | 17 | 8,5 | 17 | 1:0,5:1 | Mg |
| Micro | 10,2 | 15,3 | 15,3 | 1:1,5:1,5 | Mg Fe Cu Mn Zn B Mo |
| Lead | 11,3 | 17 | 17 | 1:1,5:1,5 |
The doses of fertilizers for single trees are determined on the basis of the trunk diameter. For every centimeter of the trunk diameter measured in height 1,2 m is the recommended dose 0,4-0,8 kg of compound fertilizer. For younger trees, several years old, doses should be halved. Trees and shrubs growing in groups are fertilized in quantity 4-8 day after 1 m². The use of mineral fertilization is not recommended in the first year after planting, because the clustered roots are easily damaged, especially when there is a shortage of water.
The fertilizer doses mentioned are indicative, and the choice of a certain size depends not only on the identified shortage, but also from this, whether strong growth of fertilized plants is desirable.
If we care about the rapid growth of a young tree, intensive fertilization will be justified. Older trees, especially these, whose further growth is not recommended, they should be less fertilized, but to the extent that ensures their proper development and health.
When fertilizing with mineral, it should be remembered, that most ornamental trees and shrubs require a slightly acidic soil (pH 5,6-6,7), which should be regulated when tilling the soil. Especially alkalizing fertilizers should be moderately toned.
The time of fertilization has a great influence on the proper use of fertilizers, that is, their effectiveness. It is most advisable to fertilize in the spring before the beginning of vegetation. On light and dry soils, it is more advisable to divide the dose into two parts. The second part can be delivered to the soil in June or in the fall after the end of growth. Mineral salts are taken from the soil, if its temperature does not drop below + 5 ° C. Fertilization during the summer (until the growth is complete) may cause an extension of vegetation, insufficient lignification of tissues before winter, and as a result shoot freezing or drying up in winter