Peculiarities of zonal fertilization systems
In all natural and climatic zones of Ukraine, an important condition for compiling a fertilization system is the specialization of the economy, the types of seeding changes and the composition of their crops. Maximum yields are provided by appropriate crop rotation in the field (crop rotation) or in a seeding shift. The seeding change is affected by the aftereffect of fertilizers, contributes to the growth of yields of the following crops and soil fertility.
The soils of the Polesie zone are podzolic, soddy podzolic and gray forest soils. Sod podzolic soils are acidic, low in humus (1-2.5%) and mobile compounds of nutrients. Gray forest soils contain 3-4% humus, have a slightly acidic reaction and a low supply of phosphorus and potassium. In this zone, there is sufficient or excessive supply of agricultural crops with moisture and insufficient or moderate heat. This creates favorable conditions for the effective action of fertilizers.
Liming is a prerequisite for an effective fertilization system for non-chernozem soils. To do this, determine the place of its primary implementation and the dose of lime materials. Organic and mineral fertilizers have the maximum efficiency with a neutral and slightly acidic soil reaction.
Another important task is the optimal combination of organic and mineral fertilizers in the seeding shift in order to maintain a deficit-free humus balance. Organic fertilizers are primarily applied for millet crops (root crops, potatoes, corn for silage, etc.)); for cover crops with sowing of grasses, which in subsequent years use the aftereffect of organic fertilizers; on light-textured soils.
Mineral fertilizers are applied primarily for vegetable and industrial crops (flax, sugar beets, etc.), which pay off most of them, as well as for potatoes, cereals culture. In addition, sufficient attention is paid to the fertilization of cultivated meadows and pastures. Increased doses of mineral fertilizers are applied on calcareous soils or areas with a controlled water regime close to neutral reaction.
The fertilization system of some crops of seeding in the zone of sod-podzolic and gray forest soils consists of the main, pre-sowing application and top dressing, with the exception of low doses (30-40 kg / ha) for sowing winter crops. Retail application of nitrogen fertilizers in this zone increases the efficiency of their use.
All crops grown in the zone require phosphorus fertilizers, and winter crops require spring fertilization with nitrogen fertilizers. Linear fertilization is effective, in particular when there is an insufficient amount of fertilization in the main fertilizer and on poor soils. For this, superphosphates, ammophos and other complex fertilizers are used.
Potash fertilizers are used primarily for potatoes, flax, vegetables and silage crops.
Top dressing of crops is mainly carried out nitrogen fertilizers. First of all, this applies to winter crops that have emerged from winter, and perennial grasses, which have fewer legumes in the herbage.Top dressing with phosphorus and potash fertilizers is carried out only if they are insufficiently applied to the main fertilizer. At the same time, it is more effective to introduce them into the soil between the rows of crops (vegetables, sugar beets, etc.).
In the zone of sod-podzolic and gray forest soils, the use of microelements is quite effective, in particular after the introduction of high doses of mineral fertilizers, liming and insufficient amount of applied organic fertilizers. Boric, copper, cobalt and molybdenum fertilizers are highly effective.
In Ukraine, the most widespread chernozem and chestnut soils, especially in the forest-steppe and steppe zones. These zones differ significantly in soil and climatic conditions, specialization of agricultural production and other factors.
Forest-steppe zone. The soils of this zone are of the greatest agricultural importance. Typical and bony chernozems prevail here. In the northern part of the zone, podzolized chernozems and gray forest soils are widespread. Due to the intensive use of these soils in agriculture, the balance of nutrients in them is characterized by a high deficit, which leads to a decrease in fertility and a deterioration in physical and chemical properties.
The climate is favorable for growing most agricultural crops, especially winter crops, corn, legumes, sugar beets. The sum of active temperatures is 2200-2600 ° С, and annual precipitation is 500-650 mm.
Chernozems are sufficiently provided with humus (3.5-5.5%), gray forest soils - up to 3%. The reaction of the soil solution in chernozems is weakly acidic and very weakly acidic, and gray forest soils have a pH <5.5. The soils are poorly provided with mobile compounds of phosphorus and better - with potassium, which, in accordance with the effect on the efficiency of the application of phosphorus and potash fertilizers. During the seeding shift, the optimal doses of fertilizers are primarily applied to sugar beets, sunflowers, corn for grain and silage, winter crops. For fertile cereals, legumes and large crops that use the aftereffect of fertilizers applied under the predecessor, low doses of fertilizers are used or only row fertilization is carried out. Taking into account the aftereffect in the 8-10-field seeding shift, it is applied 2 times per rotation, in the 4-6-field one - once is enough. It is best to use humus under the predecessors of winter crops, directly under winter crops, which are sown after clean steam, or under sugar beets, corn, vegetables, etc. The optimal dose of manure application (30-40 t/ha) should not be exceeded or underestimated.In the first case, a smaller area will be fertilized, in the second, it will not be possible to achieve uniform distribution of manure over the surface of the field, in addition, the cost of its application increases significantly.
In the main fertilizer, in the fall, nitrogen fertilizers are not applied, with the exception of winter crops after the worst predecessors. In this zone, it is quite common to apply fertilizers for pre-sowing cultivation, but its effectiveness is lower compared to the main one. Top dressing of agricultural crops is carried out only with nitrogen fertilizers in the recommended doses and at the time optimal for each crop. Fertilization of winter crops is especially effective.
In the system of fertilization of agricultural crops on dark gray and gray forest soils and podzolized and leached chernozems once per rotation of seeding change, liming should be envisaged. The best crop in the field for applying lime materials is sugar beet. To do this, you can use the waste of sugar production - defecate.
Both in the Polesie zone and in the Forest-steppe zone, there is often a strong effect of microfertilizers that contain boron, molybdenum, copper, manganese, zinc, etc. They are used taking into account the biological needs of crops and the data of agrochemical survey of soils in the fields of seeding.
In the Steppe zone, the soils are mainly chernozems and chestnut. They have a neutral reaction, therefore they do not require liming.
In the fertilization system in the steppe regions, the main fertilizer should prevail, which is used for autumn tillage.This ensures the placement of fertilizers in the soil layer with guaranteed moisture, which increases the availability of nutrients for plants.
In the steppe regions, moisture supply is the main limiting factor for the formation of the crop. Therefore, measures aimed at accumulating and retaining moisture increase the efficiency of fertilizers. In turn, fertilizers contribute to a more efficient use of moisture to create a crop. With optimal fertilization, water consumption for the creation of a unit of cyxogo substance of plants is reduced by 15-20%. It should be borne in mind that phosphorus and potash fertilizers applied to the main fertilizer have a significant aftereffect on the following crops. Sometimes their aftereffect exceeds the effect of direct action. This significantly increases the efficiency of fertilizers, which must be taken into account when calculating their payback. Since the main fertilizer can be applied once every 2-3 years, special attention should be paid to row fertilization of all crops.
Fertilizing crops in this zone is ineffective, with the exception of irrigated land and winter crops.
Source: Господаренко Г. М. Агрохімія / Григорій Миколайович Господаренко. – Київ: ТОВ "СІК ГРУП УКРАЇНА", 2019. – 560 с.