A system of rational fertilizer application for vegetable crops in open soil

A rational fertilization system in vegetable production is focused on creating optimal conditions for plant nutrition and maintaining high soil fertility. It is based on the split application of elements for the planned yield. The total need for fertilizers is calculated using the balance method, taking into account the cultivar potential and the dynamics of nutrient uptake as the plant grows. All fertilizers are divided into three groups: basic, at-sowing (at-planting), and those applied as top dressing.

Basic fertilizer is applied before sowing or planting under autumn ploughing and the first spring tillage. Usually, the full rate of organic matter, as well as half or two-thirds of phosphorus and potassium fertilizers, are incorporated before winter. Half of the nitrogen fertilizers are applied under the first spring tillage, less often — under the main autumn tillage. At-sowing application ensures rapid growth of seedlings or transplants before their roots reach the zone of the basic fertilizer.

• At-sowing fertilizer — 5–10 kg/ha of active ingredient of each element (nitrogen, phosphorus, potassium)
• Humus consumption for the mixture — 2–5 t/ha
• Incorporation depth for top dressing — 12–14 cm
• Distance from the row during application — 14–16 cm

Timing and rules for top dressing

The remaining rate of fertilizer is divided into two or three top dressings. They stimulate the increase of vegetative mass during the period of assimilation potential formation and are important for the development of product organs. The timing and objectives of top dressing are tied to specific phases of crop development.

1. First top dressing. Carried out in the 2–3 true leaf phase (2–4 weeks after emergence) or one and a half to two weeks after planting the transplants.
2. Second top dressing. Carried out at the beginning of the formation of product organs.
3. Third top dressing. Used to adjust the growth and development of plants. It can be carried out as the last one or in the interval between the first two.

If the nutrition system is strictly maintained and external conditions are favorable, one may limit the application to only the first two top dressings. Their rates and composition by nutrients are selected individually. These indicators directly depend on the soil fertility and the crop being grown.

Top dressing is carried out using cultivator-fertilizer applicators. In case of an acute deficiency of macro- or micronutrients, foliar top dressing is used. Often such spraying is combined with treating plants with plant protection products against diseases and pests.