Combined Application Of Organic And Mineral Fertilizers

2023 Author: Sebastian Paterson | [email protected]. Last modified: 2023-11-26 20:34

Read the previous part ← Types and use of mineral fertilizers

A few practical tips: do not be afraid to use mineral fertilizers, following the rumors that this is some kind of "chemistry". All of them are obtained from natural deposits, from fossils, you just need to know why and how to use them.

However, negative habits persist for a long time and cause significant harm to practical vegetable growing and horticulture. It turns out that gardeners and vegetable growers often become victims of stereotypes, false information, fables or inventions about mineral fertilizers.

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We advise you to forget about this and use mineral fertilizers more widely to enrich the soil in practical vegetable growing and horticulture.

Organic fertilizers are applied in a wide range of doses from 7-8 kg / m² to 20-40 kg / m². The optimal doses are considered to be annual doses of 10-12 kg / m². Doses of micronutrient fertilizers boric acid, copper sulfate and cobalt sulfate are about 1 g / m², ammonium molybdate, potassium iodate - 0.5 g / m², all micronutrient fertilizers are applied once every four to five years. Doses of lime fertilizers range from 400 to 1200 g / m², the average optimal dose is 600 g / m². More precisely, you can determine the dose by pH indicators (see table. 1).

Table 1. Recommended doses of lime fertilizers depending on pH values

Soils by mechanical composition	Dose of lime at pH, g / m2
	4.0	4.5	4.8	5.0	5.2	5.5
Sandy loam	1000	900	800	700	600	400
Loamy	1200	1100	1000	800	700	600
Peat	1800	1600	1500	1200	1000	900

Mineral fertilizers are applied in the range of optimal doses for nitrogen and phosphorus - 4-12, for potassium - 4-8 g / m², for magnesium - 2-6 g / m² of active ingredient. Doses of mineral nitrogen, phosphorus and potassium fertilizers can be more accurately determined on the basis of agrochemical analysis of soils, taking into account the removal of nutrients from the soil by plants, based on the planned yield of agricultural crops in accordance with the cycle of plant nutrients in nature.

Therefore, the dose of fertilizers should always be no less than the level of nutrient removal from the soil by plants. An approximate calculation of the doses of nitrogen, phosphorus and potash fertilizers is given for potatoes in Table 5. Fertilizer doses for other crops are determined in a similar way. Reference data are shown in Tables 2-4.

Table 2. Reference data on the removal of nutrients by plants

Culture	Carrying out the harvest based on 1 kg, g.
	nitrogen	phosphorus	potassium
Potatoes	6.0	2.0	9.0
Beet	2.7	1.5	4,3
Cabbage	3.4	1,3	4.4
Carrot	3.2	1.0	5.0
Green	3.7	1,2	4.0
Berry	1,3	0.3	1.5
Stone fruit	1,2	0.3	1,3
Pome fruit	1.1	0.3	1,2

Table 3. Corrections to the removal of nutrients by plants, taking into account soil fertility

Fertilizers	Corrections for the level of soil fertility: the dose is multiplied by the appropriate factor
	at low	at average	at high
Nitrogen fertilizers	1,3	1.0	0.5
Phosphate fertilizers	1.5	1.0	0.7
Potash fertilizers	1,2	0.7	0.3

Table 4. Coefficients of possible losses of nutrients from fertilizers in the first year

Fertilizers	Losses of batteries: multiply by the appropriate factor
	nitrogen	phosphorus	potassium
Mineral fertilizers	1,2	1.5	1,2

Table 5. An example of determining the doses of mineral fertilizers for the planned potato yield 3 kg / m².

one.	The removal of nutrients by the potato crop is determined per 1 kg / m2 (found according to the reference book, Table 2), d.v.: nitrogen - 6.0, phosphorus - 2.0, potassium - 9.0
2.	The actual removal of nutrients is determined by the planned yield of potatoes 3 kg / m2, g of ae: nitrogen - 18.0, phosphorus - 6.0, potassium - 27.0
3.	Corrections to doses are found in connection with the level of soil fertility, according to the reference book, table. 3, for example, with average fertility in nitrogen, average in phosphorus and high in potassium: nitrogen - 1.0, phosphorus - 1.0, potassium - 0.3
4.	The removal of nutrients is determined by the planned yield of potatoes, taking into account amendments for soil fertility, g.v.: nitrogen - 18.0, phosphorus - 6.0, potassium - 18.1
five.	Are adjustments to doses in connection with possible losses of nutrients, according to the reference book, table. 4: nitrogen - 1.2, phosphorus - 1.5, potassium - 1.2
6.	The removal of nutrients is determined by the planned yield of potatoes, taking into account possible losses of nutrients, by multiplying by the loss factor, g.v.: nitrogen - 21.6, phosphorus - 9.0, potassium - 21.72
7.	The final dose of specific mineral fertilizers (taking into account the content of nutrients in them) is determined for the planned yield of potatoes, g / m2: ammonium nitrate (34%) - 63.52, double superphosphate (45%) - 20.0, potassium chloride (53 %) - 34.47 g / m².
8.	Doses are determined for the main, pre-sowing and fertilizing fertilizers. When planting, it is necessary to add 7 g / m² of superphosphate, in top dressing - 7 g / m² of ammonium nitrate and potassium chloride. The rest is the main fertilizer for digging before planting.

Thus, in order to obtain the planned potato yield of 3 kg / m², on soil with an average level of nitrogen fertility, an average level of phosphorus and a high level of potassium, it is necessary to add 10 kg of manure, 57 g of ammonium nitrate, 13 g of double superphosphate, 28 g potassium chloride, 400 g of dolomite flour, 1 g of boric acid, 1 g of copper sulfate, 1 g of cobalt sulfate, 0.5 g of ammonium molybdate and 0.5 g of potassium iodate for each square meter of potato field when digging the soil before planting to a depth of 18 cm.

When planting potatoes, it is necessary to add 7 g / m² of superphosphate, in top dressing - 7 g / m² of ammonium nitrate and 7 g / m² of potassium chloride. In the same way, you can determine the dose of fertilizers for any other vegetable or fruit and berry crop.

This rule is also called the rule of timing. In order for plants to receive nutrients from the soil in a timely manner, it is necessary to take care of the advance introduction of organic and mineral fertilizers into the soil, that is, fertilizers must be applied in advance, ahead of time, several days before the moment when the plants require nutrients. During this time, the necessary physicochemical reactions will take place between the fertilizer and the soil, so that the fertilizer turns into nutrients for plants, and they become available to them.

Plants cannot wait for nutrients to appear at the request of the owner, because they cannot stop the process of absorption of elements by the roots, since their lifespan is very limited. Therefore, fertilizers must be applied 7-30 days before the time when the plants need nutrients for their life. Therefore, all the main fertilizers are applied before sowing in the reserve so that the nutrients from these fertilizers are available to plants during the period of their intensive growth.

To improve seed germination and growth of a young seedling until 2-3 true leaves are formed, a pre-sowing phosphorus fertilizer is necessary. It is required to be applied when sowing or planting plants so that the fertilizer can be used after about 3-10 days at germination and emergence.

When applying fertilizers in top dressing, nutrients can be available to plants only after 1-2 weeks from the moment of their introduction. This is also a lead time. It is necessary for the transfer of nutrients from fertilizers to the soil, and for the regrowth of roots. In agrotechnical measures, for example, during cultivation or when digging a furrow for line fertilization, the roots of the plants must be cut by hand. It takes time for the roots of the branch to be able to absorb nutrients. Therefore, fertilizers are always applied ahead of time - a few days before the time when the plants enter the phase of intensive growth and they need a lot of nutrients for this.

Therefore, in order to choose the right time for fertilization, it is necessary to know well the biology of plant nutrition, their growth and development phases, in order to apply fertilizers in advance and provide them with favorable growing conditions.

Thus, all gardeners and vegetable growers need to know the timing of the consumption of nutrients throughout the growing season, it is necessary to take into account the age rhythms in plant nutrition in order to properly apply fertilizers. And first you need to remember that taking into account the age needs of plants, fertilizers must be applied in three terms. The first period is before sowing, that is, 20-30 days before the period of maximum absorption of nutrients by plants from fertilizers in the phase of intensive growth.

The second period is when sowing, that is, 2-10 days before the elements are absorbed by plants during seed germination. And the third period is after sowing, that is, 15-25 days before the start of the absorption of elements from the fertilizer. Moreover, all three terms of fertilization must be fulfilled, otherwise the nutrition of this plant will be disrupted or defective.

Errors of non-compliance with the advance rule are as follows:

• poor knowledge of plant nutritional biology, critical periods and periods of maximum nutrient intake;
• too late fertilization;
• ignoring the timing of the main fertilization before sowing;
• the desire to apply fertilizers for top dressing, the desire to then "feed" the plants.

There are other mistakes too. Often gardeners and vegetable growers ask: how to feed the plants, otherwise they grow poorly? This formulation of the question is incorrect, erroneous. Delayed application of fertilizers is usually useless, it is just that the plants have already passed into another phase of their development, and now they already require other nutrients.

Read the next part. Soil pollution control, lime fertilizers →

Gennady Vasyaev, Associate Professor, Chief Specialist of the

North -West Regional Scientific Center of the Russian Academy of Sciences, [email protected]

Olga Vasyaeva, amateur gardener

Photo by E. Valentinova