How to improve fertilizer use efficiency?
If it is purposeful to apply elements of soybean technology, it is possible to significantly reduce the negative influence of the stress factor. Plants with the optimal status of nutrients have the highest degree of resistance. For the deviation of the concentration of batteries from the level of this optimum, as well as under adverse conditions, the sensitivity of plants to diseases increases.
Mineral nutrition is one of the main regulated factors used for purposeful management of growth and development of plants in order to obtain a high and stable soybean yield. Generally, nutrients are considered as building material needed for better growth and yield of plants. However, mineral elements affect the yield of plants, they not only improve the parameters of growth and the formation of elements of the structure of the crop, but also increase the immune status of the plant resistance or sensitivity to pathogens (environmentally protected plant protection).
The main fertilizer (N, P, K) under soybean and other leguminous crops should be introduced for basic soil cultivation (in autumn) or under pre-sowing cultivation (in spring) to prevent losses due to air decomposition. The introduction of a full dose of fertilizers during sowing generates an increased concentration of salts in the root zone and reduces seed germination, inhibits growth, prevents the development of tubers.
Various stress factors that influence plant physiological processes during the growing season significantly reduce the effectiveness of using doses of basic fertilizers, even if they are calculated very precisely, taking into account all soil characteristics and varietal characteristics of plants. The reason is a violation of hormonal balance.
Consequences: weak development of the root system; loss of absorption capacity of the roots; violation of physiological processes in the tissues of the leaf; reduction of transport functions of phloem and xylem; redistribution of assimilates, survival by reducing the yield.
In order to increase the efficiency of application of basic fertilizers in soil-climatic conditions that change and create a stressful situation for plants and reduce the assimilation of nutrients, there are special agro measures that correct mineral nutrition at each stage of the development of culture:
- pre-sowing seed treatment;
- Foliar (puff) feeding.
Application of complex fertilizers, which includes macro- and microelements, for pre-sowing seed treatment, together with bacterial preparations and tracheal tissues, is needed to successfully overcome the stress of the plant in the germination and seedlings phase, which will further positively affect the growth and development of soy.
According to the research results of the Soybean and Legume Cultivation Technology Laboratory of the Institute of Forage and Agriculture of the Podillya National Academy of Sciences, the use of pre-sowing seed treatments containing: inoculant + pesticide + complex fertilizer - reduced the abortion of flowers and beans, respectively, by 9.5 and 9 , 0% and the increase in the yield of soybean seeds of the Monad variety is 0.45 t / ha
A sufficient amount of nutrients in the soil still does not guarantee high yields. Different biotic and abiotic stresses have an impact on the availability of nutrients and the digestibility of the root system of soybean plants.
Potassium and nitrate form of nitrogen can be easily washed out of the soil, whereas phosphorus is chemically bonded with calcium and magnesium, forming difficult soluble compounds, and the like. At lower temperatures, consumption of food elements is slowed down: phosphorus - at a temperature of 10 ... 11 ° С, nitrogen nitrogen - 5 ... 6 ° С, potassium - at 7 ... 8 ° С.
Over the past two decades, chelates (compensators) have become a special value as a source of trace elements - intracompound compounds of organic substances with metals (B, Mo, Zn, etc.). They are not absorbed by soil, but are absorbed by plants and have a better effect than organic compounds of trace elements. The effectiveness of chelates is 10-15 times higher than the corresponding sulfates of trace elements.
As you know, soybeans, starting with the phase of the third triadic leaf, become very sensitive to the lack of phosphorus. It was during this period that there was a lack of moisture, which limits the supply of the root system of this element. In addition, on soils with high content of organic matter in the same period, there is a shortage of manganese. On soils characterized by low content of organic matter, zinc deficiency is often found. It should be noted that there is a high demand for soy for magnesium and sulfur, which, for the production of crops at the level of 3.0 t / ha soya, uses 40-60 and 30-50 kg respectively. Therefore, it is in the phase of the third triadic leaf - budding that it is necessary to carry out foliar application with multicomponent chelate compounds that have a high content of phosphorus in combination with manganese, magnesium, sulfur, zinc and molybdenum. This will ensure the intense growth and development of plants, increase resistance to high temperatures and the use of nutrients from the soil and activate the formation of root tubes.
Quite an important period of organogenesis in soy is the phase of budding - the beginning of flowering. Since then, intensive growth and development of soybeans and the laying of a future harvest begins. And it is during this period that soybeans suffer from a shortage of boron. Most of this problem is characteristic for crops on soils with high acidity and under conditions of insufficient humidification or drought. The use of multicomponent fertilizers with increased boron content will accelerate the growth of pollen tubes, activate the processes of flowering, increase the number of flowers and seeds in the plant. For soya, the most important are the first two fertilizers with multicomponent fertilizer, when the culture best responds to the abovementioned macro- and microelements. It is desirable to carry out the third extracorporeal fertilization with fertilizers with high potassium and trace elements in the phase of pouring seeds, which will improve the flow of water into plant cells, increase osmotic pressure and turgor, increase their resistance to drought and, accordingly, reduce fertility abnormality. As well as prolong the work of photosynthetic and symbiotic devices, improve the processes of pouring and improve the quality of seeds.
The studies carried out at the Institute of Forage and Agriculture of Podillya on the study of the influence of extra-root infusions on the level of fertility of the fruit elements and the yield of soybean seeds showed that the use of two extra-root crops by water-soluble fertilizers in the phase of budding and seeding began to reduce the abortion of flowers and beans, respectively, at 13, 1 and 20.6%, and an increase in the yield of soybeans of the Monad variety by 0.53 t / ha