NUTRITION vs. STRESS

How to mitigate the effects of adverse weather and climate conditions

Farmers are less likely to describe weather conditions as “ideal” and are increasingly faced with the need to deal with the negative effects of abiotic stresses. How to reduce the risk of crop loss with mineral nutrition?

On January 31, the annual EuroChem webinars started, dedicated to the most relevant topics of efficient agricultural production. Mineral nutrition experts answered the farmers’ questions: head of the agrochemical service Maria Vizirskaya and agronomist-expert in fruit crops and the South region Dmitry Sidorenko.

Stress factors and their consequences

Abiotic stress factors can be conditionally divided into two groups. The first includes stress associated with adverse weather and climate conditions. It can be air and soil drought, extreme temperatures, waterlogging and flooding, hail, sunburn, freezing and frost. In the second group, soil factors are salinity, granulometric composition and unfavorable soil pH, excess or lack of nutrients.

The consequences of abiotic stresses can be very serious. This is a halt in plant growth and photosynthesis processes, outbreaks of diseases and the dominance of pests, a reduction in the growing season and premature ripening, the death of the leaf apparatus and, as a sad consequence, a shortage of crops and a decrease in the profitability of agricultural production. The problem is that stress factors are very difficult to control over large areas, especially in the open field. According to experts, due to abiotic stress, farmers annually lose from 25 to 50 percent of the crop, and when cultivating, for example, corn or soybeans, losses can be up to 75 percent.

One common abiotic factor is lack of nutrients. For example, in apple orchards, a lack of calcium often leads to subcutaneous spotting (bitter pitting). This is one of the main reasons for the loss of apple quality, due to which the marketability of some varieties can be reduced by 30-40 percent.

“We cannot completely avoid losses associated with the lack of elements,” the EuroChem expert emphasized. “However, there is a way to significantly reduce the negative effects. You can do this with leaf power.

How effective can “preemptive work” be and is it worth taking care in advance that the plant does not fall under the strong influence of stress?

“If we are talking about fruit and berry crops, then we need to start fighting at the beginning of the growing season, before flowering and ovary formation: in the event of chlorosis, soaking or freezing,” Dmitry Sidorenko noted. – As for grain crops, it is possible to partially “pull out” the crop in later periods: if necessary, stretch the growing season and feed the plant through the leaf.

New realities of agricultural production

Soil is often the source of stress. This was recalled by the webinar speaker Maria Vizirskaya.

“Unfavorable soil properties can have a detrimental effect on crop yields,” she said. “So it is very important to know what condition the soil is in. Agrochemical analysis helps to tell farmers in which direction to act in order to solve a particular problem associated with the appearance of signs of nutrient deficiency.

The agrochemical service is in great demand among agricultural producers. In EuroChem’s client centers, it is also available to individuals. The company’s consultants can help not only in carrying out agrochemical analysis, but also explain how to do it yourself, decipher the data obtained.

Minimum set of parameters for soil analysis:

— soil solution pH;

— content of organic matter;

– mobile phosphorus;

– exchange potassium;

– available sulfur.

If problems with pH are identified, hydrolytic acidity (need for liming) should be determined and soil salinity should be analyzed.

Climate stress is the new reality. Thus, the average annual temperature in Russia over the past 20 years has increased by one degree, which is 0.3 degrees higher than in the whole planet. The average annual number of extreme weather events has increased by nine events per year.

According to experts, by 2050 the amount of carbon dioxide in the atmosphere will increase by 50 percent. On the one hand, this will stimulate photosynthesis and yield growth can be 20 percent. On the other hand, moisture consumption will increase proportionately. Another negative consequence is ​as a result of active vegetation at a high concentration of CO₂ in perennial plants, frost resistance decreases.

According to scientists, the availability of water will become a critical factor that will change the boundaries of zones suitable for agriculture and the growing season (non-stop period), by 30-40 percent increase the frequency of extreme weather events (droughts, frosts, rainstorms).

As a catalyst for extreme weather events, climate stresses have an undeniable impact on agricultural activities. So, for example, in the Stavropol Territory in 2020, return frosts reduced the yield of fruit crops by 80 percent. And in Krasnodar, heavy snowfalls in 2021 caused significant damage to the berry industry. In addition, extreme droughts annually become the reason for declaring a state of emergency.

The consequences of climate change for the agricultural sector are a decrease in the effectiveness of traditional forms of fertilizers, violation of sowing dates. It’s no longer possible to work “the old fashioned way”. Traditional agricultural practices are also becoming unreliable. The result of the shortcomings is the loss of the harvest.

“We must understand that climate change for people involved in agriculture is a new normal,” the EuroChem expert emphasized. – There is nothing unnatural in this, we just need to take measures that will help us adapt to them.

To the leaf and to the root

An effective way to adapt to climate change is to adjust mineral nutrition systems. The popularity of liquid forms of fertilizers and sustained-release products is growing. The terms and methods of application are being adjusted. In particular, they practice: refusal of fractional application without moisture at the later stages of the growing season, deeper planting of seeds in the soil and autumn application of nitrogen fertilizers.

Foliar feeding is becoming increasingly relevant, which can help with abiotic stresses at soil pH above 7.5 or below 5.5, lack or imbalance of nutrients. In addition, leaf nutrition is necessary to restore plants after frost or waterlogging, increase their winter hardiness or, conversely, heat resistance and drought resistance.

EuroChem’s product portfolio includes seven brands of Aqualis® water-soluble fertilizers capable of leveling micronutrient deficiencies in plants at any stage of vegetation.

“Due to low temperatures, plant cells with a low concentration of dry substances are the first to suffer, in addition, the root system is damaged,” Dmitry Sidorenko explained. – ​After frosts on field crops, you need to check the percentage of plants remaining alive. If this percentage is high, you need to give a complete set of macro- and microelements through leaf nutrition.

For these purposes, the expert recommended the equilibrium brand Aqualis® 20-20-20+ME. This EuroChem product also helps in the restoration of plants after flooding or waterlogging.

A special brand of Aqualis® with a high content of the chelated form of trace elements NPK 3-11-38+ME is used to increase the winter hardiness of plants. The product is especially widely used in horticulture, but it has shown high efficiency in viticulture, as well as in berry and field crops.

Significantly increase the provision of plants with phosphorus allows pre-sowing dressing of seeds using the brand Aqualis® 13:40:13 + ME. In 2021, an experiment was conducted in the Krasnodar economy on the use of the product at a dosage of 1 kg / t on winter wheat of the Grom variety. On the experimental site, a denser plant density was noted; higher than in the host’s variant, was the tillering coefficient. Aqualis® provided a yield increase of 2 dt/ha. Additional profit amounted to 2575 rubles per hectare.

Separately, the speakers focused on the nitrogen nutrition of plants. The traditional technology for the South of Russia has become the use of liquid fertilizer KAS-32 in nitrogen fertilizing. As shown by the experiments, the intrasoil application of the product increases its efficiency by 10 percent. The difference with ammonium nitrate is 20%. Thus, in the Stavropol Territory, the additional yield of winter wheat when using KAS-32 using a sprayer compared to ammonium nitrate was 6.2 q/ha. With intrasoil application, the increase is 8 centners / ha.

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