Imbalance of nutritional substances of the soil at the modern stage of development of agricultural production in Russia

Received : 05.05.2018 Accepted : 28.03.2019 The paper is devoted to the analysis of changes in the gross harvest of crops from 2008 to 2017. Nutrient removal volumes according to their types with the yield of main commercial crops, including 1 hectare of each crop area are calculated. Volumes of removal by type of nutrients are established. The removal of nutrients with the yield and the application of mineral and organic fertilizers when growing major crops are compared. The size of the nutrient removal over their application in general, including the main crops and types of nutrients is estimated. Proposals to improve the effective soil fertility by increasing the use of fertilizers are formulated. The authors consider ways of these proposals implementation.


Introduction
From a comparison of data for two five-year periods (2008)(2009)(2010)(2011)(2012) and (2013)(2014)(2015)(2016)(2017) it is clear that the gross harvest of most agricultural crops in Russia has increased significantly (Table 1). More noticeable is the growth in gross yield for sunflower, cereal crops, primarily for corn, and also for sugar beet. The growth rates for vegetables and potatoes are much lower, presumably, because the bulk of the production of these crops is in the households, where the increase in gross harvest was less intense than in the other categories of farms. The direct components of the gross harvest are the acreage in which crops were cultivated, and their productivity. Let's turn first to the acreage. The acreage of corn and sunflower expanded to the greatest extent in the second five-year period. However, the acreage of these crops has expanded to a much lesser extent than the growth of gross harvests for these crops. For the main grain crops (wheat and barley), the size of the acreage has increased by no more than 2.5%. For sugar beet, the arable area has even decreased. At the same time, as can be seen from table 1, gross harvest increased: by 14.3% for barley, by 27.6% for wheat, by 27.2% for sugar beet. As for the potato, the area of planting of this crop has decreased, due to its reduction in the household farms; the area for vegetables slightly increased with their stable sizes in household farms, at the same time, the gross harvest of potatoes increased by 8.7%, vegetables by 17.0%. At the same time, as can be seen from table 1, the gross yield increased: by 14.3 % for barley, by 27.6% for wheat, by 27.2% for sugar beet.
A comparative analysis of the dynamics of gross yields and acreage makes it possible to make a univocal conclusion: the increase in gross yields in the second five-year period is primarily due to the increase in crop yields. Due to the increase in crop yields, the gross yield of sugar beet, potatoes, wheat and barley is fully or almost completely increased, and for sunflower and corn by more than 2/3. In connection with the revealed circumstances, the question naturally arises: What are the reasons of the growth of yield increase in Russia over the past five years? At first sight, there are numerous yield factors of various agricultural crops, given the extremely wide variety of conditions for their growth in Russia. However, in any conditions, the leading factor is the availability of nutrients for plants, which is ensured by the natural fertility of the soil and fertilization. Of course, it is impossible to discount the improvement of cultivation technology, which is reflected in the introduction of new varieties and hybrids, in higher quality tillage, in shortening the duration of the main technological operations (sowing, harvesting), in using more efficient methods and means of controlling weeds and pests. However, in our opinion, the improvement of technology in general is aimed at increasing the ability of plants to absorb nutrients, as well as other important components of the cropwater and solar energy. Comparison of the obtained volumes of crop production and the nutrients used for this is done through the construction of nutrient balances. The study of the balance of nutrients in the conditions of modern Russia is devoted to numerous studies. Sychev and Saffran (2017) exploring the balance of nutrients in agriculture in Russia for the period from 1966 to 2015. in particular, they note that since the 1990s, the use of mineral fertilizers has sharply decreased, as a result of which the balance of nutrients began to take shape with a significant excess of the removal over their input into the soil. Sychev et al. (2016) expressed the opinion that, the annual decline in the yield of winter wheat and spring barley is within 1 centner/ha is the result of the imbalance of nutrients that had arisen since the 1990s in favor of their removal throughout the country. Further, these authors note that if the situation does not change, the crop shortage will increase. Monastyrsky et al. (2016) emphasizes that the immediate restoration of scientifically-based doses of the use of mineral fertilizers and plant protection products is a crucial condition for food safety. The nature of the current imbalance in favor of the removal of nutrients, including particular regions of Russia, is also reflected in (Shafran, 2016;Krasnitsky et al., 2018;Chekmarev, 2018;Yakovlev et al., 2018). This article aims to construct and analyze the balance of the main nutrients in Russia in the context of crops over the past 10 years. Constructing balances over five-year periods, on the one hand, helps eliminate the effect on the meteorological conditions of individual years on production volumes, and on the other, allows comparing balances over two periods, including major crops and nutrient types. In addition, the aim of the work is to establish the causes of the imbalance of nutrients and to propose an organizational and financial mechanism for its elimination by increasing the volume of applied fertilizers.

Material and Methods
The object of the study is the balance of nutrients for main crops, the cultivation of which took place in Russia from 2008 to 2017. As an information base we used data from the official statistical compilations of Federal State Statistical Service, as well as the standards for the removal of nutrients from the harvested crop, as indicated in the relevant educational and scientific literature. The research methodology includes the analysis of time series through a system of absolute and relative indicators, as well as constructive calculations. In particular: The absolute increase shows by how many units of measure the value of the indicator has changed in the current period compared to the previous one The growth coefficient shows how many times the value of the indicator has changed in the current period compared to the previous one The percentage growth rate shows how many percent the value of the indicator has changed in the current period compared to the previous one.
where; yi -value of the studied indicator in the current period yi-1 -value of the studied indicator in the previous period The use of the computational-constructive method made it possible to calculate the predictable amount of a fund of deductions from the sale of grain crops for export, aimed at restoring effective soil fertility: F=P×N×Q P -average price of exported grain, USD per ton (in the proposed calculations -$ 200) N -a standard proposed by the authors of contributions to the fund for the restoration of natural soil fertility in the amount of 5% Q -the amount of exported grain (in the example -30 million tons)

Results and Discussion
On the basis of data on the gross yield of main crops (Table 1) and the standards for the removal of nutrients with the unit of the harvested crops (Kidin and Torshin, 2015) the calculated volume of the annual production removal of nutrients and their removal with the main products is presented in Table 2. About 60 -70% of the total production removal of nutrients accounted for wheat and barley sowing, about 20% for sunflower sowing. With the harvest of corn and sugar beet, 7-10% of the total production removal was made. Plantingof potatoes and vegetables account for an insignificant proportion of the removal, due to the fact that the calculation was made only for sowing in agricultural organizations and farms. As for the structure of the removal of nutrients with the main products, by crops it generally corresponds to the structure of production removal, with the exception of the share of sunflower, which decreases to 10-12%. It should also be especially emphasized that the volume of both production removal and removal with the main crops in the second period increased in proportion to the growth of their gross harvests. For individual nutrients, calculations of the volumes of production removal and removal with the main products are presented in Table 3. In the structure of production removal of nutrients, about 50% is potassium, nitrogen is about 35%, and the remaining 15% is phosphorus. The structure of removal with the final products is different: up to 58% is nitrogen, about 25% is phosphorus and the remaining 16-17% is potassium. .7 * crops are combined, because according to them the removal from a unit of production is approximately the same; ** for potatoes and vegetables, the calculation was made only for agricultural organizations and farms; *** for vegetables, the calculation for the final product was not made, due to the large variation of this indicator for individual vegetable crops During the second five-year, the production removal of nitrogen and potassium increased most intensely, and with the main products nitrogen and phosphorus increased. Based on the average yield obtained by periods, the removal of nutrients per 1 hectare of sowing of the respective crops is presented in Table 4.
The largest volume of production removal from 1 hectare of sowing in both periods occurred in sugar beet, corn and vegetables, the smallest in wheat and barley. In the same approximate ratio are cultures for the removal of the direct products. The increase in yields for all crops in the second five-year period led to an annual increase in nutrient removal in the same proportion. Table 5 presents data on the application in the studied periods of mineral and organic fertilizers, as well as other measures aimed at improving the effective fertility of the soil. The materials of this table show, first of all, that despite the slight increase in the number of mineral fertilizers introduced in the second period (with the exception of potash fertilizers), more than half of the arable areas are still not fertilized. * crops are combined, because according to them the removal from a unit of production is approximately the same; ** for potatoes and vegetables, the calculation was made only for agricultural organizations and farms; *** for vegetables, the calculation for the final product was not made, due to the large variation of this indicator for individual vegetable crops The volume of work on soil deoxidation, which occupy tens of millions of hectares in Russia, is absolutely insufficient and not changing in dynamics. Let's compare the removal of nutrients from 1 hectare of crops (Table 4) and fertilization to this area (Table 5) by crops over five years. We present this comparison in Table 6. Only one tenth of the nutrients removed with the sunflower crop is compensated by the mineral fertilizers applied. For corn, the sixth-fifth part is compensated, for wheat and barley no more than 30%, for sugar beet and vegetables about a half. Only for potatoes with its very low productivity, fertilizers compensate for the entire removal of nutrients. It should be emphasized that in the second five-year period, the proportion of nutrients compensated by fertilizers for most crops decreases and only the sunflower remains the same, about 10%. This leads to a fundamental conclusion: The growth of gross harvest of agricultural crops achieved in recent years is ensured, above all, by the use of natural soil fertility. Therefore, with the continued decrease in compensation of natural fertility by fertilizers, in the long term there will inevitably be a decrease in the natural and, consequently, effective soil fertility and, as a result, a decrease in the volume of crop production. Comparison of the volumes of nutrients removed with the crop and applied with mineral fertilizers according to their types is presented in Table 7. The largest difference between the production removal and nutrients applied is in potassium: about 3 million tons in the first five years and 4 million tons in the second. For nitrogen the deficit was about 1.3 mln. tons of active substance in the first five years and 1.8 mln. tons of active substance in the second. For phosphorus, the difference between removal and application is the lowest: 700 thousand tons in the first five years, and about 800 thousand tons in the second. It is worth emphasizing that in the second five-year period, the difference in favor of the removal of all nutrients increased. After what has been said, the question is naturally: does the Russian industry have the ability to eliminate as quickly as possible the difference between the removal and application of nutrients and, therefore, prevent the degradation of Russian soils? Table 8 presents data on the annual production of mineral fertilizers in Russia over the past 10 years. This table also compares the amounts of mineral fertilizers applied and produced. The production of mineral fertilizers in the last 5 years has increased in all types of fertilizers, but only the seventh part of fertilizers produced in Russia were applied, and nitrogen and phosphorus, is one fifth and one sixth. We have a paradoxical picture that is absolutely unacceptable for common sense: we produce fertilizers, but do not apply them, constantly worsening the natural fertility of the soil. Mineral fertilizers produced in Russia at the expense of irreplaceable resources are exported. According to our calculations, in the last 5 years, on average, 14.8 million tons of mineral fertilizers were exported per year, including 4.7 million tons of nitrogen fertilizers, 4.3 million tons of mixed fertilizers and 5.8 million tons of potash fertilize. If the exported fertilizers were applied in Russia, then each hectare of arable land would receive an additional 186 kg of active substance of fertilizer. This is in principle (additional calculations are necessary, of course) would be enough to cover the removal of nutrients at the level of crop productivity achieved. Higher productivity levels will require higher doses of fertilizer. It is logical to assume that the reason that the produced mineral fertilizers are sent for export is the difference in prices (export and domestic), in the substantial benefit of export. Due to the lack of systematic data for comparing these prices, we present calculations for 2010 and 2014. Export prices: (in terms of rubles at the average annual exchange rate) generally refer to nitrogen, potash and mixed fertilizers, and domestic -to certain types of fertilizers with their classification into nitrogen, potash, mixed (Table 9).  Electronic versions 2009Electronic versions ,2011Electronic versions ,2013Electronic versions ,2015 From the data of this table 9, it follows that both export and domestic prices have increased over four years, for some types of fertilizers by 1.5 times, but the main conclusion is that export prices are not higher than domestic ones, and even lower for nitrogen and potash. Consequently, the difference in prices in favor of export should not be considered as a factor of its advantage. Obviously, the question is either in the absence of Russia's agricultural producers of financial resources for the purchase of fertilizers or in their dismissive, selfish attitude to such an important resource as soil fertility. According to our calculations, the average annual revenue of exporters of fertilizers for 2012-2016 amounted to 9010.6 million USD. In terms of rubles at an average rate of 60 rubles. per dollar annual revenue amounted to 540.636 billion rubles. If the state withdraw 10% from this revenue for the replenishment the fund for the conservation of natural fertility offered in this article, the amount of its annual replenishment will be 54.064 billion rubles. Then, even at the maximum price of 20,000 rubles per ton, the farmers will additionally get 2,730.3 million tons of mineral fertilizers, or, in terms of 1 ha of the entire arable area, about 35 kg. Along with the export of mineral fertilizers, in recent years, exports of agricultural products, primarily grain, have been growing rapidly. But, since it was established that the growth of gross grain harvest in modern Russia occurs primarily due to a decrease in natural soil fertility, an increase in grain exports actually means the alienation of the country's not replenished natural resources in the form of soil fertility elements. Table  10, based on the amount of nutrients that are not replenished by the application of mineral fertilizers, presents the calculation of the volumes of their alienation abroad. With the alienation of nutrients from 1 ton of exported products remaining in general in the second period, due to the growth of grain exports, the overall increase in the volumes of nutrients alienated for abroad increased almost 1.69 times and reached 1.537 million tons of active substance, that is about 70 % of the amount of fertilizer applied for grain. In our opinion, export supplies of grain should be another source of preserving the natural fertility of the land in Russia. Such a proposal is logical, including from the point of view of export: exporters should think not only about the present profit, but also about the possibility of its stable receipt in the future, which is excluded when effective soil fertility is reduced. With a modern export price of 1 ton of grain not lower than USD 200 per ton, exporters should, in our opinion, transfer at least $ 10 to the fund to support natural soil fertility. If we proceed from the average annual volume of grain exports in recent years in the amount of at least 30 million tons, the amount of deductions will be 300 million USD, and at the rate of 60 rubles for dollar it will be about 18 billion rubles. The use of these deductions, according to our approximate calculations, will allow increasing the doses of fertilizer application for cereals by at least 30 -40 kg of active substance per 1 hectare of the arable area.

Conclusion
The growth of gross harvests of major crops in Russia in recent years has been accompanied by a growing imbalance between the removal of nutrients from the crop and their application with fertilizers. Thus, there is an intensive decrease in the effective fertility of the soil, which, can develop into their degradation while maintaining this process. Instead of all the expected growth in crop production, the result will be an accelerated fall. Of course, this conclusion should be supported and differentiated by regional studies, including agrochemical soil monitoring.
To reduce, and in the future complete elimination of imbalance of nutrients in the soil, along with state support for the application of mineral fertilizers by economic entities, in our opinion, the immediate creation of a special fund for the conservation of soil fertility should be relevant. The main sources of replenishment of this fund can be deductions from export earnings from the supply of mineral fertilizers and grain abroad.