编号 8 (2024)

The nitrogen balance used to form the crop yield and the proportion of biological nitrogen in it were evaluated. New data on the contribution of biological nitrogen to the agroecosystems of Russia have been obtained, which showed that in the total nitrogen intake (≈3 million tons of active substance) the share of biological nitrogen is 34.7%, which is 3 times more than nitrogen supplied with organic fertilizers (11.6%). In the composition of biological nitrogen, half of it (50.1%) belongs to nitrogen fixed in crops of perennial legumes. The amount of nitrogen fixed in soybean crops was 23.1%, and leguminous crops – 19.3%. Over the past 15 years, the amount of symbiotic nitrogen has increased from 544.3 to 1025.7 thousand tons, or 1.88 times due to an increase in the acreage of legumes and their yield. The intake of biological nitrogen from legumes increased by 2.55 times, soybeans – by 2.91, and perennial legumes – by 1.69 times with a decrease in the proportion of nitrogen fixed in crops of annual grasses. Agricultural plants consume 5.38 million tons of nitrogen to form a crop, and nitrogen removal from the alienated part of the crop reaches 3.24 million tons/year. In agriculture in Russia, on average, ≈3 million tons of nitrogen enters the soil per year together with mineral and organic fertilizers, as well as as part of biological nitrogen. When calculating the cost of nitrogen for the formation of the entire crop, the nitrogen balance is formed sharply negative (–2.44 t/ha/year). When calculating nitrogen costs for the commodity part, the average annual balance becomes close to optimal (–0.30 t/ha/year).

The need to intensify the agricultural sector to ensure the food security of the growing population of the planet against the background of depletion of natural sources of phosphorous raw materials leads to an increase in the costs of agricultural producers for phosphorus fertilizers (PF), which increases the urgency of the problem of optimizing the doses of the latter. Based on the generalization of the results of long-term field experiments, the economic and environmental validity of different approaches to calculating doses of PF for cereals in the Ob region was compared. The study was conducted in 2006–2017 in long-term experiments of the SFNCA RAS on leached medium loamy medium humus chernozem in the Central forest steppe of the Ob region (54°53ʹ13.5ʺ n. w., 82°59ʹ36.7ʺ e. l.). Calculations were performed based on the results of observations in 3 crop rotations: 3-field grain-fallow (fallow–wheat–wheat), in 4-field grain-fallow (fallow–wheat–wheat–barley), in 4-field grain-fallow (fallow–wheat–wheat–wheat). The duration of the experiments was 18, 23, 38 years, respectively. The experiments were carried out against the background of nitrogen fertilizers with a complete scheme of plant protection from harmful organisms. A high agronomic efficiency of PF application has been established: the increase in grain yield with the use of P15–P30 averaged 0.5–1.2 t/ha. Phosphorus removal by the grain harvest (its alienation from the field) in the control variants was ≈20 kg P₂O₅/ha of the crop area, in the variants with fertilization it reached 30 kg/ha. Its removal by aboveground biomass was 1.6 times greater and reached 48 kg/ha. The phosphorus balance in the soil in the variants of experiments without the introduction of PF was deficient (–15…–27 kg/ha), with the introduction of P15 its deficit was –11 kg/ha, with a dose of P30 the balance was positive, i. e. the phosphorus intake was excessive. Two indicators were considered as evidence of excess doses of PF >P30 for grain agrocenoses in the forest steppe of the Ob region: accumulation of mobile mineral phosphorus in the soil and an increase in the fraction of enzymatically available phosphorus, these pools can become a source of phosphorus losses from agrocenosis. It is concluded that for the leached chernozem of the Ob region, the calculation of doses of phosphorus fertilizers based on the amount of phosphorus alienation by the grain harvest is more justified from an economic and environmental point of view in comparison with the calculation based on the amount of removal of the element by the entire aboveground (grain + straw) biomass of plants.

In the Tver region, on sod-podzolic light loamy soil, the productivity management of fiber flax varieties (Zaryanka and Diplomat) with different maturation periods was studied by optimizing their mineral nutrition. To calculate the dose of mineral nutrition, 3 methods were used: balanced modified by Kayumov, balanced to compensate for the removal, and by the ratio of elements in the fertilizer. Accordingly, the doses were N0P0K0 (control), N30P0K50, N30P22K80, and N30P60K150. It was found that despite various weather conditions, the use of fertilizers from the initial phases of flax plant growth allowed plants to accumulate a large biomass: in arid conditions, on average, for varieties by 58% more, in optimal water supply conditions – by 45%. The absorption of nutrients by flax plants increased with an increase in the dose of the introduced elements. With an equal dose of nitrogen in the fertilizer, its amount was greater both in the roots and stems of flax, with increasing doses of phosphorus and potassium in the fertilizer. The content of nitrogen, phosphorus and potassium in the flax roots of the late-maturing Diplomat variety was higher than that of the early-maturing Zaryanka. When optimizing nutrition by applying fertilizers in doses of N30P22K80 and N30P60K150, the proportion of stems in the structure of flax plants increased and amounted to 45 and 46% in the Zaryanka variety, 44 and 49% in the Diplomat variety, respectively to dosage. Without fertilizers, the share of the stem was 38%, and the share of roots and leaves was the highest – 22 and 42%. The production process in this case was less rational. The late-maturing Diplomat variety, on average, for 3 years, when applying all doses of fertilizers, had a yield of flax straw by 3.1–3.9 c/ha more than the early-maturing Zaryanka variety. In the early-maturing variety Zaryanka, a higher dose of fertilizers N30P60K150 reduced the quality indicators: the number of the long fiber and the percentage number of the entire fiber, especially during the dry growing season.

The soil diversity of coastal depressions of pulsating highly mineralized chloride lakes of the Uldza–Torey closed basin (on the example of the Lake Babie) within the Southeastern Transbaikalia area was studied. It has been established that 3 main soil types dominate: quasigley solonchaks, saline humus-quasigley soils and light-humus saline soils. The soils under study, especially the quasigley solonchaks, are characterized by unfavorable physicochemical and agrochemical properties and a high degree of salinity in most horizons with the excessive content of Na⁺ and Cl^– toxic ions. Very high concentrations of N, Ca, Mg, S, and Na⁺ and Cl^– ions were revealed in the upper saline layer (0–5 cm) of the quasigley solonchaks. A low content of the most important nutritional elements, including nitrogen and phosphorus available for plants was defined mainly in soils studied, so as biogenic microelements in humus-quasigley saline and light humus saline soils. Therefore, these soils have an extremely low level of both potential and effective fertility based on the agrochemical assessment of their production ability. When considering the ecological uniqueness and medicinal value of the lake and its lakeside ecosystems, it is recommended to exclude these soils and land resources from agricultural practice. They must be used in the form of specially protected natural landscape components as a part of reproduction areas, nature reserves, territories of medical and balneological resorts and other health care facilities.

Humic substances are a group of high-molecular biopolymers that are formed during the natural decomposition of plant and animal tissue. Due to their functional composition, humic substances of peat have a sufficiently large range of biological properties, they are quickly involved in the metabolic processes in plants. The use of humic substances as micronutrients leads to increased resistance to adverse factors, the development of the root system, improves the synthesis of chlorophyll, which increases the yield and quality of cultivated plants. The paper considers the influence of natural biopolymers such as humic substances of peat on the growth and development of agricultural plants of oats and peas. It has been established that the composition of humic substances includes various functional groups (phenolic and aliphatic hydroxyls, carboxylic, quinoid), which determine the biological and growth-stimulating effect. It has been shown that solutions of humic substances used in the experiment have a beneficial effect on seeds even in small concentrations. The purpose of this research work is to study the biological activity of humic substances of peat as growth-stimulating drugs of agricultural crops

The increase in field contamination due to the spread of minimal and zero tillage technologies requires protective measures using chemical pesticides. Due to the limitations of the use of glyphosate in the assortment, there is a vacant niche for new herbicides capable of having a general destructive effect. In field small-scale experiments conducted during the 2022 and 2023 seasons, in sunflower crops of the Yenisei variety, soybeans of the Marina variety and corn hybrids of the EU Catamaran and RNIISK 1, high efficiency of the use of pelargonic acid (525 g/l) as a herbicide before the emergence of crops was established. On average, when applying 21 l/ha of the acid, the reduction in total weed contamination was 87, 35 l/ha – 93, 49 l/ha – 96%, respectively. All weed species present in the experiment were highly sensitive to pelargonic acid (525 g/l). 15 days after its introduction at a rate of 49 l/ha, the reduction of amount of the redroot pigweed and such cereal weeds as millet, gray bristle, and barnyard millet was at the level of 94–98%, the reduction of amount of all other weed species was 100%. The reduction of clogging after the application of pelargonic acid led to a significant increase in crop yields compared with the untreated control. The increase in soybean yield reached 17.7, corn – 78.2, sunflower – 108%.

Under the conditions of a 5-year vegetation-precision experiment based on acidic sod-podzolic sandy loam soil reclaimed with increasing (from 0.8 to 24 t/ha) doses of conversion chalk (CC), the effect of liming on the value of soil acidity (pH_KCl), the content of mobile zinc compounds in the soil and its translocation into plants was studied, related to the cabbage, legume and cereal families. It was shown that with an increase in the dose of meliorant, the content of zinc available to plants in the soil decreased, and its transition to plant tissues slowed down. Quantitative parameters of zinc accumulation by spring rape plants were revealed 1 year, 4 and 5 years after liming. A relationship has been established between the zinc content in grain and straw of spring barley. In the range of meliorant doses from 0 to 2.0, calculated by hydrolytic acidity (H_a), barley grain accumulated zinc in sufficient quantities for the normal functioning of barley. The zinc content in vetch tissues, which allows plants to develop normally, varied in liming options from 0.2 to 1.7 H_a. Empirical models have been developed that adequately describe the relationship between: a – the dose of chalk application and the pH value of the soil achieved as a result of liming, b – the pH value of the soil and the zinc content in soil and plants, c – the zinc content in soil and its translocation into plant species of various biological families, d – zinc concentrations in grain and straw of plants.

The protease activity of powdery carbonate chernozems (Haplic Chernozem Hypocalcic) was studied under various types of land use – arable land, virgin land, fallow. The research area is located in the Tugnui basin, Mukhorshibirsky district, Republic of Buryatia. The activity of the protease enzyme was determined by application using photographic film, which was laid in a layer of 0–20 cm of soil. Observations of protease activity in the first year of the study showed that the maximum activity occurred at the end of July–beginning of August. On arable land, the indicator was 35–39%, on fallow land – 34– 36%, on virgin land – 33–39%. In the 2nd year of the study, proteolytic activity increased from the beginning of the growing season. The first peak of activity was observed in the 2nd half of July, which amounted to 44% in arable land, 43% in fallow, and 47% in virgin lands. The second peak of protease activity occurred in the 2nd half of August and amounted to 30% in arable land, 35% in fallow and 37% in virgin lands. In chernozems, proteolytic activity was higher in virgin lands, its intensity decreased from arable land to fallow lands. This indicated an average proteolytic activity in powdery carbonate chernozems under various types of land use. Focality and mosaic character were noted during gelatin hydrolysis as a result of 10-day exposure in all variants. This indicated an uneven distribution of enzyme systems in the soil column and the presence of separate microzones with different protease activity. Statistical processing of the data showed that the activity of proteases depended on hydrothermal conditions.

In field experiments on sod-podzolic soils, the agroecological effectiveness of long-term action of cattle manure of various humidity was studied. It is shown that the use of semi-liquid bedless and litter manure, when optimizing doses and combinations with mineral fertilizers, improved soil fertility, increased the productivity of crops and crop rotations, ensured the environmental safety of agrocenoses, reduced the risks of accumulation of nitrates and heavy metals in soil and plants. The annual application of semi-liquid manure for 15 years to sod-podzolic heavy loamy soil in the forage crop rotation in the variant of the organo-mineral fertilizer system with a content of 240 kg N/ha ensured their high efficiency – 9.8 t c. u./ ha, which was 96% more than the control. The resulting feed was characterized by high protein nutrition, and the nitrate content corresponded to the norms of feeding farm animals. The use of increasing doses of semi-liquid manure increased the productivity of forage crop rotation from 7.28 to 10.3 tons of grain/ha in variants using a single (N120) to a fourfold dose (N580). Increasing the dose of manure to N600 proved ineffective. Depending on the dose of manure, the nitrate content in the layers of the soil profile changed. Nitrates accumulated most intensively (3.7 times more than in the control) in a layer of 0–100 cm of soil in the variant with the maximum dose of manure (N600). At the same time, there was no excess of nitrate content in the soil above the MPC (130 mg NO₃^–/kg). A correlation has been established between the accumulation of nitrates and the increase in nitrogen doses introduced with manure in soil layers, especially in the upper 0–100 and 100–200 cm, with correlation coefficients r = 0.73 and 0.60. With prolonged use of litter manure on sod-podzolic light loamy soil, its combination with mineral fertilizers at a dose of N180 was effective, where the annual harvest of grain units averaged 3.1 tons per hectare over 37 years, or exceeded the control by 38.5%. At the same time, vegetable products were of high quality – the grain contained up to 14.2% protein, potato tubers – up to 13% starch at an acceptable level of nitrate content. The content of heavy metals (Cd, Pb, Zn, Cu, Ni, Hg) and arsenic, as well as nitrates in the soil, depended on the intensity of fertilization with litter manure, but generally corresponded to acceptable standards.