Purpose: to determine and scientifically substantiate the optimal combinations of regimes for regulating soil moisture by irrigation and the use of biological plant protecting agents at various stages of their growth and development, ensuring the minimization of anthropogenic impact on the environment. Materials and methods. The studies were conducted in 2021–2022 on the experimental site of the All-Russian Research Institute of Irrigated Agriculture near the village Vodny, Sovetsky district of Volgograd, in plantings of the Gulliver potato variety in a two-factor field experiment. Factor A: A₁ – the moisture content of the soil layer 0.4 m deep throughout the entire potato growing season was maintained at a level not lower than 70 % of the minimum moisture capacity; A₂ – the same, only at 80 % of the minimum moisture capacity. Factor B: B₁ – biological system of potato plant protection; B₂ – integrated protection system; B₃ – chemical protection system (control). The experiment was carried out on light chestnut, heavy loamy, low-humic, non-saline soils. In terms of precipitation, the years of research are characterized as: 2021 – average wet, 2022 – average. Results. In the first option of the irrigation regime, the irrigation rate of 2720 and 3060 cubic m/ha was provided with eight and nine irrigations. The second irrigation regime was maintained with almost twice as many irrigations – up to 15–17, but at the same time the watering rate decreased to 230 cubic m/ha, and the irrigation rate increased to 3450–3910 cubic m/ha. In the option of the moisture regime of 80 % of the minimum moisture capacity in a horizon of 0.4 m, in conjunction with a plant protection system based on the use of biological preparations, the largest green matter of 385 g/plant, which is 98 g/plant more control one was obtained. The maximum mass of tubers in the nest was also obtained in this combinable option; it was 660 g/plant, which is 30 % higher than the option with chemical protection. Conclusions: on low-fertility light chestnut soils of the Lower Volga region, potatoes are best cultivated at a moisture regime in which humidity does not fall below 80 % of the minimum moisture capacity in a soil horizon of 0.4 m, in conjunction with a plant protection system based on the use of biological preparations, which provides favorable conditions for obtaining a tuber yield of 32.4 t/ha.
Entropy as a process studied in natural phenomena is related to thermodynamics. In particular, when studying the state of the soil, its change is observed, passing through a state of equilibrium. Equilibrium states in the environment are associated with a maximum of total entropy. The purpose of the research is to determine the energy contained in the soil at various levels depending on the fractional composition of soil particles based on empirical and calculated data. Novelty. For the first time, an energy entropy analysis was performed for irrigated light chestnut soils, which makes it possible to determine the residual energy stored in the soil. Materials and methods. According to field data, the analysis of the complete granulometric composition of the soil was carried out with the determination of the weight contribution of each fraction. Calculations based on the results of chemical analysis were used to isolate the mineralogical composition of the soil. The presence of humus and plant residues was determined by a generally accepted method. The sampling was carried out on the territory of the village. The waterway of the Volga-Don interfluve. Research results. The research presents the characteristics of light chestnut heavy loamy soil. The content of physical clay in the arable horizon (2-25 cm) is 45.2%. The illuvial horizons B1 and B2 are clearly expressed in terms of silt content. The silty fraction of 27.74 - 31.22% prevails. Thermodynamic characteristics enthalpy, Gibbs energy and entropy are not absolute values. They represent the proportion of energy remaining in the soil of a particular mineral, or its property. The analysis of thermodynamic parameters showed that in the horizon of 2-25 cm the values (∆H, ∆G, ∆S) are greatest in the coarse–powdered fraction, followed by the silty fraction, fine- , medium-powdered and sand. At a depth of 26-55 cm, coarse-dusty and silty are ahead of all fractions in terms of potentially high thermodynamic parameters. At a depth of 56-75 cm, the tendency of the predominance of coarse-dusty and silty fractions persists. Conclusion. The highest indicators of thermodynamic potentials in the horizon of 25-55 cm - ∆H kJ/mol—1415,6, - ∆G kJ/mol—1328,22, ∆S J /mol grad - 66.85. This horizon is characterized by the maximum values of the potential relative residual energy. The lowest potential is deeper than 75 cm. Entropy decreases with depth, in the horizon of 25-55 cm it is maximum. EDN: DJLXOS
Purpose: scientific substantiation of the use of agro-reclamation tillage practices of light chestnut heavy loamy soils in rice cultivation with periodic irrigation by sprinkling. Materials and methods. The research was conducted at the experimental site of the All-Russian Research Institute of Irrigated Agriculture in 2022–2023 with Stalingrad 1 rice crops in a two-factor experiment: factor A (soil water regime) – two options and factor B (tillage) – three options. Generally accepted methods of laying and conducting field research were used. Results. Immediately after rice sowing, the soil density in the layer of 0.0–0.6 m, varied in the range of 1.19–1.41 t/cubic m depending on the tillage practice. The minimum value of soil density in the layer of 0.0–0.6 m was formed in the A2B3 variant and amounted to 1.23 t/cubic m. The maximum soil compaction in this layer of 1.34 t/cubic m was observed in variant A1B1. During the period of full ripeness of the grain, soil compaction occurred in all tillage options. Its minimum compaction (1.34 t/cubic m), compared with the control (winter plowing), was noted with a combination of winter plowing and spring deep loosening. The minimum values of the water consumption coefficient and irrigation water loss were obtained in the A2B3 variant, and their numerical values were 851.7 and 703.6 cubic m/t, respectively. Conclusions. It was found that winter plowing to a depth of 0.25–0.27 m in combination with spring deep loosening to a depth of 0.40 m, in comparison with traditional winter plowing in one step, provides a decrease in soil density in a layer of 0.0–0.4 m by 0.10 (after sowing) and 0.12 t/cubic m (during the period of full ripeness of grain), which contributes to the yield increase to 6.95 t/ha and a reduction in irrigation water loss by 112.4 cubic m for the formation of 1 ton of grain.
The widespread use of wheeled and tracked vehicles in forestry and agriculture is one of the reasons for compaction and subsequent soil degradation. At the same time, it is known that walking machines destroy the upper ecologically vulnerable soil layer to a lesser extent. The main types of existing walking machines that can work on weak-bearing soils are considered. It has been shown that walking movers of the cyclic type are characterized by the greatest simplicity and reliability. A prototype of a multi-purpose walking chassis (weighing about 200 kg) with cyclic propulsors has been developed. A number of technical solutions have been proposed aimed at increasing its adaptability, profile cross-country ability and maneuverability. The walking chassis prototype was tested in real terrain. Tests have confirmed its high cross-country ability and excellent traction and traction properties. In terms of the ecology of the contact effect on the soil, the walking machine is also superior to its analogues with traditional types of propulsors. The results of the work may be in demand when developing walking machines and robots for new soil-saving technologies in forestry and agriculture.
Purpose: to state hydraulic characteristics and determine priority directions for improving the irrigation module design for combined drip and micro-sprinkler irrigation. Materials and methods. The study is based on the joint use of theoretical methods – a well-known mathematical model for calculating the hydraulic characteristics of the irrigation module and experiment, which allows assessing the problem state and scale solutions in any necessary proportions. Results. According to calculations, the uniformity of watering is maintained at an acceptable level at a lower head level in the range of 1.56–1.68 atm when installing six microsprinklers on a drip line. When installing eight sprinklers, the water head along the length of the drip pipeline decreased to an unacceptable 1.39–1.40 atm. Experimental studies have shown that there is only an option with two sprinklers installed on the pipeline above the level of 1.5 atm. Already with the installation of four sprinklers, the water head along the length of the pipeline decreased to 1.45–1.47 atm. At the same time, the variation in the actual microsprinkler performance reached 16 % or more. The discrepancy between experimental and model data is explained by the fact that the calculation model does not fully take into account local resistances that arise when connecting sprinklers. Conclusions. Two main reasons of the increased uneven distribution of irrigation water over the irrigated area have been identified. The first reason is a significant increase in water flow in the irrigation pipeline when emitters and sprinklers work together. The solution to this problem is to develop structures that make it possible to separate the water flow through emitters and through sprinklers in time. The second reason is an increase in local resistance in the water diversion units to the sprinklers. The solution to this problem is to develop special water diversion structures that would be characterized by minimal local resistance.
