Biogeosystem Technique

232-242

Authors: A.I. Mamedov. G.J. Levy, C. Huang

Soil erosion and subsequent pollution by water from agricultural lands or watersheds is still in need for evaluating of the impacts of various spatio-temporal processes involved. We have summarized the contribution of soil inherent properties (predominant clay mineralogy, soil texture, and organic matter content), and extrinsic conditions (rain kinetic energy [KE], wetting rates [WR], water quality, antecedent moisture contents, tillage intensity, soil sodicity [ESP], amendments) on soil structure deterioration and erosion (runoff and soil loss) from numerous cultivated semi-arid soils. Soil loss from predominant smectitic soils was up to several times higher than from kaolinitic soils. Soil erosion seems to increase exponentially with the increase in rain KE, WR and ESP and decrease in clay content and organic matter. Rain KE and water quality (sealing, physicochemical clay dispersion) prevailed in determining erosion in medium- and coarse-textured soils, and WR (prevention of aggregate slaking) played a predominate role in fine-textured soils. Effects of minimum-tillage were soil texture and irrigation water quality dependent: erosion was notably lower under no-tillage than under conventional one, being more affective in clayey soils with stable structure, for both fresh and effluent water quality. Soils, having moisture content in the range between wilting point and field capacity were less susceptible to runoff generation and erosion. Application of a small amount of polymer in combination with gypsum may effectively decreased soil erosion. Whereas inherent soil properties cannot be changed, conditions prevailing in the soil (WR, moisture content, impact of rain KE) can be manipulated by management practices to arrive at conditions that decrease soil susceptibility to soil erosion and subsequent water quality problems. Results may assist in improving our understanding of the changes in the degree of erosion in semi-arid zone soils, and can be employed in modeling efforts aimed at the prediction of soil erodibility.

267-285

Authors: Anatoly P. Endovitsky, Angrey G. Andreev, Taniana M. Minkina, Valery P. Kalinichenko

Biogeosystem change is linked to ion’s association in soil solution. The concern of carbon sequestration problem is a soil as carbon sink drain. The carbonate calcium equilibrium (CCE) in soil solutions is important to characterize the degree soil solutions saturation with CaCO3 as a factor of terrestrial system carbonate geochemical cycle. CCE depends on the state of the chemical composition, pH, Eh, buffering properties of soil liquid phase, dissolution, migration, precipitation of carbonates in the soil profile and landscape, ion exchange processes at the interface of solid and liquid phases. At high ionic force in soil solution are formed electrically neutral ion pairs СаСО3°; CaSO4°, MgCO3°, MgSO4°, charged ion pairs CaHCO3+, MgHCO3+, NaCO3-, NaSO4-, CaOH+, MgOH+. The object of research – Southern Russia; saline chestnut soil, dry steppe zone; non-saline chernozem, steppe zone. The soil solution was extracted from soil layers 0-150 cm. Composition of soil solution was determined using standard analytical methods. The soil system is the object of mathematical thermodynamic modeling, because it is impossible to remove the solution from dry soil, on the other hand, the extraction of solution change the chemical equilibrium in solution. The approach to soil disperse system model is proposed as a discreet partially insulated form one another micro-water-basins on the internal surfaces of soil. This approach gives a new understanding of water-salt transfer, geochemical barrier functions and ecological properties of soil. On the basis of CCE algorithm, the computer programs were developed to calculate the real equilibrium ion forms and determine the nature of carbonate-calcium balance in the soil solution. The mathematical model shows the real state of associated ions at different ionic strength of low saline and saline soil solution. The concentration of free and associated macro-ion forms were calculated in iteration procedure according analytical ion concentration considering ion material balance, linear interpolation of equilibrium constants, method of ionic pairs, laws of: initial concentration preservation, operating masses of equilibrium system. Concentration constants of ion pairs dissociation were calculated following the law of operating masses. Were determined the quantity of ion free form and coefficient of ion association γe as a ratio of ions free form to its analytical contents . The association of ions is higher in saline soil layers. Depending on composition and ionic force c of soil solution in the form of ionic pairs are: 11-52% Ca2+; 22.2-54.6% Mg2+; 1.1-10.5% Na+; 3.7-23.8 HCO3-, 23.3-61.6% SO42-, up to 85.7% CO32-. To interpret a behavior of heavy metal in soil solution an additional equation for microelements is proposed for the mathematical model of macro-ions. The proposed thermodynamic calculation method for the real ion forms quantitative assessment in soil solution shows that in salted soils a chemical equilibrium in the soil solution causes a dissolved carbonate forms at high concentration of soil solution. It determines a high mobility of carbonates. Carbonate system of the soil solution is most important because on its state depends the nature of basic processes affecting formation and development of a certain type of soil. The nature of the calcium carbonate equilibrium soil is a cause why using an analytical concentration of ions only is observed the high calculated saturation degree of soil solutions with CaCO3. The association of ions in soil solutions is one of the geochemical drivers promoting transformation of solution, salt and heavy metal migration and accumulation in disperse system, soil genesis, excessive fluxes of carbon into soil, carbon sink from soil and biosphere to lithosphere and other geospheres.

298-312

Authors: Michael S. Sokolov, Jury M. Veretennikov, Valery G. Ostrovsky, Igor Ja. Paremsky, Jury Ja. Spiridonov, Leonid A. Marchenko, Alla V. Ovsyankina, Viktor G. Selivanov

The paper discusses the features and benefits of monodisperse aerosols of pesticides and hydrocarbon fuels used in plant protection and internal combustion engines as a result of long-term research. A new line of development of science, engineering, industrial and agricultural technologies – the authors’ project “Monodisperse Anthropogenic Aerosols” is proposed. The specific measures for its implementation are presented. The method of mechanics and gas-hydrodynamic effects on the torch of the fluid spray process with disk working body for drops separation. Device mode: using herbicides – droplet size in the range 250-350 microns, using insecticides – 160-250 microns, fungicides – 60-160 microns. The authors’ patent Method of Estimation of Spray Parameters of Dispersion-Capable Process Fluid and Unit for its Implementation. RU №.2516581, 02.05.2014 actually begins a new resource-saving scientific and technical branch – “Monodisperse Anthropogenic Aerosols” (MAA)* . A method for estimating the parameters of the fluid spray dispersion-capable process by means of a pulsed laser, the photographic, computer, allowing to sort drops on standard size classes. The most important condition for the MAA project implementation is creation of experimental base. Its task: a) design and technological assessment of prototypes of monodisperse and polydisperse spray devices and mechanisms; b) design and development engineering of special test stands. These stands will provide standard conditions for testing of operation conditions of various nozzles and sprayers used in different fields of science, engineering and production. It is planned to equip experimental base with the latest optical and electronic and laser systems for measurement, control and regulation of dispersion degree of the estimated dispersion-fluid systems. For the first time, a tester will be able “to see, measure, create, standardize and reproduce” substance of aerosol droplets spray generated by a sprayer. Another, no less important priority, scientific and technical task of the MAA Project is creation of modern engineering base or experimental and serial production of monodisperse small and micro-volume chamber and field sprayers. The long-term research carried out in All-Russia Research Institute of Phytopatology showed that monodisperse small and micro-volume spraying was bas on the use of conventional or even more cheaper preparative forms of pesticides. The weight of sprayer is significantly reduced due significant reduction of working fluid application rates (and thus, soil compaction is reduced in the process of its work). Productivity is increased and at least 25 % reduction in dose is provided due to elimination of losses of the working fluid in the form of inefficient small and large drops. At the same time it is important that the testers registered substantial increase of profitability indicators as a result of protective measures. Thus, decrease in spraying rate of the working fluid flow from 200 to 10 l/ha doubles the productivity. Due to this, direct costs only for treatment of a crop unit (without regard to pesticides consumption reduction) are reduced by 3 times. Sprayers with adjustable dispersion, enabling to control spraying parameters of the working fluid directly in the field fully comply with international standards of environmental safety – controlled drop application (CDA). However so far, polydisperse fluid spraying causes environmental and economic damage everywhere. And all this – at gigantic scales! We can cope with this problem if we make spraying of working fluids monodisperse and controlled.