Soil Water Physical Properties Research Articles

Positive experience in the application of soil- and carbon-saving agricultural technologies with the introduction of biochar in the conditions of the Russian Far East

Based on the positive results of a long-term field experiment on the introduction of bio-coal for vegetable crops in the Primorsky Territory on soils of heavy chemical composition, its sequestration effect and positive effect on the water-physical properties of soils were proved. After the first year of application of biochar, a significant decrease in CO2 flux in the field without a drainage system was shown by 4.5% at a dose of 1 kg/m2 of biochar and by 36.6% at a dose of 3 kg/m2 of biochar compared with a site without biochar. The decrease in CO2 flux indicates the reclamation effect of biochar due to its high sorption properties affecting the sequestration capacity of the soil. After the second year of application of biochar, the greatest decrease in CO2 flux was observed when 1 kg/m2 was applied. The greatest difference between the values of the CO2 flux at the control site and the sites with the introduction of biochar was noted in September after the abnormal amount of precipitation recorded in August (521 mm). So, at the control site in September, the CO2 flux was 2,276 mg CO2 m-2 h-1, at the site with the addition of 1 kg/m2 of biochar, the CO2 flux was 560 mg CO2 m-2 h-1, at the site with the addition of 3 kg/m2 – 975 mg CO2 m-2 h-1.

Climate Change and Land Management

The essential resources for the survival of the living world are air, water and land. By its essence land is the only non-renewable natural resource, with a potentially rapid rate of degradation and a very slow process of formation and regeneration. Water and land are resources, characterized by climate, so climate variability inevitably affects the processes in the land and its use, whose testimonies today we could find through the fossil lands. Processes affecting the lands are intensified in the last few decades around the world, such as erosion, water logging, drought, fire, loss of organic matter and the like, are associated with climate change and are visible on the territory of Republika Srpska. The basic task of humans today is to use the land rationally and to preserve it for new generations. On the basis of available measured data and climate models in the future, the following conclusions came out: land use would not be significantly impaired, nor would crop production be endangered; favorable climatic conditions would continue to prevail for the production of corn, wheat, and potatoes, with increased year-on-year variations by the end of the century; due to earlier sowing, water logging would be pronounced; regular maintenance of existing drainage systems should be fully in function, and new ones to be built in geopardize places; for the new, highly intensive orchard establishments and vegetable production, irrigation system should be designed and built; comprehensive solutions of existing erosion processes and prevention of occurrence of new ones should be envisaged, because in future climatic conditions, dry periods of higher intensity might occur, followed by strong rainstorms could cause permanent soil loss due to dried vegetation prone to erosion; considering that the soils of Republika Srpska are very poor in humus, i.e. organic carbon, it is necessary to apply agrotechnical measures to increase the intake of organic matter. Intentional burning of crop residues must be severely punished. Continuous monitoring of soil fertility on georeferenced locations is indispensable (pH, macroelements (NPK), content of organic matter, water-physical properties of soil) for better data comparison and observation of the direction of impact, whether positive or negative, in order to plan and take timely adaptation measures, ensuring proper and sustainable land use and climate change mitigation.

北京地区油松人工林不同演替类型空间结构对林下植被及土壤的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 北京地区油松人工林不同演替类型空间结构对林下植被及土壤的影响 DOI: 10.5846/stxb202112143542 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 北京市园林绿化局项目"北京市国有林场精准提质"（20210618） Effects of spatial structure on understory vegetation and soil properties in Pinus tabuliformis plantation of different succession types in Beijing Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以北京地区油松（Pinus tabuliformis）人工林不同演替类型林分为研究对象，研究油松纯林、油松-栓皮栎（Quercus variabilis）混交林和栓皮栎纯林三种不同演替类型林分的空间结构、林下植被和土壤水分的变化规律及其相互作用关系。结果表明：（1）林分水平及垂直空间结构、草本层物种多样性、更新幼树生长、土壤持水和透气性能等指标在三种不同演替类型林分间差异显著（P<0.05），林分空间结构参数中的角尺度、林层指数和开敞度显著影响了各类型林分的灌草多样性，混交度、林层指数和大小比数显著影响了更新幼树的生长，混交度和林层指数显著影响了土壤水分的变化（P<0.05）。（2）松栎混交林灌草生物量、天然更新幼树的生长以及土壤水分物理状况均好于纯林，并主要受林分混交度和林层指数的共同作用。（3）各演替类型林分内均存在栓皮栎更新幼树，混交林栓皮栎更新幼树数量最多、长势最好，对林地资源的竞争最为激烈。因此，可以通过调整林分空间结构实现种间关系及林地资源的调控，以充分发挥森林生态系统的各项功能与价值。 Abstract:Using different succession types of Pinus tabuliformis plantation in the Beijing area as the research object, this study investigated the change rules and interaction of stand spatial structure, understory vegetation, and soil water of three different succession types:Pinus tabuliformis pure forests, Pine-Quercus mixed forests, and Quercus variabilis pure forests. The results were as follows. (1) There were significant differences in horizontal and vertical stand spatial structure, species diversity of herbaceous layer, saplings growth, and soil water physical properties among the three different succession types (P<0.05). In addition, the angle index, stand layer index and opening degree index of stand spatial structure parameters significantly affected the shrub and grass diversity of each type of stand (P<0.05), while the mingling degree, stand layer index and neighborhood comparison significantly affected the growth of saplings (P<0.05), and the mingling degree and stand layer index significantly affected the change of soil water (P<0.05). (2) The biomass of shrub and grass, saplings growth, and the physical condition of soil water were all the better within the mixed forest than in the pure forest and were mostly influenced by the mingling degree and the stand layer index. (3) The natural regeneration saplings of Quercus variabilis were observed in all succession types, with mixed forest having the most saplings and the best growth and the most intensive competition for forest resources. Therefore, interspecific relationships and forest resources can be regulated by adjusting the spatial structure of stand, so as to give full play to the functions and values of forest ecosystem. 参考文献 相似文献 引证文献

Improving water management technology in rice systems for sustainable rice production

Purpose: to reduce rice irrigation rates by developing water management in rice systems for sustainable rice production. Materials and methods. The materials for the study were data obtained for 2020–2022 in production experiments in three experimental farms in Krasnodar Territory, the total area of which was 59,636 hectares. The idea of decreasing the irrigation rate by reducing the duration of flooding period, the number of discharges, the rate of one-time irrigation, the repeated flooding, the intensity of vertical filtration and physical evaporation is discussed. Water consumption, transpiration and seepage effluent were determined when defining the irrigation rate for the shortened flooding and the combined irrigation using the method of vegetation vessels with an area of 3000 cm². For an environmentally friendly technology, evaporation and transpiration were additionally determined using a GGI-500-50 evaporator at the stage of two or three leaves in rice crop during sprinkling irrigation. Results. The analysis (water-physical properties of soil, chemical analysis of soil samples, content of ferrous and ferric iron in soil) of existing (basic) rice cultivation technologies: shortened flooding and combined irrigation, was carried out. Integral curves of evaporation and evapotranspiration were constructed on the basis of observational data on vegetal discharge. Conclusions. A new environmentally friendly technology for rice cultivation was developed. As a result of evaluation the declared technology, its efficiency expressed in a reduction in irrigation rate by 10 % due to a decrease in evaporation, daily transpiration and vertical filtration was proven.

ЭРОЗИОННЫЕ ПРОЦЕССЫ ПРИ СТОКЕ ТАЛЫХ ВОД НА ЮГЕ ЕВРОПЕЙСКОЙ ЧАСТИ РОССИИ

Purpose: to determine the regularities of melt water runoff and soil erosion on the chernozems of Rostov region for a long-term observation period of 1970–2021. Methods. Field experiments were carried out on slopes on compacted arable land (perennial and winter crops) and loose arable land (autumn ploughing). Measuring of melt water runoff and precipitation during the period of snow melting and soil washout was carried out on the water balance site of Stepnoy village Rostov region. The main physical and water-physical properties of soil during the snow melting period (freezing depth, moisture content of the upper soil layer 0.30 cm, water permeability) were studied according to generally accepted methods. Results. An analysis of field observations for the period from 1970 to 2021 was carried out for the parameter “snow water reserves before melting + precipitation during the snow melting period”, which averaged 47.8 mm over 52 years on compacted arable land and 43.15 mm on loose arable land, the runoff coefficient was higher on compacted arable land and amounted to 0.25 and 0.10, respectively; with appearance of surface runoff of 10.6 t/ha, this indicator increased to 5.9 and 20.7 t/ha on loose arable land, respectively. Mathematical analysis of the data made it possible to establish the relationship between the values of runoff, soil washout and water reserves in snow, the depth of soil freezing and water permeability during the runoff period. Conclusions. Long-term studies (52 years) found that there is a greater accumulation of water in snow on compacted arable land than on loose arable land, while the runoff coefficient was 2.5 times higher on compacted arable land, but the plants retain soil particles on compacted arable land, and soil washout on average over the years with the manifestation of surface runoff, was 10.6 t/ha, while on loose arable land this figure increased to 20.7 t/ha. The relationship between runoff rate, soil washout and water reserves in snow, the depth of soil freezing and water permeability during the runoff has been determined.

The Effect of Phosphogypsum and Turkey Litter Application on the Properties of Eroded Agrochernozem in the South Ural Region (Russia)

The possibility of using industrial and poultry wastes as an ameliorant/fertilizer for erosion-prone soils was investigated. We studied the impact of phosphogypsum (PG) and turkey litter (TL) application on the physicochemical properties of weakly eroded agrochernozem in conditions of a 5-year field experiment in the South Ural region, Russia. In particular, we examined the effect of treatments on the soil moisture reserves, soil structure, microaggregate composition and particle size distribution, aggregate stability (water resistance), organic carbon content (Corg), ammonium, nitrate and alkaline hydrolysable nitrogen, available phosphorus (Pav), exchange potassium (Kex), and potato productivity/ecological quality. Treatments included the application of the PG at 5, 10, and 20 t ha–1, the TL at 40 and 60 t ha–1; and in mixes of PG and TL at ratios of 1:10, 1:5, and 1:2. The obtained results indicated that the introduction of PG and TL increased (compared to control) the moisture reserves (by 10–17%), resistance of soil aggregates to water (8–15%), the content of Corg (6–10%), available nitrogen (two orders of magnitude), Pav (3–6 times) and Kex (2–3 times), and improved, as well, soil structure. In general, years factor had a significant effect on soil water-physical properties; its influence was 44–67%, while the effect of treatments was 21–30%. The agrochemical properties (Corg and Pav) were dependent on treatments factor (77 and 95%, respectively), while the content of all forms of nitrogen depended on the year factor (34–57%). The obtained results suggest the application of PG and TL to improve agrochernozem fertility status and minimize its erodibility without soil and plant contamination.

Bioecological properties of nutrient soils based on production waste as a factor in monitoring and controlling the production process of plants

The article presents the results of research on the bioecological assessment of the effectiveness of the fertilizing properties of metallurgical waste in nutrient soils. As a result of studies to assess the toxic effects of water extracts from nutrient soils on the vital activity of daphnia (Daphnia magna), changes in the reaction of this test object were established depending on the composition of the components in the nutrient substrate. The degree of influence of the fertilizing effect of various types of nutrient soils based on soil, slag and zeolite on the germination, growth and development of seedlings of small-seeded vegetable culture of lettuce has been determined. Seed germination, plant growth and development are influenced by the water-physical properties of soils and the amount of available macroand microelements. The effectiveness of the use of visual and computer assessment of the color gamut of lettuce leaves for assessing the level of soil contamination by the intensity of nutrient consumption by plants is shown.

Assessment of evapotranspiration of licorice under saline environments: case study from Galaba farm, Uzbekistan

Land salinization is widespread in countries of the arid zone, including in the Aral Sea basin, where 4 million hectares of irrigated land are salt-affected, causing high economic losses. Current saline soil reclamation practices include soil leaching and deep drainage to remove excess water outside the irrigated zone. Growing pressure on limited water resources makes this practice ineffective. An alternative is biological methods of salinity control, which are not widely used in the region. In this study, the licorice plant was considered a potential crop for restoring the fertility of salt-affected soils. The study has two objectives: (1) to assess evapotranspiration from licorice fields, and; (2) to track changes in soil chemical properties as affected by the cultivation of licorice on irrigated land. The results of the study indicate high evapotranspiration from licorice fields under irrigation. The total amount of soluble salts may increase in the soil profile; however, after more than 10 years of cultivation of the crop, no accumulation of toxic salts has occurred and there was no deterioration in the chemical and water-physical properties of soils, while at the same time soil fertility has increased. Key words: Soil salinization, Aral Sea basin, licorice, biological reclamation, soil fertility.

Environmental safety of a humin-based formulation and its impacton crop outputboth in quantity and quality

This article studied organic fertilizers obtained from physically and mechanically stimulated peat. The conceptual difference of this formulation from analogs lies in its environmental safety, and humates and humic acids are extracted from the feedstock as fully as possible. We studied the effect of pretreatment of seeds with liquid humic fertilizer on plant growth and development, and found that this fertilizer in low concentrations when growing grain and legumes has a positive effect on the water-physical properties of soil, soil and plant microflora, on increasing mobility reserves of nutrients in the soil, as well as to improve the diet of plants. Consequently, the development and implementation of organic safe humic fertilizers is an urgent area for crop production and food production.

СОВРЕМЕННОЕ СОСТОЯНИЕ МЕЛИОРИРОВАННЫХ ЗЕМЕЛЬ В АРКТИЧЕСКОЙ ЗОНЕ ЯКУТИИ В УСЛОВИЯХ МЕНЯЮЩЕГОСЯ КЛИМАТА

On the example of the estuary irrigation system «Bolshaya Polyana» of the Verkhoyansk region, the current state of reclaimed lands in the Arctic zone of Yakutia in a changing climate is considered. Research methods included reconnaissance and topographic surveys of the study area, analysis and processing of research materials previously obtained by the author. An analysis of natural and climatic conditions showed that due to climate change, there is a reduction in the cold winter period, catastrophic amounts of winter precipitation, abnormal heat in summer periods and an increase in the average annual temperature over the past 15 years by 1.2°С, which affected the shift in the start date of irrigation of estuary meadows for early periods up to 9 days. The heterogeneity of the relief of estuary meadows and the overgrowth (cluttering) of irrigation canals were revealed, in connection with which the irrigation period reaches 25-30 days, as a result of which waterlogging of the soil occurs. Agrochemical studies determined the type of soils, frozen peat-gley soil in the hay area of estuary irrigation and frozen humus-gley soil in the natural area. Measurements of the seasonal thaw layer in the natural area show deeper thawing of soils than in the hayfi elds of the estuary irrigation system. Also, measurements at different flood depths show that the greater the flood depth, the smaller the thawing layer. These phenomena, in our opinion, are due to the type of soils and may be associated with the influence of the layer of irrigated waters on the thawing of soils. The results of the studies carried out require further measures and studies to create an optimal irrigation regime, improve the water-physical properties of soils, for which it is proposed to improve irrigation methods by building a double-regulation reclamation network and subsequent study of its effect on the thermal and moisture conditions of irrigated haylands and agrochemical indicators of soils.

Influence of various tree species on the properties of soils in the “Kamennaya Steppe”

The influence of various tree species of forest plantations on the soil properties of the “Kamenno-Stepnoye Experimental Forestry” (Talovsky District, Voronezh Region, Russia) is considered. The aim of the study is to reveal the degree of transformation of the properties of chernozems under various perennial plantations, since forest reclamation is the most important measure to optimize the agroecological state of soils. The researchers note that different tree species have different effects on soil properties. However, this issue is still insufficiently studied and relevant. The research results showed the positive role of tree species on the structural and aggregate state of soils and their water-physical properties. It was found that tree species contribute to the optimization of soil density, humus and moisture reserves. It was revealed that the influence of different tree species on the agroecological state of chernozems is not the same. Thus, under larch (Larix siberica Ldb.) And maple (Acer platanoides L.), the maximum increase in the level of soil humus was observed, as well as a significant improvement in the physical and water-physical properties of soils. What makes this breed the most promising for use in soil protection of the steppe zone.

Agrochemical and water-physical properties of sod-podzolic soil with drip irrigation of a fruit nursery

Relevance. The use of irrigation is one of the directions of intensification of fruit growing. Drip irrigation is considered one of the promising methods of irrigation, which provides the creation of the most favorable conditions for the growth and development of plants, makes it possible to supply irrigation water directly to their roots and allows the use of automation tools in the irrigation process. The results of ongoing scientific research show that changes in the water-physical and agrochemical properties of soils can be observed on irrigated lands. For the Central Region of the Non-Chernozem Zone of Russia, studies on the influence of drip irrigation on soil properties are fragmentary.Methods. Field studies were conducted on the territory of the educational experimental farm of the Michurinsky Garden fruit growing laboratory of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy. A two-factor experience in the study of different ranges of moisture for the formation of varietal plum seedlings grafted on plum tree stock was laid in the spring of 2018. Before setting up the experiment, organic fertilizers were introduced in the form of horse manure with sawdust in the amount of 100 t/ha. Soil moisture was controlled using tensiometers, calibrated based on the data of the thermostat-weight method. Irrigation rates were set in such a way as to increase the moisture content by 20% of the lowest moisture capacity. The identification of the main agrochemical and water-physical properties of the soil in the experimental plot was carried out according to generally accepted methods and techniques.Results. The data obtained on the characteristics of the water-physical and agrochemical properties of sod-podzolic soil make it possible to reasonably design the irrigation regime, reclamation and agrotechnical measures. The results of the study show that the local irrigation of soils with sparing irrigation rates with the application has led to certain changes in some soil parameters. However, the obtained research results suggest that in quantitative terms, these changes are not yet significant.

THE IMPACT OF RECREATION LOADING ON PHYSICAL AND WATER-PHYSICAL PROPERTIES OF BROWN FOREST SOILS

The article analyses the influence of recreational load on the physical and water-physical properties of brown forest soils. It is established that the complete or partial absence of litter on the pathway contributes to the rapid evaporation of moisture from the upper horizon (0−5 cm) of the soil, reducing the porosity total, increasing the density solid phase and buk density. It was found that with the increase of the buk density by 12,5 % the water permeability of the soil decreases 33 times in comparison with the control. A significant increase in the bulk density of the structure by 39−48 % was found on partway with a width of more than 2 m. On these pathway the surface runoff of water is formed. An increase in the density of the solid phase was recorded. The results of which are characteristic of the Hp horizon of brown forest soils. The overlapping of the trail with wooden flooring on the track “Stezhkamy lehendarnoyi Tustani” had a positive effect on the physical and water-physical properties of the soil. It was found that the indicators of soil bulk density and water permeability were close to the results obtained in the control and only the increase in the density of the solid phase indicates a significant recreational impact in the past. On the roadsides of the same revealed a significant increase in soil density of 1,5 times compared to the control and 1,3 times with the results obtained on the pathway, this indicates a recreational impact to date. It is proposed to use the following criteria for degradation of natural ecosystem: quantitative and qualitative changes in vegetation (meadow ecosystems), presence/absence of forest litter (forest ecosystems), soil density, presence of additional/parallel paths, path width, depth of erosion on the pathway. Establish category (stages) of recreational degression on the tracks the National Park “Skolivski Beskydy”. On the first stage/category (“Unchanged track”) of recreational degression includes trails 0,35−0,70 m wide with relatively close indicators of soil structure bulk density to control and the presence of forest litter on the pathway. The only negative aspect in this category is the insufficient water permeability of the soil. On heavy II category there is forest litter, although its redistribution is mainly traced between the trail and its roadside. In some sections of the trail, where there is no forest litter, it is fixed by increasing the bulk density of the structure to 27 %, the width of the pathway is 0,9−1,2 m and is classified as “Little-changed track”. On pathway with 2,15−3,40 m, there is a complete or partial absence of forest litter. Bulk density increased by 38−39 %, surface water runoff is formed. It is established presence distinct partway, visibled qualitative and quantitative changes in vegetation. The presented data correspond to the pathway of III category and are classified as “Endangered track”. Category IV (“Devastated track”) includes paths on which there is no forest litter, a significant increase in soil density up to 48 %, access to the surface of the root system and the width of the path is 2,60−4,90 m. Key words: recreation influence; soil bulk density; water permeable; pathway; NPP “Skolivski Beskydy”.

Agroecological assessment of water-physical properties of irrigated soils of the Trans-Urals in the analysis of the main hydrophysical characteristics

Water-physical properties of soils are a set of soil properties that determine the accumulation, preservation and water transfer in the soil stratum. One of the important indicators of water-physical properties are soil-hydrological constants. These indicators can be used in forecasting yield, calculating the irrigation rate. The determination of soil-hydrological constants is a rather laborious process. In this article, we propose to obtain soil-hydrological constants from the data of the main hydrophysical characteristics. This technique allows to analyze the data and obtain soil-hydrological constants from the data of granulometric composition. The conducted studies have shown that the use of uncontrolled irrigation has led to the transformation of water-physical properties, the content of easily mobile, productive and gravitational moisture has decreased. When modeling the MHC curve, a change in the shape on the graphs can be noted.

Spatial heterogeneity of soil water physical properties in coal gangue pile in arid desert area

Based on grid sample method (20 m×20 m), spatial heterogeneity and distribution of soil water physical properties from 0 to 5 cm of the coal gangue pile in arid desert area were explored by using classical statistics and geostatistics methods. The results showed that the variation of soil bulk density, capillary porosity, capillary maximum moisture capacity, total porosity and saturated moisture contents were weak, while water content showed a moderate variation. The best fitting model of soil bulk density was Gaussian model, and exponential model was the best fitting model for other indices. The C0/(C0+C) values of soil bulk density and water content were low and had strong spatial autocorrelation. The capillary porosity, capillary maximum moisture capacity, total porosity and soil saturated moisture showed moderate spatial autocorrelation. Soil bulk density was negatively correlated with capillary porosity, capillary maximum moisture capacity, total porosity and water content, whereas there was no significant correlation between soil moisture content and other indices. Soil capillary porosity, capillary maximum moisture capacity, total porosity, and saturated water content showed a significant synergistic effect between each other. On Kriging contour maps, capillary porosity, capillary maximum moisture capacity, total porosity and saturated moisture had a similar spatial pattern, with high values on the middle and the left side of the lower slope, whereas soil bulk density showed an opposite pattern. Soil water content was mainly affected by the slope position and increased from the upper slope to the lower slope. Our results suggested that land preparation measures should be taken to loosen the soil in root area over the coal gangue pile in arid desert area during vegetation restoration. Moreover, irrigation amount should be properly increased on the upper slope during the initial stage of vegetation restoration, which could improve soil moisture status in the overlying soil area of coal gangue and create uniform and suitable soil water physical conditions for vegetation restoration.

Biological and Chromatic Characteristics of Plants as a Factor for Monitoring and Management of Production Process When Applying Fertilizing Features of Production Wastes

The localization and intensity of technogenic flows of chemical elements causes the formation of technogenic anomalies and biogeochemical provinces with varying degrees of environmental distress. The purpose of the research is environmental assessment of the effectiveness of the fertilizing properties of metallurgical production wastes in nutrient soils. Studies have been conducted to determine the degree of influence of the fertilizing effect of various types of nutrient soils based on soil, slag and zeolite on germination, growth and development of seedlings of small-seeded lettuce. Seed germination, plant growth and development are affected by the water-physical properties of soils and the number of available macro and trace elements. Visual and computerized assessment of the color range of the lettuce leaves is proven to be effective to assess the level of soil contamination based on the intensity of nutrient consumption by plants.

Soil amelioration of different vegetation types in saline-alkali land of the Yellow River Delta, China

Yellow River Delta is an important distribution area of coastal saline-alkali land in China. Revegetation is the main technology for ecological restoration during saline-alkali land amelioration. To explore the effects of different vegetation types on soil improvement in saline-alkali land and get the suitable model in the Yellow River Delta, four tree-grass compound models, Salix americana+Distichlis spicata, S. matsudana+D. spicata, Tamarix chinensis+Medicago sativa, and Fraxinus chinensis+T. chinensis+M. sativa, were set up, with pure S. americana forest as the control. Twenty indicators, including soil moisture physical parameters, saline-alkali content, soil nutrient contents, and microorganism quantity etc. were measured. Principal component analysis, cluster analysis and fuzzy mathematics were used to evaluate soil modification effect of different vegetation combinations. The results showed that all compound models significantly improved soil physical and che-mical properties in coastal saline-alkali land by increasing soil porosity, soil water storage, soil organic matter content, available nutrient content and soil microorganism quantity and reducing soil density. Among all the models, the tree-shrub-grass mixed model of F. chinensis+T. chinensis+M. sativa was the most effective in inhibiting salt and alkali stress and increasing soil nutrients and microorganism abundance, whereas the tree-grass mixed model of S. matsudana+D. spicata was the most effective in improving soil water physical properties. The combined effects of different vegetation patterns on soil amelioration in coastal saline-alkali land of the Yellow River Delta were arranged in order of F. chinensis+T. chinensis+M. sativa> S. matsudana+D. spicata> S. americana+D. spicata> T. chinensis+M. sativa.

Ефективність прямої сівби на чорноземі звичайному важкосуглинковому Правобережного Степу

The purpose. To inform commodity producers of all patterns of ownership about efficiency of long term straight sowing at cultivation of the basic crops in conditions of risky farming agriculture. Methods. Field, laboratory, statistical. Results. It is fixed that in the humidified years and on the average for years of researches water-physical properties of soil and its security with nutrients varies as compares to plowing within the limits of HCP0,05. But in drought years at straight sowing the density of soil is always increased critical value (1,30 g/cm3) and may gain 1,43 g/cm3 with simultaneous increase of hardness of soil on 23,9% in comparison with plowing. High density and hardness in rainless conditions negatively influenced propagation of root system, receipt to it of water and nutrients, stipulating lower productivity of crops, especially tilling ones. In the humidified years the mentioned before is not observed. Weed infestation of crops in the first year of application of straight sowing remains at the level of plowing, and in the next years it sweepingly increases, and already on the 3-rd crop exceeds control index in 1,5–2 times. Change of species composition of weeds is simultaneously observed. If pink sowthistle (Cirsium arvense) and amaranth (Amaranthus) predominate at plowing, then yellow sowthistle and white goosefoot (Chenopodium album) — at straight sowing. On the average for years of researches productivity of crop rotation at straight sowing was lower as compared to plowing on 4,4%. However, general expenditures reduced on 52,6%, fuel — on 8,2 kg/hectare (42,7%), quotient of power efficiency increased on 76,4% and has made 6 against 3,4 at plowing. Conclusions. The basic deterrent of application of straight sowing on typical midhumus heavy clayloam chernozem with removal of plant residues at harvesting in comparison with plowing is substantial increase of density and hardness in rainless conditions.

Physical-chemical and water-physical properties of agricultural soils on inter-mountain hollows of Mountain Altai

The purpose of the research is the study the basic physical,chemical and water-physical properties of soils of high and medium mountain basins of the Altai mountains under different types of agricultural use (arable land, hayfields, pasture). The main features of chestnut and light chestnut soils of high-mountain basins, dark chestnut soils and common chernozem of mid-mountain basins are established. These are a light granulometric composition with a high content of coarse soil, a sharp decrease of humus content and cation exchange capacity down the profile, slightly alkaline reaction of medium, and perfect structural state, except for the lower horizons of light chestnut soil. By density of the humus horizon, the soils of hayland and pasture belong to the soils rich in organic matter. Considerable density is noted also in the chernozem ordinary under an arable land where for many decades usual dump plowing is applied, minimum - in the dark-chestnut soil under an arable land where in recent years processing is carried out by a diskator which basic purpose - preparation of the soil for crops without preliminary plowing. The density of arable horizon on arable land correspond to typical values for a cultivated or a new-ploughed arable land. With the depth of the soil profile, this ratio increases, but it is lower than typical values for the subsurface horizons. The density of the solid phase varies slightly. In the upper organogenic horizons of the hayland and pasture, it is low due to the occurrence of organic matter. In the lower horizons, it is slightly higher and corresponds to the density of the solid phase for mineral soils. The porosity of the studied soils is in inverse proportion to density. The porosity of the upper horizons is perfect, and the horizons correspond to the cultural-arable layer. The porosity of the lower horizons is satisfactory. The hygroscopic moisture content of the soils under study varies in the wide range (0,7-9,9%). The maximum hygroscopicity in the sandy loam horizons is low (2-4%) and it is higher in loamy horizons (4-7%). The permanent wilting point ranges from 2,7 to 11,7%, and total water capacity - from 25,9 to 50,4%. Comparison of physical-chemical and water-physical properties of the studied soils of intermountain basins of the Altai Mountains with those of the same type of soils of the Altai territory and adjacent regions of Western Siberia indicates their proximity and even some advantage.

Forest and grass composite patterns improve the soil quality in the coastal saline-alkali land of the Yellow River Delta, China

The Yellow River Delta (YRD) in China has a high concentration of coastal saline-alkali land, and biological measures are important techniques for the ecological restoration of this land. This study aimed to explore the soil-improving effects of various vegetation restoration patterns and identify the best vegetation pattern for improving the soil quality in this coastal saline-alkali land. Six vegetation patterns consisting of mixed forest-grass, forest-crop intercropping, and pure forest were selected from the saline-alkali land of the YRD, with bare land as the control. A total of 18 indicators were measured and analyzed, including the soil water physical properties, salt and alkali contents, nutrients, and microbial number. The soil-improving effects of the various vegetation patterns were evaluated using statistical methods such as principal component analysis, cluster analysis, and membership functions in fuzzy mathematics. The results showed that the forest-grass composite patterns significantly improved the soil physicochemical properties, reduced the soil density, increased the soil porosity and water storage, and elevated the levels of soil organic matter and available nutrient contents, as well as the soil microbial number. However, the soil-improving effects under the various vegetation patterns were significantly different. A mixed tree-grass pattern consisting of Salix matsudana + Distichlis spicata was found to be best for improving the soil water physical properties, while the mixed tree-shrub-grass pattern of Fraxinus chinensis + Tamarix chinensis + Medicago sativa showed the best effects for preventing alkalization and inhibiting salinization, as well as increasing the soil nutrients and microbial number. The mixed forest-grass patterns showed the highest effects in increasing the soil available K and available N, while these patterns had little effect on the available P. The mixed forest-grass patterns significantly increased the number of bacteria in the saline-alkali soil; the number of actinomycetes ranked second, and the number of fungi was the lowest. In the saline-alkali habitat, the mixed tree-shrub-grass pattern of F. chinensis + T. chinensis + M. sativa demonstrated the best soil-improving effects among the various vegetation restoration patterns. The mixed tree-grass pattern consisting of S. matsudana + D. spicata ranked second, followed by the forest-grass patterns of S. americana + D. spicata and T. chinensis + M. sativa. The forest-crop pattern of S. americana + Glycine max and the pure forest of S. americana showed low soil-improving effects. When biological measures are used to improve the saline-alkali soil of the YRD, it is recommended to prioritize the mixed tree-shrub-grass pattern, followed by the mixed tree-grass and shrub-grass patterns; the forest-crop intercropping or pure forest patterns should be avoided as much as possible.