Disk Plow Research Articles

Elements of fertility and productivity of arable land depending on the soil tillage system

The effect of basic tillage systems on fertility elements and arable land productivity in the cultivation of crops was studied. Research took place in 2017–2019 in a stationary experiment on the dark grey forest loamy soil of the Northern Trans-Urals. The observations were carried out during the seventh rotation of the grain-fallow crop rotation, namely bare fallow – winter rye – spring wheat – spring wheat – spring barley, spread in time and space. Moldboard, non-moldboard, combined, differentiated, minimum combined, stubble-mulch and surface soil tillage systems were studied. Various basic tillage systems did not affect significantly the agrophysical properties of soil during the research period with favorable precipitation conditions. At a very low N–NO 3 content, tillage did not have a large effect on the availability of the arable layer. Favorable conditions for phosphorus nutrition in the soil layer of 0–20 cm were formed by combined and surface soil tillage systems. The Р 2 О 5 content with these systems was higher than with moldboard tillage, in the spring by 20.6–24.4%, in the autumn by 6.6–14.3%. Non-moldboard and stubblemulch tillage systems reduced the content of Р 2 О 5 compared to the moldboard by 19.0–23.3%. The most stable positive results for grain yield from 1 ha of crop rotation area without fertilizers were obtained with moldboard (1.88 t/ha) and combined (1.84 t/ha) tillage systems. The yield of grain with the use of resource-saving tillage systems and with fertilizers was almost equal to moldboard system. The difference in productivity generally did not exceed 5%. Moreover, grain yield was 0.03–0.17 t/ ha higher when applying minimum combined tillage alternated with plowing and disk plowing, or when using stubble-mulch tillage than with moldboard system.

The Performance of the DES Sensor for Estimating Soil Bulk Density under the Effect of Different Agronomic Practices

The estimation of soil wet bulk density (ρn) and dry bulk density (ρb) using the novel digital electromechanical system (DES) has provided information about important parameters for the assessment of soil quality and health with a direct application for agronomists. The evaluation of the DES performance is particularly appropriate for different tillage methods, mulching systems, and fertilizers used to increase soil fertility and productivity, but currently, there is a lack of information, particularly in the arid areas in underdeveloped countries. Therefore, the main aim of this study was the application of a novel digital electromechanical system (DES) to evaluate bulk density, wet (ρn) and dry (ρb), under different soil treatments according to the variations in thermal efficiencies (ηth), microwave penetration depths (MDP), and specific energy consumption (Qcon) in an experimental area close to Baghdad (Iraq). The experimental design consisted of 72 plots, each 4 m2. The agronomic practices included two different tillage systems (disc plough followed by a spring disk and mouldboard plough followed by a spring disk) and twelve treatments involving mulching plastic sheeting combined with fertilizers, to determine their effect on the measured soil ρn and ρb and the DES performance in different soils. The results indicated that soil ρn and ρb varied significantly with both the tillage systems and the mulching systems. As expected, the soil ρn and ρb, MDP, and Qcon increased with an increase in the soil depth. Moreover, the tillage, soil mulching, and soil depth value significantly affected ηth and Qcon. A strong relationship was identified between the soil tillage and MDP for different soil treatments, leading to the changes in soil ρb and the soil dielectric constant (ε’).

Long term crop management effects on soil organic carbon, structure, and water retention in a cropland soil in central Ohio, USA

AbstractThe objective of this study was to determine 13‐year management effects on soil properties between a corn–soybean (Zea mays–Glycine max) cropping system (CSRS) and vegetable production systems (VPS) on a soil in central Ohio. Three treatments included in the VPS were: (1) addition of wood chips, (2) permanent raised beds (PRB) with black polyethylene film (20 μm thick), and (3) bare soil surface (BSS). Additionally, (4) animal manure was applied in all CSRS and VPS treatments except for the wood chips (WCP) added plot in the VPS. Research data from the study show that relatively more soil organic carbon (SOC) stock in the 0–20 cm soil depth of the BSS treatment (100.6 Mg ha−1) was primarily due to differences in the type of soil amendments applied. For example, composted poultry manure was applied in the BSS and PRB plots, compared with input of fresh dairy manure mixed with straw being applied in the CSRS. Furthermore, soil management practices that aided in avoiding or reducing soil compaction (i.e., PRB or application of WCP in the surface) resulted in the overall improvement in soil structure and water retention, compared with that under chisel and disc ploughing done in the CSRS. The highest plant available water capacity (1.79 cm) was observed in the CSRS compared with 0.97 cm under BSS and PRB plots. These trends suggest that the type and amount of animal manure is critical to increasing SOC stocks in intensively cultivated VPS and CSRS in central Ohio, while also improving soil structure and water retention.

Application of adaptive neuro-fuzzy inference system to predict draft and energy requirements of a disk plow

The energy and draft requirements of a disk plow have been recognized as essential factors when attempting to correctly match it with tractor power. This study examines the possible of using an adaptive neuro-fuzzy inference system (ANFIS) approach and its performance compared to a multiple linear regression (MLR) model to determine the energy and draft requirements of a disk plow. A total of 133 data patterns were obtained by conducting experiments in the field and from the literature. Of these 133 data points, 121 were arbitrarily selected and used for training, and the remaining 12 were used for testing the models. The input variables were plowing depth, plowing speed, soil texture index, initial soil moisture content, initial soil bulk density, disk diameter, disk angle, and disk tilt angle, and output variable was draft of the disk plow. Four membership functions were used with ANFIS: a triangular membership function, generalized bell-shaped membership function, trapezoidal membership function, and Gaussian curve membership function. An evaluation of the outcomes of the ANFIS and MLR modeling shows that the triangular membership function performed better than the other functions. When the ANFIS model draft predictions were compared to the measured values, the average relative error was –1.97%. A comparison of the ANFIS model with other approaches showed that the energy and draft requirements of the disk plow could be estimated with satisfactory accuracy. Keywords: ANFIS, MLR, disk plow, draft, tillage DOI: 10.25165/j.ijabe.20201302.4077 Citation: Al-Dosary N M N, Al-Hamed S A, Aboukarima A M. Application of adaptive neuro-fuzzy inference system to predict draft and energy requirements of a disk plow. Int J Agric & Biol Eng, 2020; 13(2): 198–207.

The influence of soil protection technologies on the content of organic substance in leached chernozem

The quantitative content of organic carbon and mobile organic matter, its share in the total organic carbon is estimated. A significant intraseasonal variation of organic carbon was revealed when using dump processing. For the first time, the long-term impact (9-10 years) of soil protection technologies on the dynamics of organic carbon content and its mobile forms was determined for the agricultural zone of the Krasnoyarsk territory. It is shown that the zero land treatment reduces the degree of mobility of organic matter, and the minimum treatment (disk plowing) causes a significant differentiation of the seed 0-5 cm and the underlying 5-20 cm layer according to the content of sorghum.

Determination of Draft Force for a 3-bottom Disc Plough Under Sandy Loam Soil Conditions

This study was performed to determine the draft force for a 3-bottom disc plough under sandy loam soil conditions. The experiments were conducted using five different tractor speeds (3.6, 5.4, 7.2, 9.0 and 10.8 kilometer per hour(km)) and three tillage depths (10, 20 and 30 centimeter(cm)) with a view to determine the actual implement speed at the different tillage depths. The implement speed determined from the experiment was used to determine the draft force. The effects of tillage depths and implement speeds on draft force for the 3-bottom disc plough were investigated. The results showed that increasing the tillage depth and implement speed increased draft force and the effects appeared to be linear. At a tillage depth of 10 cm, draft force for this implement at implement speed of 0.82 and 2.58 meter per second (m/s) were 0.92 and 1.18 kilonewton (kN), respectively while at 30 cm, the draft force at 0.82 and 2.58 m/s were 3.83 and 4.67 kN, respectively. A regression equation to predict draft force for 3-bottom disc plough in a sandy loam soil was developed based on tillage depth and implement speed parameter. A significant increase in draft force at 0.05 level of significance was seen for the implement with an increase in tillage depth and implement speed. This study recommends that the root length of the crop for which tillage is made should be considered in the selection of the tillage depth.

Soil organic carbon and aggregation in response to thirty-nine years of tillage management in the southeastern US

Agricultural management practices control soil organic carbon (SOC) content in croplands. Long-term cropping system experiments offer a great opportunity to understand the magnitude and direction of SOC change in response to management practices. Such information is very limited from the southeastern US, a region with warm and humid climatic conditions that typically favor SOC decomposition over accumulation. Therefore, this study was conducted to assess the effect of 39 years of chisel plow (CP), disc plow (DP), moldboard plow (MP), no-tillage (NT), NT with winter wheat (Triticum aestivum L.) cover crop (NTW), and NT with wheat-soybean (Glycine max L.) double crop (NTWD) on total SOC and SOC fractions including permanganate oxidizable C (POXC), water extractable C (WEC), resistant C (RC), and aggregate-associated SOC in a continuous soybean system. Additionally, aggregate size distribution, mean weight diameter (MWD), and wet aggregate stability (WAS) were determined. Results showed that NTW and NTWD significantly increased SOC and POXC compared to MP with mean SOC (g kg−1 soil) of 12.2 (NTW) ≥10.9 (NTWD) >7.2 (MP) and mean POXC (mg kg−1 soil) of 465 (NTWD) ≥418 (NTW) >252 (MP). The WEC and RC fractions did not differ among treatments. Across the treatments, the greatest aggregate-associated SOC concentration was found in microaggregates (0.053–0.25 mm) and the lowest in clay- and silt-size particles (<0.053 mm). Additionally, WAS under NT systems was significantly higher (45.5–52.3 %) than under tilled treatments (21.9–29.1 %). Total SOC correlated significantly with POXC (r = 0.68, p < 0.01), RC (r = 0.46, p < 0.05), WAS (r = 0.65, p < 0.01), and aggregate-associated SOC concentrations (r > 0.6, p < 0.01). Overall, this study revealed that NT enhanced SOC and POXC accumulation and macroaggregation compared to tilled treatments. Cover cropping and double cropping further improved SOC accumulation. In conclusion, long-term adoption of different tillage intensities can strongly alter SOC dynamics in bulk soil and aggregates under continuous soybean production systems of the southeastern US.

Soil fragmentation and aggregate stability as affected by conventional tillage implements and relations with fractal dimensions

Due to a lack of accurate information regarding soil aggregate size distribution and stability, farmers in Sindh, Pakistan often apply excessive tillage, creating an overly fine seedbed that can lead to the depletion of soil organic matter (SOM) and make the soil more vulnerable to wind and water erosion. The current paper investigates the effects of conventional tillage implements on soil fragmentation and aggregate stability, along with how these factors relate to fractal dimensions. The study aims to: (i) achieve a better understanding of soil structure and establish which tillage implement provides the best soil structure and (ii) determine the function that best describes the proportion of small aggregates in the soil. Six tillage treatments were studied, including: moldboard plough + disk harrow two passes (MPDH2), disk plough + cultivator two passes (DPC2), cultivator two passes (C2), cultivator four passes (C4), cultivator six passes (C6), and minimum tillage (disk harrow one pass) (MT) for a clay loam soil. At each of two depths (0-0.15 m and 0.16-0.30 m), four soil samples from randomly selected locations in each plot were collected (3 blocks × 6 tillage × 2 depths × 4 samples, n = 144) with the help of a soil auger. Aggregate size distribution was measured by a dry sieving method, and aggregate stability was determined by a wet sieving method. The correlations between mean weight diameter (MWD), mass fractal dimension (Dm), and soil aggregation were investigated. The greatest proportions of small aggregates and the lowest proportions of intermediate aggregates were found under DPC2 followed by C6, while a greater proportion of intermediate aggregates and a lower proportion of small aggregates was observed under MT. However large aggregates (>25 mm) were negligible across all treatments. The highest values of Dm were found after DPC2, while the highest values of MWD were found after MT. The highest proportion of water stable aggregates (WSA) was found under DPC2, while the lowest proportion was found under MPDH2 followed by MT. Similarly, aggregate stability was greatest under DPC2. Across all tillage implements, the highest fuel consumption was recorded under C6 followed by MPDH2, while the lowest occurred under MT. The Dm showed a negative correlation with intermediate aggregates (5.0–25.0 mm) and a positive correlation with small aggregates (<5.0 mm), while MWD had a positive correlation with intermediate aggregates (5.0–25.0 mm) and a negative correlation with small aggregates (<5.0 mm). Similarly, Dm was negatively correlated with MWD. This suggests that farmers should adopt the technique of using a disk plough followed by two passes of the cultivator to achieve the best possible seedbed conditions in a clay loam soil. Higher values of Dm and lower values of MWD may be used to quantify fine seedbeds, with the converse being preferable for quantifying coarse seedbeds.

PRIMARY TILLAGE FOR WINTER DURUM WHEAT

The primary tillage in crop cultivation determines the conditions for their growth and development. This is especially important for winter durum wheat, which has an underdeveloped root system and it requires a better approach to creating favorable conditions through tillage. There have been studied three methods of tillage: moldboard plowing on 22–25 cm (PN is 5-35); beardless plowing on 22–25 cm (PCh is2.5); disk plowing on 0–12 cm (AG is 2.4). The study was carried out in the southern area of the Rostov region in the Federal State Budgetary Scientific Institution FSBSI “Agricultural Research Center “Donskoy” (2011–2015). The trial was carried out by generally accepted methods, which made it possible to establish the advantages of the moldboard and beardless plowing of black fallow on 22–25 cm compared to disk plowing on 10-12 cm when cultivating winter durum wheat. Tillage contributed to a lower density in the arable horizon (1.08 and 1.09 g/cm3 ), to a greater microbiological soil activity (up to 37%), and to better moisture supply during the growing season. Moldboard plowing contributed to an availability increase of such nutrients as potassium and nitrogen, and disk plowing contributed to accumulation of available phosphorus. The improved physical soil properties contributed to greater productivity. At disk plowing, winter durum wheat productivity was on average 4.93 t/ha through the years of study. At boardless and moldboard plowing wheat productivity was 5.38 and 5.55 t/ha for non-plow and dump plowing, respectively. Soil treatment did not affect the quality indicators.

EFFECT OF USE TWO TYPES OF PLOWS ON GROWTH COMPONENTS AND YIELD OF WHEAT IN NINEVEH PROVINCE NORTH OF IRAQ

A field experiment was conducted during the agricultural season 2012 - 2013 in clay soil to study the effect of use two types of plows on on growth components and yield of wheat, two varieties ( Begal and sham 6) and two types of plow (mold board and disc plow ) with three replicate used, The characteristic studded in experimen. , Plant height , length of spike, number of seeds per spike, Number of spikes per unit area , weight of 1000 kernel, yield of wheat RCBD design, SAS program used to analysis the experiment, begal variety was surpassed on plant height, spike length , and yield. Disc plow was surpass on plant height, spike length, number of spike -1, and yield The interaction shown the variety bigal with disc plow gave the best result in plant height, spike length, harvest index and yield which it gave 1817.8 kg /h.

Development and Performance Evaluation of a PTO Powered Vertical Disc Plough with Seeding Attachment for Sowing of Wheat after Rice

A PTO powered vertical disc plough with seeding attachment was developed for sowing of wheat in combine harvested rice field. The performance was also compared with rototill seed drill and conventional method of sowing under un-chopped and chopped residue field condition. Experimental result showed that the powered vertical disc plough with seeding attachment (T1 ) required 2.78 h and 3.12 h less time than roto-till drilling (T2 ) and conventional method (T3 ) of wheat sowing, both under un-chopped and chopped residue field condition. Under un-chopped residue condition, the saving of time in treatment T1 over treatment T2 and T3 was 28.2 % and 77.6 %, respectively. Under same condition, the saving in fuel consumption in treatment T1 over T2 and T3 , was 11.24 % and 66.38 %, respectively. Under chopped residue condition, the fuel saving in treatment T1 was also higher compared to T2 and T3 . The germination count after 20 DAS was highest in T3 , followed by T2 and T1 .The number of tillers at 60 DAS was highest in T3, followed by T1 and T2 treatments. Maximum grain yield of 5.46 t.ha-1 was obtained in treatment T3 , followed by 5.35 t.ha-1 and 4.30t.ha-1 in treatment T1 and T2 , respectively under unchopped rice residue condition. The implement was found as an alternative for wheat sowing under minimum tillage in combine harvested rice field with un-chopped residue.

Desempeño de un subsolador integral biomimético para laboreo sustentable de suelos agrícolas

El objetivo de este estudio fue evaluar el desempeño de un subsolador integral biomimético (SIB) para el laboreo sustentable del suelo, comparado con un multiarado (M), un equipo subsolador (S) y el sistema convencional de arado (AD) y rastra de discos (Ra). El trabajo se estableció en un suelo franco arenoso, en franjas de 15 m de ancho por 110 m de longitud, sin repeticiones. Se encontró que SIB y M tienen mayor anchura de trabajo, demandan más fuerza de tiro y menor consumo de combustible por hectárea (ha), por lo que estadísticamente son diferentes a AD y S. La velocidad de trabajo de SIB repercute directamente en su rendimiento operativo (ha h-1), ya que es 33.8% mayor al rendimiento de AD. En calidad y operación de los implementos, estos no produjeron cambios temporales sobre la densidad aparente (Da), diámetro medio de los agregados (DG50), resistencia a la penetración (Rp) y humedad gravimétrica (Ɵg); estadísticamente no mostraron diferencias (p ≤ 0.05), aunque en promedio Da en M fue mayor que en AD, S y SIB para todas las profundidades de muestreo. Por tanto, se concluye que SIB representa una alternativa sustentable para la preparación primaria del suelo y puede utilizarse en lugar de la labranza convencional.

Physical and chemical processes determining soil organic matter dynamics in a managed vertisol in a tropical dryland area

Vertisols are soils with a high potential for carbon (C) sequestration. However, these soils undergo swelling and shrinkage cycles, which exert a strong influence on soil organic matter (SOM) dynamics. The long-term effects of agricultural conservation practices on SOM content and stability on a Vertisol located in a tropical dryland area was evaluated.Two tillage systems (conventional tillage [CT], disc ploughing and extraction of 70% harvest residues, and no tillage [NT], incorporating 100% of the harvest residues) in combination with three different crop rotations (sorghum-soyabean [SrSy], maize-maize [MM] or soyabean-maize [SyM]) were tested. All plots were irrigated during dry periods. The effects on soil organic C, N, microbial biomass and aggregate size class distribution were evaluated. Carbon sink capacity were assessed by studying the aggregate-associated SOM content and quality (thermal recalcitrance), as determined by thermo-calorimetry.Relative to the CT system, NT yielded a higher percentage of small macroaggregates (2-0.25 mm). It also promoted the accumulation of aggregate-associated SOM, especially in the small macroaggregates and microaggregates. Thermal analysis revealed that the aggregate-associated SOM was more recalcitrant (higher values of T50 and more energy released at 475 °C) in NT than in CT. Coinciding with these effects, the soil microbial biomass/SOC ratio was lower in NT than in CT. The gain of SOM and the higher recalcitrance of OM in the NT soils may be related to different characteristics of NT Vertisols, such as poor aeration or disruption of the swelling and shrinkage cycles. The findings show that soil conservation practices increase the capacity for long-term C sequestration in Vertisols via organomineral interactions and SOM recalcitrance, which are determined by the formation of large cracks as a result of the swelling and shrinkage cycles that are some of the specific properties and processes of these soils.

Models Designed to Increase the Work of Reversible Disc Plough

In this paper, we study the models designed to increase the work of reversible disc plough. Results of research on the use of design-engineering methods of a heightening of serviceability are reduced and it is offered to use an improved disk of digging out device root of the tillage machines. Results of a study on the application of design and technological methods revealed that one of the promising areas of increased efficiency and durability are strengthening blades durable material of variable thickness.

Comparative Study of Soil Tillage Practices Effects on Hydraulic Conductivity and Bulk Density of a Sandy Loam Soil in Tunisia

The aim of this study was to investigate the effects of different tillage practices on bulk density, and the hydraulic properties of a sandy loam soil of eastern Tunisia. A replicated randomized complete block design with treatments consisting of (i) no-tillage (NT), (ii) tillage with moldboard plow at three level depths (SM=15cm, MM=20cm and DM=25cm), (iii) and tillage with disc plow at three level depths (SD=15cm, MD=20cm and DD=25cm) practices established at the Higher Institute of Agricultural Sciences of Sousse; Tunisia was used for the study. The soil bulk density and saturated hydraulic conductivity were determined for each of the treatments. The bulk density (BD) was determined at the depths of 5, 15 and 25 cm while the saturated hydraulic conductivity was determined on the surface (0-10 cm) soil. Experimental results showed that all the tillage practices were significantly different in their effects on soil density and was in the descending order of NT>SD> MD>DD>SM>MM>DM. The soil bulk density decreased with the degree of soil manipulation during tillage practices, with NT having the highest (1.76; 1.86 and 1.81g cm-3) and DD having the least (1.60; 1.56 and 1.59g cm-3) respectively for 5, 15 and 25cm depths. The greater mean value of Ksat was found in DD while the lowest was found in NT with 36% reduction than DD. The research concluded that the best Tillage Practices to be adopted in terms of improvement in physical and hydraulic properties is Shallow tillage practice.

Evaluation Performance of Disc Plow with a Notched Disc

Evaluation Performance of Disc Plow with a Notched Disc

Effect of Ploughing Depth, Tractor Forward Speed, and Plough Types on the Fuel Consumption and Tractor Performance

Cost of fuel has a significant impact on the input costs of agricultural production, especially during primary tillage. It is affected by several parameters including tractor forward speed, depths of ploughing, and plough types. The experiment was performed in a Soil Hall at Harper Adams University, United Kingdom, in April 2015. A Massey Ferguson 8480 4WD tractor was used for investigating objectives of this study. The experiment was performed in a sandy loam soil texture at 11.73% soil moisture content and 1.35 (g/cm3) dry bulk density to study the amount of fuel consumption (l/ha) and the performance of tractor with effect of moldboard and disc ploughs as ploughs type, 15 and 20 cm as ploughing depth and 5 and 7 km/h as tractor forward speeds. The results showed that fuel consumption with a disc plough 5% was higher compared to the moldboard. Fuel consumption decreased approximately 8% when tractor at 7 km/h. Fuel consumption significantly decreased about 34% when ploughing depth increased from 15 to 20 cm. The power requirement to operate moldboard plough was higher by about 14% than a disc. The power requirement at speeds of 7 km/h was higher compared to the speeds of 5 km/h by about 27%. When the depth of ploughing increased from 15 to 20 cm, the power requirement increased by about 1.5%.

Social and technological dimensions; and constraint analysis in sugarcane cultivation of Theni district of Tamil Nadu, India

Bridging the yield gap in any crop cultivation should be the prime objective of any research efforts. By following the recommended production-cum-protection technologies, farmers can bridge the yield gap in any crop. As per sugarcane is concerned, the average cane yield in Tamil Nadu is 101 t/ha, which is lower than the potential yield of 203.7 t/ha resulting in yield gap of 50.42%. With this in mind, a study has been initiated to explore the social and technology dimensions and constraints involved in cane cultivation to addressing the issue of yield gap. Six blocks from Theni district under Rajshree Sugars &amp; Chemicals Ltd were selected as study area. Information collected from sixty sugarcane farmers with semi structured interview schedule. The study revealed that majority (91.7%) of the respondents had more than 5 years of experience in sugarcane cultivation. Further, it revealed that the technologies, seed rate (83.3%), planting season (75.00%), primary tillage with mould board / disc plough (67%), gap filling, two split application of N and K (58.3%) and Organic fertilizer application (58.3%), stubble shaving, off baring (50.0%) had adoption rate of more than 50 percentage. Major constraints faced by cent per cent of the respondents were; non availability of labour and high labour cost, prolonged drought and water scarcity, low procuring cost per by sugar factory, yield reduction due to continuous cultivation of sugarcane. The novelty and importance of the study is that it mainly analysis all the sugarcane production and protection technologies from seed rate to harvest in three point continuum viz., fully adopted, partially adopted and not adopted.

Carbon in aggregate size classes in a Rhodic Eutrudox under different cropping systems

Soil productive capacity is related to levels of carbon (C) in aggregates of different sizes. The aim of this study was to assess total organic carbon levels in different size classes of water-stable aggregates in a Rhodic Eutrudox under different production systems. The cropping systems assessed were no-tillage (NT); no-tillage scarified every three years (NTS); disk plowing (DP) and heavy disking (HD). All systems were subjected to crop succession (S) (soybean - Glycine max / wheat - Triticum aestivum) and rotation (R) (soybean, maize (Zea mays), wheat) and cover and green manure (Lupinus albus, Raphanus sativus and Avena strigosa). Intact soil samples were collected in trenches at depths of 0–0.10; 0.10-0.20; 0.20–0.30 and 0.30-0.40 m. The highest levels of carbon were found under no-tillage, irrespective of the aggregate size class. In all treatments, the top layer (0.0–0,10 m) under crop succession showed the highest carbon content for all aggregate size classes. However, at depths below 0.10 m, crop rotation exhibited the highest carbon levels (between 12 and 20 g kg-1). After 29 years of trials, cropping systems with the lowest soil disturbance combined with crop rotation were found to contribute to raising the level of carbon in the soil and maintaining stable aggregates.

Land use in agricultural landscapes with chernozems contaminated after Chernobyl accident: Can we be confident in radioecological safety of plant foodstuff?

Agricultural land use in the area of the post-Chernobyl Plavsk radioactive hotspot (Tula region, Central Russia) has raised a problem of radioecological safety of obtained plant foodstuff. Verification of 137Cs activities and inventories in components of “soil-plant” systems of the territory has been conducted in 2014–2017 in 10 agrosystems and 2 semi-natural meadows. It was revealed that density of 137Cs contamination of arable chernozems and alluvial calcareous soils nowadays varies in a range 140–220 kBq/m2 and exceeds radiation safety standard by ˜ 3.5–6 times. Deep plowing of the arable soils up to 30-cm in 1986–1987 resulted in decreasing of 137Cs inventories in rooting zone by ≈ 70% for crops cultivated with shallow disk plowing (wheat, barley), and by ≈ 35% for crops cultivated with middle plowing (buckwheat, amaranth, white mustard). The investigated plants and their compartments can be grouped on the basis of transfer factor values as follows: maize (stems and leaves) > amaranth > bromegrass > vegetation of dry meadow, galega, sunflower (seeds), vegetation of wet meadow > maize (grain), soybean (pods), barley (grain), buckwheat (grain), potatoes (tubers) > white mustard (seeds), wheat (grain). It is noticeable that generative plant compartments are characterized by less 137Cs activities in comparison with stems and leaves; and that 137Cs root uptake is not coincide with total flux of mineral nutrients in “soil-plant” systems. In sum, 137Cs soil-to-plant transfer in the area of the Plavsk radioactive hotspot is characterized by considerable discrimination, so 137Cs activities in plants are completely in accordance with national standards.