Terrace Soil Research Articles

EFFECT OF NITROGEN, PHOSPHORUS, POTASSIUM, BORON AND MOLYBDENUM ON GROWTH OF CAULIFLOWER

The results of the experiments conducted on a high land belonging to Salna Series under Madhupur Tract (Shallow Red Brown Terrace Soil) with different rates of N, P, K, S, B and Mo with cow dung and organic compost evince that the application of N120 P120 K100 S20 B1 Mo0.20OC0.5 (T16) had the best effect on the growth and yield of cauliflower followed N120 P180 K100 S20 B1 Mo0 2CD10 (T7).

Pedology of archaeological stone-wall bench terraces

Agricultural terraces are the most widespread archaeological landforms worldwide. Despite their far-reaching prevalence in many inhabited parts of the world, archaeological soils in terraces (hereafter ‘terrace soils’) are scarcely studied and their nature is poorly defined. This study aims to depict a space–time framework for the development of calcareous soils in archaeological stone-wall bench terraces and suggest modifications to their soil classification and mapping. To do so, we examined soils at the forefront of five terraces in Catalonia (Spain), that had been previously dated with optically stimulated luminescence to periods from Medieval-Late Middle Ages (1200 ± 60 CE) to Modern (1810 ± 15 CE). Local soils surrounding the terraces are Entisols and Inceptisols in the relatively drier areas and Mollisols in the moister areas. Methods applied are field survey, standard physico-chemical analyses, and soil micromorphology. CaCO3 content, P, OM and CEC show irregularly trending values throughout the profiles. Micromorphology shows abundant content of charred components throughout the profiles and slight discontinuous carbonate recrystallization, mostly biogenic. Based on these observations, the main parent material was determined to be local soil that was redeposited by workforce as fill material for terracing. We further interpret that pedogenesis mainly involved structure development under the influence of anthroturbation and bioturbation, inheritance of ex situ aggregates from parent soil, reaggregation with little occurrence of organic matter, and low levels of lessivage and CaCO3 redistribution. We found that pedogenesis in these terraces started in a chaotic manner, considerably faster than pedogenesis in natural soils, primarily influenced by the act of terracing, the maturity of its inherited parent soil material, and relatively large depth. Therefore, early stages of terrace soil development can differ greatly from known soil models, questioning paradigms of pedogenic ‘time zero’ and ‘maturity’ in terrace soil. We suggest four terrace fill settings for terrace material and propose a model for the state of entropy and development of terrace soils. We classify the studied soils as Archaeo-Anthroportic Xerorthents, (Anthrosols (Calcaric, Escalic)), and Archaeo-Anthroportic Typic Haploxerolls (Anthrosols (Calcaric, Escalic, Relocatic, Anthromollic)), both overlying buried Inceptisols (Cambisols). Our primary conclusion is that terrace soils should be separately classified and mapped by treating terracescapes as distinct morpho-stratigraphic units in which age is the same as the age of their geomorphic surface. This study advances the pedological understanding of archaeological stone-wall bench terraces and identifies gaps in the understanding of terrace soils.

Кількісна діагностика дискусійних за генезисом ґрунтів надзаплавних річкових терас Лівобережного Лісостепу

Goal. To improve the diagnostics of soils of debatable genesis to determine their ecological and genetic status using a set of morphological criteria and quantitative parameters. Methods. A set of methods was used, which contained a description of the soil profile by morphological and genetic features, as well as a set of quantitative relative coefficients of humus accumulation and the ratio of calcium and magnesium exchange cations. Results. It was determined that a significant share of the land fund of pine and single-forest terraces were podzolic soils. Soils formed by different combinations of sod process with podzolization and hydromorphism were also found. A complex method of diagnosing polygenetic soils of floodplain terraces of low hypsometric level by parameters of such indicators as profile thickness, coefficient of relative accumulation of humus, coefficient of profile accumulation of humus, and regression coefficient of organoprofile was developed. Gradations of the specified criteria for identification of soils of debatable genesis were developed as well as gradations of the relation of exchange cations of calcium to magnesium for soils of floodplain terraces as a diagnostic criterion. Conclusions. Complex diagnostics of soils, in particular of debatable genesis, based on the morphological and genetic structure of soil profile, application of gradations of humus accumulation parameters in soils according to KVAG, KPNG, KRO, and ratio of calcium and magnesium metabolism were developed.

Nutrient Release from Vermicompost under Anaerobic Conditions in Two Contrasting Soils of Bangladesh and Its Effect on Wetland Rice Crop

Although its mechanism of action, particularly under wetland condition, is not clearly understood, vermicompost, a good source of humus and plant nutrients, has been used as organic manure in many parts of the world in order to increase crop production. Here, an anaerobic incubation study and a field study were conducted to observe the nutrient release pattern from vermicompost and its influence on performance and nutrient uptake in wetland rice. Two contrasting soils, viz. highly weathered terrace soil and very young floodplain soil, were subjected to anaerobic incubation, while the field trial was conducted in the terrace soil with control (no amendments), mineral fertilizer, vermicompost (10 t ha−1) + mineral fertilizer, cow dung (10 t ha−1) + mineral fertilizer, vermicompost (20 t ha−1) + mineral fertilizer and vermicompost (local farmer’s practice) + mineral fertilizer treatments. Results showed that there were significant increases in nitrogen (N) and phosphorous (P) release in floodplain soil but not in terrace soil, suggesting that nutrient release from vermicompost is soil-dependent. The performance of Boro rice in terms of yield and yield attributes improved significantly in the case of the integrated application of vermicompost with mineral fertilizer. Specifically, combined application of mineral nutrients and vermicompost (10 t ha−1) significantly increased grain yield by 25% compared to the control treatment. We believe that this occurred due to an improvement in supply and subsequent uptake of nutrients, especially N and P. Altogether, our results suggest that vermicompost could increase crop performance under field conditions, and, although these effects may not be significant in short-term incubation studies, they may be even larger in floodplain soil.

Provenance of quartz grains from soils over Quaternary terraces along the Guadalquivir River, Spain

The characterisation of quartz grains’ chemical and mineralogical properties in sediments and sedimentary rocks is widely used in provenance studies. This paper analyses quartz grains from the coarse sand fraction in soils in Quaternary fluvial terraces (Guadalquivir River, southern Spain). The tentative soil ages are 0.3 ka (Haplic Fluvisol), 7 ka (Haplic Calcisol), 70 ka (Cutanic Luvisol), 300 ka (Lixic Calcisol) and 600 ka (Cutanic Luvisol). The quartz grains analyses shed light on the sedimentological history of these terraces. Scanning electron microscope cathodoluminescence (SEM-CL) characteristics, micro inclusion inventory established by Energy-dispersive X-ray spectroscopy (SEM-EDX) and trace element contents determined with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of quartz grains permitted distinguishing six types of grains in the soils studied: metamorphic quartz (type 1), undeformed granitic quartz (type 2), strongly altered granitic quartz (type 3), recrystallised (deformed) granitic quartz (type 4), sandstone-derived quartz (type 5) and hydrothermal quartz grains (type 6).Metamorphic quartz grains (type 1) come from the Sierra Morena (Iberian Massif) and Sierra Nevada (Internal Betic Zone). Granitic quartz grains (types 2 to 4) come from Los Pedroches batholith and its associated plutons (Santa Elena and Linares). The sandstone-derived quartz type 5 comes from the numerous sandstone outcrops scattered in the central catchment area of the Guadalquivir River. Finally, hydrothermal quartz grains (type 6) originate from hydrothermal veins associated with subvolcanic rocks of the Los Pedroches batholith.Variations were noted in the proportions of quartz types in soils of different ages, attributed to spatial and temporal changes in the catchment area. The most remarkable change occurred between 500 and 240 ka ago when the catchment area extended into Sierra Nevadás metamorphic rocks, well reflected in type 1 content (lower in P2, P4, P5 and PM) and their characteristics (quartz with less healed fractures, less Al content, bigger mica microinclusions, smaller Al/Ti ratio) in the post-500–240 ka soils.Our study shows that the combined study of SEM-CL characteristics, micro inclusions (SEM-EDX), and trace element contents (LA-ICP-MS) of quartz grains is an efficient approach for characterising the provenance of quartz grains in the sand fraction of soils.

Особенности геохимического состава почв прибрежной части юго-западного Приморья

The large diversity of the soil cover in the southern regions of Primorye makes it difficult to assess the current ecological state of soils on the basis of data from single background pits. More than 220 samples taken from topsoils of main types of background soils were analyzed by atomic absorption by atomic method to reveal the geochemical composition of soils in the coastal territory of the region, the background content of heavy metals was established. The features of accumulation of pollutant elements in the surface layer are revealed. The content of vanadium, chromium, cobalt, nickel, copper, zinc, cadmium, and lead is much lower clark. No significant difference was found between the content of heavy metals in the soils of high and low sea terraces (Histosoils, Gleysols), riverine plains (Fluvisols, Histosoils,) and outlier uplands (Albic Stagnoso, Cambisols). A series of the intensity of accumulation of total forms of elements Cu > Zn > V > Cd > Co > Ni > Pb > Сr was determined. The average values of the various geochemical indices indicate the absence of pollution and a low level of potential ecological risk of the soils of the study area, therefore, using the received data as background data is correct. The territories of neighboring states can be a potential source of pollution of the region during atmospheric transport due to the higher content of pollutant elements in soils.

Плотность потока радона-222 в почвах Тобольского района Тюменской области

The aim of the work is to determine potentially radon dangerous areas for the local population on the territory of Kondinskaya lowland within the boundaries of Tobolsk district of Tyumen region with the help of radon monitoring complex “CAMERA-01”. The density of the radon-222 flux was defined at the soil depth from 0 to 100 cm in 10 plots. The plots are located on the low above floodplain terrace, in the levee and central floodplains of the Irtysh River and a tributary of the Tobol River – the Suklyomka River. The highest average value of radon-222 exhalation from the soil surface was found in the vicinity of Makedonova village – 39 mBq/(m2·s), in the rest of the tested soil plots it was not more than 18 mBq/(m2·s). The received data on density of radon-222 flux from the surface of soils of the investigated plots make it possible to say that they do not refer to potentially radon-hazardous. At the same time it is found that the territories around the village Usharovo, the village of Makedonova and settlement Savinsky Zaton (floodplain terraces of the Irtysh River) at a depth of 40 to 100 cm have average values of the flux density of natural radionuclide exceeding 200 mBq/(m2·s). Only in soils of the floodplain terrace of the river Suklyomka – a tributary of the Tobol river the radon– 222 flux density below 80 mBq/(m2 s) – I class of radon-hazard was fixed at the whole investigated depth. The highest average density of the radon–222 flow (1200 mBq/(m2·s)) at the depth of 100 cm was found in the vicinity of the settlement Savinsky Zaton, probably associated with the transfer of radon-222 from groundwater of the liquidated well, near which the sampling of radon-222 was made.

Humus formation in soils of the Lena River Delta

The aim of the study. Nowadays close attention is paid to polar soils due to the expected landscape transformation rate under the predicted climate crisis. Intensive degradation of permafrost and the release of nutrients from their frozen state can lead to an increase in the emission of greenhouse gases into the atmosphere, as well as the loss of landscapes. The aim of the study was to investigate the peculiarities of organic residues formation and humification degree as well as humus structure and functioning in soil the Lena River Delta. 
 Location and time of the study. The study was conducted on the Samoylov and Sardach Islands in the Lena River Delta (Yakutia, Russia). Field studies were performed during the summer of 2019. 
 Objects and methodology. Soils of the Lena River Delta from the Samoylov Island (flooded area) and Sardakh (non-flooded zone), i.e. Subaquatic Fluvisol (Arenic) and Histic Cryosol (Siltic) were the objects of the study, respectively. To examine the features of humification chemical-analytical, sedimentation, micromorphological methods were used, as well as CP/MAS 13C-NMR spectroscopy. 
 Main results. The data obtained indicate a high diversity of soils and soil formation conditions in the Lena River Delta. Under non-flooded conditions Histic Cryosol (Siltic) were formed in the flooded parts of the Samoylov Island, Subaquatic Fluvisol (Arenic) were formed. These soils play an important role in the global carbon cycle, accumulation, transformation and deposition of condensed high- and low molecular mass organic compounds in the composition of soils and permafrost. The main soil micromorphology features were identified. In the young landscapes the soil microstructure was represented by poorly sorted sand with a circular type of optical orientation of the soil plasma (which indicated the influence of the river), as well as vertically oriented micas (muscovite/biotite). Soils influenced by the floodplain process were characterized by the presence of coarse amorphous humus. Due to the long-term effect of the freezing/thawing processes on the permafrost-affected soils the biogenic aggregates were formed. In such organo-mineral microaggregates humus is fixed in the composition of mineral components consisting of particles of quartz, micas and Mn-Fe nodules and is in a stable state (physical stabilization of humus). To analyze the molecular composition the 13C NMR spectroscopy method was used. According to 13C NMR spectroscopy data, up to 37% of aromatic structural fragments accumulated in soils, which indicates the process of condensation of molecules in humic acids, thus showing a relatively high level of humus stabilization in the soils of the Lena River delta. From the data obtained, three main groups of chemical structural fragments that accumulate in the delta soils can be distinguished, such as C,H - alkyls ((CH2)n/CH/C and CH3), aromatic compounds (C–C/C–H, C–O) and the OCH group (OCH/OCq). In the studied humic preparations aliphatic structural fragments of HAs (63–64%) predominated, which indicated a deficiency of lignin and lignin-like compounds in the composition of humification precursors. The predominance of aliphatic structures is typical of humic substances formed under reduction conditions, including the aqueous humic substances, as well as in soils, the precursors of humification of which are typical tundra vegetation (mosses and lichens) with a predominance of carbohydrates (up to 80%). A significant amount of aromatic fragments accumulated in the delta in the alluvial soils of the first terrace of the river (flooded zone). This is apparently due to the formation of vascular plants in the flooded areas of the Lena River Delta. The chemical composition of vascular plants includes components such as tannins, flavonoids and lignin (arenas). Thus in the samples formed under vascular plants with a lignin content of about 30%, an increase in signals in the range of 110-160 ppm were observed. Aromatic and carboxyl fragments in the structure of HA were formed during the transformation of lignin, which leads to the resistance of HAs to biodegradation.
 Conclusion. Under the floodplain condition humus is represented by coarse amorphous forms, whereas without the influence of flooding humus is fixed in mineral microaggregates. Specific humic acids composition in the studied regions is determined by bioclimatic conditions, cryogenic processes and the composition of humification precursors. High abundance of aromatic structures in humus substances suggests relatively stable humus status (most likely due to the putative condensation of humic acids) in the Lena River Delta during the study period.

Soil Chemistry and Clay Mineralogy of an Alluvial Chronosequence from the North Carolina Sandhills of the Upper Coastal Plain, USA

Temporal changes in soil development were assessed on fluvial terraces of the Little River in the upper Coastal Plain of North Carolina. We examined five profiles from each of six surfaces spanning about 100,000 years. Soil-age relationships were evaluated with inter-surface clay mineral comparisons and regression of chemical properties versus previously reported optically-stimulated luminescence ages using the most developed subsoil horizon per profile. Bases to alumina (Bases/Al2O3) ratios have negative correlations with age, whereas dithionite-Fe (FeD) concentrations are positively correlated with time and differentiate floodplain (<200 yr BP) from terrace (≥10 ± 2 ka) soils and T4 pedons (75 ± 10 ka) from younger (T1-T3b, 10 ± 2–55 ± 15 ka) and older (T5b, 94 ± 16 ka) profiles. Entisols develop into Ultisols with exponentially decreasing Bases/Al2O3 ratios, reflecting rapid weatherable mineral depletion and alumina enrichment during argillic horizon development in the first 13–21 kyr of pedogenesis. Increasing FeD represents transformation and illuviation of free Fe inherited from parent sediments. Within ~80–110 kyr, a mixed clay mineral assemblage becomes dominated by kaolinite and gibbsite. Argillic horizons form by illuviation, secondary mineral transformations, and potentially, a bioturbation-translocation mechanism, in which clays distributed within generally sandy deposits are transported to surface horizons by ants and termites and later illuviated to subsoils. T5b profiles have FeD concentrations similar to, and gibbsite abundances greater than, those of pedons on 0.6–1.6 Ma terraces along Coastal Plain rivers that also drain the Appalachian Piedmont. This is likely because the greater permeability and lower weatherable mineral contents of sandy, Coastal Plain-sourced Little River alluvium favor more rapid weathering, gibbsite formation, and Fe translocation than the finer-grained, mineralogically mixed sediments of Piedmont-draining rivers. Therefore, recognizing provenance-related textural and mineralogical distinctions is crucial for evaluating regional chronosequences.

Soil organic carbon stabilization mechanisms and temperature sensitivity in old terraced soils

Abstract. Being the most common human-created landforms, terrace construction has resulted in an extensive perturbation of the land surface. However, our mechanistic understanding of soil organic carbon (SOC) (de-)stabilization mechanisms and the persistence of SOC stored in terraced soils is far from complete. Here we explored the factors controlling SOC stability and the temperature sensitivity (Q10) of abandoned prehistoric agricultural terrace soils in NE England using soil fractionation and temperature-sensitive incubation combined with terrace soil burial-age measurements. Results showed that although buried terrace soils contained 1.7 times more unprotected SOC (i.e., coarse particulate organic carbon) than non-terraced soils at comparable soil depths, a significantly lower potential soil respiration was observed relative to a control (non-terraced) profile. This suggests that the burial of former topsoil due to terracing provided a mechanism for stabilizing SOC. Furthermore, we observed a shift in SOC fraction composition from particulate organic C towards mineral-protected C with increasing burial age. This clear shift to more processed recalcitrant SOC with soil burial age also contributes to SOC stability in terraced soils. Temperature sensitivity incubations revealed that the dominant controls on Q10 depend on the terrace soil burial age. At relatively younger ages of soil burial, the reduction in substrate availability due to SOC mineral protection with aging attenuates the intrinsic Q10 of SOC decomposition. However, as terrace soil becomes older, SOC stocks in deep buried horizons are characterized by a higher temperature sensitivity, potentially resulting from the poor SOC quality (i.e., soil C:N ratio). In conclusion, terracing in our study site has stabilized SOC as a result of soil burial during terrace construction. The depth–age patterns of Q10 and SOC fraction composition of terraced soils observed in our study site differ from those seen in non-terraced soils, and this has implications when assessing the effects of climate warming and terrace abandonment on the terrestrial C cycle.

Terrace Soil Suitability for Highway Construction: Case Study in Lesser Himalaya (CPEC Project E-35), North Pakistan

In this study, terrace soil investigation was carried out in project E-35 (phase-I) China-Pak Economic Corridor, Lesser Himalayas, North Pakistan. The methodology in current research is based on tests that include sieve analysis, plastic index, proctor, California Bearing Ratio, Los Angeles, sand equivalent and specific gravity. The results of these tests for different layers were compared with AASHTO and NHA specifications. The results show that the embankment, subgrade and subbase layers were composed of silt, sand and gravel, respectively while the aggregate base coarse was composed of sand, aggregate and less amount of fine clay material. The sieve analysis test shows that soil and aggregate base coarse has less clay with high silt, sandy material and index plastic to low plastic, which is appropriate for the construction. The California Bearing Ratio shows that the soil and aggregate base coarse have high load-bearing capacity. The Los Angeles abrasion reveal that the sub base and aggregate base coarse are resistive. The sand equivalent shows that aggregate base coarse has high sand material. The specific gravity illustrates that aggregate base coarse material is denser. The current study shows that terrace soil is suitable for the construction of the road in project E-35 (phase-I) China-Pak Economic Corridor.

Lime and Manure Amendment Improve Soil Fertility, Productivity and Nutrient Uptake of Rice-Mustard-Rice Cropping Pattern in an Acidic Terrace Soil

Acid soil is an obstacle to agricultural development and a concern regarding food and environmental security. Therefore, a study was carried out for two consecutive years to see how lime and organic manure (OM) amendments affect yield and nutrient absorption in the Transplanted (T.) Aman–Mustard–Boro cropping pattern in an acidic terrace soil. With nine treatments and three replications, the experiment was set in a randomized complete block design. The treatments were applied to the first crop, T. Aman, with different dosages of lime (dololime at the rate of 1 and 2 t ha−1), OM (cow dung at 5 t ha−1, poultry manure at 3 t ha−1) and lime–OM combination, and their residual effects were studied in the following mustard and boro rice crops. Results demonstrate that the effect of lime and manure was more pronounced in the case of the second and third crops in the first year and of all crops in the pattern in the second year. In the first year, grain and straw yield of T. Aman as well as the overall system productivity were not influenced significantly by the application of lime and manure, but significant increases were obtained in the second year. As an average of both years, the highest grain yield of 5.2 t ha−1 (12% over control) was recorded for T. Aman, 1.7 t ha−1 (41% over control) for mustard and 5.9 t ha−1 (47% over control, 3.9 t ha−1) for boro rice when dololime was applied in combination with poultry manure. In both years, N, P, K and S uptake were significantly increased compared to the control in all the crops due to the combined application of lime and cow dung or poultry manure. Combined application of lime and manure amendment significantly improved nutrient availability and soil quality. Therefore, applying lime in combination with manure can be practiced to uplift crop productivity in acidic terrace soils.

Modulation of Yield and Yield Attributes of Transplanted Aman Rice through Organic and Inorganic Fertilization in Terrace Soil

Rice production has increased almost doubled over the last decade in Bangladesh as a result of additional application of chemical fertilizers and high yielding varieties. Present experiment was undertaken for elucidating the combined effect of organic materials (OM) and nitrogen (N) fertilizer on yield contributing attributes and yield of transplanted aman ( T. aman) rice. Experiment was set in a factorial randomized complete block design (RCBD) with three replications. Five types of OMs viz. RS (rice straw), VC (vermicompost), RHB (rice husk biochar), CD (cowdung) and PM (poultry manure) considering two ton carbon per hectare and three level of N viz. N0, N100 and N150 kg ha-1 were used in this experiment. Findings revealed that among the five OMs; cowdung significantly improved the studied parameters. Besides 150 kg ha-1 dose of N has pronounced effect on the grain yield of T. aman rice. In general OMs alone cannot contribute to the maximum yield and yield contributing parameters. Maximum plant height (98.5cm), no of tillers (20), no of effective tillers (18), no of grains (145.0 g), no of filled grains (138), no of unfilled grains (7.0) per panicle, length of panicle (27.5 cm), 1000-seed weight (23.65g), straw yield (8.97 t ha-1), grain yield (5.41 t ha-1) and biological yield (14.34 t ha-1) was attributed by the mixed application of PM and N150 dose of nitrogen. While maximum harvest index (45.09%) was found in the plot received RS in combination of N150 treatment and its minimum value was recorded also solely in RS treated plot. Findings suggest that the use of PM along with 150 kg ha-1 N can render superior crop growth and yield of T. aman rice.

Features of soils and soil formation of natural monument «Park «Sergievka»» (Saint Petersburg, Russia)

Parks maintain crucial ecological functions and provide different benefits for city dwellers. These facts made studying of park ecosystems important task. Soil cover and patterns of its formation were studied in natural monument “Park “Sergievka” (Saint Petersburg). The structure and composition of the soil cover of the park depend mainly on relief, groundwater level and features of soil-forming materials. The soil cover of the park “Sergievka” is characterized by taxonomic diversity, complexity and heterogeneity. Natural soils occupy 75% of the park area. Gleysols and Fluvisols dominated on the modern marine terrace, Umbric and Histic Gleysols are typical for the first terrace, and Retisols are the most abundant soils of the second terrace. Urbic Technosols were found near buildings, ponds and along the highway. Terric Anthrosols occur on the Lower Meadow in front of the Palace. Despite the presence of artefacts and higher humus content, anthropogenic soils have acidic reaction and redoximorphic features typical for native soils of the park territory. The results of the study indicate the dominance of natural soil formation processes in the park due to absence of measures aimed at maintaining the effect of earlier work on soil drainage and cultivation.

Alleviation of arsenic accumulation in rice by applying silicon-rich rice husk residues in Bangladesh soil

While the accumulation of arsenic in rice (Oryza sativa L.) has been highlighted as a major concern in Bangladesh, sustainable measures are critically needed to reduce the uptake of arsenic by rice plants. In the present study, a pot-experiment was conducted using a Boro rice variety (BRRI dhan-29) in two geomorphologically different soils from Holocene floodplains and Pleistocene terraces, in which silicon-rich fresh rice husk (FRH) and rice husk ash (RHA) were applied, as silicon fertilisers, in the soils at the rate of 1% (w/w) of rice residue:soil.In the Holocene floodplain soils, the application of FRH was found to decrease arsenic in grain, husk and straw by 42, 56 and 51%, respectively, whereas the soil incorporation of RHA decreased arsenic in grain, husk and straw by 26, 37.5 and 36%, respectively. In the Pleistocene terrace soils, the application of FRH reduced the grain, husk and straw arsenic by 38, 38 and 44%, respectively, whereas the RHA decreased the grain, husk and straw arsenic by 26, 30 and 29%, respectively. Fresh rice husk was found to be more effective in alleviating arsenic accumulation in rice than RHA. In both the Holocene floodplain and Pleistocene terrace soils, the grain concentrations of calcium, phosphorus, silicon, and zinc were found to be increased with the decrease of arsenic in the grain due to the use of FRH and RHA. The present study suggests that silicon-rich rice husk residue scan be used as silicon fertilisers to reduce arsenic accumulation in rice in Bangladesh. Bangladesh J. Sci. Ind. Res.56(3), 195-206, 2021

Haverkamp Modelin 4 Terimli Uzantısını Kullanılarak Teras Zeminin Doygun Hidrolik İletkenlik ve Sorptivite Tayini

Uzunçayır water retention Dam is located in the Tunceli province. This semi-arid mountainous region in eastern Turkey is prone to erosion. To combat this phenomenon, terraces along the edge of the Munzur University campus were built on sloping ground with pine plantations. The objective is twofold, on the one hand to mitigate soil erosion and protect the dam from sediments deposits, and on the other hand to promote the infiltration of rainwater and the vegetation of the sloping soil. However, the so-called ecofunctions of the terraces over the time are not proven. Monitoring the infiltration capacities of the terraces over time and space will allow a better understanding of their contribution to the hydrology of the watershed and their effect on soil erosion. The Beerkan infiltration technique offers simple and inexpensive experimental protocols. In addition, treatment methods are constantly improving. More recently, the four-term expansion of the implicit Haverkamp cumulative infiltration equation has been proposed. This complicated but robust formulation was used in this study to estimate the soil sorptivity S and saturated hydraulic conductivity Ks of terrace soil at Tunceli. The average Ks value of studied site was estimated to be 0.0852 mm/s with a standard deviation of 0.0112 mm/s. The soil sorptivity values were more extensive with mean value of 2.1227 mm/s0.5 and a standard deviation of 0.5855 mm/s0.5. The fit of the model used was perfect, showing that fast and robust estimation of S and Ks are possible using the new model.

Volume estimation of soil stored in agricultural terrace systems: A geomorphometric approach

High-resolution topographic (HRT) techniques allow the mapping and characterization of geomorphological features with wide-ranging perspectives at multiple scales. We can exploit geomorphometric information in the study of the most extensive and common landforms that humans have ever produced: agricultural terraces. We can only develop an understanding of these historical landform through in-depth knowledge of their origin, evolution and current state in the landscape. These factors can ultimately assist in the future preservation of such landforms in a world increasingly affected by anthropogenic activities. From HRT surveys, it is possible to produce high-resolution Digital Terrain Models (DTMs) from which important geomorphometric parameters such as topographic curvature, to identify terrace edges can be extracted, even if abandoned or covered by uncontrolled vegetation. By using riser bases as well as terrace edges (riser tops) and through the computation of minimum curvature, it is possible to obtain environmentally useful information on these agricultural systems such as terrace soil thickness and volumes. The quantification of terrace volumes can provide new benchmarks for soil erosion models, new perspectives to stakeholders for terrace management in terms of natural hazard and offer a measure of the effect of these agricultural systems on soil organic carbon sequestration. This paper presents the realization and testing of an innovative and rapid methodological workflow to estimate the anthropogenic reworked and moved soil of terrace systems in different landscapes. We start with remote terrace mapping at large scale and then utilize more detailed HRT surveys to extract geomorphological features, from which the original theoretical slope-surface of terrace systems were derived. These last elements were compared with sub-surface information obtained from the excavations across the study sites that confirm the reliability of the methodology used. The results of this work have produced accurate DTMs of Difference (DoD) for three terrace sites in central Europe in Italy and Belgium. Differences between actual and theoretical terraces from DTM and excavation evidence have been used to estimate the soil volumes and masses used to remould slopes. The utilization of terrace and lynchet volumetric data, enriched by geomorphometric analysis through indices such as sediment conductivity provides a unique and efficient methodology for the greater understanding of these globally important landforms, in a period of increasing land pressure.

الخصائص الطبيعية لتربة المدرجات الزراعية بمنطقة الباحة

لم تنل تربة المدرجات الزراعية على منحدرات جبال السروات حقها في البحث والدراسة، ولهذا السبب رأت الطالبة أن هذا الموضوع جدير بالاهتمام ولابد من معرفة الخصائص الطبيعية لتربة المدرجات الزراعية على منحدرات جبال السروات وستکون نقطة انطلاق أوسع لمعرفة جميع الخصائص لهذه التربة التي کانت من الأسباب الرئيسية في الاستيطان البشرى على منحدرات جبال السروات. وقد توصلت الباحثة في هذه الدراسة إلى نتيجة أن معظم تربة المدرجات الزراعية تتکون من الغرين(silt) أو ما يسمى اللويس، بينما نسبة قليلة تنتمى إلى الرمل والطين. وتختلف نسبة الغرين والرمل والطين من واد إلى آخر تبعا للترکيب الجيولوجى في وادى بنى سعيد الذى يتکون من صخور الجرانيت التي تعرضت للتجوية الکميائية في الزمن الثالث کانت نسبة الرمل به أکثر من نسبة الرمل في وادى غرير الذى تتکون صخوره من الشست. کما توصلت الطالبة إلى أن تربة المدرجات الزراعية نقلت من الربع الخالى ومن القارة الافريقية بواسطة الرياح ورسبت على سفوح جبال السروات والمدرجات الزراعية ونقلت من سفوح الجبال إلى المدرجات الزراعية بواسطة المياه وتعتبر في هذه الحالة رواسب ثانوية. Abstract Little attention has been paid into agricultural terrace soil properties. For this reason the current research aimed to study the physical characteristics of such soils as an initial step in obtaining a broader understanding of their properties. This is important because these the sites terraces are closely associated with human settlement in this mountain zone. During the course of the research several important findings were made may be the important finding were made may be that the highest percentage of soil were silts (loess), sand and clay are different from valley to valley. This may be result of local geology. Rocks in the Ghazeer valley are schist and those in the Bani Saeed valley are very weathered granites relating to former Tertiary climates and plate movements of the Peninsula when it was in equator and terraces silts are probably originally blown in from Africa and the Rub’ al Khali and on slopes have been transferred by flood water into terraces and it called secondary deposits

Efecto de los factores climáticos en las fases fenológicas de Mauritia flexuosa Lf. en plantaciones de terraza baja en Ucayali, Perú

The aim of this study was to determine the influence of air temperature and rainfall on the phenological development of Mauritia flexuosa in plantations located in Ucayali, Peru. For this, during a 24-month period, 191 19-year-old palm trees were evaluated, distributed in three plantations established on low terrace soils. The results showed that the 45% of palm trees did not manifest their sexual maturity, meanwhile, 42% and 13% of individuals with male and female sex, respectively, were verified. It was found that the phenological cycle was biannual, with overlapping phenophases and staggered events. In female individuals, maximum flowering was observed in phenophase FLA1 (4-5%) from September to November 2018 and maximum fruiting FRM1 (4-6%) from October 2018 to January 2019; In male individuals, the FLA2 flowering phenophase occurs in two periods between September 2018 and February 2020, meanwhile, the open flower phenophase of both sexes is synchronous in a higher proportion between September and November. It was determined that pluvial precipitation and air temperature (maximum and minimum) did not show correlation (p ≤ 0.05) with the productive phenophases of Mauritia flexuosa. The pluvial precipitation, the maximum temperature and the minimum air temperature showed null association with each one of the phenological phases of the Mauritia flexuosa palm trees during the evaluation period. In order to obtain information for the planning of silvicultural management activities for the conservation of the species, it is recommended to evaluate for more years the influence of climatic elements on the productive development of Mauritia flexuosa.

Soils of Ancient Agricultural Terraces of the Eastern Caucasus

The morphological and chemical properties and biological activity of soils on ancient agricultural terraces in the middle-high mountains of the Eastern Caucasus are considered. The studied terraces were constructed on sandstone, limestone, clay shale, and colluvium of clay and sandstone. The properties of soils formed on these terraces are determined by the properties of soil-forming rocks, as well as by the duration and intensity of human activity. The more favorable for agricultural development the initial soils, the longer and stronger their anthropogenic transformation. Diagnostic features inherent to all lithological varieties of mountainous anthropogenic soils of the Eastern Caucasus and features characteristic of soils developed on the particular types of soil-forming rocks have been identified. The most important diagnostic feature of the soil cover on agricultural terraces is the regular replacement of agrolithozems in the rear parts of the terraces with dark-humus stratozems in their front parts, near the terrace brows. Also, a common diagnostic feature for all soils of terraces is the presence of gravels (up to 3–5 cm in size) evenly distributed throughout the arable layer. Additions to the classification system of Russian soils have been proposed. The soils of human-made agricultural terraces should be classified as a new subtype in the type of stratozems. The proposed subtype name—agristratified soil (or Terrasozem)—reflects the mechanism of the development of stratified soil thickness, i.e., the long-term agricultural impact (agristratified soil, ast). The results of our study can be used in the assessment of the potential for agricultural use of soils in the Eastern Caucasus.