Terrace Soil Research Articles

Soil nitrogen storage and availability to crops are increased by conservation agriculture practices in rice–based cropping systems in the Eastern Gangetic Plains

On-farm adoption of minimum soil disturbance and increased residue retention will alter nitrogen (N) dynamics in soils and N fertiliser management in the intensive rice–based triple cropping systems of the Eastern Gangetic Plains. However, the consequences of changes in N forms, N mineralisation and its availability for crops have not been determined. Field experiments were conducted at two locations (Alipur and Digram) of north–west Bangladesh (NWB) to examine N cycling under three planting practices (conventional tillage (CT), strip planting (SP) and bed planting (BP)) with increased (HR) or low residue retention (LR– the current practice) on Calcareous Brown Flood Plain and Grey Terrace soils. Total N and available N were measured on soil samples as was N uptake by crops at different growth stages in the 13–14th (Alipur) and 12–13th (Digram) crops since treatments commenced. At each location (0–10 cm soil depth), SP, including non–puddled transplanting of rice seedlings (NP), together with HR increased total N by 9 and 32 % relative to BPHR, and CTHR and by 62 % relative to the current farm practice (CTLR). In general, the cumulative available N in soils during mustard and rice cropping under CT with HR was higher than other crop establishment and residue retention practices while under wheat and jute, total availability of N did not vary among crop establishment types with increased residue retention. Nitrogen availability in the initial phase of crop growth (0–60 DAS) was generally higher with CT than SP and BP. By contrast, for all crops, the estimated potentially mineralisable N was higher and its decay rate was lower under SPHR than other crop establishment and residue retention practices. Conservation Agriculture practices (SP, and NP of rice, together with HR) have altered the N cycling by reducing the level of mineral N available to plants in the early growing season when crop demand is low, but by increasing soil total N (0−10 cm) and plant N uptake which enhanced the synchrony between crop demand and available N supply.

Instability Analysis of a Low‐Angle Low‐Expansive Soil Slope under Seasonal Wet‐Dry Cycles and River‐Level Variations

There were a small amount of obvious offsets at the bearing of bridge piers built on an artificial gentle canal bank terrace and many tensile cracks visible at the surface of the mortar block stones covering the terrace soil in several years following construction. To determine these reasons, a comprehensive site investigation and a wide variety of tests were implemented, which included geophysical tests, in situ tests, laboratory tests, pile integrity detection, and numerical analysis with the finite element method (FEM). The results revealed that the soil of the low‐angle slope was the potentially low‐expansive clay soil. The reduction in soil shear strength deriving from seasonal wet‐dry cycles and river‐level variations led to the instability and failure of the low‐angle low‐expansive soil slope, which triggered the collapses of the soil slope and lots of fractures in the piles of the bridge foundation. The typical characteristics of the instability and failure of the low‐angle low‐expansive soil slope were tractional detachment and slow sliding.

Effect of Elemental Sulfur on Phosphorus Availability and Wheat (Triticum aestivum L.) Grown on a High Terrace Soil in Northern Sudan

The effect of elemental sulfur on some chemical soil properties and wheat grown was studied by two performing experiments, under high terrace soils of northern region of the Sudan. First experiment (incubation experiment) was executed to quantify the rates and application time of elemental sulfur to be applied in the field experiment. It consisted of five rates of elemental sulfur (0, 165, 330, 495 and 660 kg sulfur feddan-1) and five application times (2, 4, 6, 8 and 10 weeks). In the second experiment (field experiment), two wheat varieties (Wadi Elneel and Debeira), three sulfur rates (0 kg S feddan-1, 495 kg S feddan-1 and 660 kg S feddan-1) and three application times (0, 5 and 7 weeks) were arranged in split plot design with four replications. Wheat varieties were assigned to the main plots and the combination of the rates and time application to the sub plots. Results obtained from the incubation experiment indicated differences in soil pH among treatments. Application of elemental sulfur decreased soil pH in each of the two experiments. The effect of elemental sulfur on wheat grain yield and the other studied yield components was not limited the plant height and the 1000 seeds weight. The nitrogen content of the plant tissue was affected by the applied elemental sulfur. Application of 495 kg sulfur feddan-1, 6 weeks before sowing gave the lowest soil pH (7.8) and the least available phosphorus compared to other treatments.

<i>Ficus carica</i> L. on terraced agro-brown soils of the Southern Coast of the Crimea

The reaction of fig plants to the properties of agro-brown terraced soils of the Southern Coast of the Crimea (SCC) was studied, unfavorable soil properties for plants, as well as their optimal and permissible parameters were revealed. The dependence of the volume mass of fine grained soil on the content of silt particles and silt with fine dust in the layer of 0-60 cm and in the root layer was revealed. The quantitative dependences of fig tree trunk circumference on the properties of agro-brown terraced skeletal soil were revealed. The growth of figs depended on the depth of dense underlying rocks, fine grained soil reserves in the layer deeper than 60 cm, as well as in the root layer. Valid parameters are set for these values. The tendency to the dependence of the circumference of the tree trunk on the humus reserves in the root layer and the content of the skeleton in the layer deeper than 60 cm was revealed.

Ancient runoff farming and soil aggradation in terraced wadi fields (Negev, Israel): Obliteration of sedimentary strata by ants, scorpions and humans

Ancient terraced fields in ephemeral stream valleys in the Negev desert enabled farming based on runoff water from local rainfall. The runoff was captured by stone terrace walls, which were built across suitable wadis in various archaeological periods. Runoff floods added not only water to the fields but also fine sediment. However, alluvial stratification is usually absent in such terraced wadi fields. Why? We addressed this question at the rural archaeological site of Horvat Haluqim in the central Negev highlands. Our geoarchaeological excavations in Area 3 of Terraced Field 12 revealed the existence of laminar alluvial stratification, but only in the upper 5 cm. Micromorphology showed a gradual decline in the preservation of laminae with depth. Radiocarbon dating showed that the upper 50 cm of the terrace soil accumulated during the past 1300 years. Therefore, the average aggradation rate seems about 0.4 mm/year, similar to modern sedimentation measurements. We found evidence for bioturbation, particularly by ants and scorpions, in the terraced wadi fields at Horvat Haluqim. Scorpions evict the soil crumbs, excavated from the subsoil, on one side of the crescent-shaped entrance to their burrows. Ants, on the other hand, place the excavated soil crumbs all around the entrance to their underground nest. Besides bioturbation, human soil disturbance by farming is far more destructive to alluvial stratification. Hoeing and ploughing (tillage) can erase alluvial laminae from the surface to a depth of about 10 cm in one farming season. Clear evidence of ancient farming activities in Area 3 was found in darker soil layers from a depth of 45 cm–92 cm. Laminar alluvial strata have not survived in these layers. Micromorphology revealed fine charcoal, bone and pottery fragments, interpreted as kitchen/household refuse added as fertilizer to the aggrading soil surface. In addition, non-burned dung fragments and non-charred spherulites were found, indicating also the use of animal dung as manure. Darker soil layers have a lower bulk density and a high porosity with an extremely large amount of fine pores, probably ancient root channels of barley or wheat. Though runoff flows kept adding laminated alluvial layers to the aggrading terraced wadi fields, the fine laminae (initial facies) did not endure the tooth of time. They were gradually obliterated by bioturbation and/or rapidly erased by human farming activities (tillage and manuring), so that laminae are non-existent in the ultimate facies of the aggrading sediment-soil in agricultural terraced wadi fields.

A Physiographic Study and Land Evaluation of the Soils of some Eastern Desert Wadies , Egypt, Using Landsat Images Interpretation

The soils of both wadies Qift and Zeidun are considered one of the promising parts of Eastern Desert, due to a wide area of arable land and the high potential of ground water. Additionally, the area is considered a good model for representing many of the landscape features, in the Eastern Desert. So this study aims to identify the different physiographic units including soil developed in this area by interpretation landsat ETM 8 image, as to determine soil suitability class that have closely relationships with physiographic characteristics. This technique plays an important role for utilizing these scanned promising areas. The area under consideration lies between latitudes (26o 00ˉ) and (25o 50ˉ) North and longitude (32o 45ˉ) and (33o 05ˉ) East and covered by Landsat TM8 image bands 2,4 and 7. The data obtained show that the studied area were identified physiographically, as:(1) Rubble Terraces (stony pediment soils), old alluvial terraces (high & low),young alluvial plain terraces (high & low) , fan and outwash plane, wadies (wadi bottom and wadi plain) and Miscellaneous land types (Rock land). According to the morphological features and analytical data, the soils developed on the main physiographic units are classified till the family level into: A: Aridisols , soil families are : 1-Typic Calcigypsids, sandy skeletal, mixed , hyper thermic, (old and young alluvial terraces(high & low) and wadi bottom soils.2- Typic Calcigypsids, loamy skeletal, mixed ,hyper thermic at the soils of old alluvial terraces (high) and wadi bottom soils. 3- Lithic Haplocalcids, loamy skeletal, mixed , hyper thermic, (Rubble terraces stony pediment). 4- Typic Haplocalcids, sandy skeletal, mixed, hyper thermic at old and young alluvial terraces (low) and wadi bottom soils. 5- Typic Haplocalcids, loamy skeletal (young high terraces) and wadi bottom. B: Entisols included: 1- Typic Torripsamments, sandy skeletal, mixed, hyper thermic young alluvial terraces (low), fan and outwash plain. 2- Typic Torriorthents, sandy, mixed, hyper thermic (wadi plain soils). The soil evaluation results of the studied soils revealed that the soils of wadi bottom and wadi plain soils currently marginally suitable lands (S3) and moderately suitable (S2). Fan and out wash plain and some soil of low young alluvial terraces currently are marginally suitable lands (S3). Whereas, Rubble terraces stony pediment soils, and some soil of old alluvial terraces, and high young alluvial terraces are currently not suitable (N1). In addition, the limiting factors for soil productivity are topography, soil texture effective, soil depth, CaCO3 content, salinity and alkalinity. Potential suitability was identified after required land improvements and reveal that all the studied soils are placed between marginally and moderate suitable (S3 & S2). The limiting factors for soil productively are soil texture and soil depth.

Diverse biological sources of core and intact polar isoprenoid GDGTs in terrace soils from southwest of China: Implications for their use as environmental proxies

Archaea are important participants in soil biogeochemical cycles. Their membrane lipids are usually composed of isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs), which are ubiquitous in the environments and widely applied as biomarkers for archaeal biogeochemical processes and palaeothermometry. However, the biological sources of iGDGTs and environmental factors controlling their distribution in soils are elusive. We examined the archaeal lipid composition and community structure along an altitudinal soil transect in the Hani terrace wetlands in Southwest of China by combining organic geochemical and high-throughput sequencing approaches. The results show that monoglycosyl -iGDGTs (1G-iGDGTs) are the dominating intact polar lipids (IPLs) and possible precursor of core-iGDGTs preserved in soils. iGDGTs from Hani soils may come from several archaeal lineages based on their significant positive correlations in both core lipids and IPLs. Thaumarchaeota Group I.1b most likely contribute to crenarchaeol and its regio-isomer in non-paddy soils, while Bathyarchaeota, Methanobacteria and Methanomicrobia may predominantly contribute to GDGT-0 in water-saturated paddy soils. Our results indicate that the paleotemperature proxy TEX86 in soils can be affected by changes in archaeal community structure in addition to environmental variables such as soil water content and pH, but not independently by temperature. In addition, the lower TEX86 in humid soils may be partly attributed to the insufficient peak separation of iGDGTs with cyclopentyl moieties, which contain abnormally high abundances of shoulder peaks that may be contributed by anaerobic Archaea. This study sheds light on the increasing role of microbial community structure in affecting the fidelity of TEX86 in terrestrial environment, which should be taken into consideration when applying it to paleo-soil temperature studies.

Nutrient Mineralization and Soil Biology as Influenced by Temperature and Fertilizer Management Practices

High soil temperature due to climate change may influence nutrient mineralization and soil biology. An incubation study was conducted at Bangladesh Rice Research Institute to determine the effect of temperature (28°C and 45°C) on nutrient mineralization and soil microbial population of two different soils (terrace and saline soil) having different nutrient management practices (chemical fertilizer and integrated nutrient management). Terrace soil was clay loam and saline (6 ds m-1) soil was sandy loam in texture. Total N and organic C content was significantly high in terrace soil compared to saline soil. High temperature (45°C) enhanced C mineralization by 33% in integrated nutrient management (INM) of terrace soil and 41% in chemical fertilizer treatment in saline soil. The NH4+-N mineralization was increased by 3 fold in saline soil at 45°C as compared to the same at normal temperature of 28°C. Temperature and nutrient management options also significantly influenced phosphorus (P) and potassium (K) mineralization. High temperature significantly enhanced P mineralization in INM compared to chemical fertilizer amendment. In terrace soil, at 28°C temperature K mineralization was high in chemical fertilizer amended soil as compared to INM treatment. Temperature and nutrient sources affected soil bacterial population significantly compared to fungi, and actinomycetes. Phosphate solubilizing bacteria (PSB) were more resistant to high temperature compared to free-living N2 fixing bacteria. In general, high temperature and nutrient management practices affected C, N, P, K mineralization and soil biology; although mode of action varied and depending on soil types and nutrient management practices.

Ultramafic Aridisols on a sequence of fluvial terraces in Baja California

Practically all arid ultramafic soils in North America are in Baja California. An arid watershed in Baja California was found to have terraces with soil parent materials dominated by serpentinized peridotite. The soils on a sequence of four fluvial surfaces in the watershed were studied in order to trace the path of serpentine soil development in an arid climate. Flood-plain soils in the arid watershed are Torrifluvents and terrace soils are Argidurids (Durisols) and Duric Petroargids (Luvisols). There were no calcareous horizons in them. Duripans are well developed and practically continuous at about one meter depths in the terrace soils. Mass ratios of Ca:Mg from aqua regia digestion were about 0.05 in all of the soils. Average molar exchangeable Ca:Mg ratios were about 1.5 in the flood-plain soil, and 0.7 and 1.1 in the surface and subsoils on the terraces. Very fine sand contents in the terrace soils were two to three times greater in the surfaces than in the subsoils. The extra sand was mostly quartz and some feldspars, but serpentine dominated the fine sand and quartz was absent from the coarse sand fractions. Apparently, the Ca input from dust and other aerosols was sufficient to maintain exchangeable Ca:Mg ratios that are high for ultramafic soils, but insufficient to produce Ca-carbonates. Clay minerals in the flood-plain soil were serpentine, chlorite, smectite, and palygorskite. Palygorskite was a minor mineral in the flood- plain soil to prominent in terrace soils. There was substantial quartz in the clay <4 μm fraction.

Environmental sustainability and water productivity on conservation tillage of irrigated maize in red brown terrace soil of Bangladesh

Abstract Conservation tillage (CA) is an option for maintaining soil health and the surrounding environment for intensive agriculture, especially on the tropical climate. A three years lengthy research experiment was performed in arid climate from 2014 to 2016 at Bangladesh Agricultural Research Institute (BARI) to evaluate the effect of conservation tillage approaches on environmental sustainability and water productivity of irrigated maize cultivation. The conservation tillage practices (Zero tillage-ZT and Minimum tillage-MT) are evaluated in comparison to the traditional farmer’s practices. Amongst these, the treatment combination having MT with optimum irrigation best suits for cost-effective sustainable technique in maize cultivation without compromising with the yield at the dry season in the red brown terrace soil of Bangladesh. This combination of CA treatment is environment-friendly for maize cultivation as the treatment combination consumes the lowest amount of fuel (29.70 L/ha) for tilling purposes and required fewer water resources (only 2 time irrigation) for irrigation purposes and thus reduces the amount of carbon dioxide and other emitted toxic gaseous molecules to the surrounding environment. Therefore, MT with optimum irrigation is evaluated as the best options for continuous maize cultivation in the red brown terrace soil without any yield penalty.

Changes in soil organic carbon and total nitrogen stocks in response to walnut plantation in the southern region of the Loess Plateau, China

Afforestation of croplands has been widely adopted on the semi-arid Loess Plateau in recent decades. However, knowledge of soil carbon and nitrogen changes after afforestation is still limited because of the complexity of afforestation approaches. Therefore, an experiment was conducted on two dominant arable soils (tableland soil and terrace soil) on the southern Loess Plateau to evaluate the impact of two afforestation approaches (walnut monocultures and walnut-based agroforestry) on the soil organic carbon (SOC) and soil total nitrogen (STN) content within 2 m soil profiles. In the tableland soil, compared with the continuous crop monoculture (135.90 t C ha−1), SOC stocks in the agroforestry and walnut monoculture system increased by 7.91% and 1.91%, respectively. While in the terrace soil, compared with crop monoculture (102.95 t C ha−1), SOC stocks in the agroforestry and walnut monoculture system decreased by 3.86% and 0.20%, respectively. The STN stock was lower in the tree monocultures and SOC content was significantly correlated with STN. Afforestation increased the SOC and STN stocks in the 0–10 cm soils, but decreased them in the 10–60 cm soils. In the deep soil layers (60–200 cm), SOC content increase was only found in agroforestry in the tableland soil, and no significant differences were found in the terrace soil. Converting cropland to agroforestry has advantages in terms of soil carbon sequestration.

Quality and Nutritive Value of Faba Bean (V&lt;i&gt;icia faba L.&lt;/i&gt;) as Affected by Production Environment and Genotype

Faba beans (Vicia faba L.) represent an essential source of food protein for many people in Sudan, especially those who cannot afford to buy animal meat. The demand for faba bean seeds is greatly increased in recent years, and consequently its production area was extended where the climate is marginally suitable, these marginal environments’ were affect the quality aspects of faba bean. An experiment was conducted for three consecutive seasons (2005/2006, 2006/2007 and 2007/2008), at five environments representing different soil types. The objective was to study the effect of these environments on cookability (quality) of Faba bean with consideration to the prevailing temperature and relative humidity of these environments. The environments were: (E1): Al Salama location to represent lower terrace soil (Riverian); (E2): Hudeiba Research Station Farm to represent middle terrace soil (Kuru); (E3): Almatara location; to represent high terrace soil; (E4): Wad Medani location= Gazira Research Station Farm to represent central clay plain soil (Vertisols); (E5): Ed Damer Food Security Scheme location to present high terrace soil. Six Faba bean lines were selected: Small-medium seeded (H.72/7/1, Daba.1/1, Z B F.1/1, C.86, Triple White and Large seeded Turki. The experiment was arranged in a randomized complete block design with three replications. The results showed that soil types had significant effects on cookability aspect. The high cookability seed of faba bean under all production environments was recorded from lower terrace soil (Riverian) in E1 (Al Salama location) and the poor cookability seeds of faba bean were recorded from the high terrace soils in E3 (Almatara location) and E5 (Ed Damer) Food Security Scheme). The new production area E4 (Wad Medani) location) produced a moderate cookability seed.

Cd, Cu, Pb i Zn u terasiranim tlima na flišnim naslagama obalnog područja Kaštelanskog zaljeva, Hrvatska

The aims of this study were: (i) to determine concentrations of heavy metals (HMs): Cd, Cu, Pb and Zn in terraced soils on flysch deposits of Kastela Bay coastal area, Croatia, (ii) to highlight their possible sources and (iii) to compare concentrations of HMs among olive groves, vineyards and abandoned agricultural land (grassland). In a total of 26 topsoil samples (0-25 cm) were analyzed for pH, carbonates, organic carbon, K2O, P2O5, texture and concentrations of the HMs. The elements were extracted with aqua regia and determined by inductively coupled plasma - optical emission spectrometry (ICP-OES). The following mean values of Cd, Cu, Pb and Zn concentrations were 0.39, 46.54, 15.82 and 51.39 mg*kg-1, respectively. The principal component analysis (PCA) and the correlation matrix (CM) revealed weak relationships HMs with soil properties and strong similarity among Cd, Pb and Zn concentrations indicating its common origin, controlled by different anthropogenic activity. The Cu poorly correlated with all other metals that point to its different origin - application of copper-based fungicide. The mean concentrations of Cd, Pb and Zn in vineyards, olive groves and grasslands were not statistically significant difference. The Cu concentrations in vineyards were significantly higher compared to other land use types

Response Agronomic Traits of Lentil Varieties to Zinc Fertilization in Calcareous and Terrace Soils of Bangladesh

Zinc (Zn) fertilization is reflected a significant agronomic strategy for global food security. Deficiency of zinc in soils could be caused to decrease the crop yield. Hence an experiment was made over two years at the research farm of Pulses Research Sub-Station of Bangladesh Agricultural Research Institute (BARI), Gazipur and in the research farm of Regional Agricultural Research Station (RARS), Ishwardi and Jessore, during Rabi season to assess the sensitivity of different varieties of lentil to Zn fertilization and evaluate the Zn in terms of yield and Zn mineral content in seed. There were 12 treatment combinations comprising six lentil varieties (V1 = BARI Masur-2, V2 = BARI Masur-3, V3 = BARI Masur-4, V4 = BARI Masur-5, V5 = BARI Masur-6 and V6 = BARI Masur-7) and two levels of zinc (0 and 2 kg ha-1). The experiment was laid out in split-plot design with three replications. Results reveal that growth, yield attributes and yield varied positively by zinc level and variety. Among the varieties, BARI Masur-7 followed by BARI Masur-6 gave the highest seed yield. Interaction of variety and zinc the highest mean seed yield (1568 kg ha-1 at Gazipur, 2396 kg ha-1 at Ishurdy and 1639 kg ha-1 at Jashore) produced by the treatment V6Zn2. The improved protein content (28.5% at Gazipur, 28.9% at Ishurdy and 29% at Jashore) and zinc content (70.2 ppm at Gazipur, 73.6 ppm at Ishurdy and 69.9 ppm at Jashore) was achieved in V6Zn2 treatment. The result, suggest that 2 kg Zn ha-1 could be applied in any lentil variety for quality improvement and yield maximization in terrace and calcareous soils of Bangladesh. The current study recommended conducting another experiment for further monitoring and determining the appropriate Zn dose for lentil production through application of different zinc rates in Zn- deficient soils.

Productivity and life length of oak (Quercus robur L.) artificial crop in the Northern Ergeny, Kalmykia

The paper deals with the current state, productivity and durability of oak tree (Quercusrobur L.) stand in the Northern Ergeny (Kalmykia, Russia). The best forest-growing conditions are formed on light alluvial-deluvial soils of river terraces during the first years of plant life as well as in large depressions of placers with dark-colored soils and the horizon below onemeter. Large deep gulches of Ergeny partially overgrown with natural tree and shrub vegetation play the most important role for massive (continuous) afforestation in the territory of Kalmykia. When cultivating forest stands under these conditions, the most productive and durable breed is the pedunculate oak. Seed generation of oak can develop according to I-III class of forest appraisal index (the forest density stored up to this age is 160-190 m3 ha-1) and survive to 80-100 years and in the case of timely cutting – to form a stable coppice stand. Effective methods of cultivation of viable plantings on placers are: formation of a long-term reserve of soil moisture, creation of pure plantations of medium density from relatively shade-tolerant tree species and large shrubs frequent removal of dead wood and unpromising trees, formation of a shadowy underbrush or undergrowth in rapidly dilapidated stands.

Yield and Fruit Quality of Tomato as Influenced by Calcium and Mulching in Rooftop Cultivation

The experiment conducted in containers known as pot placed on rooftop of a building using noncalcareous grey terrace soil was carried out from October, 2012 to March, 2013 at Kazla, Motihar, Rajshahi, Bangladesh to investigate the influences of calcium and mulching practices on yield and fruit quality of tomato. The study was laid out in a split-split plot design with three replications. The trials comprised three factors: 1) three tomato varieties viz, BARI F1Tomato-5, BARI F1Tomato-6 and BARI F1Tomato-7; 2) four levels of calcium (Ca) treatment (40 ppm, 60 ppm, 80 ppm, 120 ppm) and 3) mulching practices. Results of the experiment revealed that fresh yield of tomato was significantly increased by applying mulching practices due to conservation of soil moisture by mulches and therefore, reduced Ca-deficiency symptoms. The highest number of fruits per plant and fresh yield were obtained from the variety BARI F1Tomato-5. The same trend of yield and yield contributing parameters were likely to be better by using T3treatment (80 ppm) than those of other treatments. In contrast, BARI F1Tomato-7 variety in control treatment without mulching practice gave poor quality and yield of tomato. Results suggested that BARI F1Tomato-5 variety receiving 80 ppm calcium treatment with mulching condition exposed better quality, yield and yield contributing characters of tomato. However, the T3 treatment (80 ppm) with mulching would be recommended as the best combination to grow BARI F1Tomato-5 for the farmers in Bangladesh.

Clay minerals in the late Quaternary sediment of Tulare Lake, California: Implications for climate change, weathering, and erosion processes

The clay mineralogy of Tulare Lake sediment was examined to investigate hydroclimatic and environmental changes in the southern Sierra Nevada Mountains (SNM) since the most recent glacial maximum. Evolution of clay mineral assemblages elucidates significant changes in weathering, erosion, and hydroclimatic condition in the catchment. During the last glacial period (24.4–15.1 cal ka BP), low illite content implies less physical erosion of the granitic batholith rocks and a cold and arid environment in the southern SNM. Abrupt increases of illite content at 21.8–20.8 and 17.6 cal ka BP resulted from the glacier advances to the ablation zone and illite-rich glacier flour was transported down to the lake. The gradual increase of smectite induced by progressive depletion of illite-rich glacier flour from 17.6 cal ka BP toward the end of this period indicates climate was beginning to get warm and wet. From 11.9 to 5.3 cal ka BP, two warm and wet periods (10.7–9.4 and 8.2–5.2 cal ka BP) were characterized by high smectite/illite content ratios and low illite crystallinity values, suggesting intensive rainfall precipitation and more physical erosion in the highland and lowland catchment as well as more smectite formation in the terrace soils. Since the last glacial period, physical erosion, in comparison to the chemical weathering, was the dominant process responding to the hydroclimatic change in the Tulare Lake catchment. Moderate to weak chemical weathering was signified by the mostly low illite chemical weathering index of the core sediments. Such results suggest that vegetation cover in the southern SNM was low and limited.

Response of broccoli to USG and prilled urea in shallow red-brown terrace soil under Madhupur tract

A field experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the period from 2012-13 to verify the effectiveness of urea super granule (USG) and prilled urea (PU) on the yield and quality of broccoli, to assess the comparative performance of USG and PU on nutrient uptake and nitrogen use efficiency and to evaluate the effect of USG and PU on post-harvest nutrient status in Shallow Red-Brown Terrace Soil of Madhupur Tract (AEZ-28). The experiment was designed in a randomized complete block with three replications having 5 treatments as T1: Control, T2: USG-N140, T3: USG-N160, T4: USG-N180 and T5: PU-N180. Result showed that USG performed better than PU. The comparative performance of USG in relation to yield, head quality (ascorbic acid, β-carotene and chlorophyll content), SPAD value, nutrient (NPKS) uptake and N use efficiency was found higher as compared to PU. USG treated broccoli plants gave significantly higher yield where the highest yield (13.49 ton ha-1) was recorded with USG-N160 kg ha-1. Moreover, USG showed higher β-carotene and chlorophyll content over PU and those were increased with increasing levels of N. However, ascorbic acid content was slightly decreased with increasing rate of N fertilizer. Nitrogen, phosphorus and potassium uptake increased with increasing N rate upto USGN180 but sulphur uptake was increased upto USG-N160. Nitrogen use efficiency was higher in USG treated plots than that of PU having the highest value of 111.71% with USG-N160 kg ha-1. Post-harvest soil nutrient status was not significantly influenced by the treatments although it was slightly higher in USG as compared to PU. Considering all, USG @ 160 kg N ha-1 (USG-N160) with other recommended fertilizers (@ 53 kg P, 83 kg K, 20 kg S, 2.0 kg Zn, 1 kg B and 0.8 kg Mo ha-1) could be the best USG based fertilizer dose for quality broccoli production in Shallow Red-Brown Terrace Soil of Madhupur Tract.Bangladesh J. Agril. Res. 43(4): 557-574, December 2018

Response of chickpea varieties to boron application in calcareous and terrace soils of Bangladesh

An experiment was conducted at Madaripur and Gazipur during rabi (winter) season of 2012-13 and 2013-14 to determine the optimum dose of B for different varieties of chickpea (Cicer arietinum L.). There were 12 treatment combinations comprising three varieties (BARI Chola-5, BARI Chola-8 and BARI Chola-9) and four levels of boron (0, 1, 1.5 and 2 kg ha-1) along with a blanket dose of N20P20K25S10Zn2 kg ha-1. Boron was applied as H3BO3. Results showed BARI Chola-9 with 1.5 kg B ha-1 produced the highest seed yield of 1338 kg ha- 1 at Madaripur and 2218 kg ha-1 at Gazipur. Nodulation, nitrogen (N) and protein contents were also found highest for the same variety and B treatment. The other two varieties (BARI Chola-5 and BARI Chola-8) also performed higher yield in the plot receiving 1.5 kg B ha-1 compared to 1 kg B ha-1 or 2 kg B ha-1 at both locations. The results suggest that BARI Chola-9 and 1.5 kg B ha-1 along with N20P20K25S10Zn2 kg ha-1 could be used for achieving higher yield of chickpea in calcareous and terrace soils of Bangladesh.Bangladesh J. Agril. Res. 43(4): 543-556, December 2018

Göynük Nehri (Bingöl) Teraslarında Oluşan Toprakların Sınıflandırılması ve Fiziko-Kimyasal Özelliklerinin Belirlenmesi

Soils are constantly changing due to topographical factors, agricultural practices and climate characteristics. Along with the formation processes, soils generally have different characteristics due to the impacts of the factors they are exposed to. This study determined the physical, chemical and hydraulic characteristics of three terraces formed by the Bingöl-Göynük River and the terrace soils were classified according to Soil Taxonomy. Soil profiles were excavated on each terrace, and horizon-based sampling was performed. The 1st terrace over the river bed was composed of alluvial deposits. The 2nd and 3rd terrace soils had structural development and advanced horizon development. The soil moisture regime was xeric, the temperature regime was mesic, and the climate was related to soil formation. The most distinctive soil formation process was identified as carbonate accumulation in the 2nd terrace. According to Soil Taxonomy, all three soil profiles were classified within Entisol and Vertisol orders.