Red-brown Soil Research Articles

Urzhumian Pedocomplexes of the Kazan Volga Region (Eastern Europe): An Example of Paleoclimate and Paleolandscapes of the Subtropics of the Continental Pangea in the Middle Permian

The paleosol profiles of the Urzhumian from the section on the right bank of the Volga River near the village of Grebeni were studied by field and laboratory methods. Two paleosol profiles on red clayey siltstones were identified. They were classified as strongly developed Vertic Calcisols based on their pedogenic features such as horizonation, carbonate nodules, slickensides, etc. The climate during their formation was found to be seasonally wet and warm. The mean annual precipitation was calculated from the geochemical indices of the paleosols and amounted to 522 mm/year for the Late Urzhumian. The reddish-brown soils in the dry subtropics of the Mediterranean or Australia can be considered as modern analogs of these paleosols.The upper paleosol profile is a pedocomplex consisting of four single soils separated by nonpedogenic carbonate layers in the middle part. The pedocomplex structure contains one lacustrinepalustrine and two lacustrine-playa sedimentary microrhytms, which indicate the setting of lacustrinealluvial plains and make it possible to estimate the duration of its formation spanning thousands to tens of thousands of years.A pedocomplex with a similar structure was identified in the upper part of the Urzhumian of the reference section in the Cheremushka Ravine. Both pedocomplexes have very similar mineralogical, chemical, and granulometric composition of their siliciclastics, as well as the isotopic composition of pedogenic nodules. The biostratigraphic position of the pedocomplex in the Cheremushka Ravine shows that it is coeval with the pedocomplex of the Grebeni section. The correlation between them is direct, making them a useful pedostratigraphic marker. It is suggested to label this marker horizon as the “Crimson Clay pedocomplex”.

Soil Based Adsorption Media for Permeable Reactive Barriers to Adsorb Lead (Pb<sup>2+</sup>) & Cadmium (Cd<sup>2+</sup>)

Groundwater contamination is one of the predominant environmental problems in Sri Lanka and it is suspected as one of the unseen factors of the country’s widespread kidney disease. Heavy metals Cadmium (Cd2+) and Lead (Pb2+) are two potentially harmful contaminants found in polluted groundwater samples in Sri Lanka. Permeable reactive barrier (PRB) is an on-site, costeffective and efficient groundwater heavy metal remediation technique. However, the effectiveness of the PRB system is highly dependent on the characteristics of the reactive materials being used. Accordingly, Rendzina soil (Hunugala series), Reddish Brown earth soil (Nonagama series), Reddish brown latosolic soil (Melsiripura series), and Bog Soil (Wagura series) were selected based on the basic soil properties which were found by previous researchers. Sieve analysis, Atterberg limits, and Procter compaction tests were carried out to determine the physical properties of the selected soils. The batch tests were carried out to determine the absorption rate of heavy metals, namely, Lead (Pb2+) and Cadmium (Cd2+), and to assess the effects of pH, contact time, and initial concentration on the adsorption characteristics of the selected reactive materials. The results reveal that the Rendzima soil is the most suitable reactive material out of all the reactive materials tested.

Quaternary paleoenvironments based on pedogenic, sedimentary and karstic processes in the coastal geosystems of Cozumel Island, Mexico

The Quaternary carbonatic deposits of the Cozumel Island are mainly reefs and calcarenites in which karstic features, red clayey paleosols and layers of calcretes provide a record of terrestrial paleoenvironments still poorly explored. A main section, Cantera Payo, and three complementary sections: Cantera Transversal, Aerolito and Chempita were studied. Besides field work, micromorphology, physicochemical and mineralogical analyses of soils and calcretes were done. C and O stable isotope analysis was also conducted in calcretes. The cyclicity of sedimentary, karstic and pedogenetic processes was established. The chronological frame was obtained through the correlation dated calcretes and coral samples from Yucatan Peninsula, with ages ranging between ∼Marine Isotope Stage (MIS) 7 to MIS 1. Two paleo-karstic surfaces were identified, labeled as PK1 (older) and PK2 (younger). The PK1 surface showed multi-face karst features as collapse breccias, dissolution pits and pipes, and karstic pockets filled with lithified brown and red paleosols. The red paleosols exhibited abundant redoximorphic features. Clay mineralogy in paleosols and modern soil is similar, with vermiculite and minerals of the kaolinite group. We interpret they are the result of moderate weathering under a seasonal tropical climate like that of present-day conditions. PK1 is capped by a calcrete layer, whose age probably corresponds to the Marine Isotope Stage (MIS) 6 (164 a 135 ka). Therefore, the host rock and the karstification and pedogenetic processes should occur before (probable during MIS 7) The stable carbon isotope composition of this calcrete has a mean δ13C value of −10.40 ‰ that suggests the presence of a C3 plant cover. During the MIS 5, poorly cemented calcarenites accumulated in the island related to the sea level rise during this interglacial stage. This calcarenite level has less developed karstification and pedogenetic processes. Another laminar calcrete with root traces and septal alveolar structure is found on top of the studied sections formed in the MIS 5 and the transition to MIS 4. Its δ13C value ranges between −9.40 ‰ and − 10.27 ‰ also related to a C3 plant cover. In the period between MIS 4 and MIS 1, karst development and pedogenesis is observed on the island, evidenced by the formation of caves and reddish-brown soils.

Evaluation of the purification capacity of soils: case of the Kouogouo and Djeleng V quarters in Bafoussam City (West Cameroon).

This work aimed at evaluating the purification capacity of the Kouogouo and Djeleng V quarters' soils (West Cameroon). Soil mapping was carried out, from which representative soil samples were collected, followed by their physical, chemical, and hydrodynamic characterization. Two types of effluents were identified, characterized, and subjected thereafter to filtration into these soil samples. The filtrates were then analyzed, in view of evaluating the performance of these soils through influent-effluent indicator level (physico-chemical parameters and fecal coliforms). The main results show four soil units in the study area, among which the indurated red brown clay soils and red clay loam soils with rock fragments were dominant, with 51.8% and 35.4%, respectively. The clayey texture was dominant (94.7%). These soils were classified as neutral to slightly acidic (5.83 to 7.19), while the permeability values ranged from 25.59 to 0.014cm/h. Moreover, the hydrologic balance indicated a surplus of about 989.3mm, which can contribute to the recharge of the water table at low depth, traditionally supplying wells and sources of drinking water, but also potentially to their pollution by the influx of organic and mineral matter. Two types of effluents were identified: these are latrines and domestic waste. They had contrasted physico-chemical and bacteriological pollution potentials, but sufficient to have a harmful effect on the population, compared to the WHO standards. The persistence of coliforms in some filtrates confirmed that water was exposed to pollution by the previous effluents and argued in favor of the installation of a safety distance between potential sources of pollution and water supply on the other hand.

Determining and GIS Mapping Some Soil and Land Properties in Nigde Province of Turkey

This study was carried out within the scope of spatial evaluation of majör soil groups, land slope, erosion degrees, soil depth classes, and other soil properties by using 1/25.000 scaled digital soil maps in Niğde province. Arc GIS 10.3.1 software, which is one of the Geography Information Systems (GIS) software, was used for spatial analysis. Classification results were evaluated according to the "Soil and Land Classification Standards Technical Instruction" published by the Ministry of Agriculture and Rural Affairs in 2005. As a result of the research, it was seen that the class covering the largest area in terms of major soil groups was brown soils with 224466.1 ha. Red-brown soils cover the least area with 45.4 ha. Areas with a steep slope with a 5% slope on the land slope cover the largest area of 140325.7 ha. Areas with a very steep slope of 6%, on the other hand, cover the least area with 69064 ha. Areas with C class (50-90 cm) soil depth in the study area cover the largest area with 294054.7 ha. The areas with E class (0-20 cm) soil depth were seen in the least area with 22203.5 ha. In terms of soil erosion classes, the most common erosion class is III. These are areas with a degree of erosion risk and their total area is 269374.8 ha. It has been determined that areas with slightly salty, alkaline, weak, and adequate drainage are seen in an area of 234.1 ha in the research area. Areas with insufficient drainage have an area of 7350.9 ha. In this study, spatial analysis of some land and soil properties in Niğde province was carried out and distribution maps were produced. It is thought that the results of the research will make significant contributions to the agricultural investments operating in the region.

Soil-sediment-configurations on slopes of Central and Western Crete (Greece) and their implications for late Holocene morphodynamics and pedogenesis – A conceptual approach

Geomorphological processes and soil formation in slope positions within the Mediterranean area have been in the focus of research for a long time. Many of the surface-near soil-sediment-configurations in the Mediterranean area have been termed soils and have been interpreted as typical (zonal) Mediterranean reddish-brown soils (RMS) of Terra Rossa type associated with clay illuviation as main pedological process. However, there has been an extensive scientific debate which (late) Holocene geomorphological and pedological processes in fact dominate current soil-sediment-configurations, especially before the background of a long-lasting history of intense human land use impacts.In the present study, we present field evidence as well as analytical data for a number of representative soil-sediment-profiles located in a variety of geological, geomorphological and climatic settings in central and western Crete (Greece). We have grouped the profiles in three schematic geomorphological categories in order to provide a geomorphological instead of a pedological context for their interpretation and comparison. Based on geochemical, mineralogical, geophysical and micromorphological evidence we could show that in most of the studied profiles, (late) Holocene pedogenesis is comparatively weak, except for bioturbation in combination with surprisingly high TOC-contents. Discontinuities within profiles are the result of geomorphological processes and the corresponding deposition of clearly distinguishable parent materials (substrates) rather than pedologic processes resulting in the in-situ differentiation of soil horizons. Furthermore, characteristic and ubiquitous peaks in grain size distribution within the clay and silt grain size fractions could be identified and are most likely related to long-range dust inputs. Whether the weak degree of recent pedogenesis is due to the long-lasting history of intense land use or rather due to the (naturally) high intensity of geomorphological processes and sediment relocation remains one of the main open questions raised by the results of this study.

Effect of Selected Leguminous Cover Crop Species on the Productivity of Coconut Cultivated in Reddish Brown Latosolic Soils in Sri Lanka

This study was conducted for six years to assess the effects of two widely grown cover crops Gliricidia sepium (T1) and Puereria phasioloides (T2) on coconut yields and soil characteristics. Experiments were carried out on coconuts planted in Reddish Brown Latosolic soils located in the low country intermediate zone-IL1 of Sri Lanka. Results showed that treatments 1 and 2 were significantly (p≤0.05) effective over the control treatment (no cover crop) in suppressing weed biomass. Soil samples were collected and analyzed for physical, chemical and biological properties. Results showed that soils where G. sepium and P. phasioloides were grown were superior in most of the properties compared to the control. Soils under P. phasioloides showed significantly higher moisture contents compared to G. sepium and control treatments. Significant increases on soil properties were likewise observed in G. sepium and P. phasioloides plots: nitrogen (by 77% and 76 %), organic carbon content (by 86% and 148%), soil microbial activity (by 52% and 73%), respectively. On the other hand, soil bulk densities were reduced significantly by 20% and 27% under G. sepium and P. phasioloides, respectively. There was no significant increase observed on available P but P content improved with the establishment of cover crops. Significant increases in mean annual nut yields were observed during the 4th, 5th, and 6th years after cover crops establishment. Nut yields were found to increase with G. sepium and P. phasioloides by 46% and 58%, respectively when compared to that of control treatment plots.

Effect of soil type on spatial distribution and nutritive value of grass species growing in selected rangelands of South Africa

The distribution and status of grass species is essential for sustainable management of rangelands. Therefore, this study assessed the spatial distribution and nutritive value of grass species as influenced by soil type in selected rangelands of the North West province of South Africa. Grass species were harvested from four communal areas (clay loam and red brown sand soil types) using three transects per study area. Each transect was sub-divided into near (0.5–0.7 km), middle (0.70–1.4 km) and far sub-transects (1.4–2.2 km) based on distance from homesteads. Within each sub-transect, 10 m × 10 m homogeneous vegetation units (HVU) were marked and quadrats (1 m2) were randomly placed within each HVU to sample soil and grasses. Species composition, abundance, biomass and nutritive value of grass species were measured. Only 21% of grasses identified in the study areas were determined to be of high grazing value. Aristida species were more common and dominant in both soil types. Eragrostis cylindriflora 2 Hochst. had higher crude protein content and the highest in vitro ruminal dry matter degradability after 24 and 48 hours. Thus, E. cylindriflora was the most valuable grass species for livestock farming in the study areas and could be earmarked for rangeland restoration.

Modelling Salinity and Sodicity Risks of Long-Term Use of Recycled Water for Irrigation of Horticultural Crops

Long-term use of recycled water (RW) for irrigation in arid and semiarid regions usually changes the soil solution composition and soil exchange characteristics, enhancing the risk for salinity and sodicity hazards in soils. This modelling study focuses on developing alternative management options that can reduce the potentially harmful impacts of RW use on the irrigation of wine grapes and almonds. The multicomponent UNSATCHEM add-on module for HYDRUS-1D was used to evaluate the impact of long-term (2018–2050) use of irrigation waters of different compositions: good-quality low-salinity (175 mg/L) water (GW), recycled water with 1200 mg/L salinity (RW), blended water of GW and RW in the 1:1 proportion (B), and monthly (Alt1) and half-yearly (Alt6) alternate use of GW and RW. The management options include different levels of annual gypsum applications (0, 1.7, 4.3, and 8.6 t/ha soil) to the calcareous (Cal) and hard red-brown (HRB) soils occurring in the Northern Adelaide Plain (NAP) region, South Australia. Additional management scenarios involve considering different leaching fractions (LF) (0.2, 0.3, 0.4, and 0.5) to reduce the salinity build-up in the soil. A new routine in UNSATCHEM to simulate annual gypsum applications was developed and tested for its applicability for ameliorating irrigation-induced soil sodicity. The 1970–2017 period with GW irrigation was used as a warmup period for the model. The water quality was switched from 2018 onwards to reflect different irrigation water qualities, gypsum applications, and LF levels. The data showed that the GW, B, Alt1, and Alt6 irrigation scenarios resulted in lower soil solution salinity (ECsw) than the RW irrigation scenario, which led to increased ECsw values (4.1–6.6 dS/m) in the soil. Annual gypsum applications of 1.7, 4.3, and 8.6 t/ha reduced pH, SAR, and ESP in both soils and reduced the adverse impacts of irrigation, especially in surface soils. A combination of water blending or cyclic water use with 3.8 t/ha annual gypsum applications showed promise for the SAR and ESP control. Additionally, irrigation with RW, a 0.2 LF, and annual gypsum applications limited the harmful salinity impacts in the soils. However, in the RW irrigation scenario, ECsw and ESP at the bottom of the crop root zone (90–120 cm depth) in the HRB soil were still higher than the wine grape and almond salinity thresholds. Thus, annual amendment applications, combined with the long-term use of blended water or cyclic use of RW and GW, represent a sustainable management option for crop production at the calcareous and hard red-brown soils.

SPATIAL EVALUATION OF LAND AND SOIL PROPERTIES IN THE EXAMPLE OF NEVŞEHİR PROVINCE, TURKEY

In this study, some land and soil properties were spatially evaluated with the help of 1/25.000 scaled digital soil maps belonging to Center of province in the Central Anatolia Region, Turkey. Land use capability, large soil groups, soil depths, erosion, slope and spatial distributions of current land uses were carried out in the research. Arc GIS 10.3.1 software, which is one of the Geographic Information Systems (GIS) software, was used for spatial analysis. With a maximum of 262518 in the study area, VI. class lands. Class I cover an area of ​​247 . In terms of large soil groups, and soils are dominant and the area covered by these soils is 450187 . The least area was found to be reddish brown soils with 124 . It has been determined that the least area in the depth classes is A class (greater than 150 cm) soils. In the study area, it is the soil with the maximum C class (50-90 cm) depth. When the land was examined in terms of slope, it was determined that the land with the highest 3rd degree slope (12-20%) was formed. The research area consists of soil structure that can be exposed to the 2nd degree erosion class at most. When the current land uses are examined, it is the garden area with the least usage area in the region and the area it covers is 3400 . It has been observed that the most dry farming areas are located in the study area. It is thought that the results obtained as a result of the study will be the basis for the agricultural studies to be carried out in Center of province.

Properties and biological activity of rainfed gray soils formed in neogenic slopes in Uzbekistan

In Uzbekistan, along with gray soils formed in lyoss deposits, reddish soils formed in Neogene deposits are also widespread, which are distributed in mountainous and foothill areas. Reddish soils differ from gray soils formed in lyoss deposits by their appearance, genesis, and properties. The reddish-gray soils formed in the Neogene deposits are widespread in many parts of Uzbekistan and are subject to various levels of erosion. The reddish-brown soils formed in the Neogene deposits are mainly formed in the parent rocks that form a homogeneous lyoss soil, in some places these layers are very shallow and in the strata occur tertiary and calcareous loams, sands and conglomerates. The reddish-gray soils formed in the Neogene deposits are eroded to varying degrees as they are spread on different levels of slope. Erosion damages the fertile layer on the surface of the soil and reduces its fertility. Eroded soils are washed to varying degrees. Under the influence of the erosion process, the amount of humus and nutrients in the soil decreases sharply. Erosion processes adversely affect the mechanical composition, physical, agrochemical properties and biological activity of the soil. As a result, soil fertility decreases. For the soil to be fertile, it is necessary to maintain and increase the amount of humus and nutrients in it.

Physio-morphological Characteristics of Soil of Akure, Ondo State SW, Nigeria

Soil physical properties influence soil water infiltration rate, plant rooting depth, amount of available water, air and nutrients which are of utmost importance in agricultural production and, hence there is need to describe in-situ spatial organization and physical properties of soil in Akure. Sixteen profile pits were dug. The soils were characterized and described on the field and samples collected for textural analysis. The area occurs on level plain with little slope gradient, the surface horizons (A1 and A­2) were weak medium crumby to moderate medium crumby structures while the subsurface horizons (Bt1 and Bt2­) showed moderate medium blocky structure. The soils are generally deep and well drained at the top soil with coarse texture; the subsoils are characterized by prominent presence of mottles, which suggest that the subsoils are poorly drained. The distribution of clay content increased with soil depth for all pedons. Most of the Pedons had reddish gray colour (2.5YR 4/1) and dull reddish brown 2.5YR 4/3 at the surface horizons (A1 and A2), over brownish colour (7.5YR 4/4) and dull reddish brown (5YR 4/4) sub soil. The particle size distribution revealed that sand dominated the particle size fraction of the soil in all the profiles, which could be managed with appropriate organic manure.

Spore abundance and morphological root modifications of arbuscular mycorrhizal fungi-infected black pepper (<em>Piper nigrum</em> L) plants in reddish brown latesolic soil of Matale in Sri Lanka

Arbuscular Mycorrhizae (AM) is a symbiotic association between fungi and roots of higher plants, which enhances plant growth and production. Black pepper (Piper nigrum L: Family Piperaceae), the second most valuable spice crop in Sri Lanka, is also identified as a host crop of mycorrhizae. However, existing indigenous AM species, their spore abundance and root colonization is not yet well studied or documented. Therefore, the present study was conducted to collect data on AM spore density and morphological features of modified roots due to infection of existing AM species in black pepper fields. Rhizosphere soils of randomly selected, 20 well-grown black pepper plants in RBL soils of Matale in Sri Lanka were evaluated for pH, moisture and major nutrients while AM spore abundance and AM colonization in stained roots were examined microscopically. The soil pH (4.7-5.9), total N (0.18-0.23 %), and organic C (1.57-1.75%) levels in study sites were preferable for biological activities while variability was observed in available P (4.4-29 ppm), exchangeable K (188-788 ppm) and volumetric moisture (9.8-24%). The AM spore (size >50 μm) density in examined soils were high and ranged from 1600-9000 spores kg-1 soil. Both live (slight yellowish to dark brown in colour) and dead (black) spores were present and globular or spherical in shape without any special hyphal attachments. About 95% of examined roots were infected with AM with modifications such as arbuscules or vesicles or both. Networks of non-septate, extra-radical hyphae and branched intra-radical hyphae could be seen. Arbuscules observed were in different maturity and highly branched. Both inter or intracellular vesicles found were oval or ellipsoid in shape. Thus, most of the mature black pepper plants in RBL soils of Matale were found infected with indigenous vesicular arbuscular mycorrhizae (VAM) and morphological features of their spores, hyphae, arbuscules and vesicles were similar to fungi of order Glomerales, which consisted with Glomus spp.

MIDDLE PALEOLITHIC SITE RUBAN’ IN TRANSCARPATHIA: STRATIGRAPHY, CHRONOLOGY, INDUSTRY

The Ruban’ Paleolithic site was discovered in 2005 by the Transcarpathian Paleolithic expedition of the Archaeological Museum of the IA NASU. The site is located on the territory of the former Zatysnansky chemical plant (Fig. 1b) at a distance of 800 m north of the eastern outskirts of the village of Gorbky, Vynohradiv district, in the Transcarpathian region, in the Ruban’ tract, and about 2 km to the southeast of the Korolevo site.
 At the time when the site Ruban’ was discovered, the upper part the quarry wall where the site is located, has been ruined by the quarrying that made it impossible to determine a stratigraphic position of the archaeological layer and to establish the age of the culture. In order to solve these problems, 15 geological profiles of the Quaternary deposits have been set along the less disturbed quarry wall in 2016—2017. The stratigraphic subdivision of the sections, according to the Quaternary stratigraphic framework of Ukraine, and their correlation with the profile of the archaeological site have been carried out that enables to determine the geological age of the cultural layer.
 The geological site Ruban’ is located along the paleoslope and, thus, there are erosional brakes in its sedimentary record. The lowermost stratigrpahical unit is represented by reddish-brown soil of Martonosha unit overlain by gleyed loam of Sula unit and strongly dissected by wedges of the Sula cryogenesis. The other Lower and Middle Pleistocene units have been truncated and now they are represented by pedosediments (with exception of the yellowish-brown soil of Upper Zavadivka unit).
 Kaydaky unit (the brown forest soil of a warm interglacial climate) is separated from Zavadivka soil by the level of wedges of the Dnieper cryogensis.
 Pryluky unit is represented by two soils (pl1 and pl3), separated by cryogenic fissures and, in places, by a thin loess layer (pl2). The dark-brown soil pl1 is characterized by both manganese concretions and thick managanese films in its upper part, whereas the brown forest soil pl3 is overlain by a thin layer of dense iron-manganese concretions (pl3c). This layer reflects unstable hydrothermal regime during the transition from the warm interstadial to the cold stadial climate of the Uday time. Uday unit is represented, in places, by a thin loess layer, which is overlain by brown forest soil of Vytachiv unit. The latter is dissected by cryogenic fissures, filled with the non-soil material of Bug unit. The Holocene unit is truncated in many places but the Holocene pedogenic processes (translocation) overprint the underlying units.
 The stratigraphic correlation of the studied sections with the archaeological site (excavation 1) demonstrates that the archaeological layer is located in the transitional bed of iron-manganese concretions (pl3c). According to the accepted comparison of the Ukrainian stratigraphy with marine isotopic-oxygen scale, the chronostratigraphic position of the archaeological layer corresponds to the transition from the end of the MIS 5 (5a) i. e. 74—64 ka BP.
 In the industry of Ruban’ site are prevailing the non-Levallois reduction methods of exploataion of Kombewa, centripetal, crossed and sub-crossed cores with a flat working surface. The parrallel reduction system is not typical and random. Blades are practically absent.
 In the collection of tool-kit dominated side scrapers, among which there is a series of natural backed side scrapers with a thick working edge, created by 2—3 rows of a stepped scaled retouch (Quina retouch type). Such samples can be attributed to a specific type of side scrapers, such as Quina or Semi-Quina (Fig. 7).
 In general, the main technological and typological features of the Ruban’ site industry are closely related to the cultural layer II of the Korolevo I site. These collections can be attributed to the local variant of the so-called Charantienne Techno-Complex.

Influence of Long Term Application of Green Manure on the Productivity of Coconut Cultivated in Reddish Brown Latosolic Soils in Sri Lanka

Organic matter contributes in maintaining soil fertility in agriculture. Green leaf biomasses of Gliricidia sepium and Tithonia diversifolia are high in plant nutrients and recognized as potential green manure sources for many crops. In a field experiment carried out in a coconut plantation with Reddish Brown Latosolic soil, two green manure crops were grown to study their abilities and establishment in coconut avenues and to evaluate their effect on nut yield. In situ green manuring, especially with legumes, had the most beneficial effect on soil improvement. The use of green biomass alone has improved soil properties. The biomasses of Gliricidia and Tithonia decomposed rapidly after application to the soil, and incorporated biomass would be an effective source of N, P and K for crops. Results showed that, coconut yields were significantly increased with the incorporation of green biomass of Gliricidia and Tithonia than with commercial inorganic fertilizer application. Mean nut yield for five years in the green manure applied plots was (37-46%) significantly (P < 0.05) higher, compared to that of the inorganic fertilizer applied plots towards the latter part of the experiment. Addition of green manure has significantly (P < 0.05) improved the soil parameters i.e. soil N (by 75%), organic C content (by 86%) and soil microbial activity (by 52%). Soil bulk density has been reduced by 20% which enhances the root growth. The improvement of soil moisture content by 92% is of great importance for coconut in withstanding the frequent dry spells which are on increasing trend with the present climatic change situations. There was no significant effect of green manures on soil pH and P but P content was improved with the use of green biomasses of Gliricidia and Tithonia.

English

Acid, infertile reddish-brown soils characterize large amounts of central Mozambique. Few of these soils are in food production representing a missed opportunity for agricultural productivity and a missed alternative to improve the food security of the country. Low levels of soil nutrients such as calcium, phosphorus, and potassium limit crop growth. Local agricultural amendments for acid, infertile soils such as limestone and rock phosphate exist but are unexploited. An experiment was conducted to assess the feasibility of using local Evate rock phosphate (40.7% total P2O5) as a corrective to supply phosphorus. The rock phosphate was applied at rates of 20, 40, 80 and 160 kg total P ha-1. Comparison triple super phosphate was also added at four P levels (0, 10, 20 and 40 kg P ha-1). A long growth cycle crop of pigeon pea (Cajanus cajan L., Mill sp. variety “ICAEP00020”) with a growth cycle of 190 days was used to assess effectiveness of the local rock phosphate. A pigeon pea grain yield of 1000 kg grain ha-1 was possible with an application of 80 kg ha-1 of total P added as Evate rock phosphate. By comparison 20 kg P ha-1 as TSP was needed to reach a maximum yield of pigeon pea grain. This ratio suggests that Evate rock phosphate was 25% as effective as TSP on a total P basis. This research suggests that the Evate rock phosphate can be an effective amendment that can enable or enhance food grain production on the acid, infertile upland soils of Central Mozambique. Whether for direct application for acid-tolerant crops or acid soils or processed into soluble fertilizer phosphate, the existence of such a valuable resource provides a great opportunity for improved local food crop production. Key words: Rock phosphate, pigeon pea, acid soils, food grains, food security.

Basic Physicogeographical Characteristics of the Rava Island in the Zadar Archipelago

The island of Rava (3,62 km2 and 120 inhabitants, 1991) is one of those small islandssituated in the Zadar archipelago, on the eastern coast of the Adriatic. From the geographical point of view it has not been much elaborated so far. The paper gives physicogeographic characteristics, which is connected with the project on small Croatia’s islands. The first part of the paper treats the position of the island, its size and extent. According to its area, this is the 53rd island in Croatia,and the 37th with regard to the number of inhabitants (1991). The highest point is Babićovac (98m). The sea cliff of Ravica appertains to it. The island makes part of the middle range of Zadar islands and, administratively, belongs to the city of Zadar. It is an autonomous cadastral commune and Roman Catholic parish. The settlement consists of two separated nuclei along SW coast: Vela Rava in the central part of the island and Mala Rava in its NW part. Its geological structure is relatively simple. There is a predominance of nonlayered greyish lower-upper cretaceous dolomites, to 600m thickness. These are the oldest sediments in the Zadar archipelago. Their form is anticlinal. There are two smaller unexamined speleological objects in the NW part of the island. The island is well carved. The coast is 15.45 km in length. The coastline index is 2,29. There are many more coves and promontories in the central and SE parts. Larger coves are Lokvina, Vićabok, Paladinjica, Marnjica, Tanko, Vališina, Ivanoševica, Pavajsko, Pestehovac, Dražice, Golubovac, Martinjica, Grbavač and Grbačina. Relief features show dry dolinas and torrents with well expressed slope drainage and weathering. Along the coastthere is a shallow zone (1,5 m deep, called singular) large several metres, followed by deeper waters. There is a small number of flat superficies, which are used as gardens, while slopes serve for olives and less often as vineyards. The island surfaces are divided into properties by horizontal stone walls (mocira) and vertical ones (trmezal). The authors emphasize a numerous and interesting toponimy connected with the terrain geomorphology. From pedological point of view there are not remarkable soil zones. It is a question of shallow and poor reddish-brown soils originated from degraded dolomites. There is plenty of rocky soil and broken stones. There is no superficial running water on the island. There are several wells with brackish water, and potable water is found in a 40 metres deep pit on the nearby islet of Mrtovnjak. There is also a Pool in Vela Rava. Because of water deficiency, the inhabitants have built public cisterns in both settlements and the owners of new houses have their own cisterns. The authors study in particular the sea water surrounding the island. Physical properties of the sea (depth, sea bottom, temperatures, density, transparency, colour, currents, tides, waves) are elaborated in accordance with accessible data. Chemical characteristics follow (salinity, oxygenconcentration, pH factor, the quantity of silicate, phosphate and nitrate, ammoniac) and biological data (organic world: plankton, nekton, benthos). Climatic indicators connected with insolation, global radiation and cloudness are elaborated. Temperature data follow (annual t. ca 15oC; ca 23,5oC in July and ca 6,8oC in January), precipitation (ca 880 mm per annum), winds. Mediterranean climate conditions adequate vegetation. The island of Rava belongs to the climazonal association of holm oak (Quercus ilex). Mediterranean sorts are numerous. The present day high and low maquis and garigues predomine and, here and there, even larger specimens of trees grow. It is significant that cupresses can be seen on certain locations. The paper ends with elaborating the significance of physicogeographical basis for the social and economic development of the island. Consideration is given to the population since the oldest times of Mediterranean polyculture. Cultivation of olives, figs and grape vine (the latter till not long time ago) has considerable importance as well as breeding small cattle. Restrictive factors of development (lack of water and fertile soils, isolation, depopulation) are analysed too. The influence of regional centre Zadar is also important, as well as the prospects of tourist and aquaculture objects.

Chapter 13 Jadeitite and other high-pressure metamorphic rocks from the Jade Mines Belt, Tawmaw area, Kachin State, northern Myanmar

The world's largest jade deposit, containing the highest-quality jade, is exposed in the Pharkant-Tawmaw (also spelled Hparkant or Hpakan and Tawhmaw) Jade Mines Belt, northern Myanmar. This belt is located between latitudes 25° and 26° N and longitudes 96° 12′ and 96° 25′ E in the Myitkyina district (Fig. 13.1). The belt extends in a north–south direction, covering an area of c. 1200 km2 (Chhibber 1934 b ). Major jade production sites are located in the Pharkant, Lonkin, Tawmaw, Haungpa and Hwekha areas. In these areas the rock type jadeitite, containing more than 90 vol% of the mineral jadeite, is associated with serpentinites, albitites, low- to medium-grade metamorphic rocks, chlorite schists, garnet–mica schists, graphite schists, glaucophane schists and amphibolites. Fig. 13.1. Geological map of the Jade Mines Belt (JMB) showing the localities mentioned in the text and the location of the samples described. Compiled by Thet Tin Nyunt, modified from Chhibber (1934 a ), Bender (1983), Than Tun (1997) and Thet Tin Nyunt (2009). The Jade Mines area of northern Myanmar is a highly dissected upland, higher in the north than in the south, with ranges of hills forming the Chindwin–Irrawaddy watershed. The main jade area around Tawmaw is situated on a plateau 840 m above sea level. Mountain ranges in the western part of the area rise to 600 m and are covered by dense vegetation. The eastern margin is bounded by the Uru River. The Tawmaw area is characterized by very high rainfall and, due to the tropical climate, the rocks are highly weathered and covered by a reddish-brown soil of thickness a few metres to tens of metres. Fresh samples of jadeite can be collected only from mine sites or from stream courses. In the Tawmaw area jadeitite is quarried from both primary deposits and as …

Distribution of exogenous phytase activity in soil solid–liquid phases and their effect on soil organic P hydrolysis

AbstractThe bioavailability and stability of organic phosphorus (P) in the soil may be affected by exogenous phytase (EPase) activity and distribution, but remain poorly understood. The distribution of EPase activity and hydrolysis ability of EPase on organic P in soil solid‐liquid phases was investigated. The EPase addition to soil suspension (1:20, w/v) from three soil types (red soil, brown soil, and cinnamon soil) under three treatments (untreated soil, removing clay from soil, and removing organic matter from soil) with different characters in the solution and solid phases was assayed. The results showed that the disappearance pattern of EPase activity from solution was similar for all soils, whereas the enzyme activity on the solid phase was dependent on soil types and treatments with the greatest in red soil and untreated soil. When EPase was added to soils, the adsorption ratio of organic matter and clay was 10 to 25% and 3 to 7%, respectively, with sorption capacity of organic matter being significantly (p < 0.05) stronger than that of clay. Additionally, soil dehydrogenase activity, which is the indicator of overall soil microbial activities, increased after EPase addition and the two enzymes showed significant negative relation in the soil suspension and solution. At the same time, the organic P decreased significantly (p < 0.05) after the addition of EPase in the soil solid, which had a varied rate under –40% after incubating 192 h, whereas organic P in the solution phase increased significantly (p < 0.05). This study demonstrated that organic matter had a strong protective and adsorptive effect on EPase effectiveness and microbes mightbe directly affect EPase longevity and decay. This finding suggests that EPase activity in the solid phase played a more important role in organic P hydrolysis.

Factors Controlling Magnetism of Reddish Brown Soil Profiles from Calcarenites in Southern Spain: Dust Input or In-situ Pedogenesis?

Under aerobic conditions, the A and B horizons of soils are magnetically enhanced due to neoformation of ferrimagnets through pedogenesis. This study systematically investigated soils developed on calcarenites of Neogene age in southern Spain to determine the dominant factors controlling the soil magnetism. Geochemical and clay mineral analyses indicate that aeolian dust significantly contribute to the A and B horizon material of the Spanish soil. Nevertheless, the magnetic enhancement of soils can be simply attributed to the pedogenically produced ferrimagnets in-situ. Therefore, the magnetism of Spanish soils is still linked to paleoclimatic variations regardless of the complexities of aeolian inputs from the Northwestern Africa.