Geochemistry of cryoconite and soils in the Central Caucasus region and its environmental implications

Climate change and deglaciation are active processes in current changing environments.In the Central Caucasus region rapid degradation of glaciers is caused often by the formation of superficial blackcolored sediments-cryoconite.Cryoconite plays a crucial role in changing ecosystems and may contribute to the formation of primary soils after glacier retreat.Over the past 20 years,the frequency of mudflows and other dangerous mountain events have increased in the Central Caucasus,which is associated with the glacial retreats.Intensification of tourism results in increasing of traffic,recreational activity and environment contamination.Determination of the cryoconites geochemical properties in comparison with other types of sediments and local soils is crucial for investigation of geochemistry and contamination state of superficial glacial sediments.This environmental aspect is important in terms of the Central Caucasus settlements safety under conditions of deglaciation and anthropogenic influence.The sediments studied(cryoconite,mudflow,moraine)were sampled at Garabashi and Skhelda glaciers as well as some local soils at the Baksan gorge.Sampled materials were investigated in terms of physicochemical and agrochemical parameters.The concentrations of trace elements(Cu,Pb,Zn,Ni,Cd)were also determined and contamination indices(geoaccumulation index-Igeo,contamination factor-CF and degree of contamination-Cdegree)were used to evaluate the pollution status of studied material.Data obtained shows much higher content of organic carbon in soils(up to 7.82%)in comparison with cryoconite(max.1.63%)due to presence of vegetation,however,the basal respiration values in some cases were similar betweenсryoconite and soils,indicating high rates of microbial activity in a cryoconite holes.It was found that almost all materials studied have sandy structure.Cryoconite sediments on both of the glaciers are enriched with phosphorus,high values of K_(2)O(max.298 mg·kg^(-1))and N-NH4(max.247 mg·kg^(-1))are identified at Garabashi glacier which could be influenced by long-distant transfer but mostly a result of local anthropogenic activity.In case of trace elements,the highest content is identified for Zn(62 mg·kg^(-1) for cryoconite and 60.5 mg·kg^(-1) for soils)and the most contaminated materials are cryoconite from Garabashi glacier and Entisols,up to moderate level,which is mostly associated with local anthropogenic activity.

Genesis and Classification of Some Soils of the River Nile Terraces: A Case Study of Khartoum North, Sudan

Soils developed in the alluvium terraces of the River Nile at Khartoum North, Sudan was analyzed in an attempt to classify it as well as to refer them to their origin. Three river terraces comprising nine profiles were selected to cover the physiographic positions. Lack of B horizon and carbonate accumulation were main pedogenic processes in subsurface horizons, whereas orhric epipedon was developed on top soil surface. The microscopic inspection of heavy sand mineralogy indicated that the origin of the sand was the Ethiopian plateau. The most abundant clay mineral was smectite, followed by illite, kaolinite and chlorite. The presences of micas (illite) and chlorite in all studied soil samples might emphasize that these soils were young from the pedological viewpoint and less weathered. The soils of the River Nile terraces at Khartoum North were classified into: Typic Torrifluvents (1st terrace), Entic Haplocambids (2nd terrace) and Typic Haplocambids (3rd terrace). Mineralogy analysis indicated that the Entisols and Aridisols of the River Nile terraces in the study area had the same origin that of the igneous and metamorphic rocks from Ethiopian plateau.

Effect of Organic Manure and Chemical Amendments on Soil Properties and Crop Yield on a Salt Affected Entisol

A field experiment was conducted for two consecutive years in a farmer's field at Haji Mora Village, Dera Ismail Khan (D.I. Khan) in the Northwest Frontier Province (NWPP) of Pakistan to compare various management practices, such as the effect of various organic manures and gypsum in a rice-wheat cropping system on a saline-sodic Entisol (Zindani soil series). The treatments consisted of 1) a control (rice-wheat), 2) gypsum, 3) farmyard manure (FYM), 4) berseem (Trifolium alexzndrinum L.) as green manure (GM), and 5) dhancha (Sesbania sp.) as GM. All treatments increased yields of both rice and wheat significantly (P < 0.01) over the control, with the green manure treatments proving more economical than the others; while they decreased pH, electrical conductivity (EC), and sodium adsorption ratio (SAR) of the soil. Saturation percentage and available water of the soil were raised for all treatments due to an increase in organic matter content of the soil.

Effect of Foliar Copper Fertilizer on Pineapple cv. N36 Planted on BRIS Soil at East Coast of Peninsular Malaysia

The physical and chemical properties of BRIS soil are unsuitable for agricultural purposes. A proper fertilizer and crop management practices are required. An attempt was made to convert this land into a sustainable production land for pineapple. Therefore, the objective of the study was to determine the effect of foliar copper fertilizer on the growth and fruit quality of pineapple cv. N36, for fresh consumption planted in Entisol type BRIS soil at the east coast of Peninsular Malaysia. The complete randomized design （CRD） method with three replications was used at 0 to 6.6 kg.ha^-1 of copper sulfate. Results demonstrated that the unpleasant effect of BRIS soil on brix value was restored with copper fertilizer. The most suitable quantity of foliar copper fertilizer for pineapple cv. N36 planted in Entisol type BRIS are between 1.6 to 3.3 kg.ha^-1 of copper sulfate.