Bulgarian Journal of Soil Science

81-89

Authors: Kameliya Petrova

Dystric/eutric Cambisols diagnostic features from TEFR Petrohan were investigated in the present study, which morphologically corresponded to Podzols. Diagnostic horizons were investigated to establish presence or absence of podsolization process and to classify the soil type according to the modern requirements of WRB, (2006, 2007; 2014). Humus forming process insitu, clearly expressed in the Ah horizon, acidification, degradation of clay minerals, formation of E horizon, which is clay-poor with increased content of sand, accumulation of Fe and other mobile elements in Bw horizon were established. The metamorphic Bw horizon had some diagnostic properties, which met these of spodic horizon. This horizon is specific for the Podzols. The content of organic carbon in it was less than 0.5 %. Cambisols properties are predominant.It was established that the soil-forming process in the investigated Cambisols is directed to podsolization process.

104-118

Authors: Marija Galic, Milan Mesic, Aleksandra Percin, Ivana Sestak, Zeljka Zgorelec

This field study shows how different crops and soil treatments with different nitrogen fertilization levels affect sulphur balance. Sulphur deposition, leaching through soil and water seepage, availability and uptake by crops, effects on crop yield and losses were investigated. The research was conducted on a field trial from 1996 to 2014 in temperate continental climate on Stagnosols. The soil was treated 10 times with mineral nitrogen fertilizers in an ascending doses from 0 to 300 kg N ha-1 and additional two 250 kg N ha-1 treatments, one with phosphogypsum and one with zeolite tuff and CaCO3. Drainpipes and lysimeters were installed to collect water samples and measure the effects of N doses, amendments and precipitation on sulphur losses. Average annual sulphur losses were from 4.9 to 68.7 kg ha-1 through drainage water, and from 1.5 to 24.9 kg ha-1 through lysimeter water. Depending on a crop, year and yield, average crop losses ranged from minimal 2.8 kg ha-1 in winter wheat up to 17.6 kg ha-1 in oilseed rape. Average total S content in soil varied from 882 to 1764 kg ha-1. Overall agroecosystem S balance between input and output, calculated for all crops and all treatments was positive only in the treatment with phosphogypsum for winter wheat, corn and oilseed rape. Water shortage in 2011 caused positive S balance for soybean in other treatments too, not only in the treatment where phosphogypsum was applied.

134-142

Authors: Zorintsa Mitreva, Veselin Pankov

Areas facing natural constraints represent a serious obstacle for Bulgarian farmers and to a great extent limit their development. In this regard, it is necessary to look for alternative options for optimal use of these areas so that they are as efficient as possible despite the limitations they have. The paper presents the basic requirements of lavender in terms of climatic and soil conditions. There is also a soil and climate characterization of a village located in area of high altitude - the land of the village of Borika, Sofia in order to be able to indicate which soil types in the Borika land are best suited for lavender growing.

4 - 12

Authors: Tsetska Simeonova, Maya Benkova, Lyuba Nenova, Irena Atanassova

The cationic and anionic composition, i.e. K +, Na+ , Ca2+, Mg2+, Cl- , NO3 -, phosphates,SO4 2- and dissolved organic carbon (DOC) in soil solutions of Technogenic soils (Technosols)from the area of Maritsa-Iztok coal mine basin in Bulgaria was analyzed and links with overburden strata were discussed. Two sites are located at the Mednikarovo village with humus and non- humus reclamation under grass vegetation. The other two are situated near the village of Obruchishte (non-vegetated and pine-vegetated). The sites differ in their textural composition, physico-chemical and hydro-physical properties. It was found that major cations and anions in the soil solutions at Mednikarovo site did not exceed the maximum permissible concentration limits (MPCL) for drinking water, while in solutions from the Obruchishte Technosols, composed of black clays intermixed with coal ash maximum permissible concentrations of sulphate (250 mg.l -1), phosphate (0.5 mg.l-1 ), calcium (150 mg.l-1 ) and magnesium (80 mg.l-1 ) were exceeded and may pose a threat to contamination of surface and sub-surface water of reclaimed soils.

27 - 33

Authors: Alexander N. Sadovski

The paper traces the emergence and development of the problem of scheduling irrigation as a scientific and practical issue at the Institute of Soil Science "N. Poushkarov" for half a century. The main participants in this process and the leading scientific publications are noted.

48 - 62

Authors: C.M. Ahukaemere, N.S. Obasi

Land capability classification (LCC), fertility capability classification (FCC) and land suitability evaluation of some soils of Ebonyi State were carried out for cassava, yam and maize cultivation. Land capability and fertility capability classes were obtained using the method of United State Development of Agriculture (USDA) while suitability evaluation was done using the Food and Agricultural Organization of the United Nations’ (FAO) conventional method. Four (4) pedons were investigated, two from Akaeze (Asu river group)and two from Abakaliki (Asata nkporo shale) . Results of LCC showed that sites 1 and 2 (Asu river group) were classified as class II soils while sites 3 and 4 (Asata nkporo shale) were classified as class IV soils. According to FCC results, the major classes obtained were SM,g,k for site 1, A,g,k for site 2 and SA,e,k,r for sites 3 and 4 respectively. The results of land suitability evaluation showed that despite climatic factors and topography, there was no highly suitable (S1) land for maize, yam and cassava cultivation. Total nitrogen and organic carbon contents of pedons 1, 2 and 4 were marginally (S3) suitable for the production of yam and cassava while the nitrogen and organic carbon contents of pedon 3 were currently not suitable (N1) for yam and cassava cultivation. Soil texture, pH, ECEC and available phosphorus made the 4 sites moderately suitable (S2) for cassava and yam cultivation. Also, the acidic condition of the soils made all the sites moderately suitable for maize production. From the results of the aggregate suitability ratings, the major constraint for yam, cassava and maize cultivation in the sites was soil fertility (f) resulting from low organic carbon and total nitrogen contents of the soils. Though not optimum for the cultivation of the crops evaluated, the soils can still produce increased and sustainable crop yield if the appropriate husbandry practices are adopted, with particular reference to organic and nitrogen fertilizer application.