Mineralogical and micromorphological characterisation of two soil sequences of the UNZA-FARM(Zambia)
| dc.contributor.author | Shitumbanuma, Victor | |
| dc.date.accessioned | 2011-03-31T16:25:04Z | |
| dc.date.available | 2011-03-31T16:25:04Z | |
| dc.date.issued | 2011-03-31 | |
| dc.description.abstract | The land has been the ultimate source of nourishment and origin of man and other living organisms. Man has depended and still depends on plants and animals for his survival. These in turn depend on the earth and other organisms. The cultivation of crops has been known to man for a long time, and the use of different techniques to manipulate the soil and plants has resulted in increased crop production. With the increased human population, the demand on the land has increased, and man has to find better and more effective means of utilizing this now scarce resource of soil. Various disciplines of science have studied the soil from different angles, with the ultimate aim of bettering their understanding of it. As the soil is quite a heterogeneous material, its study calls for a combined approach of study. Of the various branches of soil science, a new branch, employing the aid of microscopic and ultramicroscopic techniques has emerged. Micropedology, which aims to search for the processes responsible for the formation of soils as well as specific features both of natural and artificial origin has become an important tool in investigating into the genesis, classification and management of soil. In this study, which was originally meant to cover two soil sequences, a soil sequence has been studied, from a mineralogical and micromorphological view, with the aim of knowing something about its genesis and management properties. Routine physical-chemical analyses, micromorphological and mineralogical analyses were carried out on the soil samples from profiles on the sequence. It was found that there is a colour differentiation along the sequence, due to change in drainage condition. The profiles have been found to have a pellicular to bridged grain surface horizon, overlying illuvial horizons. This kind of microstructure is seen to increase with depth downslope, and this has been attributed partly to the translocation of soil material downslope. Illuviation of clay with free iron and fine organic material has been found to be evident in all the profiles in this sequence. The upper two well drained horizons, have a granular aggregate microstructure in subsurface horizons which gives them a good permeability to water and air. The low land soil, was found to be partly drained and with a higher content of in situ formed nodules. It was found that there was a coincidence between the presence of brown spots in the profile, with the presence of oriented reddish brown clay coatings. The soils have been found to be depleted of most weatherable minerals and to be dominated by resistant, generally nutrient poor mineral grains. Kaolinite is the most dominant clay mineral, with mica, being the other constituent. The silt fraction, shows high amounts of quartz and mica. From the study of heavy minerals and soil thin sections, the parent material show evidence of metamorphic origin, and lateritic origin. The soils have been found to have low CEC and a relatively high amount of iron oxides The presence of the iron oxides, and kaolinite, with micas, has been used to explain the observed low CEC. As regards management properties, it has been found that the low CEC of these soils may be a limitation to good crop yield. The low pH of the upland soils may require application of lime to expect good response from fertilizer application. The low land soils have been found to have a limitation of aeration | en_US |
| dc.identifier.uri | http://dspace.unza.zm/handle/123456789/263 | |
| dc.language.iso | en | en_US |
| dc.subject | Soil | en_US |
| dc.title | Mineralogical and micromorphological characterisation of two soil sequences of the UNZA-FARM(Zambia) | en_US |
| dc.type | Thesis | en_US |