To study the quality response of beetroot to nitrogen fertilizers, a pot trial was conducted in the glasshouse facility of the Department of Soil, Crop and Climate Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, during the 2011 season. The effect of five nitrogen sources (limestone ammonium nitrate, ammonium nitrate, urea, ammonium sulphate and urea ammonium nitrate) at five nitrogen levels (0, 50, 100, 150 and 200 kg N ha-1) on beetroot (Detroit Dark Red) on a Bainsvlei soil type was investigated. The data collected was analyzed using Tukeyâs Least Significant Difference test, at 5% level of significance to determine statistically significant differences between means. The results showed that all fertilizers used resulted in a reduction in plant height for the first six weeks of growth. Nitrogen application only increased plant height significantly from week 8 where the height of plants that received nitrogen, irrespective of the fertilizer used, were significantly taller than control plants. At week 8 no significant differences in height were noted between various nitrogen application rates, but by week 10 significant differences in plant height were noted between the 50 kg N ha-1 and 150 kg N ha-1 or 200 kg N ha-1 application rates. The findings showed that beet plants reacted better to N-fertilization using ammonium sulphate nitrate and urea ammonium nitrate than other nitrogen sources, although limestone ammonium nitrate and ammonium nitrate also produced improvements in plant growth, whereas plants that received urea showed no improvements. Nitrogen at 100 kg ha-1 resulted in more leaves per plant than its application at other levels. Urea ammonium nitrate as a nitrogen source significantly improved plant leaf area, leaf fresh mass, total fresh mass and root diameter. Application of nitrogen at 200 kg ha-1 also increased leaf area, leaf fresh mass, total fresh mass, beet diameter and beet volume. Urea ammonium nitrate increased leaf dry mass by an average of 397% while the lowest leaf dry mass by (139.42% of control) was observed with the use of limestone ammonium nitrate as a nitrogen source. The greatest leaf dry mass was obtained at the highest rate of nitrogen application (200 kg ha-1) and the lowest leaf dry mass was observed at the control level. Beet yields were found to increase as the nitrogen application rate increased, from 2.99 t ha- 1 in the control treatments to 14.37 t ha-1 in the treatments that received 200 kg N ha-1. Fertilizing with urea ammonium nitrate gave the highest yields (12.17 t ha-1), while using limestone ammonium nitrate gave the lowest yields (9.00 t ha-1). Application of nitrogen at 50 kg ha-1 resulted in firmer beets than nitrogen application at other levels. Beets from plants that did not receive any nitrogen were significantly softer than those that received nitrogen at higher levels. The darkening of beet colour (decrease of L*) was experienced at the control level while the highest changes of colour (increase of L*) was obtained at the highest nitrogen level. Nitrogen at 100 kg ha-1 influenced the lowest change of coefficient a from red to green while the control level resulted in more intensive change. The results showed that nitrogen at the control level led to more intensive changes of coefficient b colours from yellow to blue and its application at the highest level resulted in less intensive changes of coefficient b colours from yellow to blue. Neither nitrogen source nor nitrogen level had any effect on the pH, sucrose or fructose contents of the roots. Application of nitrogen at 150 kg ha-1 resulted in greater total soluble solids content in the roots, while the starch content of plants that received no nitrogen was significantly greater than that of plants receiving nitrogen. Nitrogen application at 100 kg ha-1 and at the control level influenced the glucose content, which was significantly higher in these plants than in those that received 50, 150 and 200 kg N ha-1, however, the highest glucose content of the roots was observed at the control level. Nitrogen application at 200 kg ha-1 resulted in higher nitrogen content in the leaves as compared to application of other nitrogen sources at different levels. Limestone ammonium nitrate influenced potassium content of the leaves more than other nitrogen sources. Nitrogen application at 200 kg ha-1 resulted in a greater calcium content in the leaves than other nitrogen sources. The highest sodium content of the leaves was observed at 150 kg N ha-1 while the lowest sodium content was observed at 50 kg N ha-1. Urea ammonium nitrate had a greater positive influence on the manganese content of the leaves than other nitrogen sources. Plants that received no nitrogen had significantly greater levels of iron in the leaves than at all nitrogen levels. Ammonium nitrate as a nitrogen source influenced the calcium content of the beets more than other nitrogen sources. Other root minerals such as phosphorus, potassium, sodium, magnesium, manganese, copper, iron and zinc were not significantly influenced by nitrogen source or nitrogen level, or the interaction between these factors.

Wetland hydrology controls the function of the wetland ecosystem and hence it is the principal parameter for delineation and management of wetlands. It is defined as the water table depth, duration, and frequency required for an area to develop anaerobic conditions in the upper part of the soil profile leading to the formation of iron and manganese based soil features called redoximorphic features. The redoximorphic features must occur at specific depths in the soil profile with specific thickness and abundance to qualify for a hydric soil indicators. Therefore, hydric soil indicators are used to evaluate the wetland hydrology if such a relationship has been verified. The aims of the study were i) to determine soil variation and hydric soils indicators along a toposequence, ii) to determine the relationships between soil water saturation, redox potential and hydric soil morphological properties and iii) to determine the distribution of soil properties and accumulation of soil organic carbon in hydric and non-hydric soils. The study was conducted at the upper head-water catchment of the Bokong wetlands in the Maloti/Drakensberg Mountains, Lesotho. The soil temperature ranged between -10 and 23°C. The soils had a melanic A overlying an unspecified material with or without signs of wetness, or a G horizon. The organic O occurred in small area. Soil profiles were dug along a toposequence and described to the depth of 1000 mm or shallower if bedrock was encountered. Redoximorphic features were described using standard soil survey abundance categories. Soil samples were collected from each horizon and analysed for selected physical and chemical soil properties. The soils had low bulk density ranging from 0.26 in the topsoil to 1.1 Mg m-3 in the subsoil. Significantly low bulk density was observed in the valleys and highest bulk densities were observed on the summits. The soil organic carbon content ranged between 0.18% in the subsoil and 14.9% in the topsoil. The soil also had a high dithionite extractable Fe (mean 93±53 g kg-1) and low CEC (mean 26±9 cmolc kg-1). Soil pH and CEC were relatively lower in the valleys and higher on the summits. Principal component analysis indicated four principal components accounted for 60% of the total variance. The first principal component that contributed 23% of the variation showed high coefficients for soil properties related to organic matter turnover, the second components were related to inherent fertility, the third and fourth were related to acidity and textural variation. Hydric indicators identified in Bokong were histisols (A1), histic epipedon (A2), thick dark surfaces (A12), redox dark surfaces (F6), depleted dark surfaces (F7), redox depressions (F8), loamy gleyed matrix (F2) and umbric surfaces (F13). The thick dark surfaces with many prominent depletions and gley matrix (A12 and F7) occurred in the valleys, while the midslopes and footslopes were dominated by umbric surfaces (A13). The indicators F6, F7 and F8 were not common. Indicators that were related to the peat formation (A1, A2 and F13) were frequently observed. The relationship between soil water saturation and redoximorphic features was verified by monitoring the groundwater table with piezometers, installed in ten representative wetlands at depths of 50, 250, 500, 750, and 1000 mm for two years from September 2009 to August 2011. Redoximorphic feature abundance categories were converted into indices. Strong correlations were observed between redoximorphic indices and cumulative saturation percentage. The depth to chroma 3 and 4 (d_34) and depth to the gley matrix (d_gley) correlations were R2 = 0.77 and R2 = 74 respectively. All redoximorphic indices were poorly correlated with average seasonal high water table. Strong correlation were also observed between profile darkening index (PDI) and cumulative saturation (R² = 0.88) and weak correlations were observed between PDI and average seasonal high water table (R² = 0.63). A paired t test indicated that soil pH, exchangeable Mg and Na, dithionite extractable Fe and Al were significantly different between hydric and non-hydric soils. Hydric soils had significantly higher Mg, Na and Fe content, and significantly low soil pH and Al content. Generally it appeared that soluble phosphorus, Fe and exchangeable bases accumulated in hydric soils, while the soil pH and Al content decreased. The mean soil organic carbon contents were 3.61% in hydric soils and 3.38% in non-hydric soils. However, non-hydric soil relatively stored more organic carbon (174.4 Mg C ha-1) than hydric soils (155.1 Mg C ha-1). The mean soil organic carbon density of the study area was 166±78.3 Mg C ha-1) and the estimated carbon stored was 21619 Mg C (0.022 Tg C; 1Tg = 1012g) within the 1000 mm soil depth. About 384.9 Mg C was stored in the hydric soils within the study area, which was about 1.9% of the total carbon stored in the area to the bedrok or depth of 1000 mm. Among the wetland types, bogs had significantly higher organic carbon levels (6.17%) and stored significantly higher carbon (179 Mg C ha-1) with at least 44% was store in the A1 horizon. It was concluded that the strong correlation observed between PDI, d_34, d_gley and cumulative saturation representing hydric indicators such as histisols (A1), histic epipedon (A2), umbric surfaces (F13), loamy gleyed matrix (F2) can be used to determine the duration and frequency of the water table in the landscape studied. These hydric indicators can be used to delineate wetlands, however, more indicators can be developed.

South Africa mainly produces oil seed sunflowers of which 86% is produced in the Free State and North West provinces which are known for their sandy soils. Temperatures can rise to 42°C in these soils when planting commences during November to January. These conditions, in combination with other factors such as planting date and planting depth, soil type, different cultivars, and seedling vigour, can influence the emergence rate of sunflower seedlings. This will cause uneven stand which could affect the yield negatively. In an attempt to evaluate the influence of soil factors and planting techniques on sunflower emergence, three experiments were conducted in the greenhouse at the Department of Soil, Crop and Climate Sciences of the University of the Free State. These experiments evaluated the effect of seed size, planting techniques, and soil factors, and high soil temperatures on the emergence rate of selected sunflower cultivars. Three seed sizes (seed size one to three) of three cultivars (PAN 7049, PAN 7057, and PAN 7063) were planted at two planting depths (25 and 50 mm respectively) during three planting dates (September 2010, November 2010, and February 2011) to determine the influence on the emergence rate of seedlings. It was found that a smaller seed size, such as seed size three, emerged faster than larger seeds, seed size one. The influence of two planting depths (25 and 50 mm) during the previously mentioned planting dates with two soil types (Bainsvlei and Tukulu) on the emergence of sunflower seedlings was also tested. Cultivar emergence was faster at 25 than at 50 mm. It was also observed that the emergence rate was faster during February 2011 than during September and November 2010. Although the emergence was faster during February 2011, above ground growth (plant height and dry weight) was greater during November 2010 than during September 2010 and February 2011. The influence of four soil temperatures (35, 40, 45, and 50°C respectively) on the emergence of sunflower cultivars was tested. An under floor heating wire (23 kW) was attached to a galvanised metal grid and was used to simulate day and night temperatures in the top soil. The grid and seed were placed at a depth of 25 mm (planting depth). Emergence index declined gradually from 35 to 45°C, but a rapid decline in emergence index was observed from 45 to 50°C. Emergence can be measured or calculated as an emergence index. Emergence is determined as the moment that the seedling is visible above the ground and different formulas exist to determine the emergence. Experiments differ from one another and therefore different emergence index models were developed to accommodate the experiment methods or crop that was used. It can therefore be concluded that differences in emergence exist between cultivars. It is also necessary for producers to acknowledge that soil factors and planting techniques play a vital role during planting until the seedling emerge.