E horizons formed in soils by reduction and eluviation are considered to be an indicator of subsurface lateral flow (SLF) between the A and B horizons -a hydrological process important in generating streamflow. There is, however, uncertainty in the interpretation of the hydropedological behaviour of some E horizons. This study used a physical index (SLFI) to estimate the importance of SLF in profiles with E horizons, where SLFI is . Data were obtained from the South African Land Type database. For criteria development, 156 profiles were used and an additional 80 profiles were used to validate the criteria. SLFI values were determined for the 156 profiles and then divided into 3 groups, with high, medium and low values. The basic hypothesis was that the individual quantifiable and qualitative soil and landscape properties influencing the pedogenesis of E horizons, and their integrated pedogenetic expression in soil forms, would be most and least strongly expressed in the profiles of the 'high' and 'low' SLFI groups, respectively. This concept was employed in a unique way to allocate numerical values expressing the estimated importance of the criteria with regard to SLF. In order to validate the pedological criteria the 80 test profiles were subjected to a similar procedure to that used to develop the criteria, resulting in an integrated pedological criterion value for each profile, which was then correlated against its SLFI value. Selected measured properties, i.e. organic matter, Fe, Mn and clay content, of the test profiles were also correlated against their SLFI values in the validation process. The results provide supporting evidence for the validity of the pedological criteria.

Droughts, resulting in low crop yields, are common in the semi-arid areas of Ethiopia and adversely influence the wellbeing of many people. The introduction of any strategy that could increase yields would therefore be advantageous. The objective of this study was to attempt to assess the influence of in-field rainwater harvesting (IRWH), compared to conventional tillage, on increasing the amount of water available to a crop like maize on a semi-arid ecotope at Melkassa situated in the eastern part of the Rift Valley.To achieve the objective of the study rainfall-runoff measurements were made during 2003 and 2004 on 2 m x 2 m plots provided with a runoff measuring system and replicated 3 times for each treatment. There were 2 treatments: conventional tillage (CT) on which hand cultivation was practised in a way that simulated the normal local CT; and a flat surface simulating the no-till, undisturbed surface of the IRWH technique (NT).Rainfall-runoff measurements were made over 2 rainy seasons during which there were 25 storms with > 9 mm of rain. From the 25 storms, only the 2 nd season storms (8 storms) had runoff measurements. These storms were used for calibration and validation of the Morin and Cluff (1980) runoff model (MC Model). Appropriate values for final infiltration rate (I f ), surface storage (s) and for the crusting parameter (γ) were found to be: 6 mm•h -1 ; 1.0 mm for NT and 6.0 mm for CT; 0.6 mm -1 , respectively.The measured runoff (R) for the 2004 rainy season expressed as a fraction of the rainfall during the measuring period (P), i.e. R/P, gave values of 0.59 and 0.40 for the NT and CT treatments, respectively. There was a statistical difference between the runoff on the 2 treatments.Selected results from 7 years of field experiments with IRWH at Glen in South Africa were used together with measured maize yields and climate data over 16 seasons on the nearby Melkassa Experiment Station to estimate the yield benefits of IRWH compared to CT on the ecotope studied. The results ranged between 35 and 1 437 kg with a mean of 711 kg•ha -1 over the 16 years. At Melkassa this was an estimated yield increase ranging from 13% to 49%. The mean increase was 33%.

Sucrose, glucose and fructose were the major tree sugars in the leaves, stems and inflorescences of T. triandra, while small quantities of rhamnose, xylose, galactose, man nose, ribose, cellobiose, sedoheptulose and erythrose were also present. Several polysaccharides and components with lower molecular weights, possibly dextrins and oligosaccharides, were extracted by water at room temperature (20°C) and boiling point (96°C). These carbohydrates were biosynthesized from a number of different monosaccharides. No fructans were found, confirming T. triandra's classification among the panicoid grasses which mainly store reserve carbohydrates in the form of sucrose and starch. S. Afr. J. Plant Soil 1986, 3: 71 -75 Sukrose, glukose en fruktose was die hoof vrye suikers in die blare, stingels en bloeiwyse van T. triandra, terwyl klein hoeveelhede ramnose, xilose, galaktose, man nose, ribose, sellobiose, sedoheptulose en eritrose ook teenwoordig was. Verskeie polisakkariede en komponente met laer molekulere massas, moontlik dekstriene en oligosakkariede, is deur water by kamertemperatuur (20°C) en kookpunt (96°C) geekstraheer. Hierdie koolhidrate is vanaf 'n aantal verskillende monosakkariede gesintetiseer. Geen fruktane is gevind nie en dit bevestig die klassifikasie van T. triandra onder die paniko"iede grassoorte wat reserwe koolhidrate hoofsaaklik in die vorm van sukrose en stysel berg. S.-Afr. Tydskr. Plant Grand. 1986,3: 71 -75

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