Determining the Optimum Inflow Rates for Micro-flood Irrigation on the Tukulu Soil     

Sabelo Sicelo Wesley Mavimbela  ;Leon Daniel van Rensburg  ;Alain Cloot 《农业科学与技术》2014,(8):633-649

The performance of micro flood irrigation （MFI） under different inflow rates was evaluated on 90 m closed ended furrows in the South African Tukulu soil. A single irrigation was used to characterise the surface and subsurface soil water distribution from the 20, 40, 80 and 160 L/min inflow rates treatments. Neutron access tubes were installed to a depth of 1 m at every 10 m distance interval starting at 5 m from the furrow inlet. Soil water content measurements were taken using the WaterMan neutron water meter. The HYDRUS-2D software was also used to provide insight on irrigated furrows soil water content and subsurface water distribution. The 20 L/min produced a stream flow that could advance up to the 60 m furrow distance. The stream flow from the rest of the inflow rates were able to reach the furrow end with the 180 L/min recording the fastest advance time of 23 min. The 20 L/min and 40 L/min had recession period of less than 7 min while the 80 L/rain and 160 L/min lasted more than an hour. Distribution uniformity （DU） at longer furrow distances was the highest from the 80 L/min and 160 L/min with the 20 L/min and 40 L/min recorded similar performances at shorter distances. The 40 L/rain was one of the smaller inflow rates that recorded the highest DU of 0.96 for the generated average infiltrated depth of the 30 m long furrow and therefore should be adopted for furrow distances of less than 60 m on the Tukulu soil.  相似文献   

Characterising Vertical Redistribution on Irrigated Furrows in the Tukulu Soil     

Sabelo Sicelo Wesley Mavimbela  Leon Daniel van Rensburg  Alain Cloot 《农业科学与技术》2013,(7):542-560

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Infiltration-excess runoff properties of dryland floodplain soil types under simulated rainfall conditions     

Sabelo Sicelo Wesley Mavimbela  Phesheya Dlamini  Leon Daniel van Rensburg 《Arid Land Research and Management》2019,33(3):235-254

The study estimated infiltration-excess runoff properties of three floodplain soil-types under aquifer water management at Anglo American Kolomela Iron Ore mine in Postmasburg, Northern Cape Province of South Africa. Rainstorm regimes of amounts 60 (high), 30 (medium), and 15 (low) mm with respective intensities of 1.61, 0.52, and 0.27?mm min^?1 were simulated on 1 m² plot with 1% slope. Infiltration-excess runoff properties were affected by a rainstorm, but not soil-type. When combined with rainstorm, soil-type affected accumulative run-off rates. High rainstorm had different (p?≤?0.05) accumulative runoff rates (0.1–0.61?mm min^?1) and increased with clay content. Different response times of 4, 10, and 17?min for respective high, medium, and low rainstorms were quickest on higher clay plus silt content and bulk-density under high and lower rainstorms, respectively. Lower rainstorms had similar effects on accumulative runoff rates (0.01–0.05?mm min^?1), total runoff yield (0.59–18?mm), and runoff coefficients (4.29–18%). Under the high rainstorm, total runoff yields (11.4–25.8?mm) and runoff coefficients (19–42.9%) were different and increased with clay plus fine-silt content. Although simulated rainstorms had constant intensities, results showed high rainstorms to be of primal influence on infiltration-excess runoff. Clay plus silt content and bulk-density influenced infiltration-runoff properties for respective high and lower rainstorms. Apart from rainstorm characteristics, surface clay plus silt content and bulk-density are important for harnessing surface runoff in floodplains for aquifer recharge.  相似文献   

The nutritive value of marula (Sclerocarya birrea) seed cake for broiler chickens: nutritional composition,performance, carcass characteristics and oxidative and mycotoxin status     

Mthiyane  Doctor Mziwenkosi Nhlanhla  Mhlanga  Bhekumusa Sabelo 《Tropical animal health and production》2017,49(4):835-842

This study was aimed at investigating the nutritive value of marula seed cake (MSC) as an alternative protein source for broilers. In a completely randomised design involving six replicate pens of five chickens assigned to each of five treatments, body weight gain (BWG), feed intake (FI), feed conversion efficiency (FCE) and carcass characteristics were measured in an experiment in which 150 28-day-old broilers were fed maize-based diets containing, respectively, 0, 5, 10, 15 and 20% MSC at finisher phase. The results showed MSC to be remarkably high in CP (470.0 g/kg DM) and EE (343.5 g/kg DM), with moderate CF (58.2 g/kg DM), ash (54.3 g/kg DM), Ca (1.1 g/kg DM) and P (11.0 g/kg DM). Whilst very poor in lysine, MSC was found to be rich in methionine, cyst(e)ine, arginine and glutamic acid; it also contains good levels of valine, glycine, threonine, isoleucine, leucine, histidine, phenylalanine, serine, proline and alanine. Also, it contained 85.24% oleic (OA), 9.65% palmitic and 5.11% stearic acids, with a high peroxide value and low levels of mycotoxins deoxynivalenol (DON) and T-2 toxin. BWG, FI and FCE of broiler chickens significantly decreased (P < 0.001) as the dietary level of MSC increased. Further, dietary MSC significantly decreased bird live weight at slaughter (P < 0.001), plucked weight (P < 0.001), dressed weight (P < 0.001) and weights of the liver (P < 0.001) and neck (P < 0.05). The results therefore demonstrate MSC to be a good source of CP, fat, Ca, P, amino acids (except lysine) and OA that can replace soya bean meal (SBM) in broiler diets. However, its use is currently limited by lipid peroxidation and presence of mycotoxins.

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