Myns insiens ... beplan jou herfsmaande

Weidingsbestuur is ’n filosofie. Jy kan resepte hê, maar enige bestuur op ’n plaas is omgewingspesifiek. Dit beteken jy moet jou aksies aanpas binne ’n filosofiese raamwerk. As ’n mens na die situasie in die land kyk, is dit moeilik om reëls neer te lê wat oral geld. Kom ons aanvaar dus dat elke boer op grond van sy eie situasie hierdie riglyne sal aanpas.http://www.veeplaas.co.za

Weidings in die lente

Teen die einde van winter en met die aanbreek van die lente is weidingsbeplanning vir die komende groeiseisoen vir somerreënvalgebiede belangrik. Beplanning en voorbereiding vir 'n droër en warmer somer in die winterreënvalgebiede is egter net so belangrik.http://www.veeplaas.co.za

Weiding in die winter

Ter voorbereiding van die komende winter wil die meeste weidingsboere 'n situasie hê waar: Die meeste natuurlike subtropiese weidings lig bewei word, sodat die plante reserwes kan opbou om vinnig te kan herstel tydens die lentegroeitydperk. Aangeplante weidings al gesny is vir hooi of kuilvoer om die voerbank vir die winter aan te vul wanneer weidingsgehalte in somerreënval en rypgevoelige gebiede laag is. Alle weidings vir staande hooi goeie bemesting en goeie groei gehad het. Gematigde weidings reeds gevestig is indien ekstra grond en voldoende besproeiing beskikbaar was. Bestaande en nuwe weidings in winterreënvalgebiede gevestig is en goed bemes is.http://www.veeplaas.co.za

Sustainable plant production on degraded soil / substrates amended with South African class F fly ash and organic materials

South Africa is a country with very little prime farmland. A large percentage of this high agricultural capability land is generally acidic and nutrient poor, and situated in areas where large coal mining activities occur. Coal mining and agriculture are important industries in South Africa. They impact extensive land areas, and often compete for the same land. The surface mining of coal seriously damages the surface soil, local flora and fauna. Mining wastes viz. overburden, discards and mine effluents, have also created land degradation problems. Three of the most common factors that characterize degraded substrates are soil acidification, nutrient depletion and loss of biological activity. To ensure a healthy and productive vegetation, disturbed soils need to be ameliorated effectively. Using conventional methods is costly and is often not sustainable. The challenge is, therefore, to use potential alternative ameliorants in an economically, ecologically and socially sustainable manner. Fortunately, South Africa has plenty of industrial and organic by-products, which might be used as alternative ameliorants. There is an enormous amount of international literature on the use of class C fly ash, (Sub bitumious or lignite CCB – [Coal combustion byproduct]), and to a lesser extent class F fly ash (Bitumious CCB), as opposed to South African class F fly ash, which is predominantly produced in this country. Fly ash, either by itself, or together with other wastes such as biosolids, can serve as a soil ameliorant by providing a good source of micro-, macronutrients and organic material for the reclamation of land. Previous research has shown that when sewage sludge is mixed with class F fly ash and a suitable source of reactive lime in a specific ratio, sewage sludge pasteurization will occur. The SLudgeASH (SLASH) mixture has been extensively evaluated as a soil ameliorant and has proven to be viable for the reclamation of poor and marginal soils. This study, has focused on the effect of soil ameliorants on the chemical-, physical- and microbiological properties of degraded agricultural land, mine land and other mining wastes (tailings and discards) requiring rehabilitation. This study also evaluated the affects of class F fly ash and SLASH amelioration of soils and substrates on plant production and revegetation, in comparison with conventional liming and fertilization methods currently in use. Species such as maize (Zea mays) and wheat (Triticum aestivum); pasture legumes such as lucerne or alfalfa (Medicago sativa); sub tropical grasses such as Foxtail Buffalo grass (Cenchrus ciliaris), Rhodegrass (Chloris gayana) and Smutsfinger grass (Digitaria erianthra) have been evaluated. The success of enhanced plant production, re- vegetation and sustainability of once degraded soils / substrates is an indication of the amelioration success achieved. Seed germination, root development, plant yield, plant density, botanical diversity and biological activity are parameters which can all be used to support the conclusion that alternative substrate amendment practices can improve the plant growth medium. Based on the results obtained in this study, it was concluded that fly ash and fly ash/organic material mixtures (SLASH) improved soil chemical properties such as pH, ammonium acetate extractable K, Ca, Mg and Bray 1 extractable P levels. All parameters measured were significantly influenced by the fly ash and SLASH. For example, the pH of soils impacted by acid mine drainage was improved by 240% by the use of SLASH. Other results illustrate improvements in soil physical properties such as texture, bulk density, water infiltration rate and hydraulic conductivity, by class F fly ash based soil ameliorants. In addition to the beneficial effects on soil physical properties, the microbial properties were also improved, as indicated by the beneficiation of symbiotic relationship of the Rhizobium bacteria and the important host plant Medicago sativa. Improvements in crop yields, such as: wheat yields on SLASH and fly ash treatments were 270% and 150% better than the control respectively; yields of maize and alfalfa were improved by 130 % and 450% respectively, were also registered. Fly ash and SLASH ameliorated soils resulted in approximately 850%, 266% and 110% higher dry matter production on gold mine tailings, AMD impacted soil and acidic mine cover soil, respectively, relative to the control treatments. Results also clearly illustrated that the abundance of certain species can be related to the higher fertility levels of the rehabilitated soil. Data collected over the past seven years, illustrates how the botanical composition has changed, and that soils receiving class F fly ash and sewage sludge had a higher dry matter production, whereas the control (no treatment) had a better biodiversity. With respect to the reclamation of coal discard materials, significant increases in yield, of up to 200%, were noted for soils and discards treated with class F fly ash, relative to the untreated control. The pH of cover soil was the most strongly affected soil parameter during the experimental period. Class F fly ash and SLASH have the potential to improve the chemical, physical and microbiological properties of degraded soils and substrates. From this experimental work it can be concluded that class F fly ash from Lethabo definitely has a much higher CaCO3 equivalent than what was originally assumed and that other SA sources probably have an even better neutralizing value. Class F fly ash and SLASH, are good sources of micronutrients and some macro nutrients, and may play a significant role in neutralizing acidity due to their residual alkalinity, and thus ability to continuously change the soil chemical balance so that nutrients become more available for plant uptake and use, thereby enhancing growth. Agricultural, domestic and industrial byproducts unfortunately, vary greatly in nutrient content, trace metals and liming potential, and these factors can affect both re-vegetation success and the environmental impact of reclamation. Co-utilization of by-products can often combine beneficial properties of the individual by-products to eventually have a more pronounced effect on the degraded soil or substrate.Thesis (PhD(Pasture Science))--University of Pretoria, 2008.Plant Production and Soil SciencePhDunrestricte

Probleemplante vir vee en veeboere : Deel 1 : Inleiding en oorsig

Ekonomiese veeproduksie, wat reeds gebuk gaan onder stygende insetkoste en wisselvallige beskikbaarheid van byvoedings en konsentrate, kan ’n groot hupstoot kry deur die optimale benutting van natuurlike en aangeplante weidings. Een enorme struikelblok vir die daarstel van goeie weiding en hoë drakrag, is die aanwesigheid van onsmaaklike en/of giftige plantsoorte wat met gewenste soorte gemeng is. Droogte, verkeerde beweiding of enige ander vorm van die agteruitgang van grond, kan lei tot indringing deur nuwe probleemplante en die bevoordeling van soorte wat oor tyd gevestig geraak het. Die beheer en bestuur van probleemplante behoort ’n integrale deel van weidingbestuur te wees.http://www.veeplaas.co.za

Probleemplante : die kruipende gevaar Xanthium strumarium (kankerroos) en Xanthium spinosum (boetebossie) (Deel 6)

Xanthium behoort tot die Asteraceae- familie wat insluit asters en sonneblomme. Dit is ’n eenjarige plant wat slegs deur middel van saad voortplant. Beide soorte wat hier behandel word, kom van Suid-Amerika (waarskynlik Argentinië). Hulle het reeds in die negentiende eeu wyd verspreid voorgekom tussen breedtegraad 53˚N en 33˚S. Albei soorte kom deur die hele Suid-Afrika voor, selfs in die dorste dele van die land, mits daar gewas- en veeproduksie bedryf word.http://www.veeplaas.co.za

Probleemplante vir vee en veeboere (Deel 4) Solanum elaeagnifolium Cav (satansbos)

Satansbos, Solanum elaeagnifolium Cav, is ’n uitheemse indringerplant met sy oorsprong in die halfwoestynagtige Amerikas. Die Engelse naam vir satansbos is silverleaf nightshade. Dit het die vermoë om vinnig te versprei en sterk te kompeteer met gewenste plante in gewaslande en natuurlike weiveld.http://www.veeplaas.co.za

Probleemplante vir vee en veeboere (Deel 3) Dichapetalum cymosum (gifblaar)

Gifblaar is ’n klein dwergagtige struik wanneer dit bogronds beskou word. Ondergronds het dit egter sulke uitgebreide stam- en wortelvertakkings dat daarna as ’n ondergrondse boom verwys word, waarvan net die punte van takke bo die grond uitsteek.http://www.veeplaas.co.za

Seasonal monitoring of biochemical variables in natural rangelands using Sentinel-1 and Sentinel-2 data

Rangelands are natural ecosystems that serve as essential sources of forage for domesticated livestock and wildlife. Therefore, accurately mapping nutrient levels in rangelands is crucial for sustainable development and effective management of grazing animals. Remote sensing tools offer a reliable means to explore nutrient concentrations across large spatial areas. This study aimed to estimate and map seasonal foliar concentrations of nitrogen (N), phosphorus, and neutral detergent fibre (NDF) in mesic tropical rangelands of Limpopo using Sentinel-1, Sentinel-2, and the integration of S1 and S2 data. Fieldwork was conducted to collect samples for seasonal foliar nutrients (N, P, and NDF) during early-summer (November-January 2020), winter (July-August 2021), and late-summer (February-March 2022). Various conventional and red-edge-based vegetation indices were computed. The results demonstrate that integration data from S1 and S2 can effectively estimate and predict foliar concentrations of N, P, and NDF in mesic rangelands throughout the seasons, achieving R2 values of 0.76, 0.78, and 0.71, with corresponding RMSE values of 0.13, 0.04, and 2.52. Notably, red-edge variables emerged as the most significant parameters for predicting seasonal N, P, and NDF concentrations. Additionally, factors such as season and slope significantly influenced the distribution and occurrence of these foliage nutrients, with higher foliage production observed during late-summer and on steeper slopes. The study concludes that the integration of S1 and S2 data can effectively monitor the seasonal dynamics of biochemical parameters. This finding holds significant implications for policymakers and rangeland users, offering a comprehensive understanding of the intricate variations within rangeland ecosystems. Further research could expand on these findings by applying the knowledge to various datasets, exploring different rangelands, and examining additional ecological factors such as slope altitude to detect foliar fibre biochemicals. Finally, the applications of this research extend beyond individual properties, providing practical tools for sustainable rangeland management and informed decision-making in resource utilization and conservation.http://www.tandfonline.com/loi/tres20hj2024Geography, Geoinformatics and MeteorologyPlant Production and Soil ScienceSDG-15:Life on lan

Seasonal evaluation and mapping of aboveground biomass in natural rangelands using Sentinel-1 and Sentinel-2 data

DATA AVAILABILITY : All the Sentinel data are free of cost and are in the open domain, and field data port the published claims and fulfill with field requirements.Rangelands play a vital role in developing countries’ biodiversity conservation and economic growth, since most people depend on rangelands for their livelihood. Aboveground-biomass (AGB) is an ecological indicator of the health and productivity of rangeland and provides an estimate of the amount of carbon stored in the vegetation. Thus, monitoring seasonal AGB is important for understanding and managing rangelands’ status and resilience. This study assesses the impact of seasonal dynamics and fire on biophysical parameters using Sentinel-1 (S1) and Sentinel-2 (S2) image data in the mesic rangeland of Limpopo, South Africa. Six sites were selected (3/ area), with homogenous vegetation (10 plots/site of 30m2). The seasonal measurements of LAI and biomass were undertaken in the early summer (December 2020), winter (July–August 2021), and late summer (March 2022). Two regression approaches, random forest (RF) and stepwise multiple linear regression (SMLR), were used to estimate seasonal AGB. The results show a significant difference (p < 0.05) in AGB seasonal distribution and occurrence between the fire (ranging from 0.26 to 0.39 kg/m2) and non-fire areas (0.24–0.35 kg/m2). In addition, the seasonal predictive models derived from random forest regression (RF) are fit to predict disturbance and seasonal variations in mesic tropical rangelands. The S1 variables were excluded from all models due to high moisture content. Hence, this study analyzed the time series to evaluate the correlation between seasonal estimated and field AGB in mesic tropical rangelands. A significant correlation between backscattering, AGB and ecological parameters was observed. Therefore, using S1 and S2 data provides sufficient data to obtain the seasonal changes of biophysical parameters in mesic tropical rangelands after disturbance (fire) and enhanced assessments of critical phenology stages.Open access funding provided by University of Pretoria.http://link.springer.com/journal/10661am2024Geography, Geoinformatics and MeteorologyPlant Production and Soil ScienceSDG-15:Life on lan