Fertiliser value of human manure from pilot urine-diversion toilets

Ecological sanitation is a system that, unlike the traditional waterborne sewerage and pit toilet systems, regards human excreta as a resource to be recycled rather than as a waste. There is, however, little or no information on the fertiliser value of human excreta in South Africa. This study, therefore, evaluated the effectiveness of human manure as a source of nutrients using cabbage as a test crop at Ntselamanzi location, Alice, South Africa as part of a project intended to generate knowledge and good practice in ecological sanitation. Treatments were arranged in a randomised complete block design with 4 replications and consisted of a control, 100 kg N·ha-1 as goat manure, and 4 non-zero rates of human manure and NPK fertiliser applied to supply the equivalent of 50, 100, 200, and 400 kg N·ha-1. Human manure resulted in higher cabbage yields than goat manure but was out-yielded by inorganic fertiliser. The greater effectiveness of human manure when compared with goat manure was attributed to the fact that it was a better source of K and P for plants as it maintained higher levels of these nutrients in soil than goat manure. For greater agronomic effectiveness, the human manure should be co-applied with some inorganic N fertiliser as it proved to be a poor source of nitrogen. The human manure increased soil pH and therefore has potential for improving crop growth in acidic soils through its liming effects as well. The dry human manure was evaluated as comparable to Type B sludge in South Africa with respect to microbial content and could therefore be used to fertilise some crops/plants provided stipulated restrictions to minimise human exposure are adhered to

Effects of sheep kraal manure on growth, dry matter yield and leaf nutrient composition of a local amaranthus accession in the central region of the Eastern Cape Province, South Africa#

Indigenous vegetables that supply abundant amounts of protein, vitamins, calories and minerals could alleviate problems of malnutrition, in developing countries. Amaranthus is one such vegetable that could be domesticated and cultivated but information on its fertility requirements is scanty. A dry-land field experiment was therefore conducted to study the effects of sheep kraal manure application rates on growth, fresh and dry matter yields, nutrient uptake and grain yield of one of the Amaranthus accessions that grow in the wild in the Eastern Cape. The treatments were sheep kraal manure rates rangingfrom 0 to 10 t/ha and an NPK {2:3:4(30) + 0.5% Zn} fertiliser as a positive control at 150 kg/ha. Low manure rates (.2.5 t/ha) resulted in plant heights and fresh matter yields which were comparable to those in the unfertilised control, whereas higher rates (5 and 10 t/ha) and NPK fertiliser gave greater plant heights and higher yields at both 30 and 60 days after transplant (DAT) (

Reduced dosages of atrazine and narrow rows can provide adequate weed control in smallholder irrigated maize (Zea mays L.) production in South Africa

An on-farm experiment was conducted in Zanyokwe irrigation scheme to investigate the effects of row spacing (45 and 90 cm) and atrazine dosage (33, 67 and 100% of the label recommended dosage) on weed density and biomass and on maize yield. Overall percent kill of weeds increased with increase in atrazine dosage and with reduction in row spacing. Percent kill varied according to weed species with a 100% kill of broad leaf weeds such as Amaranthus hybridus, Nicandra physaloides and Bidens pilosa regardless of herbicide dosage while Digitaria sanguinalis, Cyperus esculentus, Cynodon dactylon and Oxalis latifolia could not be controlled even at the LRD. Weed density at maize physiological maturity decreased by 11% when row spacing was decreased from 90 to 45 cm. Atrazine dosage and row spacing did not have significant interactive effects and their main effects did not significantly affect weight of green cobs, cob length or grain yield. The study demonstrated the possibility of incorporation of reduced herbicide dosages and narrow rows to achieve adequate weed control and optimise on yields in smallholder farming systems.Key words: Row spacing, reduced atrazine dosages, weed density, weed biomass, maize yield

Effectiveness of combined thermophilic composting and vermicomposting on biodegradation and sanitization of mixtures of dairy manure and waste paper

Thermophilic composting is commonly used for the treatment of organic wastes or for production of organic/natural fertilizers. Vermicomposting (V) is also increasingly becoming popular. These two techniques have their inherent advantages and disadvantages. In this study, vermicomposting and a combination of thermophilic composting and vermicomposting were compared as ways of sanitizing and biodegrading dairy manure and waste paper mixtures with C:N ratios of 30 and 45. Wastes with a C:N ratio of 30 proved more suitable for both vermicomposting and combined thermophilic composting and vermicomposting as their composts were more stabilized and with higher nutrient contents than composts made from wastes with a C:N ratio of 45. Both vermicomposting and combined compostingand vermicomposting were effective methods for the biodegradation of dairy manure and paper waste mixtures with C:N ratio of 30 but the latter was more effective in the biodegradation of waste mixtures with a C:N ratio of 45. Combining therrmophilic composting and vermicomposting eliminated the indicator pathogen Escherichia coli 0157 from the final composts whereas vermicomposting only managed to reduce the pathogen population

Smallholder irrigation schemes in South Africa: A review of knowledge generated by the Water Research Commission

The status and characteristics of the 302 smallholder irrigation schemes found in South Africa are discussed and knowledge on South African smallholder irrigation schemes generated by the Water Research Commission (WRC) over a period of nearly 20 years is reviewed. Themes covered include planning, design and technology; plot-holders and their livelihoods; institutions and organisations; support services; agronomic practices; and revitalisation. The availability of guidelines on most of these aspects is highlighted. Gaps in the knowledge of social, human and economic aspects of smallholder irrigation schemes are pointed out.Keywords: smallholder, irrigation scheme, plot size, technology, livelihoods, farmer support, institutions, organisations, revitalisation, managemen

EFFECTS OF RESIDUE MANAGEMENT ON ARTHROPODS POPULATIONS UNDER CONSERVATION AGRICULTURE

Maize (Zea mays L.) production in South Africa by smallholder farmers is primarily hampered by several factors, including institutional constraints, soil degradation, low input production, and insect pest attacks. Conservation agriculture (CA) is perceived as an approach that can help arrest or reverse the processes of soil degradation, improve soil fertility, pest management, and promote water conservation. However, results on the role of CA in pest management are contradictory. They show spatial and temporal variations due to the agroecosystem’s complex interactions among biotic and abiotic components. This study employed the approach of the component omission to investigate the probable effects of crop residue management on insect pest populations in a maize-based cropping system. Field experiments were carried out at ongoing CA trials at the University of Fort Hare farm (UFH) (32o 47′ S and 27o 50′ E) and Pandulwazi High School (32o 39′ S and 26o 55′ E). The trial was set up in a splitsplit plot design with 16 treatments and 3 replicates. Main plots were allocated to two tillage levels, which were split into four different crop rotation levels as sub-plot treatments. The sub-sub plots were allocated to two residue management levels. For conventional tillage study, two levels of crop rotation and residue management were considered as the different CA adoption levels by smallholder farmers. The results revealed that crop rotation and residue management influence arthropod abundances, diversity, richness, and evenness, which can be used to predict or monitor pest outbreaks. However, the synergistic influence of environmental/climatic regimes cannot be separated from the individual agronomic practices. Furthermore, pest indices cannot be independently used to predict insect pest infestation and possible outbreaks; instead, they are dependent. Hence, they are site and time specific