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 ranging from 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) (p<0.05). At 30 DAT, manure application rates of ≥2.5 t/ha and the NPK fertiliser treatment, produced greater shoot dry-matter yields (≥29.35 g/plant) than the unfertilised control (17.11 g/plant). Uptake of N and P in the leaves increased with increase in manure application rate with N uptake reaching a maximum of 308 mg N /plant at a manure rate of 2.5 t/ha which corresponded with the maximum dry matter yield of 45.97 g/plant. There was no effect of manure rate or fertiliser on residual soil N and Ca, whereas P, K, Mg and Zn were increased (p<0.005). The findings suggested that ≥2.5 t/ha sheep kraal manure could result in growth, nutrient uptake and yield comparable to 150 kg/ha NPK fertiliser for the Amaranthus accession used in this work.Keywords: Amaranthus accession, sheep manure, dry matter yield, nutrient composition, residual nutrient

Dataset on the use of the Soil Management Assessment Framework (SMAF) in evaluating the impact of conservation agriculture strategies on soil quality

This data article is a presentation of data related to the research article entitled “Crop rotation and residue management effects under no-till on the soil quality of a Haplic Cambisol in Alice, Eastern Cape, South Africa” (Gura and Mnkeni, 2019) [1]. A number of soil experimental techniques were used to acquire the soil indicators data and the data was interpreted using the Soil Management Assessment Framework (SMAF) to assess and quantify the impacts of conservation agriculture strategies on soil quality. The data was processed and analyzed using the JMP statistical package (SAS Institute Inc., 2013) [2]. The data is made available for further use and for furthering the understanding of the key findings of the related research. Keywords: Soil quality, Soil Management Assessment Framework (SMAF), Soil quality index (SQI), Conservation agriculture (CA

The use of indigenous knowledge systems in soil classification, appraisal and soil productivity rating for maize cropping: A case of the Xhosa speaking people in Raymond Mhlaba Municipality, South Africa

An understanding of indigenous knowledge on soil classification, and their perceptions on soil productivity could complement scientific approaches in providing answers to challenges of soil resources management. The article sought to explore farmers’ indigenous knowledge of their soil  resources in the Raymond Mhlaba Municipality in the Eastern Cape and compare them to knowledge gathered through scientific approaches. Key informants and focus group discussions were first used in the interviews after which 175 farmers were then interviewed using close-ended  questionnaires. Data on indigenous soil classifications and soil potential for maize production were collected. Soil laboratory analyses were carried out to correlate indigenous knowledge with scientific findings. Six soil types were described by the farmers based soil colour, texture and soil depth. The most productive soils were umhlaba omnyama (soils with mollic properties); dongwe (brown clays); santi (sandy soils); isidhaka (high activity clays); umhlaba obomvu (red clays) and urhete (stony soils). Generally, there was good agreement between farmers’ assessment and scientificapproaches. The findings underscored the need to combine indigenous and scientific approaches in give practical management interventions acceptable to farmers. Keywords: Indigenous knowledge, natives, soil classification, Xhosa speaking

Phosphate Sorption Characteristics and External P Requirements of Selected South African Soils

The Transkei is the largest consolidated area in South Africa where land is held by smallholder farmers but little is known about the extent of phosphate fixation in the region. This study was conducted to determine the phosphate sorption properties and external P requirements (EPR) of selected soils from the Transkei region, South Africa and to relate derived sorption values to selected soil parameters. The P sorption maxima and EPR values varied widely ranging from 192.3 to 909.1 mg P kg−1 and from 2 to 123 mg P kg−1−1 soil, respectively. Citrate dithionite bicarbonate-extractable aluminum explained most of the observed variations in P sorption. About 43% of the soils were found to be moderate P fixers and may need management interventions to ensure adequate P availability to crops. The single point sorption index accurately predicted the EPR of the soils obviating the need to use multiple point sorption isotherms. The results suggested that the use of blanket phosphate fertilizer recommendations may not be a good strategy for the region as it may lead to under-application or over-application of P in some areas

Crop production management practices as a cause for low water productivity at Zanyokwe Irrigation Scheme

Generally, smallholder irrigation schemes (SIS) in South Africa have performed poorly and have not delivered on their development objectives of increasing crop production and improving rural livelihoods. Limited knowledge of irrigated crop production among farmers has been identified as one of the constraints to improved crop productivity, but research that investigates the relationship between farmer practices and productivity is lacking. A monitoring study was therefore conducted at the Zanyokwe Irrigation Scheme (ZIS) in the Eastern Cape to identify cropping systems and management practices used by farmers and to determine how these were related to performance. Evidence from 2 case studies showed that water management limited crop productivity. Irrigation application and system efficiencies were below the norm and irrigation scheduling did not take crop type and growth stage into account. Monitoring of 20 farmers over a 3-yr period showed that cropping intensity averaged only 48% and that the yields of the 2 main summer crops, grain maize (Zea mays L.) and butternut (Cucurbita moschata) averaged only 2.4 and 6.0 t∙ha-1, respectively. In addition to poor water management, other main constraints to crop productivity were inadequate weed and fertiliser management and low plant populations. The results indicated that a lack of basic technical skills pertaining to irrigated crop production among farmers was a possible cause of inadequate management. In this regard, it is expected that farmers could benefit from ‘back to basics’ training programmes in the areas of crop and irrigation water management. Research needs to focus on labour-saving production technologies, establishing farm-specific fertiliser recommendations, the identification and use of affordable sources of nutrients, as well as strategies to improve plant population in maize by preventing bird damage to newly-planted stands. Keywords: smallholder irrigation schemes, cropping pattern, constraints to crop productivity, research agend

Crop production management practices as a cause for low water productivity at Zanyokwe Irrigation Scheme

Generally, smallholder irrigation schemes (SIS) in South Africa have performed poorly and have not delivered on their development objectives of increasing crop production and improving rural livelihoods. Limited knowledge of irrigated crop production among farmers has been identified as one of the constraints to improved crop productivity, but research that investigates the relationship between farmer practices and productivity is lacking. A monitoring study was therefore conducted at the Zanyokwe Irrigation Scheme (ZIS) in the Eastern Cape to identify cropping systems and management practices used by farmers and to determine how these were related to performance. Evidence from 2 case studies showed that water management limited crop productivity. Irrigation application and system efficiencies were below the norm and irrigation scheduling did not take crop type and growth stage into account. Monitoring of 20 farmers over a 3-yr period showed that cropping intensity averaged only 48% and that the yields of the 2 main summer crops, grain maize (Zea mays L.) and butternut (Cucurbita moschata) averaged only 2.4 and 6.0 t∙ha-1, respectively. In addition to poor water management, other main constraints to crop productivity, were inadequate weed and fertiliser management and low plant populations. The results indicated that a lack of basic technical skills pertaining to irrigated crop production among farmers was a possible cause of inadequate management. In this regard, it is expected that farmers could benefit from ‘back to basics’ training programmes in the areas of crop and irrigation water management. Research needs to focus on labour-saving production technologies, establishing farm-specific fertiliser recommendations, the identification and use of affordable sources of nutrients, as well as strategies to improve plant population in maize by preventing bird damage to newly-planted stands