Characterisation of soil physical properties and resistance to erosion in different areas of soil associations

Understanding the effects of soil physical properties on resistance to erosion is important for land use planning and soil erosion management. The objective of this study was to characterise the physical soil properties of areas of soil associations and determine the influence of litter source on aggregate stability and rates of soil loss in areas of soil association in the Ntabelanga area, Eastern Cape Province, South Africa. Soil was sampled from 21 randomly selected points in the areas of soil associations. Soil was incubated for 30 weeks after increasing the SOC to > 2% by adding Vachellia karroo leaves (low C/N) and Zea mays stover (high C/N) and rate of soil loss (t ha-1) determined at 1, 3, 8, 14, 23 and 30 weeks of incubation. The soil physical properties, resistance to dispersion and aggregates distribution varied significantly (P < 0.05) across soils. All soils had significantly (P < 0.05) low (< 2%) SOC (%) and high (> 0.02)[(t\ua0ha\ua0h)\ub7(ha\ua0MJ\ua0mm)-1] K-factors indicating high erodibility. Vachellia karroo and Z. may organic matter significantly (P < 0.05) reduced soil loss from 1 to 8 weeks after incubation thereafter lost its effectiveness. Organic matter stabilised the soils, but only for a short period (8 weeks). It is recommended to minimise soil disturbance in the Ntabelanga area as this will exacerbates the problem of erosion.Il est important de comprendre les effets des propri\ue9t\ue9s physiques du sol sur la r\ue9sistance \ue0 l\u2019\ue9rosion pour la planification de l\u2019utilisation des terres et la gestion de l\u2019\ue9rosion du sol. L\u2019objectif de cette \ue9tude \ue9tait de caract\ue9riser les propri\ue9t\ue9s physiques du sol des zones d\u2019associations de sol et de d\ue9terminer l\u2019influence de la source de liti\ue8re sur la stabilit\ue9 d\u2018agr\ue9gat\ua0de\ua0sol et les taux de perte de sol dans les zones d\u2019association de sol dans la r\ue9gion de Ntabelanga, Province du Cap oriental, Afrique du Sud. Le sol a \ue9t\ue9 \ue9chantillonn\ue9 \ue0 partir de 21 points choisis au hasard dans les zones d\u2019associations de sols. Le sol a \ue9t\ue9 incub\ue9 pendant 30 semaines apr\ue8s avoir augment\ue9 le COS \ue0 > 2% en ajoutant des feuilles de Vachellia karroo (faible C / N) et de la souche de Zea mays (C/N \ue9lev\ue9) et le taux de perte de sol (t ha-1) d\ue9termin\ue9 \ue0 1, 3, 8, 14, 23 et 30 semaines d\u2019incubation. Les propri\ue9t\ue9s physiques du sol, la r\ue9sistance \ue0 la dispersion et la distribution des agr\ue9gats variaient consid\ue9rablement (P <0,05) d\u2019un sol \ue0 l\u2019autre. Tous les sols avaient significativement (P <0,05) un SOC faible (<2%) (%) et \ue9lev\ue9 (> 0,02) [(t ha h).(ha MJ mm)-1] facteur K indiquant une forte \ue9rodabilit\ue9. Vachellia karroo et Z.may peuvent consid\ue9rablement r\ue9duire la perte de sol de 1 \ue0 8 semaines apr\ue8s que l\u2019incubation ait perdu son efficacit\ue9. La mati\ue8re organique a stabilis\ue9 les sols, mais seulement pendant une courte p\ue9riode (8 semaines). Il est recommand\ue9 de minimiser la perturbation du sol dans la r\ue9gion de Ntabelanga car cela aggravera le probl\ue8me de l\u2019\ue9rosion

Weed seed bank response to tillage and residue management in semi-arid Zimbabwe

The influence of conservation agriculture (CA) on weed ecology has been a concern to many researchers across the world and is the focus of this study in southern Africa. An experiment to look at the impacts of various tillage systems with different levels of crop residue on maize (Zea mays L.) was established in 2004/2005 season. The experiment was carried out at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Matopos Research Station, Zimbabwe. Three main tillage systems were compared, ripping tillage (RT), planting basins (PB) and conventional tillage (CT), with three different crop residue levels: 0, 4 and 8 tons ha−1. In 2007 soil samples were collected in the inter-row and in-row positions prior to tillage at 0–50 mm, 50–100 mm and 100–200 mm depths. The objective was to determine the effect of the treatment factors on weed seed bank species after three cropping cycles using the germination method. Nine major weed species were identified, with all the weeds unaffected by either tillage or mulching level. Eleusine indica, Corchorus tridens and Setaria species were the dominant weed species across all treatments. Setaria spp. was the dominant weed in the inter-row position of ripped plots. Although there was no significant individual treatment effect, there were significant (p < 0.05) interactions, with CT having reduced seed banks of Setaria spp. and E. indica compared to RT and PB. Percentage increases point to E. indica and Setaria spp. increasing under PB and RT compared to CT. C. tridens was significantly higher in PB compared to RT and CT in the 0–50 mm depth in the in-row position. This study probably coincided with the transition period in the weed bank succession process and needs to be repeated at a later date in the rotation. The majority of the weed species were not affected by any of the treatment combinations, a response attributed to plasticity of weeds to the tillage and residue level selection pressur

Integrated weed management in Zimbabwe’s smallholder sector, where are we? : a review

The introduction of the Integrated weed Management (I WM) in Zimbabwe’s small holder sector seemed to be the answer to the weed management problem in the sector. However up to the present moment the drudgery associated with weeding still dominat e in the sector. Research in Zimbabwe has investigated various techniques varying from cultural, chemical to mechanical weed management techniques. Despite the fact that some of them have produced excellent results, the in tegration of these techniques into a weed suppressive cropping system still lags behind. Research information accessibility by both extension personnel and the smallholder sector constitutes one of the major challenges

Exploring food fortification potential of neglected legume and oil seed crops for improving food and nutrition security among smallholder farming communities : a systematic review

A systematic review of literature on value-addition and food fortification of cereals using neglected legume and oil seed crops among smallholder farming communities was done. There is scanty and very limited empirical evidence on the use of legumes in food fortification of cereals at the household level. This is largely because of a neglect of local micronutrient provision initiatives at the household level, with much attention being done at policy and industrial scale food fortification levels. Besides, the current policies do not provide for the fortification of most food crops commonly grown in smallholder farming communities and there are very few initiatives that are in place to promote localised fortification options among rural communities. The paper consolidated existing knowledge on food fortification in general, value addition of small grains and neglected legume and oil seed crops. It explored fortification potential of sesame, cow pea and groundnuts and mapped existing gaps and missing links hampering the enhancement of food security and nutrition. This study recommends the promotion of groundnuts and sesame production, their value addition, and their use in the fortification of cereal food products to complement protein, Vitamins, Fe, K, Na, Mg, Zn, and Ca provision. This will significantly contribute to the alleviation of malnutrition among rural communities particularly in developing countries where agriculture is the mainstay of economies.The Regional Universities Forum for Capacity Building in Agriculture (RUFORUM) and RUFORUM Community Action Research Programme PLUS (CARP+).http://www.journals.elsevier.com/journal-of-agriculture-and-food-researchhj2022Anthropology and Archaeolog