Rangeland degradation in a semi-arid South Africa—I: influence on seasonal root distribution, root/shoot ratios and water-use efficiency

Snyman, H.A.

doi:10.1016/j.jaridenv.2004.06.006

Cited by 72 publications

(76 citation statements)

References 89 publications

(124 reference statements)

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“…Options for plants to increase water available are to increase the root length in the deep sub-soil layers or concentrate to the soil surface (Shan and Chen, 1993). In the present study, the distribution of roots throughout the profile, with a high concentration at the top and decreasing with depth (Figures 2 and 3) was expected since such patterns have been reported in most other studies taken in dry areas (Synman, 2005).…”

Section: Discussionsupporting

confidence: 86%

“…Because of site conditions, developmental stage and genotype, root systems show wide variations both between and within species, which lead to variations in the efficiency of water and nutrient uptake (Kirkham et al, 1998;Neukirchen et al, 1999). Crop specific information about root dynamics and root system size will greatly assist the estimation of the water and nutrient uptake and eco-adaptation in different plant species (Synman, 2005). Root data has become more significant important in evaluating environmental impacts of agriculture (Campbell and de Jong, 2001), especially in arid and semi-arid regions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Seasonal and spatial root biomass and water use efficiency of four forage legumes in semiarid northwest China

Xu¹,

Lun²,

Li³

et al. 2007

Afr. J. Biotechnol.

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Shoot biomass continued to increase from April to November for all the four legumes. In November, the root biomass for milkvetch and alfalfa accounted for about 2.93 and 2.30% of the total biomass (root plus shoot) respectively, while in sainfoin and L. davurica it accounted for 6.00 and 4.44% respectively. There were significant differences between the four legumes in WUE, and the order was same as shoot biomass, ranked as milkvetch>alfalfa>sainfoin>L. davurica. The seasonal and yearly high shoot biomass and low proportion of root biomass resulting to low root : shoot ratio may explain the significantly higher WUE of milkvetch and alfalfa in comparison to sainfoin and L. davurica.

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Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Seasonal and spatial root biomass and water use efficiency of four forage legumes in semiarid northwest China

Xu¹,

Lun²,

Li³

et al. 2007

Afr. J. Biotechnol.

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“…This is the major zone of plant root development, and increased porosity and infiltration ratios are beneficial to plant growth by facilitating the supply of water and nutrients to roots and increasing aeration (Snyman, 2005). This is reflected in higher moisture levels in the A-horizon where beetles not only increase porosity but introduce organic matter (dung) with a higher moisture holding capacity.…”

Section: Discussionmentioning

confidence: 99%

Dung beetles (Coleoptera: Scarabaeidae) can improve soil hydrological properties

Brown

Scholtz

Janeau

et al. 2010

Applied Soil Ecology

121

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a b s t r a c tAlthough dung beetles are known to perform a multitude of ecosystem services, their effects on water infiltration, runoff, porosity, moisture and erosion of soil have never been thoroughly researched. Maintenance of these hydrological properties is important in agro-ecosystem functioning where overgrazing results in negative impacts on the soil. The study site was located in the Potshini catchment in KwazuluNatal (South Africa), an area heavily grazed by livestock. We conducted two rainfall simulations on three 1 m −2 control (no dung) and six dung-treated plots in December 2008, and repeated the study in June 2009 on the same plots. Natural populations of dung beetles were allowed to colonise the dung. Simulations were conducted for 30 min at an intensity of 30 mm h −1 . Key variables calculated were pre-runoff amounts (Pi), infiltration ratios (Ki), and soil losses. Samples were collected for bulk density determination during the same time periods in order to measure differences in porosity and moisture in control and dung-treated plots at different depths. Using multivariate statistics we found significant differences between dung-treated and control plots in three of four simulations. After 48 h of beetle activity, Pi and Ki values were significantly increased and remained at elevated levels six months later. Soil losses were initially higher in dung-treated plots than controls, but had declined to less than control values after six months. Bulk density in the A-horizon (0-10 cm) was significantly reduced after 48 h of beetle activity and remained so for six months. No difference in bulk density was observed at greater depths. Soil moisture initially increased significantly in the A-horizon, as well as at 20 and 30 cm depths after six months of activity. We conclude that dung beetles positively influence hydrological properties of the soil by increasing water infiltration and soil porosity, and reducing surface water runoff. Contrasting effects on soil losses are problematic to reconcile from this study. High losses initially observed may be offset in the long-term by reductions associated with the increased infiltration ratios, though this remains to be confirmed.

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“…Moreover, in such arid rangeland, trees provide better protection of herbaceous groundcover. In addition, the greater plant cover under canopied areas has a positive effect on fertility and water balance of soil, further creating a better microclimate for palatable perennial species with a high water-use efficiency, OM decomposition and nutrient dynamics (Abule et al 2005;Snyman 2005). This better performance in plant cover and DM yield from arid grassland has been reported by other researchers in tropical and subtropical conditions (Abule et al 2005;Snyman 2005; Abdallah et al 2008).…”

Section: Plant Cover and Dry Matter Yieldmentioning

confidence: 99%

In vitro fermentation, digestibility and methane production of tropical perennial grass species

Gemeda

Hassen

2014

Crop Pasture Sci.

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Abstract. This study characterised 16 tropical perennial grass species in terms of in vitro methane output and related their digestibility and rumen fermentation with methane output. The grass samples were collected, dried in a forced oven, and ground and analysed for nutrient composition. In vitro gas production and organic matter digestibility (IVOMD) were determined using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production through in vitro incubation at 398C. Anthephora argentea and Stipagrostis ciliate produced the highest concentration of methane in terms of g kg -1 digestible dry matter (DDM) and g kg -1 digestible organic matter (IVOMD). Cenchrus ciliaris, Setaria verticillata and Panicum coloratum produced the lowest (P < 0.05) methane when expressed in terms of g kg -1 DDM and g kg -1 IVOMD. Ash, ether extract, non-fibrous carbohydrate, neutral and acid detergent insoluble nitrogen, and crude protein were negatively correlated with methane production. Methane production positively correlated with neutral and acid detergent fibre, cellulose and hemicellulose. It is important to focus on screening and selecting perennial grass with higher nitrogen content and low methane production to mitigate methane production under tropical conditions.

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Rangeland degradation in a semi-arid South Africa—I: influence on seasonal root distribution, root/shoot ratios and water-use efficiency

Cited by 72 publications

References 89 publications

Seasonal and spatial root biomass and water use efficiency of four forage legumes in semiarid northwest China

Seasonal and spatial root biomass and water use efficiency of four forage legumes in semiarid northwest China

Dung beetles (Coleoptera: Scarabaeidae) can improve soil hydrological properties

In vitro fermentation, digestibility and methane production of tropical perennial grass species

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