African Journal of Range and Forage Science

Book Review. Ekologiese Restourasie in Namakwaland: ’n Praktiese Gids

Suzanne Milton — Tue, 16 Apr 2024 00:00:00 +0000

No Abstract

Drought release and post-drought changes in herbaceous composition and diversity in two land uses subjected to selective bush control in a semi-arid Kalahari savanna

N. van Staden, A. Marquart, K. Kellne — Tue, 16 Apr 2024 00:00:00 +0000

Land degradation due to bush encroachment and drought threatens the well-being of land users and forage production in the semi-arid savannas of southern Africa. This study aimed to analyse how herbaceous vegetation in the Kalahari savanna can recover from drought, and how this is affected by previously implemented bush control measures. We compared plant species composition and diversity of the herbaceous layer across a droughtrelease (2021) and post-drought (2022) year within two land use types (game and livestock) in bush- encroached and controlled areas, respectively. Diversity decreased significantly during the post-drought year. Annual species dominated in the drought-release year, which were replaced by perennial forbs and dwarf shrubs in the post-drought year. Selective bush control enhanced herbaceous species abundance and richness due to decreased competition. The species richness was higher in the game ranch compared to the cattle farm during the droughtrelease year. Herbaceous abundance, however, increased on the cattle farm. The management strategies, feeding behaviour and animal movement may have contributed to these differences in these two contrasting land use types. This study showed that herbaceous plant communities can recover rapidly after a drought period and in areas where bush control was applied.

Selection and evaluation of promising indigenous fodder trees and shrubs as supplemental diets for ruminant animals across different agroecological environments

Tue, 16 Apr 2024 00:00:00 +0000

The aim of this study was to select and evaluate promising potential indigenous fodder trees and shrubs (IFTS) as supplemental feeds for ruminant animals. Through interviews with farmers and field inventories, 107 IFTS species were identified as ruminant feeds, from which 37 potential IFTS species were selected. The chemical composition and anti-nutritional factors of the selected IFTS were analysed. Among the 37 selected IFTS species, crude protein (CP) ranged from 83.3 to 230.5 (mean, 134.3) g kg⁻¹ dry matter (DM); CP was greater than 80 g kg−1 DM in all selected species. Condensed tannin (CT) content varied from 2.57 to 210.91 g kg−1 (p < 0.05) among the selected species, of which 72% had < 40 g kg⁻¹ DM, an amount that is tolerable for ruminants. Farmers’ preferences and the nutritive value of the selected fodder species were positively correlated (p < 0.05) for CP (0.61), organic matter digestibility (0.303) and metabolisable energy (0.25). Farmers’ preference ranking and the nutritive value of the plants were considered to select the top 14 IFTS, all of which had CP > 110 g kg⁻¹, neutral detergent fibre (NDF) < 350 g kg⁻¹, and CT < 40 g kg⁻¹. Thus, the selected potential IFTS need further evaluation for their agronomic practice, biomass production and animal performance.

Participatory establishment of Cenchrus ciliaris forage grass among pastoralists in a semi-arid rangeland area of eastern Tanzania

Tue, 16 Apr 2024 00:00:00 +0000

In the semi-arid areas of Africa many pastoralists move their livestock to find better grazing when forage is scarce during the dry season. However, the practice of forage cultivation can sustain fodder supply for effective livestock feeding during these times. This study was undertaken to (1) assess grazing land management, and perception among Maasai pastoralists, and 2) evaluate Cenchrus ciliaris L. (Buffel grass) establishment and biomass yield under four levels of fertilisation and three seedbeds in a semi-arid area of eastern Tanzania. The seedbeds were not tilled (NT), tilled flat (TF) and tilled sunken (SN) with manure applied at rates of 0, 5, 10 and 15 t ha⁻¹. The 2 m × 3 m subplots were replicated three times per seedbed-manure treatment. Communal grazing land was perceived to be in poor condition by pastoralists due to the long time spent by their livestock in search of forage. Private forage reserves for dry-season feeding were present and could be used for forage cultivation. The TF, manure at 10 and 15 t ha⁻¹ treatments had significantly higher (p < 0.001) C. ciliaris establishment rates (97%) and biomass than other treatments. The TF10 and TF15 t ha⁻¹ treatments had biomass values of 9.8 and 10.1t DM ha−1, respectively, by Week 10. Pastoralists preferred the TF method because of its high forage yield and low cost. Cultivation of C. ciliaris is important for livestock production and it can be established on privately owned forage reserves.

Herbage intake and performance of grazing lambs in tropical erect grass pastures maintained at different heights

Tue, 16 Apr 2024 00:00:00 +0000

One of the main constraints for sheep production in tropical and subtropical areas is the lack of knowledge of how to manage erect tropical grasses for lambs. The objective of this study was to assess the effect of pasture height and structure of an erect tropical grass, Aruana Guinea grass (Megathyrsus maximus cv. IZ-5) on the intake and performance of young weaned lambs. The experiment was repeated in two consecutive years. Thirty young weaned lambs were equally assigned, each year, to three pasture heights: (1) Tall 75 cm; (2) Medium 50 cm and (3) Short 25 cm. Herbage mass (HM), pasture height, plant morphological composition, pasture nutritional quality, lambs’ average daily gain, gain per hectare and herbage intake were measured. The Short treatment had higher (p < 0.05) leaf:stem ratio (L:S; 2.6 ± 0.27) and average daily gain (ADG; 92 ± 10 g day−1) than the Tall treatment (0.9 ± 0.11 and 40 ± 13 g, respectively). The Medium treatment showed intermediate ADG (69 ± 11 g) and L:S ratio (1.4 ± 0.09). The height of the pasture affects the rate at which the number of stems increases relative to the number of leaves. There was a significant interaction between treatment and period (summer and early autumn) for herbage intake. Intake decreased markedly on the Tall treatment from the first to the second period. This study showed that for a better performance of weaned young lambs during summer–autumn, it is important to maintain tropical swards at a short height (25 cm). However, if the grass height exceeds this condition, the use of cattle or a mower are good options to maintain the sward height.

Does the presence of tall or dwarf elephant grass genotypes change the nutritive value of butterfly pea in grass–legume intercrops?

Tue, 16 Apr 2024 00:00:00 +0000

Adding tropical legumes into grass-based forage systems may increase the nutritive fodder value, but competition may decrease legume quality. We evaluated the nutritional values and agronomic responses of tall and dwarf elephant grass genotypes (Cenchrus purpureus (Schumach.) Morrone.) and butterfly pea (Clitoria ternatea L.) grown as binary intercrops. Two tall (Elephant B and IRI-381) and two dwarf elephant grass genotypes (Mott and Taiwan A-146 2.37) were the grass components of intercrops in a two-year trial. Higher acid detergent fibre (ADF) and lignin contents were found in tall than dwarf elephant grass genotypes (p < 0.0001), while lower coefficients of in vitro digestible dry matter (IVDDM) were recorded in tall than dwarf elephant grass genotypes (p < 0.0001). There was no intercrop effect on the herbage accumulation (p = 0.1278), dry matter (DM) contents (p = 0.2338), neutral detergent fibre (NDF) (p = 0.2022), lignin (p = 0.7179) and condensed tannins (p = 0.1699) of the butterfly pea. The butterfly pea grown with tall genotypes had higher crude protein (CP) concentrations (p = 0.0001) and coefficients of IVDDM (p = 0.0086) than when intercropped with dwarf genotypes. The study showed that tall elephant grass genotypes improved the butterfly pea’s nutritional value in grass–legume intercrops through increases in leaf/pod ratio. Intercropping with butterfly pea may compensate for the lower nutritive fodder value of tall elephant grasses compared to dwarf genotypes.

Biostimulant effects on the herbage yield and nutritive composition of a mixed ryegrass–clover pasture

J. de Beer, P.A. Swanepoel, J.H.C. van Zyl, L. Steyn — Tue, 16 Apr 2024 00:00:00 +0000

Dairy producers are continuously searching for environmentally friendly and economically sustainable alternatives to increase pasture herbage yield and reduce reliance on chemical fertilisers. A possible means to reduce fertiliser reliance is the use of biostimulants. Biostimulants such as fulvic acid and bioflavonoids help to increase N uptake efficiency, thereby increasing herbage quantity and quality. The aim of this study was to determine the effects of a soil application of a carbohydrate-derived fulvic acid and bioflavonoid biostimulant on herbage yield and nutritive composition of a mixed perennial ryegrass–clover pasture. Biostimulant treatment resulted in a lower ryegrass component of the mixed sward, in both winter and summer grazing cycles. However, the nutritive composition and total herbage yield of the pasture were not significantly affected by biostimulant treatment. The treatment did show a tendency to affect total herbage yield within a season. This suggests that total herbage yield could be increased if additional N fertiliser is applied together with a biostimulant soil treatment, although further investigation is needed to confirm this postulation. Biostimulant treatments have the potential to lead to reduced fertiliser inputs on perennial ryegrass–clover pastures as they may increase nutrient uptake efficiency.

Effect of plant spacing and cutting intensity on the morphology and productivity of forage cactus [Opuntia stricta (Haw.) Haw.

Tue, 16 Apr 2024 00:00:00 +0000

The forage cactus cultivar Mexican elephant ear (MEE) [Opuntia stricta (Haw.) Haw.] has been widely used in the semi-arid of Brazil because of its resistance to carmine mealybug. Therefore, it is necessary to establish planting and harvesting management strategies for this cultivar. This study evaluated the effect of cutting intensity (preservation mother cladode, and mother + primary cladodes) and different planting densities (55 555; 27 777; 13 888 and 6 944 plants ha⁻¹) on the morphology and productivity of the forage cactus cv. MEE, in 10-year-old cultivation under rainfed conditions. A split-plot design was used where planting density was allocated to the main plots and harvesting intensity to the sub-plots. Each treatment combination was replicated four times. The data were submitted to ANOVA, Tukey’s test, and principal component analysis at 5% (p < 0.05). Post-harvesting preservation of the primary cladodes promoted greater dry matter production (9.2 t ha⁻¹ year⁻¹), crop water accumulation (86.6 t ha⁻¹ year⁻¹), and rainwater use efficiency (11.4 kg of DM mm⁻¹) (p < 0.01). Primary cladodes preservation positively influenced the productive characteristics of the forage cactus, and the planting density of 13 888 plants ha⁻¹ (0.72 m2) favoured the productivity of this cultivar. These findings can guide planting and harvesting strategies for cultivating MEE cactus.