Biogeographical patterns of grasses (Poaceae) indigenous to South Africa, Lesotho and Eswatini

The ecological and economical importance of African grasses in sustaining animal production prompted studies to quantify the wealth of grass genetic resources indigenous to southern Africa. Plant collection and occurrence data were extracted from two southern African datasets, BODATSA and PHYTOBAS, and analysed to establish biogeographical patterns in the grass flora indigenous to South Africa, Lesotho and Eswatini. A total of 1 648 quarter degree grid cells, representing 674 grass species, were used in an agglomerative hierarchical clustering to determine biogeographical units being referred to as grasschoria. Six distinct groups formed, mainly following existing biome vegetation units, termed the Grassland, Indian Ocean Coastal Belt, Fynbos, Savanna, Central Arid Region and Succulent Karoo grasschoria. The description focuses on associated phytochoria, floristic links, key species, climate and soil properties. The main gradient distinguishing grasschoria was a rainfall-temperature gradient. The collection, conservation and breeding of pasture grass species adapted to especially arid and semi-arid environments, could be managed more efficiently by using these results, but also calling on the need to describe and label infraspecific genetic variants, including ecotypes.http://www.tandfonline.com/toc/tarf20/currentpm2021Plant Production and Soil Scienc

Microbial Inoculation to High Moisture Plant By-Product Silage: A Review

Use of microbial inoculants during silage making have drawn interest to silage producers including those who are feeding their livestock on silage produced from by-products (e.g. pulps). Many farmers in the developing countries rely on agro-industrial by-products to feed their livestock, which is limited by the high moisture content of the by-products. This review pertains to issues related to silage production from high moisture plant by-products (e.g. pulps or pomaces), challenges involved in the ensiling of these resources, the use of additives (e.g. microbial additives), and growth performance of the animals that are fed silage from these resources. This information will be helpful to better understand the key roles of silage production from these resources

A global meta-analysis of woody plant responses to elevated CO2: implications on biomass, growth, leaf N content, photosynthesis and water relations

Abstract Background Atmospheric CO2 may double by the year 2100, thereby altering plant growth, photosynthesis, leaf nutrient contents and water relations. Specifically, atmospheric CO2 is currently 50% higher than pre-industrial levels and is projected to rise as high as 936 μmol mol−1 under worst-case scenario in 2100. The objective of the study was to investigate the effects of elevated CO2 on woody plant growth, production, photosynthetic characteristics, leaf N and water relations. Methods A meta-analysis of 611 observations from 100 peer-reviewed articles published from 1985 to 2021 was conducted. We selected articles in which elevated CO2 and ambient CO2 range from 600–1000 and 300–400 μmol mol−1, respectively. Elevated CO2 was categorized into  700 μmol mol−1 concentrations. Results Total biomass increased similarly across the three elevated CO2 concentrations, with leguminous trees (LTs) investing more biomass to shoot, whereas non-leguminous trees (NLTs) invested to root production. Leaf area index, shoot height, and light-saturated photosynthesis (Amax) were unresponsive at  700 μmol mol−1. However, shoot biomass and Amax acclimatized as the duration of woody plants exposure to elevated CO2 increased. Maximum rate of photosynthetic Rubisco carboxylation (Vcmax) and apparent maximum rate of photosynthetic electron transport (Jmax) were downregulated. Elevated CO2 reduced stomatal conductance (gs) by 32% on average and increased water use efficiency by 34, 43 and 63% for  700 μmol mol−1, respectively. Leaf N content decreased two times more in NLTs than LTs growing at elevated CO2 than ambient CO2. Conclusions Our results suggest that woody plants will benefit from elevated CO2 through increased photosynthetic rate, productivity and improved water status, but the responses will vary by woody plant traits and length of exposure to elevated CO2

Essential metal and metalloid elements in the Philippi Horticultural area, and their uptake into selected vegetable crops

This study evaluated Co, Cr, Mn, Ni, Se, Sn and V status in the soils of the PHA, as well as the vegetables produced on these soils. We also determined the agronomic sources of these elements to the soils in the PHA. Farmyard manures applied as fertilizer amendments to the soils in the PHA were found to be the major agronomic sources of the metal and metalloid elements. These elements were however, retained in significantly higher concentrations in the soils compared to the concentrations found in the edible portions of the vegetable crops collected. This, in turn, resulted in these vegetables being poor sources of several of the essential mineral nutrients. It is therefore suggested that: (1) a wider variety of crops are assessed for their mineral nutrient status, (2) to find ways to increase the availability of these mineral nutrients and (3), that the possibilities of micronutrient and trace element deficiencies be assessed in the communities surrounding the PHA

Biogeographical patterns of grasses (Poaceae) indigenous to South Africa, Lesotho and Eswatini

The ecological and economical importance of African grasses in sustaining animal production prompted studies to quantify the wealth of grass genetic resources indigenous to southern Africa. Plant collection and occurrence data were extracted from two southern African datasets, BODATSA and PHYTOBAS, and analysed to establish biogeographical patterns in the grass flora indigenous to South Africa, Lesotho and Eswatini. A total of 1 648 quarter degree grid cells, representing 674 grass species, were used in an agglomerative hierarchical clustering to determine biogeographical units being referred to as grasschoria. Six distinct groups formed, mainly following existing biome vegetation units, termed the Grassland, Indian Ocean Coastal Belt, Fynbos, Savanna, Central Arid Region and Succulent Karoo grasschoria. The description focuses on associated phytochoria, floristic links, key species, climate and soil properties. The main gradient distinguishing grasschoria was a rainfall-temperature gradient. The collection, conservation and breeding of pasture grass species adapted to especially arid and semi-arid environments, could be managed more efficiently by using these results, but also calling on the need to describe and label infraspecific genetic variants, including ecotypes

Assessing legumes indigenous to South Africa, Lesotho and Swaziland for their pasture potential

In contrast to the exploration and use of southern African grass plant genetic resources over the past century, only a few indigenous legume species are currently used as forages, notwithstanding the vast untapped legume diversity available in southern Africa. The aim of this study was to assess legumes, indigenous to South Africa, Lesotho and Swaziland and propose a list of species with pasture potential for further evaluation. Towards this end, legume species documented as being cultivated, grazed or browsed as well as plant collection data from the National Herbarium, South Africa, were used. The majority of cultivated, grazed or browsed species were recorded in the Central Bushveld, Lowveld and Mopane Bioregions, the Drakensberg Foothill and Coastal Region, Savanna Group and Northern Mistbelt leguminochoria and is largely enclosed by the Wolkberg Centre of Plant Endemism. The Phaseoleae tribe was found to contain the highest percentage of cultivated legume species. Legume species adapted to low soil phosphorus levels were identified, with 22 of these species previously noted for their pasture potential. It is suggested that the results of this study be used in the continued search for alternative indigenous legumes species for eventual integration into local and international pasture systems.https://www.tandfonline.com/loi/tarf20hj2020Plant Production and Soil Scienc