OP05:Impact of land use on selected soil organisms (part1) [compatibility mode]Document Transcript
IMPACT OF LAND USE ON SELECTED SOIL • Conservation and sustainable use of biodiversity is one of
ORGANISMS IN TAITA AND EMBU BENCHMARK the pillars of development.
• Ecosystem services such as decomposition, nutrient cycling
and disease/pest regulation are products of Biodiversity
• Sensitivity to loss of biodiversity is of great concern to the
BGBD Kenya team • This has catalyzed the channeling of resources to research
hi h l d h h li f h
The BGBD National Office, on biodiversity.
University of Nairobi, Kenya, • However, soil biodiversity has not received adequate
Tel: 254-020-4442115, Email: attention despite its contribution to sustainable agricultural
• This study was therefore undertaken to determine the effect
of land use on soil biota in Embu and Taita benchmark sites.
Benchmark sites Methodology
• The benchmark sites selected • Grid method was used to establish the sampling points
across land use intensification • Methods and criterion for soil sampling were as described
by Moreira et al. (2008).
– Embu - stretching from Irangi
forest into the adjacent farms.
• Samples were analysed for selected functional groups which
– Taita Hills stretching from included
Ngangao forest into the farms • Characterization, Micoregulators, Mesofauna, macroafauna
and plant pathogens
– Biodiversity hotspots,
supporting some endemic plant
and animal species.
Nematode trapping Colembola Acari
Trichoderma along land use types
• There was a general change of soil biota with increased land
• Soil pathogens (Pythium and Fusarium) and Plant parasitic
nematodes increased with increased land use intensity.
• Nematode trapping fungi increased with increase land
Land use types and Nutrients- Arbuscular Nematode destroying Fungi
Mycorrhizal Fungi (AMF)
Effect of land use on occurrence of nematode destroying fungi Parasitism index of plant parasitic nematodes in different land use types.
Frequency of occurrence %
Pa paras index
5 P lant at ion Nat ural Napier Fallow Coffee Maize Veget able
Land use t ype
Forest Shrub Napier Maize/ beans Vegetables
Abundance of mites across land use types in dry and wet seasons in Embu Abundance of Collembola across land use types in dry and wet seasons in Embu
Abundance of Collem bola
Mean abun dance of m ites
Land use types
Land use types
Bacteria in association with Legumes
• There was a general decline of soil biota
with increased land intensification.
• Soil pathogens (Pythium and Fusarium)
and Plant parasitic nematodes increased
Land use system No. of sampling Rhizobia populations
points (n) (cells g-1 soil) with increased land use intensity.
Coffee 8 1.1 × 102 ± 3.71
Tea 10 1.1 × 102 ± 3.32
• Nematode trapping fungi increased with
Maize, beans intercrop 8 1.1 × 102 ± 3.71 increase land intensification
Napier 6 6.1 × 10 ± 3.19
Fallow 7 2.3 × 102 ± 5.73
Indigenous forest 8 0