Jefwa, J.

Kuyper, T.W.

Muchane, M.N.

Vanlauwe, B.

English

Wageningen UR (University & Research Centre): Publication System

 Long-term effects of NP applications and farmyard 
manure on Arbuscular Mycorrhizal Fungal (AMF) 
communities in Kabete, Kenya 
 
 
  
 
  
 
M.N. Muchane1, T.W. Kuyper1, J, Jefwa2 and B. Vanlauwe2 
1Department of Soil Quality, Wageningen University , P.O. Box 47, 6700 AA Wageningen, The Netherlands email: mary.muriithi@wur.nl 
2Tropical Soil Biology & Fertility Institute (TSBF CIAT), P.O. Box 30677-00100, Nairobi, Kenya  
 
 
 
Figure 1: Study area Figure 2: Kabete field trial 
Study area: Long term field trial, Kabete central Kenya, established in 1976 (Figs 1 
& 2). 
Method 
 Study was done during the long (March-September, 2008) and short (October, 
2008 – February, 2009) rainy seasons 
 Experiment comprised of 3 (manure) x 3 (NP) x 2 (residues) factorial experiment 
in a complete randomized block design replicated three times.  
 The plots received farmyard manure at 0t/ha (FYM0), 5 t/ha (FYM1) and 10t/ha 
(FYM2) and nitrogen-phosphorus (NP) fertilizer at 0 kg N & P/ha (N0P0), 60 kg 
N & 26.4 kg P/ha (N1P1) and 120 kg N & 52.8 kg P/ha (N2P2), with (R1) or 
without (R0) crop residue (maize stover).  
 AMF inoculum potential (IP) was assessed using bioassays with undisturbed soil 
cores and three fast growing crops (Leek, Cow pea and sorghum).  
 AMF species composition was assessed in field soil and with the help of trap 
 Unbalanced addition of mineral fertiliser and organic 
amendments reduced diversity and abundance of AMF 
communities.  
 Long-term field trials provide a unique opportunity to 
assess effects of treatments to revert low soil fertility on 
communities of AMF. 
 Negative effects of crops residues in some aspects of AMF 
activity may be associated to phytotoxic effect of un-
composted crop residues on growth and functioning of the 
extra-radical hyphae (Kahiluoto et al., 2012). 
References 
Kahiluoto, H., Ketoja, E. and Vestberg, M. (2012) Plant-available P supply is not the 
main factor determining the benefit from arbuscular mycorrhiza to crop P 
nutrition and growth in contrating cropping systems. Plant and Soil. 350: 85-98 
Okalebo,  J., Othieno, C., Woomer, P., Karanja, N., Semoka, J., Bekunda, M., Mugendi, 
D., Muasya, R., Bationo, A. and Mukhwana, E. (2007) Available technologies 
to replenish soil fertility in East Africa. In, Advances in Integrated Soil Fertility 
Management in sub-saharan Africa: In Bationo, A (ED) Challenges and 
opportunities. Springer Netherlands: pp. 45-62. 
Vanlauwe, B. (2004) Integrated soil fertility management research at TSBF: the 
framework, the principles, and their application. In: Bationo, A. (Ed.), Managing 
Nutrient Cycles to Sustain Soil Fertility in sub-Saharan Africa. Academy 
Science Publishers, Nairobi, pp. 25–42. 
  
 
Figure 4: Effect of manure on AMF species 
 
Figure 5: Effect of NP fertilization on AMF species 
 
Figure 6: Effect of manure on AMF colonization of field crops 
Materials and Methods 
Introduction 
Low inherent soil fertility in most African countries causes low and unsustainable
crop yields (Okalebo et al., 2007). To restore soil biodiversity and biological function 
of these depleted soils, organic amendments are proposed (Vanlauwe, 2004).
However, little is known on how improved land management (addition of organic
amendments) contributes to the restoration of soil biodiversity in particular
Arbuscular Mycorrhizal Fungi (AMF) which play an important role in enhancing
chemical, physical and biological soil quality. Understanding long-term effects of 
organic and inorganic fertilization on AMF communities may ensure an opportunity
for management. The aim of this study was to investigate community structure and
diversity of AMF in a maize-bean rotation system fertilized with 3 levels of organic
input (farm yard manure) and NP fertilization in presence or absence of crop residues
in a 32 years old field trial. We hypothesized abundance and diversity of AMF are 
higher after addition of organic amendments.  
16 AMF species from five genera were observed. Most common genus was 
Acaulospora  (60% of spores), followed by Scutellospora (20%). Species 
composition was similar in different treatments. NP and manure treatments 
explained only 3% of total variation in the data set.  
 
Both manure and NP fertilizer negatively affected on AMF species richness and 
abundance resulting in a decline of 24 and 34% in spore abundance and 9% in 
species richness. Some species of Acaulospora (A. sp. 1, A. scrobiculata) 
showed a significant decline due to manure (Fig 4) and NP (Fig. 5). Manure 
increased root colonization (Fig. 6). Residue application had only minor effects.  
 
 
 
S. pellucida  Glomus sp.  
 
Ac. mellea 
 
Ac. scrobitulata 
 
Results  
Conclusions 
Figure 3: Some AMF species in the study site
Field trial 


Long-term effects of NP applications and farmyard manure on Arbuscular Mycorrhizal Fungal (AMF) communities in Kabete, Kenya

https://library.wur.nl/ojs/index.php/AE2012/article/download/13078/12541

Long-term effects of NP applications and farmyard manure on Arbuscular Mycorrhizal Fungal (AMF) communities in Kabete, Kenya

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