RP-School of Environmental Studies

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Morphological Structure and the Anthropogenic Dynamics in the Lake Naivasha Drainage Basin and its Implications to Water Flows
(Summer School 2005) Onywere, S. M.
Throughout its length, the Kenyan Rift Valley is characterized by Quaternary volcanoes. At Lake Naivasha drainage basin, the Eburru (2830m) and Olkaria (2434m) volcanic complexes and Kipipiri (3349m), Il Kinangop (3906m) and Longonot (2777m) volcanoes mark the terrain. Remote sensing data and field survey were used to make morphostructural maps and to determine the structural control and the land use impacts on the drainage systems in the basin. Lake Naivasha is located at the southern part of the highest part of Kenya’s Rift Valley floor in a trough marked to the south and north by Quaternary normal faults and extensional fractures striking in a N18°W direction. The structure of the rift floor influences the axial geometry and the surface process. Simiyu and Keller (2001) interpret the rift floor structure as due to thickening related to the pre-rift crustal type and modification by magmatic processes. The rift marginal escarpments of Sattima and Mau form the main watershed areas. From the marginal escarpments the Rift Valley is formed by a series of down-stepped fault scraps. These influence the nature of the soils and the rainfall regime. The drainage is also influenced by the fault trends. At the Malewa fault line for example the drainage is south-easterly influenced by the trend of the Malewa fault line (Thompson and Dodson, 1963). The morphotectonic control on the drainage has implications on ground water recharge in the Naivasha basin. This may also influence the spring water supply and geothermal reservoirs. The nature of the terrain, human development processes and their impact on the lake was visualized using Landsat TM satellite data (path 169/Raw 060) from three dates (28/1/1986 L5, 1/3/1989 L4
In-kind transfers of maize, commercialization and household consumption in Kenya
(Journal of Eastern African Studies, 201) Wambugu, Stephen K.; Djurfeldt, A. A.
This article discusses in-kind food transfers and whether such transfers should be interpreted as a sign of the failure of grain markets to meet the food demands of the poor. The article elucidates on aspects of both consumption and in-kind transfers of maize against a backdrop of poorly functioning markets. It adds to the theoretical understanding of household based linkages and provides a documentation of in-kind commodity flows missing in many discussions of such linkages. The purpose of the article is twofold: first, it sheds light on the phenomenon of in-kind transfers of staple crops in the Kenyan context; secondly, it assesses the wider reciprocal and livelihood implications for the transferring households. The article relies on three sets of data with respect to methodology. It uses quantitative data collected at the household level in 2008, qualitative data collected at the village level in 2002 and 2008, as well as qualitative household level data gathered through in-depth interviews with 30 heads of household and farm managers in Western Kenya in June and July 2006. The survey found that 38% of the households transferred maize to their relatives. The explanations for in-kind transfers are not primarily related to poor price incentives, but the functioning of household support systems across space. In-kind transfers therefore at times drain the food resources of sending households while constituting important sources of food security for receiving households. While the focus in the literature is generally on rural–urban linkages, the direction of maize transfers was primarily rural-to-rural. The article concludes that existence of food transfers underpins the necessity of improving commercial incentives for maize and other foodstuffs and eliminating physical barriers to free movement of foodstuffs across the national space.
Potential role of cereal-legume intercropping systems in integrated soil fertility management in smallholder farming systems of sub-Saharan Africa
(Third RUFORUM Biennial Meeting, 201-09) Mucheru-Muna, M.; Matusso, J. M. M.; Mugwe, J. N.
The sub-Saharan Africa’s population is growing exponentially and it has to fulfill its food and nutrition requirement. An attractive strategy for increasing productivity and labour utilization per unit area of available land is to intensify land use. Intercropping is advanced as one of the integrated soil fertility management practices consisting of cultivating two or more crops in the same space at the same time, which have been practiced in past decades and achieved the goals of agriculture. Also, intercropping systems are beneficial to the smallholder farmers in the low-input and/or high-risk environment of the tropics, where intercropping of cereals and legumes is widespread among smallholder farmers due to the ability of the legume to contribute to addressing the problem of declining levels of soil fertility. The principal reasons for smallholder farmers to intercrop are flexibility, profit maximization, risk minimization, soil conservation and improvement of soil fertility, weed, pests and diseases control and balanced nutrition. This is a review paper that explores the role of cereal legume intercropping systems in integrated soil fertility management in smallholder farms of Sub-Saharan Africa. The intercropping systems are useful in terms of increasing productivity and profitability, water and radiation use efficiency, control of weeds, pests and diseases. The critical role of biological nitrogen fixation and the amounts of N transferred to associated non-leguminous crops determines the extent of benefits. In intercropping, land equivalent ratio (LER), benefit cost ratio (BCR) and monetary advantage index (MAI) are used to assess the productivity and its economic benefits. In this study, the work carried out by various researchers about different intercropping system is discussed, and it would be beneficial to the researchers who are involved in this field.
Intracavity pulse compression with glass: a new method of generating pulses shorter than 60 fsec
(Optical Society of America, 1983) Diels, J.C.; Fontaine, J. J.; Dietel, W.
The introduction of a glass prism in a ring dye laser is shown to provide simultaneous wavelength selection and pulse compression.
Functional Evaluation of Pedotransfer Functions for the Estimation of Soil Hydraulic Properties
(Elsevier, 1992-09) Diels, J.; Vereecken, H.; VOrshoven, J. V.; Feyen, J.; Bouma, J.
Pedotransfer functions (PTFs) are often used for estimating hydraulic properties such as the moisture retention characteristic and the pressure head-hydraulic conductivity relationship. Both properties are essential for the description of water and solute movement in unsaturated soils. Frequently, PTFs are not evaluated with respect to specific applications. The criteria, presently used to evaluate the goodness of fit for a PTF do not provide information about the performance of these functions for applications such as the prediction of the downward water flux below the soil root zone or of the soil moisture deficit during the growing season. We performed functional evaluations of PTFs. In a first sample problem, the influence of uncertainty in the PTF was examined on the basis of two functional criteria: the moisture supply capacity (MSC) and the downward flux below the root zone (DFR). In a second sample problem the effect of the uncertainty in the PTFs and the variability in soil properties within a map unit on the simulated MSC distributions were analyzed. The MSC distributions were calculated and compared for two map units known by soil surveyors to differ considerably during a dry year. It was found that an improved estimate of the hydraulic properties, obtained by calibrating PTFs using detailed textural information, did not substantially reduce the dispersion of the MSC and DFR distributions. Results from the second sample problem indicated that >90% of the variation in the simulated MSC was caused by estimation errors in the hydraulic properties, overwhelming the map unit variability.
A deterministic evaluation analysis applied to an integrated soil-crop model
(Elsevier, 1995-08) Diels, J.; Feyen, J.; Viaene, P.; Vanclooster, M.
The WAVE-model (Water and Agrochemicals in the soil and Vadose Environment), simulating one-dimensional transport of water, solute and heat in the unsaturated zone, was used to simulate the behaviour of water and nitrogen in soils cropped with winter wheat and sugar beet. Soil water transport was modelled using the Richards equation, while solute transport was described with a convection equation. Soil mineral nitrogen transformations were simulated using first-order kinetics, while for the organic matter turnover three organic matter pools were considered. A summary model was used to simulate crop growth. The performance of the integrated model was evaluated in a deterministic way using field data for a three-year period. The data of the first year were used for the model calibration. The remaining set of data was used to evaluate the capacity of the model to predict soil water content, the soil nitrate-N content, the soil ammonia-N content, the soil temperature, the soil water pressure head, the leaf area development and the dry matter accumulation in different plant organs. A screening sensitivity analysis indicated that the calculated nitrogen balance was sensitive to the soil hydraulic properties and the crop Kc-factors for the given scenario. The effect of uncertainty of the sensitive hydraulic properties on the calculated nitrogen balance was investigated using Monte Carlo simulation. Taken into consideration the variability on the soil hydraulic parameters, predicted nitrate-N flux out of the soil profile at a depth of one meter ranged for the simulated period (three years) between −10 and +10 kg ha−1.
Impact of residue quality on the C and N mineralization of leaf and root residues of three agroforestry species
(Springer Verlag, 1996) Vanlauwe, B.; Nwoke, O. C.; Sanginga, N.; Merckx, R.
A laboratory incubation experiment with 15N labeled root and leaf residues of 3 agroforestry species (Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla) was conducted under controlled conditions (25 C) for 56 days to quantify residue C and N mineralization and its relationship with residue quality. No uniform relation was found between the chemical composition of the above and below residues. The leucaena and dactyladenia roots contained more lignin (8 and 26% respectively) and less N (2.0 and 1.0% respectively) than the respective leaves (2 and 13% lignin and 2.9 and 1.4% N, respectively), whereas the differences between the lignin and N contents of the flemingia leaves and roots were not significant (4.6 and 3.0% lignin and 2.63 and 2.68% N, respectively). The leucaena leaves contained more polyphenols than the roots (6.4 and 3.6%), while the polyphenol content of the leaves and roots of the other residues was similar (5.0 and 5.1% for dactyladenia and 4.0 and 3.5% for flemingia). Three patterns of N mineralization could be distinguished. A first pattern, followed by residues producing the highest amounts of CO2, showed an initial immobilization of soil derived N, followed by a net release of both soil and residue derived N after 7 days of incubation. A second pattern, followed by the flemingia leaf residues which produced intermediate amounts of CO2 and had an intermediate quality, showed no significant immobilization of soil derived N, and significant mineralization of residue N. A third pattern, followed by both low quality dactyladenia residues, showed a low release of residue derived N and a continued inmobilization of soil derived N. Residue C mineralization was significantly (p<0.05) correlated with the residue lignin content, C-to-N ratio, and polyphenol-to-N ratio. The proportion of residue N mineralized (immobilized) after 56 days of incubation was significantly correlated with the residue N content (p<0.01) and the C-to-N ratio (p<0.05). The relations were quadratic, rather than linear. The ratio of the proportion of residue N mineralized (immobilized) over the proportion of residue C mineralized after 56 days was highly significantly correlated with the lignin content (p<0.01) and C-to-N (p<0.001), lignin-to-N (p<0.01), polyphenol-to-N (p<0.01) and (lignin+polyphenol)-to-N ratios (p<0.01) in a linear way. This indicates that due to the low availability of the residue C, relatively less N is immobilized for the very low quality residues ((lignin+polyphenol)-to-N ratio: 29.7) than for the residues with a relatively higher quality ((lignin+polyphenol)-to-N ratios between 3.3 and 12.5).
Dispersion measurements with white-light interferometry
(1996) Diels, J.C.; Diddams, S.
White-light interferograms provide a simple, accurate, and physically intuitive picture of what happens to broadband optical pulses on transmission through, or reflection from, common optical materials. Quantitative measurement of group delay are made with an accuracy of ±0.1 fs and with high spectral resolution. This measurement accuracy is applied to the determination of d2n/dλ2 and d3n/dλ3 of fused silica with an accuracy of ±5 × 10−5 µm−2 and ±1 × 10−3 µm−3, respectively. Further applications are found in the measurement of the dispersion of broadband mirrors and a multiple-quantum-well structure.
Predicting the Decomposition Patterns of Tree Biomass in Tropical Highland Microregions of Kenya
(Kluwer Academic Publishers, 1996) Mugendi, D.N.; Nair, P. K. R.
Decomposition- and nitrogen-release patterns of biomass from three agroforestry multipurpose trees (Calliandra calothyrsus, Cordia africana and Grevillea robusta) were investigated in four contrasting environments (microregions) in the Kenyan tropical highlands during two cropping seasons. Dried leafy biomass was placed in 2-mm litter bags, buried at 15-cm depth and recovered after 2, 4, 7, 10, 15 and 20 weeks. Decomposition patterns were best described by first-order exponential decline curves. The decomposition rate constants ranged from 2.1 to 8.2 yr−1, and the rates of decomposition among the species were in the order: calliandra ≥ cordia > grevillea. There was a species-by-environment interaction during both seasons, but the nitrogen released did not follow such a pattern. Among the three tree species, calliandra released the highest amount of cumulative N, followed by cordia and grevillea. Using multiple regression techniques, decomposition pattern was described as a function of three groups of factors: biomass quality (N, C, lignin and polyphenol), climate (soil temperature and rainfall), and soil conditions (pH, soil organic C, total N and P). For all the species and factors combined, the adjusted R 2 values were 0.88 and 0.91 for seasons 1 and 2, respectively. Among the three groups of factors, climate and biomass quality had the most influence on decomposition rates. Climatic factors accounted for 75% of the total rate of decomposition in season 1 (‘irregular’ season with less rainfall and more soil temperature fluctuations), whereas biomass quality factors were more influential in season 2 (‘regular’ season), accounting for 65% of the total variability.
Puberty and the family formation process in Sudan: age-at-menarche differential fecundity hypothesis revisited
(Social Biology, 1998) Otor, S.C.J.; Pandey, Arvind
This paper revisits and extends an inquiry on the age-at-menarche differential fecundity hypothesis. Earlier studies have interpreted the difference in the onset of female pubertal maturation as indicative of biological differences in fecundity between early and late menarcheal women. Using the WFS data for Sudan, the authors address the entire reproductive life of the women in terms of their transition from one parity to the next, as well as the speed with which birth intervals are closed, as a way to infer biological fecundity among the women. The study concludes that there is little evidence that early menarcheal women are more fecund than their late puberty counterparts
Alley cropping of maize with calliandra and leucaena in the subhumid highlands of Kenya: Part 2. Biomass decomposition, N mineralization, and N uptake by maize
(Kluwer Academic Publishers, 1999) Mugendi, D.N.; Nair, P. K. R.; Mugwe, J. N.; O'Neill, M. K.; Swift, M. J.; Woomer, P.
A major challenge in developing agroforestry approaches that utilize tree-leaf biomass for provision of N to crops is to ensure synchrony between the N released from decomposing prunings and N demand by crops. A study was conducted in the subhumid highlands of Kenya to assess the rate of decomposition and mineralization of soil-incorporated Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena) tree biomass and maize roots (Zea mays L.) both in an alley cropping and a sole cropping system. The amount of mineralized N peaked four weeks after planting (WAP) maize in all the treatments during both seasons of 1995. Cumulative mineralized N at week 20 ranged from 114 to 364 kg N ha−1 season−1, the absolute control treatment giving the lowest and the prunings-incorporated treatments giving the highest amounts in the two seasons. Total N uptake by maize, ranging from 42 to 157 kg ha−1 season−1, was lowest in the 'alley-cropped, prunings-removed' treatments, and highest in the 'non alley-cropped-prunings-incorporated' treatments. The apparent N recovery rate by maize was highest in the fertilizer applied treatments in the two seasons. Decomposition rate constants (kD) ranged from 0.07 to 0.21 week−1, and the rates among the different plant residues were as follows: leucaena < calliandra < maize roots. Nitrogen release rate constants (kN), ranging from 0.04 to 0.25 week−1, followed a similar pattern as the rate of decomposition with leucaena releasing the highest amount of N followed by calliandra and lastly by maize roots.
Adolescent transition to coitus and premarital childbearing in sudan: a biosocial context
(Cambridge University Press, 1999) Otor, S.C.J.; Pandey, Arvind
The effects of woodfuel consumption in the ASAL areas of kenya: the case of marsabit forest
(Wiley, 2000-03) Kirubi, C.; Wamicha, W. N.; Laichena, Justus K.
In the arid and semiarid lands (ASAL) of Kenya, fuelwood and charcoal constitute 95–98% of the total energy demand for cooking, heating and lighting. The resultant deleterious ecological effects are severe and need urgent remedial interventions. A study was carried out in Marsabit District, which is a vast ASAL region, to examine the effects of woodfuel consumption on Marsabit Forest and the surrounding areas. It was found that wood for fuel harvested from Marsabit Forest was approximately 56,000 tons y−1. The rate of deforestation was estimated at 1.6 ha y−1. This resulted in great loss of indigenous biodiversity, destruction of vital ecosystems and habitats. To control further degradation of the forest, it is recommended that an immediate ban be imposed to stop harvesting of the indigenous species such as Olea spp. and Teclea spp., which are seriously endangered. Also, woodfuel conservation through wider and more efficient use of the improved energy-saving technologies should be enhanced.
Nitrogen recovery by alley-cropped maize and trees from 15N-labeled tree biomass in the subhumid highlands of Kenya
(Springer-Verlag, 2000-05) Mugendi, D.N.; Nair, P. K. R.; Graetz, D. A.; Mugwe, J. N.; O'Neill, M. K.
The effectiveness of tree-leaf biomass as a source of N to crops in agroforestry systems depends on the rate at which crops can obtain N from the biomass. A study was conducted to determine the fate of 15N labeled, soil-applied biomass of two hedgerow species, Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena), in the subhumid highlands of Kenya. Labeled biomass obtained from 15N fertilized trees was applied to microplots in an alley cropping field and maize planted. N uptake and recovery by maize and hedgerow trees was periodically determined over a 20-week period during the short rain (1995) and the long rain (1996) growing seasons. In maize crop from treatments that received leucaena biomass, higher N uptake and recovery were recorded than in maize from the plots that received calliandra biomass. However, N uptake and recovery were higher in calliandra tree hedges than in leucaena hedges, indicating differences in N uptake by the two tree species. The largest fraction (55–69%) of N in the applied tree biomass was left in the soil N pool, 8–13% recovered by maize, 2–3% by tree hedges, and 20–30% could not be accounted for. Some of the unaccounted for N may have been left in the wood and root portions of the tree hedges and in the bulk soil below the 20-cm depth. The study shows that only a small fraction of the N contained in the N-rich biomass that is applied to the soil is taken up by the current season's crop, suggesting that a major benefit may be in the build-up of the soil N store.
Phenotypic nutrient up-take differences in an alley cropping system in semi-arid Machakos, Kenya
(IOS Press, 2001-01-01) Mugendi, D.N.
Alley cropping of Cassia siamea and maize was studied in semi-arid Kenya for soil fertility improvement. Katumani composite maize was planted except in the short rains of 1988 (SR88) when a hybrid variety was sown. Therefore the grain yield per row increased differently in the alley cropped maize (CM). Sole maize (SM) and CM yields were higher in SR88 than in the long rains of 1988 (LR88) by 62% and 38%, while yields from the same treatments in LR89 were only 21% and 45% of those in SR88. These differences in relative maize yields are attributed to differences between the two maize varieties in competition under nutrient stress conditions.
Suppression of Root-knot Nematode by Mycosymbionts on Pyrethrum (Chrysanthemum cinerariefolium Vis.)
(AJOL, 2002) Waceke, W.; Waudo, S. W.; Sikora, R.
Five arbuscular mycorrhiza fungi (AMF) obtained from pyrethrum fields were screened for efficacy in improving pyrethrum (Chrysanthemum cinerariefolium Vis.) growth and in suppressing a root-knot nematode, Meloidogyne hapla Chitwood in the greenhouse. The fungi screened were Glomus macrocarpum Tul and Tul, G. constrictumTrappe, G. monosporum Gerd. & Trappe, Scutellospora calospora (Nicol. Gerd.) Walker & Sanders and Gigaspora gigantea (Nicol. Gerd.) Gerd. & Trappe. A mixed fungal inoculum was incorporated into sterilized sand-soil mixture before transplanting 6-week-old pyrethrum seedlings. The inoculum consisted of the growth medium, spores, external mycelia and infected root segments. The plants were inoculated with 6000 M. hapla second stage juvenile (J-2) 3 months after fungal inoculation. Dry shoot weights, fresh root weights, percent root colonization by the fungi, nematode gall indices, number of eggs and females in the root system and number of J-2 in the soil were determined at the end of the experiment, 2 months after nematode inoculation. Glomus macrocarpum and S. calospora significantly improved top biomasses of fungus-treated and fungusnematode- treated plants. Glomus macrocarpum was the most effective, causing a 35% top biomass increase. Glomus constrictum, G. monosporum and G. gigantea improved top biomasses of fungusnematode- treated plants. Scutellospora calospora and G. constrictum significantly increased fresh root weights of pyrethrum by 46% and 53%, respectively. Except G. constrictum and G. monosporum, all the other fungi suppressed M. hapla disease severity and egg production. Glomus macrocarpum was the most effective, causing 87% nematode suppression. Scutellospora calospora and Gigaspora gigantea suppressed disease severity and egg production by up to 33% and 37%, respectively. All the fungi significantly reduced the number of females and J-2 in pyrethrum roots. Nematodes did not affect root colonization by the fungi except in G. constrictum and G. monosporum-colonized plants.
Beyond Land Titling for Sustainable Management of Agricultural Land: Lessons from Ndome and Ghazi in Taita-Taveta, Kenya
(Kassel University Press, 2002) Waswa, F.; Eggers, H.; Kutsch, T.
This paper is based on a 1996-1999 case study that was done in semi-arid Ndome and Ghazi, Taita-Taveta District, in Kenya to determine the root causes of persistent erosion damage in the area. More than 10 years after land adjudication was done in these areas, more than 70% of the farmers still operate under tenure insecurity mainly due to lack of title deeds (r = 0.94**). Contrary to conventional expectation of land development, owning of land under private property rights was motivated by the sense of belonging, wealth, power and to some degree for speculative purposes. Adoption of structural soil and water conservation measures was still well below 50%. Preference was still given to indigenous land and water management (ILWM) technologies, with adoption rates ranging from 60% to more than 90%. No evidence existed that directly linked land improvement to land titling. For sustainable land management, land titling remains a critical incentive to farmers. However it will have to be accompanied by land use policy reforms that address four main issues, thus: deliberate efforts to preserve agricultural land, equitable distribution of available land, putting as much land as possible to agricultural use, and mechanisms to enhance prevention and control of land degradation. How these objectives can be achieved within the Kenyan context is the conceptual gist of this paper.
The Impact of Export Processing Zone Development on Employment Creation in Kenya
(WILEY, 2002-12-19) Mireri, C.
This paper examines the contribution of Export Processing Zones (EPZ) to employment creation in Kenya. The results suggest that employees in non-EPZ businesses are better paid than those in the EPZ. Firms in the EPZ employ more women than the Kenyan national average, although the proportion is less than the international average amongst EPZs. Against the general fear that EPZ enterprises offer little employment, the number of employees in the EPZ enterprises are comparable to those found outside as are working hours. A weak trade union movement, inefficient and inadequate social security, lack of employment benefits, lack of opportunities for training and promotion and low pay are problems encountered by those working in an EPZ
Enhancement of food productivity using leguminous shrubs in the Eastern highlands of Kenya
(Elsevier, 2003) Mugendi, D.N.; Mucheru-Muna, M.; Mugwe, J. N.; Bationo, A.
Declining soil productivity is a major challenge facing smallholder farmers in eastern highlands of Kenya. This decline is caused by continuous cultivation of soils without adequate addition of external inputs in form of manures and fertilizers. A study was initiated in 1992 to evaluate the feasibility of using two leguminous shrubs Calliandria (Calliandra calothyrsus ) and Leucaenia ( Leucaena leucocephala ) for improving soil productivity. The shrubs were evaluated in alley cropping and biomass transfer systems. Over the 11 years of study, calliandra and leucaena biomass transfer with half recommended rate of inorganic fertiliser treatments gave the best average maize yields of 3.2 t ha -1 . On the other hand calliandra alley cropped with prunings removed treatment recorded the lowest maize yield of 1.2 t ha -1 . Though treatments with calliandra biomass transfer had similar yields compared to those of leucaena biomass transfer, all the treatments that were leucaena alley cropped did better than calliandra alley cropped treatments both with prunings incorporated and prunings removed. These long-term results indicate that biomass transfer system of these leguminous shrubs is a more feasible option as opposed to alley cropping in the region.
Soil Invertebrate Macrofauna Composition within Agroforestry and Forested Ecosystems and their Role in Litter Decomposition in Embu, Kenya
(CIAT, 2004) Mugendi, D.N.; Mwangi, M.; Kung'u, J.B.; Swift, M. J.; Albrecht, A.
Adequate food to meet the needs of an ever-increasing population is a major challenge for most developing countries, especially in the tropics. Despite this, few new technical packages capable of increasing net returns without deteriorating the environment have been developed. Crop yields in Embu, Kenya are poor due to declining soil fertility prompted by continuous cropping and application of fertilizers in non-sufficient quantities by farmers. Studies have shown that soil biota provides the means and regulates the transformation of organically bound nutrients into plantavailable forms through mineralization. An experiment was conducted to investigate soil macrofauna composition within agroforestry and forested ecosystems and their role in litter decomposition. This was anticipated to address poor crop yields in the study region. The study was conducted during the long and the short rains of the year 2000 on-station at Embu in an ongoing hedgerow intercropping experiment. Two types of Standard PVC litterbags with mesh size 7 mm and 1mm, were used. The 7 mm mesh size allowed macrofauna to enter while the 1 mm excluded the macrofauna. Two types of litter: Calliandra calothyrsus (low quality) and Leucaena leucocephala (high quality), were placed in the litterbags in duplicate in selected treatments of the Embu trials and were sampled at 1, 2, 4, 8, and 16 weeks. Decomposition rate constants (k) were estimated using a non-linear module in the EXCEL spreadsheet upon fitting first order exponential equations. Results from the study depicted that different management practice and/or land use affect soil macrofauna in varied manner. Soil invertebrate macrofauna enhanced the rate of decomposition of C. calothyrsus and L. leucocephala litter.

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