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An analysis of the efficiency of indigenous chicken marketing channels in Makueni County, Kenya
(201-04) Kabuage, L.; Ayieko, D.M.O.; Bett, E.K.;
The indigenous chicken (IC) (Gallus domesticus ) production is an important agricultural activity in many households in Kenya. Despite its importance, little research has been carried to enhance its productivity. Focus now is on IC because it presents an ideal poverty-food insecurity exit strategy especially for smallholders. It has been recently noted that market linkages is key in enhancing agricultural productivity and sustainability. However, there is little information on the marketing efficiency of IC in Makueni. Therefore the objective of this study was to analyse the marketing efficiency of the IC market and make policy recommendations to support IC value chain. A total of 66 IC traders and 130 producers were selected using purposive random sampling in Makueni and Nairobi counties. A pretested questionnaire was administered and data analysed using the shepherd index and multiple regression. A total of 8 marketing channels were identified, with a marketing efficiency index of between 5.29 and 1.81. Marketing cost, number of intermediaries, marketing margin, profit and price of IC had a significant effect on the marketing efficiency. Therefore it was recommended that contract models should be adopted for collective marketing and an improved marketing efficiency.
The behaviour of nitrogen fertilizers in neutral and acid loess soils II. Distribution and balances of 15 N‐tagged nitrogen
(Wiley-VCH Verlag, 1983) Mochoge, B. O.; Beese, F.
A study, to investigate the remaining fertilizer-N in undisturbed soil columns from agricultural and forest soils after 60 days of percolation (see part I), was carried out. The columns were fertilized with two 15-N tagged nitrogen fertilizers (Ca(NO3)2 and (NH4)2SO4) at a rate of 80kg N/ha. The investigation involved the distribution and fractionation of nitrogen in the soils. The soil columns were therefore cut into 8 segments and nitrogen forms analyzed were: total N, fixed-NH4-N, exchangeable NH4-N, NO3-N and organic N. Consequently, the N-balances were established.It was ascertained that immobilization and gaseous losses from the fertilizers were higher after NH4- than after NO3-application in both soils. Immobilization in all treatments was temperature dependent and concentrated at the upper segments of the columns. The forest soil had higher incorporation than the agricultural soil. Nitrification was low in the forest soil while in the agricultural soil there was a fairly high nitrification even at 4°C. The balances showed losses of nitrogen in the range of 10 to 35 %. While this agrees with the findings of other workers in case of the agricultural soil, it leaves however, some questions unanswered in case of the forest soil.Das Verhalten von Stickstoffdüngern in neutralen und sauren Böden aus Löß II. Verteilung und Bilanzierung von 15 N-markiertem StickstoffAn ungestörten Bodensäulen aus je einem Acker- und einem Waldboden wurde der Verbleib von appliziertem N-Dünger nach 60 Tagen Auswaschung (Teil I) untersucht. Die Säulen wurden mit zwei 15-N markierten N-Düngern (Ca(NO3)2 und (NH4)2SO4) entsprechend einer Gabe von 80kg/ha gedüngt. Die Untersuchung umfaßte die Tiefenverteilung und Fraktionierung des Stickstoffs im Boden. Zu diesem Zweck wurden die Säulen in Segmente zerlegt und auf folgende Fraktionen untersucht: Gesamt-N, fixierter NH4-N, austauschbarer NH4-N, Nitrat-N und org.N. Im Anschluß wurden die N-Bilanzen erstellt.Es wurde festgestellt, daß die N-Immobilisierung und die gasförmigen Verluste aus dem Dünger-N nach NH4-N Gabe größer waren als nach NO3-N Zufuhr. Bei allen Behandlungen war die N-Immobilisierung temperaturabhängig und in den oberen Abschnitten der Böden am größten. Der Waldboden wies eine höhere Incorporation des N in die org. Fraktion als der Ackerboden auf. Die Nitrifikationsraten im Waldboden waren gering, während sie im Ackerboden auch bei niedrigerer Temperatur noch beträchtliche Werte aufwiesen. Die Bilanzen wiesen N-Defizite in der Größenordnung von 10–35 % auf. Dies deckt sich mit den Ergebnissen anderer Autoren im Hinblick auf den Ackerboden. Beim Waldboden dagegen bleibt eine Anzahl von Fragen offen.
Simulation of nitrate movement in undisturbed soil columns
(Elsevier Masson, 1984) Mochoge, B. O.
In order to simulate the behaviour of nitrate movement in soils, two loessal soils were used which differed in their physical and chemical fertility. Undisturbed soil columns of 30 cm in length and 15 cm diameter were sampled. An unsaturated steady-state water flow in the columns was established and maintained by a Darcian flow of 5 cm solution/day. The nitrate fertilizer (tagged) was applied in solution form to the top of columns and in one lot. The study took place at 4 and 23°C in the laboratory. The results show that there is good agreement between computed and measured curves. (This was achieved by the curve-fitting approach.) This demonstrates that measured curves can easily be described by simple computer models. However, to be able to merge the two curves, one has to take into consideration the physical and chemical characteristics of the soil. These factors have great influence on the transport of nitrate and other ions in soils.
Leaching of plant nutrients from an acid forest soil after nitrogen fertilizer application
(Springer Verlag, 1986) Mochoge, B. O.
In a laboratory experiment, the effect of nitrogen fertilizers on the leaching patterns and input-output budgets of plant nutrients in an acid soil (dystric cambisols) was studied. An amount of N corresponding to 80 kg/ha was applied to the top surface of undisturbed soil columns of 30 cm layers with a diameter of 14.4 cm as Ca(NO3)2 or (NH4)2SO4. After establishing steady state flow condition, a flux of 0.5 cm solution/column was applied daily for 60 days. The leachates were collected and analysed every four days. It was found that not only the amount and quality of the applied cation influences the leaching pattern of plant nutrients in an acid soil but also the accompanying anion. To interpret leaching data properly, it was necessary to know the magnitude of N transformed in the different processes. Although the two applied salts influenced plant nutrient transport in different ways, total outputs of cations and anions were somewhat similar though outputs after (NH4)2SO4 were slightly higher than after Ca(NO3)2 addition.
The Orma Boran—ten years of field observations
(ILRAD, 1994) Munga, L.K.; Dolan, R.B.; Alushula, H.; Mutugi, M.; Mwendia, C.; Okech, G.; Sayer, P.D.; Stevenson, P.G.W.; Baker, R.L.; Magadi, M.
Presents the Orma Boran field observations carried out under tsetse fly challenge on Galana ranch in Kenya since 1980. Their response to trypanosomiasis has been compared to that of the ranch bred Kenya (Galana) Boran. The mean monthly prevalence of trypanosomiasis observed in Orma steers over five years was 17 percent compared with 31 percent in the Galana Borans. Mean annual mortality over five years was 35 percent in untreated Orma steers compared with 71 percent in untreated Galana steers. The primary difference appeared to be in their response to Trypanosoma vivax challenge. Their ability to acquire resistance has also been investigated under field conditions and both acquired and innate resistance appear to play a role. Steers monitored weekly over two years and treated with diminazene aceturate immediately on detection of infection showed some evidence of improved control of anaemia. In contrast, steers treated only when the PCV fell to 15 percent showed little evidence of improved anaemia control over two years. There was strong evidence for an innate component and the repeatabilities of PCV and infection rate were significant between the two years. Orma calves born on Galana ranch and herded together with their Galana counterparts were detected parasitaemic less often and the pre-weaning mortality was 7 percent compared with 17 percent for the Galana calves. The trypanosome prevalence in both groups of calves was lower than that observed over the same period in their dams and the vivax ratio was higher. Orma calves, however, had significantly lower birth & weaning weights than their Galana counterparts.
Gender, Environment and Population
(Wiley, 1994-01) Oniang'o, R.; Joekes, S.; Heyzer, N.
A Spatio-Temporal Analysis of Periodic Markets in Nyeri District, Kenya
(1995) Wambugu, Stephen K.
This paper examines the degree of spatiotemporal synchronization of markets in Nyeri District, Central Province, Kenya. Information on marketplaces and the days on which markets are held was obtained from Nyeri County Council, Nyeri Municipal Council, Karatina Town Council and Othaya Urban Council. Interviews with the market masters and gate fee collectors confirmed this information. The results show that the spatial and temporal location of periodic markets in Nyeri District favours consumers more than itinerant traders. The fact that market meetings are not sequenced in favour of itinerant traders hampers the proper movement of goods from areas of surplus to areas of deficit. In view of the importance of marketplaces for a peasant society, the author recommends the synchronization of market days and the establishment of new marketplaces and market days, together with the establishment of complementary institutions, such as schools, hospitals, and administrative centres, to promote the overall development of the region. Bibliogr., sum
A Spatio-Temporal Analysis of Periodic Markets in Nyeri District, Kenya
(1995) Wambugu, Stephen K.
This paper examines the degree of spatiotemporal synchronization of markets in Nyeri District, Central Province, Kenya. Information on marketplaces and the days on which markets are held was obtained from Nyeri County Council, Nyeri Municipal Council, Karatina Town Council and Othaya Urban Council. Interviews with the market masters and gate fee collectors confirmed this information. The results show that the spatial and temporal location of periodic markets in Nyeri District favours consumers more than itinerant traders. The fact that market meetings are not sequenced in favour of itinerant traders hampers the proper movement of goods from areas of surplus to areas of deficit. In view of the importance of marketplaces for a peasant society, the author recommends the synchronization of market days and the establishment of new marketplaces and market days, together with the establishment of complementary institutions, such as schools, hospitals, and administrative centres, to promote the overall development of the region. Bibliogr., sum.
Concentrations of isometamidium chloride (Samorin®) in sera of Zebu cattle which showed evidence of hepatotoxicity following frequent trypanocidal treatments
(Blackwell Publishing, 1997) Eisler, M.C.; Stevenson, P.; Munga, L.K.; Smyth, J.B.A
The concentrations of isometamidium circulating in poorly nourished Zebu cattle which showed morbidity, mortality, and biochemical and histopathological evidence of hepatotoxicity, following frequent treatments with isometamidium chloride and diminazene aceturate were investigated using the isometamidium-ELISA. As few as two isometamidium treatments one month apart were associated with significant weight loss, and cattle treated with diminazene aceturate after three or four isometamidium treatments suffered a 50% mortality. Although there were no obvious, marked elevations in isometamidium concentration which might have allowed the use of the ELISA as a predictor of a potential toxicity problem, concentrations did increase significantly with the number of monthly treatments administered, suggesting drug accumulation, and the increases were significantly higher in cattle to which diminazene had also been administered. In cattle treated with both trypanocides, weight loss and serum glutamate dehydrogenase levels were correlated with isometamidium concentrations. These observations, together with the histopathological findings, support the hypothesis that the morbidity and mortality observed were related to the repeated treatment with isometamidium in conjunction with diminazene aceturate, and that the pathogenesis involved a component of hepatic damage. It is therefore recommended that cattle, particularly those under nutritional stress, are not subjected to repeated treatments with isometamidium at intervals as short as one month, and particularly not with concurrent administration of diminazene.
An epidemic of besnoitiosis in cattle in Kenya
(AOSIS OpenJournals, 1998) Munga, L.K.; Njagi, O.N.; Ndarathi, C.M.; Nyaga, P.N.
A total of 17 head of cattle presenting with typical "Elephant skin disease" were isolated from the rest of the herd within a beef ranch for further clinical observation. On physical examination, all the animals had characteristic sclero-conjunctival cysts of Besnoitia besnoiti. In addition, some of the animals had characteristic skin nodules on the legs, ears and back. Histological examination of skin sections revealed typical large Besnoitia cysts. Microscopic exami• nation of crush preparations of skin scrapings revealed crescent-shaped organisms with a more pointed anterior than posterior end (banana-shaped morphology) confirming that the cysts belong to the genus Besnoitia. To the best of our knowledge, this is the first clinical record of bovine besnoitiosis in Kenya.
Rinderpest vaccination and the incidence and development of trypanosomosis in cattle.
(Springer Verlag, 1999) Munga, L.K.; Stevenson, P.; Ndung'u, E.K.; Rossiter, P.B.; Dolan, R.B.
An investigation was made into whether recent vaccination of cattle with tissue culture rinderpest virus would cause immunosuppression and lead to more frequent or more severe infection with trypanosomes in animals grazing in tsetse-infested areas. Herds of cattle on Galana Ranch in Kenya were divided, with approximately half of each herd being vaccinated with tissue culture rinderpest virus strain Kabete 'O', while the rest remained unvaccinated. The herds were then exposed to the risk of natural infection with trypanosomes on the ranch. Three experiments were performed during different seasons. Infections with Trypanosoma congolense and Trypanosoma vivax were frequently detected but there was no evidence that vaccinated animals were more likely to acquire trypanosome infections or to show a more severe disease than unvaccinated cattle. It is concluded that tissue culture rinderpest vaccine does not cause immunosuppression and can safely be used in cattle likely to be exposed to tsetse flies and trypanosomosis
Alley cropping of maize with calliandra and leucaena in the subhumid highlands of Kenya Part 1. Soil-fertility changes and maize yield
(Kluwer Academic Publishers., 1999-06-01) Mugwe, J. N.; Mugendi, D.N.; Nair, P. K.; O’neill, M. K.; Woomer, P. L.
Although N-rich leaf biomass of multipurpose trees is known to be a good source of N to crops, integrating such trees into crop production systems is a major challenge in the development of viable agroforestry systems. An approach to integrating calliandra (Calliandra calothyrsus Meissner) and leucaena (Leucaena leucocephala (Lam.) de Wit), two promising agroforestry tree species, into maize (Zea mays L.) production system was investigated in the subhumid highlands of central Kenya during four maize-growing seasons from 1994 to 1996. The experiment consisted of maize plots to which tree prunings obtained from hedgerows grown either in situ (alley cropping) or ex situ (biomass transfer from outside) were applied. When alley-cropped with leucaena, maize produced significantly higher yields compared to maize monoculture (both non-fertilized and fertilized) treatments, but when alley-cropped with calliandra, the yield of maize was less than that of the monocropped unfertilized control. Application of ex situ grown calliandra and leucaena prunings with or without fertilizer resulted in higher maize grain yield than in the nonfertilized and fertilized treatments. Yields of calliandra alleycropped maize were 11% to 51% lower than those of nonalley-cropped treatments receiving calliandra prunings from ex situ grown trees; the decrease was 2% to 17% with leucaena, indicating that calliandra hedges were more competitive than leucaena hedges. The alley-cropped prunings-removed treatments produced the lowest maize yields. The study showed that, in the subhumid tropical highlands of Kenya, inclusion of calliandra hedges on cropland adversely affected maize yields. On the other hand, alley cropping with leucaena was advantageous
Short communication effect of lime, urea and triple super phosphate on nitrogen and phosphorus mineralisation in an acid soil during incubation
(Bioline International,, 2000) Mochoge, B. O.; Onwonga, Richard N.; Lelei, Joyce J.
A significant portion of soil N and P occurs in organic forms that are not available for crop uptake unless mineralised ( Stevenson, 1986; Tisdale et al., 1990). Slowed nitrification rates (Weber and Gainey, 1962) and P fixation (Stevenson, 1986) greatly hinder the conversion of organic N and P to their mineral forms in acid soils. Other factors include soil temperature, moisture, pH, fertiliser additions and the C/N ratio of the organic material (Dalal, 1977; Jansson and Persson, 1982; Hendrickson, 1985). Organic N and P mineralisation in acid soils are stimulated mainly through liming (Dalal, 1977; Kamprath and Foy, 1985; Hue, 1989) and/or P fertiliser application (Dalal, 1977; Evans, 1985). Liming raises soil pH, thereby creating favourable conditions for microbial growth, especially nitrifyers and actinomycetes (Anderson and Domesch, 1980), and decreases the solubility of Al- and Fe-hydroxides but increases the solubility of Al- and Fe-phosphates. After P application, there is competition between inorganic and organic P compounds for soil sorption sites resulting in a substantial increase in dissolved organic P (Evans, 1985). Laboratory incubation experiments are a convenient way of quantifying and studying the N mineralisation processes (Bremner, 1965a; Keeney, 1982). Bremner (1965b) and Keeney (1982) found that incubation of soil under favourable conditions provides a rational measure of N availability. This is because the agents responsible for release of mineral N during incubation are the same ones which avail N from the organic soil pool for crop growth during the growing season. Lathwell et al. (1972) also found that N produced during incubation was highly correlated with N released to crops in the field. This method (Laboratory incubation) is however, unsatisfactory because either several simultaneous occuring processes are measured (in situ net mineralisation rate) or they establish potential nitrification rates rather than actual rates (Woldendorp and Laanbroek, 1989). There is scanty literature on the behaviour of P mineralisation under laboratory incubation. Nevertheless, the factors controlling P mineralisation are more or less the same as those of N (Vaughan and Malcolm, 1985). The purpose of this study, therefore, was to investigate the effect of various soil amendments on N and P mineralisation in an acid soil through laboratory incubation.
Response of meloidogyne hapla to mycorrhiza fungi inoculation on pyrethrum
(2001-12) Waceke, J. W.; Waudo, S. W.; Sikora, R.
Five arbuscular mycorrhiza fungi (AMF) isolated from pyrethrum were screened in the greenhouse for efficacy in improving pyrethrum growth and in suppressing a root-knot nematode, Meloidogyne hapla. The fungi screened were Glomus spp. (isolates LM61, ML34 and ML35), Scutellospora sp. (isolate KS74) and Gigaspora sp. (isolate LM83). A 20g 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, two months after nematode inoculation. Glomus LM61 and Scutellospora KS74 significantly improved top biomasses of fungus-treated and fungus-nematodetreated plants. Glomus LM61was more effective (33% top biomass increase). Glomus ML34 and ML35 and Gigaspora LM83 improved top biomasses of fungus-nematode-treated plants. Scutellospora KS74 and Glomus ML34 significantly increased fresh root weights of pyrethrum by 45% and 50%, respectively. Glomus LM61, Scutellospora KS74 and Gigaspora LM83 caused 86%, 32% and 37% nematode suppression, respectively. All the fungal isolates significantly reduced the number of females and J-2. The presence of nematodes in fungus-treated plants did not affect root colonization by the fungi except in plants treated with Glomus ML34 and ML35.
Assessment of erosion damage in Ndome and Ghazi, Taita Taveta, Kenya: Towards an integrated erosion management approach
(GeoJournal, 2002-01-02) Waswa, F.; Gachene, C.K.K.; Eggers, Helmut
Aerial photograph interpretation on erosion trends from 1961 to 1998 showed that by 1998, approximately 17 and 50% of agricultural land in Ndome and Ghazi respectively had been permanently lost due to the combined effect of rill, inter-rill, and gully erosion, and sand deposition. Although abnormally heavy rains received between 1996–98 caused much of the present land damage, the severity of the damage was enhanced by inappropriate and persistent human perturbations in the land-system notably through vegetative degradation and destruction of soil structure through inappropriate tillage practices. With soil organic matter contents of 1.6 and 1.9%, and clay ratios of 10.1 and 10.6 for Ndome and Ghazi, respectively, the areas inherent erodibility was considered as high thus pointing to the need for careful use and management of the soil resource. That farmers appreciated only land quality indicators that were visible to the naked eye and that directly affected their subsistence, revealed a knowledge gap that saw damages from intrinsic processes like rill and inter-rill erosion proceed unnoticed. This paper argues that the spread of erosion damage in rural agro-ecosystems is survival-driven. And as a remedy to this problem, there is need for the diversification of livelihood endeavours to alternative off-farm income sources to reduce pressure on the already fragile land resource. Further, being the ultimate implementers of conservation technologies and by virtue of the multiplicity and inter-relation of rural household needs, adoption of an integrated erosion management approach with food security as paramount presents the most practical entry point for sustainable land management in such rural agro-ecosystems.
Technical Efficiency of Rice Producers in Mwea Irrigation Scheme
(2003) Kabuage, L.; Ommeh, H.; Kuria, J.N.; Mbogo, S.; Mutero, C.
A study to investigate the technical Efficiency associated with rice production was carried in Mwea irrigation Scheme. Two groups of farmers were compared, one group consisting of farmers growing a single crop of rice in a year and the other growing a double crop of rice in a year. Most of rice production in Kenya comes from Mwea Irrigation Scheme. Until 1998, the Government’s National Irrigation Board was running the Scheme. Since, the management has been taken over by a local farmer’s cooperative society, the Mwea Multipurpose Rice Growers. This latter management however lacks the resources and facilities for effective management and this has led to a decline in rice production in the Scheme. There have been constraints in credit and extension facilities as well as other physical production inputs. The study uses a stochastic frontier production function model in which the technical inefficiency effects are assumed to be a function of farmer’s specific characteristics as well as institutional factors. Empirical results indicated that farmers growing a single crop of rice were more technically efficient that those growing a double crop of rice in a year. Farmer’s education level and farming experience as well as availability of credit and extension facilities were found to be significant variables influences technical efficiency. The study recommended that a policy to facilitate the availability of credit and extension services to farmers has to be drawn, as well as a policy which would encourage research on a dry land crop to rotate with rice rather than growing two crops which are technically inefficient.
Soil Productivity improvement technologies for increased food production in Meru South District, Kenya
(African Crop Science Society, 2003) Mugwe, J. N.; Mucheru-Muna, M.; Mugendi, D.N.; Kangai, R.; Kung'u, J.B.
Declining crop productivity is a major problem facing smallholder farmers in Central highlands of Kenya. This decline is caused by continuous cultivation of soils without adequate addition of external inputs in form of manures and fertilizers. This low soil fertility has an enormous contribution to one of the greatest challenges facing Kenya currently; the inadequate food production for the rapidly growing population. A multidisciplinary farmers participatory trial was established in the main maize growing areas of Meru South District, Kenya in 2000 with the main objective of offering small-scale resource poor farmers feasible soil nutrient replenishment technologies for improving soil fertility. Results indicate that, the average maize grain yield across the treatments ranged from 1.1 to 4.0 Mg ha-1 during the five seasons. On average tithonia with half recommended rate of inorganic fertilizer recorded the highest maize yield followed by sole tithonia while crotalaria and absolute control recorded the lowest yields. The improved maize grain yields in the 2000/2001 short rains, 2001 long rains, 2001/2002 short rains and 2002 long rains seasons from the 2000 long rains season demonstrate the positive impact of these technologies in the area
Trends in Adoption of Soil Fertility Improvement Strategies in Chuka, Eastern Kenya
(African Crop Science Society, 2003) Mugwe, J. N.; Mugendi, D.N.; Mucheru, M. W.; Otor, S.C.J.; Waswa, B. S.; Kung'u, J.B.
A study was conducted in Chuka division, eastern Kenya to assess trends in adoption of soil fertility replenishment strategies. Eighty two (82) farmers adopted the soil fertility improvement technologies during the short rains season 2001.During the subsequent two seasons, 163 and 206 farmers representing an increase of 99% and 150% above the initial adopters practiced the soil fertility improvement strategies. Technologies involving use of Tithonia diversifolia And Calliandra calothrysus alone or in combination with inorganic fertilizer were readily adopted due to the high yields obtained as well as being sources of fodder in case of calliandra. Constraints to the adoption of the proposed soil fertility improvement strategies were identified as inadequate labor, poor yield observed from some of the technologies at the demonstration trial, inadequate organic and inorganic resources and laxity due to fear of failure
Adoption Potential of Soil Replenishment Resources: Feasibility and Acceptability of Leguminous Plants and other Organic Resources for Soil Fertility Improvement in Meru South District, Kenya
(African Crop Science Society, 2003) Mugendi, D.N.; Mugwe, J. N.; Mucheru-Muna, M.; Kung'u, J.B.
A preliminary study to assess adoption potential of legumes and other organic soil replenishment resources was carried out in Chuka division, Meru south District, Kenya during 2002 long rains season. The study examined feasibility, acceptability, biophysical responses, farmers experiences - constraints and modifications of technologies as indicators of adoption. In a collaborative project between Kenyatta University and Kenya Agricultural Research Institute on integrated soil fertility management, a follow-up was done on how farmers selected technologies for soil fertility improvement after field days held every growing season, and a formal survey was carried out to find out how farmers implemented and modified the technologies. Selection of technologies by farmers was variable. Farmers initially selected soil fertility improvement resources that combined both organic and inorganic resources, but majority of the farmers implemented tithonia and cattle manure. Herbaceous legumes were least preferred due to competition with foodcrops while majority of the farmers used the new technologies on relatively small plots ranging from 0.02 to 0.05 acres citing reasons that they wanted to see the results first. Farmers practicing the technologies mainly benefited from increased crop yields and improved soil fertility. Among the main constraints farmers indicated were facing were lack of adequate biomass for incorporating into the soil and lack of cash to purchase inputs like hybrid maize and inorganic fertilizer. Farmers have responded by planting trees for biomass production on their farms and by 2002 long rains season some farmers had planted up-to 700 trees. The study has revealed the need to monitor how farmers adopt technologies as it facilitates in identification of issues and constraints that might hinder adoption and that could possibly feed into second generation research agenda. There is need to carry out more studies to validate the farmers innovations and to explore further the long-term sustainability of using tithonia.
The role of agroforestry trees in intercepting leached nitrogen in the agricultural systems of the central highlands of Kenya.
(East African Agricultural and Forestry Journal, 2003) Mugwe, J. N.; Wamicha, W.; Mugendi, D.N.; Kung'u, J.B.; Kanyi, M.
Application of N-rich tree biomass to crop fields in agroforestry associations can cause a build-up of mineral-N in the top soil in excess of crop demand during early stages of crop growth. It is therefore important to monitor movement of such mineral-N in the soil, so that management options to minimise its potential loss via leaching can be designed. A randomised complete block experiment to investigate mineral-N movement down a soil profile in an agroforestry system was conducted in an Ultisol in the central highlands of Kenya during the Long and Short Rains of 1998 cropping seasons. The trial consisted of 10 treatments repricated 3 times. Maize was used as the test crop, and was grown alone or in hedge row intercropping with or without fertiliser/ prunings applications. The hedge row tree species were Leucaena leucocephala and Calliandra calothyrsus. The results indicated that the bulk of mineral-N in these soils was in the form of nitrate-N with ammonium- nitrate comprising less than 10%. During the first season which had plenty of rain, mineral- N progressively moved (was leached) down the soil profile as the season progressed, accumulating in the deeper soil horizons in stark contrast with the second dry season where mineral-N accumulated in the top soil layers. Treatments that received tree leafy- biomass but had no trees ± fertiliser recorded higher amounts of mineral-N in the 100-to- 300 cm depth averaging 15 to 30 mg N/kg. On the other hand, soils in treatments with Leucaena leucocephala and Calliandra calothyrsus tree hedges recorded an average I of 1 to 3 mg N/kg in the same depth, indicating that trees are capable of intercepting and recapturing the crop- inaccessible nutrients, below the roots of the annual crops by the action of their deep roots. Indeed, results on the total root length indicated that less than 5% of all the maize roots were located below the 90 cm soil depth while 75% leucaena and 40% calliandra roots were found below the same depth.

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