Effect of plant biomass, manure and inorganic fertilizer on maize yield in the central Highlands of Kenya

Soil fertility degradation remains the major biophysical cause of declining per capita crop production on smallholder farms in sub-Saharan Africa. Appropriate soil fertility regimes, are therefore, critical for improved crop productivity. This study investigated the feasibility of using sole organics or their combinations with inorganicfertilisers to improve maize (Zea mays) production in the highlands central Kenya. Sole application of Calliandra calotyrsus, Leucaena trichandra trichandra, Mucuna pruriens, Crotalaria ochroleuca, Tithonia diversifolia and cattle manure at 60 kg N ha-1 or combined application of the organic materials (30 kg N ha-1) plus inorganic fertiliser (30 kg N ha-1) gave significantly (P < 0.05) higher maize grain yields than the recommended rate of inorganic fertiliser (60 kg N ha-1). These treatments maintained maize yields at 4 to 6 t ha-1. Farmers had theirown innovations where they combined organic resources and generally appreciable yields (3.0 to 5.6 t ha-1) were obtained from these innovations. However, there was a maize yield gap between on station and on farm trials with on station yields having on average 65% more yields than the on-farm yields. This was mainly attributedto differences in management practices arising from partial adoption of recommended rates. There is need therefore to develop and implement mechanisms tailored to ensure that farmers’ modications recommended soil amendment regimes and other agronomic practices are appropriate for enhanced crop productivity. Further studies are needed to establish the optimum mixture of different organic materials

Applicability of conservation agriculture for climate change adaptation in Rwanda’s situation

Improving food security and environmental conservation should be the main targets of innovative farming systems. Conservation agriculture (CA), based on minimum tillage, crop residue retention and crop rotations has been proposed against poor agricultural productivity and soil degradation. This paper discusses the applicability and potential benefits of CA in Rwanda under the unfolding climate change scenario. The potential and benefits from CA may vary with rainfall regime. In high rainfall areas (For example North and West of Rwanda), the soils are susceptible to soil erosion and face fertility decline while in low rainfall areas (For example East of Rwanda) crops fail due to sub-optimal water use efficiency. Furthermore, low organic carbon content lower fertilisers response and government targets of increasing production through Crop Intensification Program, is limited. It has been shown that CA can: Reduce soil loss from 35.5 to 14.5 t/ha/year, have 50-70% greater infiltration and increase 42% of organic carbon. Long term analysis using Agricultural Production System Simulator showed that CA can increase yield from 3.6 to 4.4t/ha in areas having >770 mm. Based on the evidence from regional research, CA has a good potential for climate change adaptation in both high and low rainfall areas of Rwanda. However, decreased yield observed in high rainfall areas, increased labour requirements when herbicides are not used and lack of mulch due to priority given to feeding of livestock constrained CA adoption. We conclude that there is a need for critical assessment under which ecological and socio economic conditions CA is suited for smallholder farming in Rwanda

Integrating scientific and farmers' perception towards evaluation of rain-fed agricultural technologies for sorghum and cowpea productivity in Central Kenya

Integration of a minimal addition of organic and inorganic inputs on valued traditional crops with adequate rainfall under normal farming practices in semi arid lands is an option that may improve food security in the Central highlands of Kenya. Agricultural production is affected by the high variability of rainfall onset, distribution, and frequent droughts which usually occur during the growing season, often resulting in depressed yields and persistent crop failures. This study assessed a farmers’ participatory evaluation on selected water harvesting and integrated soil fertility management technologies for sorghum and cowpea productivity. Their evaluations were consistent and accurate

Adoption potential of selected organic resources for improving soil fertility in the central highlands of Kenya

Abstract Soil fertility decline is the major cause of declining crop yields in the central highlands of Kenya and elsewhere within the African continent. This paper reports a study conducted to assess adoption potential of two leguminous trees, two herbaceous legumes, cattle manure, and Tithonia diversifolia either solely applied or combined with inorganic fertilizer, for replenishing soil fertility in the central highlands of Kenya. The study examined biophysical performance, profitability, feasibility and acceptability, and farmers experiences in managing and testing the inputs. The study was based on a series of studies incorporating both sociological and experimental approaches for two and a half years. Results of on farm trials showed that manure ? fertilizer and tithonia ? fertilizer treatments increased yields by more than 100% above the control. These treatments were the most profitable having highest net benefits and benefit cost ratios. They were also the most commonly preferred by farmers who used them on larger plots compared to the other inputs. In conclusion, cattle manure and tithonia were found to be the organic materials with the highest adoption potential for soil fertility improvement in this area. Calliandra calothyrsus and Leucaena trichandra, on the other hand, have potential for use as animal fodder. The herbaceous legumes had the least adoption potential due to poor performance recorded on Andre Bationo was formerly working for Tropical Soil Biology and Fertility Institute of CIAT (TSBF-CIAT) as the African network Coordinator

Bentley Fellowship Award / Bourse Bentley

Perception of soil fertility as a current problem, and distance from the demonstration plots, were significantly associated with adoption of soil fertility replenishment practices at 5 % probability level. Other factors were farm management, ability to hire labour, hiring out of own labour and number of months in a year when households bought food to meet family deficits. Ability to hire labour was positively associated with adoption while hiring out of labour was negatively associated with adoption. Adopters had significantly less numbers of mature cattle, more tea bushes and more numbers of adult males than the nonadopters

Bentley Fellowship Award / Bourse Bentley

Perception of soil fertility as a current problem, and distance from the demonstration plots, were significantly associated with adoption of soil fertility replenishment practices at 5 % probability level. Other factors were farm management, ability to hire labour, hiring out of own labour and number of months in a year when households bought food to meet family deficits. Ability to hire labour was positively associated with adoption while hiring out of labour was negatively associated with adoption. Adopters had significantly less numbers of mature cattle, more tea bushes and more numbers of adult males than the nonadopters

Effect of Plant Biomass, Manure and Inorganic Fertiliser on Maize Yield in the Central Highlands Of Kenya

Soil fertility degradation remains the major biophysical cause of declining per capita crop production on smallholder farms in sub-Saharan Africa. Appropriate soil fertility regimes, are therefore, critical for improved crop productivity. This study investigated the feasibility of using sole organics or their combinations with inorganic fertilisers to improve maize ( Zea mays ) production in the highlands central Kenya. Sole application of Calliandra calotyrsus , Leucaena trichandra trichandra , Mucuna pruriens , Crotalaria ochroleuca , Tithonia diversifolia and cattle manure at 60 kg N ha-1 or combined application of the organic materials (30 kg N ha-1) plus inorganic fertiliser (30 kg N ha-1) gave significantly (P < 0.05) higher maize grain yields than the recommended rate of inorganic fertiliser (60 kg N ha-1). These treatments maintained maize yields at 4 to 6 t ha-1. Farmers had their own innovations where they combined organic resources and generally appreciable yields (3.0 to 5.6 t ha-1) were obtained from these innovations. However, there was a maize yield gap between on station and on farm trials with on station yields having on average 65% more yields than the on-farm yields. This was mainly attributed to differences in management practices arising from partial adoption of recommended rates. There is need therefore to develop and implement mechanisms tailored to ensure that farmers&apos; modications recommended soil amendment regimes and other agronomic practices are appropriate for enhanced crop productivity. Further studies are needed to establish the optimum mixture of different organic materials.La dégradation de la fertilité de sol reste la cause biophysique majeure du déclin du par capita production agricole sur les fermes de petit exploitant en Afrique au sud du Saharan. Les régimes de fertilité de sol appropriés, sont donc, critiques pour améliorer la productivité des récoltes. Cette étude a examiné la possibilité d&apos;utiliser des organiques seuls ou leurs combinaisons avec les engrais inorganiques pour améliorer la production du maïs ( Zea mays ) dans les pays de montagne au centre du Kenya. L&apos;application de Calliandra calotyrsus , Leucaena trichandra trichandra , Mucuna pruriens , Crotalaria ochroleuca , Tithonia diversifolia et le fumier de bétail à 60 kg N ha-1 ou application combinée des matériels organiques (30 kg N ha-1) plus l&apos;engrais inorganique (30 kg N ha-1) a donné significativement (P <0,05) des hauts rendements de grain de maïs que le taux recommandé d&apos;engrais inorganique (60 N kg ha-1). Ces traitements ont maintenu des rendements de maïs à 4 à 6 t ha-1. Les fermiers ont eu leurs propres innovations où ils ont combiné des ressources organiques et des rendements généralement appréciables (3,0 à 5,6 t ha-1) ont été obtenu de ces innovations. Cependant, il y avait une différence entre le rendement de maïs des essais sur station et sur ferme, le premier ayant en moyenne 65% plus de rendements que les rendements de sur ferme. Ceci a été principalement attribué aux différences dans les pratiques de gestion résultant de l&apos;adoption partielle de taux recommandés. Il y a donc besoin de développer et appliquer des mécanismes adapter pour s&apos;assurer que les modifications recommandées des régimes d&apos;amendement de sol et les autres pratiques d&apos;agronomiques par les fermiers soient appropriées pour l&apos; amélioration de la productivité de récolte. Plus d&apos;études sont nécessaire pour établir le mélange optimum de matériels organiques différents