Accessibility and Reliability of Information Sources in Dissemination of Soil Fertility Management in Eastern Kenya

Increased recognition of soil fertility depletion as the main factor limiting crop production in many small holder farms in sub-Saharan African has renewed interest in the dissemination of soil fertility management technologies. Despite soil technology development and research outputs, few of the recommendations from various soil fertility management research activities have been adopted by the small-scale farmers on a large-scale level. Only a small proportion of allocated research resources is invested in dissemination among research institutions. The objective of the study was to investigate communication channels used in dissemination of soil fertility management practices in Mbeere and Meru South Districts. Two hundred and forty randomly selected farmers were interviewed. Data collected was analyzed using SPSS. The study revealed that 32.5% of the farmers who used combined organic and inorganic fertilizers received information from government extension officers while 41.3% of the farmers who use animal manure utilized their own farming experience. In disseminating soil erosion control measures, 51.2% of the farmers indicated that, farmer to farmer extension was the most commonly used. Also, 33.8% mentioned demonstration as the main method used in training soil fertility management practices. In general, the most common source of information was other farmers while there was least participation of researchers and agro input dealers in dissemination of soil fertility technologies. Thus, the study recommended more participation of stakeholders other than government extension officers as well as use of combined extension methods with farmer involvement in dissemination of soil fertility management practices.  Keywords: manure, extension agents, farmer to farmer extension method, demonstration DOI: 10.7176/DCS/10-11-03 Publication date: November 30th 202

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

Agronomic and economic performance of legume-legume and cereal-legume intercropping systems in Northern Tanzania

Open Access Article; Published online: 20 Dec 2022CONTEXT Cereal-legume intercropping, a common practice among farmers in sub-Saharan Africa (SSA), is important for crop diversification, soil fertility improvement, household nutrition and climate adaptation. However, cereals often outcompete the intercropped legumes for growth resources resulting in low legume yields. OBJECTIVE The objectives of this study were: i) assessing the effects of different intercropping options (crop spatial configurations) and maize crop (Zea mays L.) management innovations on productivity and economic benefits to farmers and ii) examining how farmers adapt new intercropping technologies to meet their household food security needs. METHODS The study was undertaken in six on-farm researcher-designed and managed trials in high and low rainfall agro-ecological zones of Babati District in Tanzania, during four cropping seasons (2018–2021). The cropping systems tested included a sole maize system rotated with a legume-legume intercrop (Doubled-up legume), an innovation involving two maize rows intercropped with two legume species (Mbili-Mbili), maize-legume intercrop both with and without de-topping, maize-legume intercrop (2 maize plants at 50 cm intra-space, de-topped), maize-legume system (maize with vertical leaf architecture) and a farmer practice. The Mbili-Mbili technology adaptation assessment was conducted on 225 farmers during the 2021 cropping season. RESULTS AND CONCLUSIONS Overall, maize grain yields increased by up to 56% in improved compared to farmer intercropping practices (P ≤ 0.05). There were no significant differences in maize grain yield among the improved practices. Significantly higher pigeonpea (Cajanus cajan) yields of between 71% and 113% in 2020 and between 65% and 140% in 2021 were observed under Doubled-up legume and between 63% and 124% under local farmer practices in 2020 than in the improved cereal-legume practices. Across the study period, net revenues of sole maize and Doubled-up legume rotations were both the highest and lowest relative to other intercropping options, depending on the starting phase (US$653 sole maize and US$ 326 legume phase starting). These were also associated with the highest variances indicating instability. Mbili-Mbili intercropping system had not only high net revenue i.e., a mean of US$623 per hectare, but also more stable. Farmers perceived that Mbili-Mbili increased food security and 96% were willing to implement the system without project support. SIGNIFICANCE Mbili-Mbili is recommended for adoption by farmers because of its potential economic benefits, food security and resilience in the current unpredictable weather and climate patterns

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

Managing soil organic carbon in tropical agroecosystems: evidence from four long-term experiments in Kenya

In sub-Saharan Africa, maize is one of the most important staple crops, but long-term maize cropping with low external inputs has been associated with the loss of soil fertility. While adding high-quality organic resources combined with mineral fertilizer has been proposed to counteract this fertility loss, the long-term effectiveness and interactions with site properties still require more understanding. This study used repeated measurements over time to assess the effect of different quantities and qualities of organic resource addition combined with mineral nitrogen (N) on the change of soil organic carbon (SOC) contents over time (and SOC stocks in the year 2021) in four ongoing long-term experiments in Kenya. These experiments were established with identical treatments in moist to dry climates, on coarse to clayey soil textures, and have been conducted for at least 16 years. They received organic resources in quantities equivalent to 1.2 and 4 t C ha−1 yr−1 in the form of Tithonia diversifolia (high quality, fast turnover), Calliandra calothyrsus (high quality, intermediate turnover), Zea mays stover (low quality, fast turnover), sawdust (low quality, slow turnover) and local farmyard manure (variable quality, intermediate turnover). Furthermore, the addition of 240 kg N ha−1 yr−1 as mineral N fertilizer or no fertilizer was the split-plot treatment. At all four sites, a loss of SOC was predominantly observed, likely because the sites had been converted to cropland only a few decades before the start of the experiments. Across sites, the average decline of SOC content over 19 years in the 0 to 15 cm topsoil layer ranged from 42 % to 13 % of the initial SOC content for the control and the farmyard manure treatments at 4 t C ha−1 yr−1, respectively. Adding Calliandra or Tithonia at 4 t C ha−1 yr−1 limited the loss of SOC contents to about 24 % of initial SOC, while the addition of sawdust, maize stover (in three of the four sites) and sole mineral N addition showed no significant reduction of SOC loss over the control. Site-specific analyses, however, did show that at the site with the lowest initial SOC content (about 6 g kg−1), the addition of 4 t C ha−1 yr−1 farmyard manure or Calliandra with mineral N led to a gain in SOC contents. The other sites lost SOC in all treatments, albeit at site-specific rates. While subsoil SOC stocks in 2021 were little affected by organic resource additions (no difference in three of the four sites), the topsoil SOC stocks corroborated the results obtained from the SOC content measurements (0–15 cm) over time. The relative annual change of SOC contents showed a higher site specificity in farmyard manure, Calliandra and Tithonia treatments than in the control treatment, suggesting that the drivers of site specificity in SOC buildup (soil mineralogy, soil texture, climate) need to be better understood for effective targeting management of organic resources. Farmyard manure showed the highest potential for reducing SOC losses, but the necessary quantities to build SOC are often not realistic for smallholder farmers in Africa. Therefore, additional agronomic interventions such as intercropping, crop rotations or the cultivation of crops with extended root systems are necessary to maintain or increase SOC.</p

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

Minimum tillage, tied ridging and mulching for better maize yield and yield stability in the Central Highlands of Kenya

© 2017 Elsevier B.V. Most smallholder farmers in Sub-Saharan Africa and in Kenya have been experiencing a decrease in crop yields in the recent decades. Droughts and prolonged dry spells are common and water is becoming the main limiting factor during crop growing seasons threatening smallholder farmers’ livelihood. Hence, availability and adoption of conservation-effective management practices (CEM) that foster soil conservation, water retention, improved crop yield and yield stability under the small-holder rainfed farming system is desirable. Based on this, we evaluated effects of selected CEM techniques on maize (Zea mays L.) yields, yield stability and farmers’ willingness to take up the techniques. We hypothesized that, the CEM techniques will not only increase maize yield but also the yield stability. The selected CEM were minimum tillage (MT), mulching (MC) and tied ridging (TR) tested alongside a control (conventional tillage) (CT) in two sites, a semi-arid (with predominant soil type being Cambisols with cambic B horizons) and sub-humid agro-ecologies (with predominant soil type being Humic Nitisols), in the Central Highlands of Kenya. We implemented field trials on-farm for four seasons: short rains 2011 (SR11), long rains 2012 (LR12), short rains 2012 (SR12) and long rains 2013 (LR13). The test crop was Maize (Zea Mays L.). A key informant's interview with the farmers who implemented the field trial was conducted to assess their willingness to take up CEM techniques. Rainfall distribution and amount varied widely between the two sites. Maize grain yields were significantly higher in TR and MC treatments during the LR12, SR12 and LR13 seasons in the semi-arid site compared to CT. Tied ridging doubled grain yields during SR12 season in the semi-arid site. In the sub-humid site, grain yields significantly increased under all the tested CEM techniques during SR11, LR12 and SR12 seasons. Maize grain yields were more stable under TR and MC with residual variances of 0.107 and 0.183 Mg ha−2, respectively in the semi-arid site. Mulching, MT and TR techniques indicated yield stability with residual variances of 0.017, 0.039 and 0.155 Mg ha−2, respectively, in the sub-humid site. We concluded that, under semi-arid conditions, tied ridging is a better CEM technique that not only positively affect maize yields but it also enhances yield stability. Under sub-humid agro-ecological conditions, mulching technique performed comparatively well in terms of increasing maize grain yields and yield stability. The n were further affirmed by the farmers’ willingness to continue practicing TR and MC practice in Mbeere South and Meru South, respectively.status: publishe

Effects of organic and mineral fertilizer inputs on maize yield and soil chemical properties in a maize cropping systems in Meru South District, Kenya

Soil nutrient depletion as a result of continuous cultivation of soils without adequate addition of external inputs is a major challenge in the highlands of Kenya. An experiment was set up in Meru South District, Kenya in 2000 to investigate the effects of different soil-incorporated organic (manure, Tithonia diversifolia, Calliandra calothyrsus, Leucaena leucocephala) and mineral fertilizer inputs on maize yield, and soil chemical properties over seven seasons. On average, tithonia treatments (with or without half recommended rate of mineral fertilizer) gave the highest grain yield (5.5 and 5.4 Mg ha?1 respectively) while the control treatment gave the lowest yield (1.5 Mg ha?1). After 2 years of trial implementation, total soil carbon and nitrogen contents were improved with the application of organic residues, and manure in particular improved soil calcium content. Results of the economic analysis indicated that on average across the seven seasons, tithonia with half recommended rate of mineral fertilizer treatment recorded the highest net benefit (USD 787 ha?1) while the control recorded the lowest (USD 272 ha?1). However, returns to labor or benefit-cost ratios were in most cases not significantly improved when organic materials were used