D. Mugendi

Continuousdecline in soil productivity is a major constraint to the improvement of livelihoods of smallholderfarmers of Kenya. In highlands, levels of soil nitrogen, phosphorus and sometimes potassiumare low and the situation is worsened by the methods of cultivation that results in nutrientmining rather than nutrient build up. Low soil fertility contributes to one of the greatest challenges currently facing Kenya; inadequate food production for the rapidly growing population. There is a need to seek for environmentally friendly and economically viable technologiesto assist in soil fertility improvement and hence high and sustainable crop yields. To thisend, a multidisciplinary research team of scientist and farmers implemented a participatory trialin Meru South district, one of the main maize growing areas of central Kenya. The trial was farmer-researcher managed with a general objective of offering small scale resource poor farmers withfeasible soil nutrient management techniques ...

Climate variability is among the main threats to rain-dependent smallholder farming in most sub-Saharan Africa countries. Hence, farmers should make efforts at the local level to utilize indigenous knowledge (IK) combined with conventional knowledge to adapt to climate variability impacts. We assessed; IK used by farmers in climate forecasting, their perceptions of climate variability and adaptation strategies, and their correlation with conventional approaches. We conducted the study in Tharaka South and Kitui Central sub-counties of Kenya. We used the triangulation approach to obtain the quantitative and qualitative data. To select respondents, we used purposive and random sampling strategies combined with the snowballing technique. Observed rainfall and temperature data from 1998 to 2018 were obtained from the Kenya Meteorological Department (KMD). Results showed that there were significant (p < 0.05) differences in the use of indigenous indicators such as observation of the behavior of the sky (2 = 14.631), moon (2 = 7.851), and wind (2 = 5.864). The majority of the smallholder farmers (87%) used the change in the behavior of trees as the indigenous indicator in weather forecasting. The most common adaptation strategies (over 80%) used were food storage for future use (88.5%) and change of planting dates (87.5%). The analysis output of conventional data from KMD conformed with the farmers' observations and perception of climate variability over the reference period. Because farmers are still using IK that agrees with conventional knowledge, there is a need to integrate IK with conventional knowledge for use by rain-fed-dependent smallholder farmers in climate forecasting.

This study reviews and synthesizes the soil fertility status, management among smallholder farmers and research in the three countries of east Africa, namely Kenya, Tanzania and Uganda. We observe that many studies note the declining soil fertility, mainly due to soil fertility mining, putting crop production in an unsustainable path. Studies have shown that the current soil fertility management practices

Decline in crop yields is a major problem facing smallholder farmers in Kenya and the entire Sub-Saharan region. This is attributed mainly to the mining of major nutrients due to continuous cropping without addition of adequate external nutrients. In most cases inorganic fertilizers are expensive, hence unaffordable to most smallholder farmers. Although organic nutrient sources are available, information about their

Understanding gender differentials in adoption of soil nutrient replenishment technologies is critical to their successful implementation by farmers. This study was conducted to examine gender differentials in choices of soil fertility management technologies adopted by male and female-headed households; and lastly, to investigate socio-economic, institutional, farm and demographic factors influencing their adoption. The results indicated gender differences in the choice of cattle manure and in organic fertilizer. A logistic regression model developed revealed that different factors influenced adoption at household level. In male-headed households, adoption was significantly and positively influenced by; number of cattle owned, access to credit, number of adults working on farm and farmer group membership. For femaleheaded households, adoption was positively influenced by area under cash crops, number of goats owned, number of adults working on farm, participation in project activit...

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. ...

tillage practices with various surface management technologies under sub-soiling stabilizes yield over time as compared to use of surface management strategies alone. Partners: Regional Universities Forum for Capacity Building in Agriculture (RUFORUM), Kenyatta University (KU) -is This pamphlet funded by RUFORUM -soiling -; Recommendation Sub Sub soiling helps to break the compacted soil layers allowing the rain water to percolate into the soil (Figure 5) This technique is very important especially in areas where soils compact forming a hard pan. In Mbeere yields of above 1.5 t/ha were achieved in farmers' elds with the use of sub-soiling. Minimum Tillage Reduced tillage is a practise in which the soil is tilled to some extent but not completely inverted. Reduced tillage means a smaller volume of soil is exposed to erosion and moisture loss by evaporation hence, conserving moisture (Figure 6) Figure 6: Minimum tillage Fig 5: Sub-soiling

Why use local indicators in weather forecasting? • Most of agriculture in Tharaka and Kitui is rain-fed and the bulk is under small-holder farming. • Cropping systems in the region are often limited by variations in climate (rainfall and temperature). • The conditions caused by climate variability have negative effects on agricultural productivity by introducing unfavourable growing conditions into the existing cropping calendar. • There is therefore need for adaptation as a fundamental and necessary response to the unfavorable conditions introduced into the existing cropping calendar. • The adaptive responses include among others the use of indigenous knowledge (IK)/ local indicators that are passed on among local communities in addition to the conventional knowledge and this helps to predict disasters caused by climate variability

Smallholder farmers in Tharaka and Kitui suffer the adverse effects of climate variability, especially variations in rainfall and temperatureThis has had a negative impact on agricultural production and is attributed to the fact that most of their agriculture is rain-fed There is therefore need for adaptation as a fundamental and necessary response to the threats posed by climate variability Adaptation refers to all adjustments that reduce the vulnerability of farmers to conditions caused by climate variability Smallholder farmers in these areas have characteristically adopted adaptation/coping mechanisms to help in reducing the overall vulnerability to climate variability shocks.

Continued declines in per capita agricultural productivity in the Central Highlands of Kenya are mainl y due to: • Soil nutrient deficiencies • Low soil water availability (rainfall variability & prolonged dry spells/ droughts) • Crop response to fertilizer highly depends on seasonal distribution of rainfall due to its influence on soil water content • Use of organic residues is limited due to other competing uses of the organic residues in the farm

SUMMARYThere is continued decline in per capita agricultural productivity in the drier parts of Kenya's central highlands. The declines have been linked to low and declining soil fertility, soil water, high atmospheric heat, prolonged dry-spells and erratic rainfall. Integrated soil fertility management (ISFM) technologies have been developed and tested in the region. Despite their significant impacts, high variability in local soils and climate contributes to large variations and inconsistency in research results among replications. Experimentation is expensive and limited to a few years, sites and scenarios. Crop-growth simulation models suitably complement experimental research, to support decision making regarding soil fertility and water management. This study evaluated the performance of the Agricultural Production Systems Simulator (APSIM) model. APSIM was parameterized and calibrated based on a rain-fed randomized complete block trial (2009–2012) at a research station in...

This study examined the extent of seasonal rainfall variability, drought occurrence, and the efficacy of interpolation techniques in eastern Kenya. Analyses of rainfall variability utilized rainfall anomaly index, coefficients of variance, and probability analyses. Spline, Kriging, and inverse distance weighting interpolation techniques were assessed using daily rainfall data and digital elevation model using ArcGIS. Validation of these interpolation methods was evaluated by comparing the modelled/generated rainfall values and the observed daily rainfall data using root mean square errors and mean absolute errors statistics. Results showed 90% chance of below cropping threshold rainfall (500 mm) exceeding 258.1 mm during short rains in Embu for one year return period. Rainfall variability was found to be high in seasonal amounts (CV = 0.56, 0.47, and 0.59) and in number of rainy days (CV = 0.88, 0.49, and 0.53) in Machang’a, Kiritiri, and Kindaruma, respectively. Monthly rainfall va...

SUMMARYDeclining land productivity is a major problem facing smallholder farmers today in Sub-Saharan Africa, and as a result increase in maize grain yield has historically staggered behind yield gains that have been achieved elsewhere in the world. This decline primarily results from reduction in soil fertility caused by continuous cultivation without adequate addition of external nutrient inputs. Improved soil fertility management practices, which combine organic and mineral fertilizer inputs, can enable efficient use of inputs applied, and can increase overall system's productivity. The trials were established at two sites with different soil fertility status to determine the effects of various organic sources (Tithonia diversifolia, Mucuna pruriens, Calliandra calothyrsus and cattle manure) and their combinations with mineral fertilizer on maize grain yield, economic return and soil chemical properties. Drought spells were common during the peak water requirement periods, an...

SUMMARYThis study investigated the feasibility of using sole organics or a combination of organics with inorganic fertilizer to improve maize production in on-station and on-farm experiments in central Kenya. In the on-station experiment, combined application of Calliandra calothyrsus, Leucaena trichandra and Tithonia diversifolia at 30 kg N ha−1 plus inorganic fertilizer (30 kg N ha−1) consistently gave significantly higher maize grain yields than the recommended rate of inorganic fertilizer (60 kg N ha−1). Sole application of calliandra, leucaena and tithonia also increased maize yields more than the recommended rate of inorganic fertilizer. In the on-farm experiment, calliandra, leucaena, tithonia and cattle manure either alone or combined with inorganic fertilizer increased maize yields with a similar magnitude to that of inorganic fertilizer. These organic resources could therefore be used to supplement inorganic fertilizer as a whole or in part. There was a yield gap between o...

SUMMARYDeclining soil fertility is a major cause of low per capita food production on smallholder farms of sub-Saharan Africa. This study attempted to provide an empirical explanation of the factors associated with farmers' decisions to adopt or not to adopt newly introduced integrated soil fertility management (ISFM) technologies consisting of combinations of organics and mineral fertilizer in Meru South district of the central highlands of Kenya. Out of 106 households interviewed, 46% were ‘adopters’ while 54% were ‘non-adopters’. A logistic regression model showed that the factors that significantly influenced adoption positively were farm management, ability to hire labour and months in a year households bought food for their families, while age of household head and number of mature cattle negatively influenced adoption. The implication of these results is that the adoption of ISFM practices could be enhanced through targeting of younger families where both spouses work on ...

... Jayne Mugwe1 , Daniel Mugendi2, Monicah Mucheru-Muna2 , Roel Merckx3, Bernard Vanlauwe4, Regina Karega2 and Justin Muriuki5 1Kenya Forestry Research Institute (KEFRI). ... Institute,Kenyatta University, Katholieke Universiteit Leuven, Tropical Soil Biology and ...

ABSTRACT Dependence on uncertain rainfall and exposure to unmitigated climate risk are major obstacles in efforts to sustainably intensify agricultural production and enhance rural livelihoods. There is generally enough seasonal total rainfall; the challenge is its poor distribution over time and across the season. The amount of water available to plants strongly depends on the rainy season's onset, length, temporal distribution and cessation and can indirectly indicate the climatic suitability of the crop and its chances of success or failure in a season. Thus, the objective was to determine rainfall pattern; temporal distribution, onset, cessation and length of growing seasons in the tropical sub-humid and a semi-arid regions with contrasting rainfall patterns and agricultural potential in central highlands of Kenya. The study was carried out in Maara and Meru South Sub-Counties in Tharaka Nithi County and Mbeere North and South Sub-Counties in Embu County of the central highlands of Kenya (CHK). Central highlands of Kenya cover both areas with high potential for crop production and low potential, attributed to rainfall differences. Meteorological data were sourced from Kenya Metrological Department (KMD) headquarters and research stations within the study areas. Length of growing season, onset and cessation dates for both Long (LR) and short (SR) rains seasons were determined based on historical rainfall data using RAIN software and derived using various spatial analysis tools in ArcGIS software and presented spatially. Generally there was high frequency of dry spells of at least 5 days length in all the sites with Kiamaogo site having the highest (84 occurrences during LR season) and Kiambere having the least (44 occurrences during LR season) in 10 years. The occurrence of dry spells longer than 15 days in a season was more rampant in the lower altitude parts (semi-arid regions) of the study area as reflected by the Kiambere, Kiritiri, Machang’a and Kamburu sites in both seasons. For the higher altitude regions, average LR onset, representative of the normal/conventional growing period, ranged from 22nd to 26th March to end of April in the region. For the lower altitude region, it ranged from 16th to 30th March. For SR, onset was generally earlier in the high altitude areas with Kiamaogo having the earliest on 13th October. In the low altitude region, onset was comparatively late compared to the higher potential region, but unlike the LR season, spatial and temporal variation was narrower. The high frequency of dry spells more than 15 days long, coupled with the generally low total amount of rainfall receive per season makes agriculture a risk venture. Homogeneity test revealed that the generated onset and cessation dates for the two rain seasons were homogeneous over the 10 years for each of the seven stations. This indicates that, there has been no shift in onset and cessation within the period under consideration. Dynamic derivation of the spatial onset and cessation data at a local scale can be useful in monitoring shifts in onset dates and hence advice small scale farmers and other stakeholders in agriculture sector accordingly in the quest for enhanced agricultural productivity.