Monicah Mucheru-Muna

• PhD
• Professor (Associate) at Kenyatta University

Smallholder farmers in East-Africa commonly intercrop maize (Zea mays L.) with grain legumes to maximize utilisation of land and labour, and attain larger crop yields. Conventionally, one legume line is intercropped between each pair of maize lines. This study evaluated the potential of a modified two-by-two staggered arrangement (MBILI) to increas...

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 st...

In 2007 two long-term trials were established in Kenya to contribute research-based evidence to the global debate on the productivity, economic viability and sustainability of different agricultural production systems. These trials compare conventional (Conv) and organic (Org) farming systems at high and low input levels at two locations, i.e. Chuk...

Context Crop productivity in sub-Saharan Africa cannot be substantially improved without simultaneously addressing short-term crop nutrient demand and long-term soil fertility. Integrated soil fertility management tackles both by the combined application of mineral fertilizers and organic resource inputs but few studies examined its‘ long-term effe...

The accomplishment of sustainable development goals in Somalia remains severely hampered by changes in the climate, particularly when it comes to food security. It jeopardizes national food security by threatening agricultural productivity. Designing practical strategies and policies for agricultural development and food security requires an unders...

The production gap between current and attainable yields is highest on Africa’s smallholder farms, and some studies indicate that they might not benefit from the yield gains offered by conventional farming. Simultaneously, alternative farming systems like organic provide biodiversity and soil fertility advantages, but their ability to produce suffi...

p> Background: Soil fertility degradation remains the major biophysical cause of declining per capita crop production on smallholder farmers in Central Kenya highlands. The study was carried out for 3 consecutive seasons in Embu County classified as semi-arid lands in Kenya. Objectives: To determine the effect of Soil Water Harvesting (SWH), croppi...

Sustainable intensification schemes such as integrated soil fertility management (ISFM) are a proposed strategy to close yield gaps, increase soil fertility, and achieve food security in sub-Saharan Africa. Biogeochemical models such as DayCent can assess their potential at larger scales, but these models need to be calibrated to new environments a...

Maize productivity in sub-Saharan Africa often falls below its potential due to soil fertility challenges. Researchers assessed the potential to counteract soil organic carbon (SOC) losses and yield declines using different organic resource treatments, with and without mineral nitrogen (N) fertilizer. While all treatments that received mineral N ha...

The world’s multiple landscape crises have placed agroforestry among the cost-effective nature-based solutions with numerous ecological, social, and economic benefits. This study examined the farmer and land factors influencing the adoption of agroforestry practices in the Gambia’s Central River Region. Stratified random sampling was used to collec...

Introduction Intercropping systems have a great potential for crop diversification thus increasing smallholder systems' resilience to climate change while improving soil health. However, optimal benefits associated with intercropping systems are rarely realised because of the interspecific competition for growth resources among the intercropped spe...

Low levels of secondary and micronutrients, and soil acidity strongly challenge the attainment of two critical pillars of Climate Smart Agriculture (CSA); 1) secured food through increased productivity and (2) increased resilience to adapt to climate change. Despite this soil fertility trend, empirical and review studies on secondary and micronutri...

Population growth and climate change challenge our food and farming systems and provide arguments for an increased intensification of agriculture. Organic farming has been seen as a promising option due to its eco-friendly approaches during production. However, weeds are regarded as the major hindrance to effective crop production which varies depe...

Introduction Nitrogen (N) and phosphorus (P) are essential nutrients for plant growth, commonly supplied through costly inorganic amendments. However, despite the benefits of nutrient mineralisation, there is limited quantitative information on its monetary value, and the extent of associated potential financial relief to smallholder farmers, parti...

Long-term experiments (LTEs) are critical for evaluating strategies that can maintain or increase crop yields, soil fertility and soil organic carbon (SOC), and help adapt to climate change. Yet, scientific knowledge is advancing and research questions are evolving. Therefore, it is important to review the objectives of LTEs over time. A change in...

Purpose: Like other poor states and post-conflict countries, Somalia faces significant challenges in achieving the SDGs, particularly concerning food security. Because agricultural productivity is compromised, it immediately and significantly jeopardizes the nation's food security. Adapting to climate change can maximize its benefits and lessen man...

Introduction Soil bacterial community structure, abundance and diversity, important in biogeochemical cycling, are influenced by several anthropogenic and edaphic factors. Numerous agronomic practices have been promoted to improve soil fertility and crop production in western Kenya, but little is known on their impacts on soil microbial diversity i...

Soil fertility decline and moisture deficits are major challenges facing crop production in semi-arid areas. Soil water conservation, in combination with nutrient management, might be useful in agricultural land restoration in tropical developing countries. This study aimed to examine the interactive effect of Zai pits and conventional planting wit...

Zinc is an important nutrient for plant growth and development. Its availability is influenced by zinc solubilizing microbes (ZSMs). The effects of commonly promoted agronomic practices on the abundance of ZSMs are so far not well understood. In this study, conducted in 2019, we assessed the effects of farmyard manure (FYM) application, either sole...

Zinc is an important nutrient for plant growth and development. Its availability is influenced by zinc solubilizing microbes (ZSM). Effects of commonly promoted agronomic practices on the abundance of ZSM are so far not well understood. In this study, we assessed the effects of farmyard manure (FYM) application, either sole, or in combination with...

Sustainable intensification schemes that increase crop production and soil fertility, such as integrated soil fertility management (ISFM), are a proposed strategy to close yield gaps and achieve food security in sub-Saharan Africa while maintaining soil fertility. However, field trials are insufficient to estimate the potential impact of such techn...

Deficits in soil moisture and low soil fertility are the major constraints to smallholder farming systems in the SSA (sub-Saharan Africa) region. This study evaluated the effects of tied ridging and selected soil fertility inputs on; soil water content at different depths, maize yields, and economic returns. The treatments were: Tithonia diversifol...

Declining agricultural productivity has been a challenge worldwide and especially in Sub-Saharan Africa (SSA). Low agricultural productivity has been attributed to factors such as poor farm management practices, soil moisture stress, soil infertility, and soil degradation, among others. The nations in the SSA are prone to insufficient crop yields d...

Acidic soils pose a major challenge for crop production in heavily weathered tropical soils, especially due to the high toxicity of aluminum (Al), low cation exchange capacity, and low availability of phosphorus (P) to plants. Lime application was recommended to alleviate soil acidity problems. Granular CaCO 3 lime was introduced into the Kenyan ma...

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 interacti...

Soil erosion poses a challenge to the environment and the sustainable use of natural resources, particularly in relation to agricultural production. The study aimed to assess the influence of different soil organic carbon (SOC) levels on runoff and soil erosion under varying levels of rainfall intensity. The study was conducted in pre-selected farm...

Zinc deficiency in agricultural soils is a current global agroecosystems challenge. Maize exhibits elevated susceptibility to Zn deficiency and low response to zinc fertilization. As a result, there are contradicting literature reports on the crop response to zinc fertilization. This meta-analysis synthesized the current evidence on maize response...

Soil moisture scarcity and soil fertility decline in the drylands contribute to declining crop productivity. The possible synergistic effects of integrating soil & water conservation, and soil fertility management practices on soil moisture, and hence water use efficiency (WUE) in the drylands of Tharaka-Nithi County in Kenya was assessed. The expe...

CONTEXT 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...

The adoption of conservation agriculture and agroforestry has been cited as the solution to the degradation and low profitability challenges in the drylands. The two systems have been known to result in high profitability through the improvement of yields and lowering of crop production costs. The study was carried out as part of ongoing experiment...

Low and continuously deteriorating soil fertility coupled with frequent droughts and extended mid-season dry spells scenarios brought about by low and unreliable rainfalls have had a significant negative influence on agricultural productivity in most semi-arid regions of the world. The farmers' limited capacity to change their farming practices and...

In sub-Saharan Africa, 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 understan...

14 Cereal-legume intercropping, a common practice among farmers in sub-Saharan Africa (SSA), is 15 important for crop diversification, soil fertility improvement, household nutrition and climate 16 adaptation. However, cereals often outcompete the intercropped legumes for growth resources 17 resulting in low legume yields. The objectives of this st...

DEDICATION This work is dedicated to my family and friends for their continuous support of my study. iv ACKNOWLEDGEMENTS

Water and nutrients are the main factors limiting grain production in the dry regions of sub-Saharan Africa. Given the onset of global climate change, the effects of drought stress on crop yield becomes more pronounced. Different approaches have been initiated to address this; however, they have been introduced at different times, in isolation, and...

The multiple ecosystem services and livelihood assets development challenges facing the world, including climate change, land degradation, and high poverty levels, have necessitated cross-cutting solutions. Such includes agroforestry technologies, where trees are integrated with crop and pasture lands to yield multiple ecosystem goods and services....

Erosion causes soil nutrients and financial losses, and negatively impacts the environment. We sought to assess the effects of integrated soil fertility and soil & water management practices on nutrient losses, their equivalent economic losses, and environmental disturbance in the drylands of Tharaka-Nithi County. An experiment was set in a randomi...

The multiple ecosystem services and livelihood assets development challenges facing the world, including climate change, land degradation, and high poverty levels, have necessitated cross-cutting solutions. Such includes agroforestry technologies, where trees are integrated in crop and pasture lands to yield multiple ecosystem goods and services. T...

Deteriorating soil fertility, low unreliable rainfall and soil moisture stress has resulted to low crop yields among farmers of sub-Saharan Africa (SSA), necessitating a search for more sustainable production practices. Zai technology has the ability to promote soil moisture retention and enhances soil fertility. A four-seasons field experiment was...

A major constraint to crop production in Sub-Saharan Africa is nutrient deficiency, especially phosphorus (P) deficiency. Phosphorus plays a crucial role in photosynthesis but is usually deficient in acidic soils since it is converted to less available forms, affecting crop yields. There is a need to improve phosphorus availability to crops for max...

A major constraint to crop production in Sub-Saharan Africa is nutrient deficiency, especially phosphorus (P) deficiency. Phosphorus plays a crucial role in photosynthesis but is usually deficient in acidic soils since it is converted to less available forms, affecting crop yields.There is a need to improve phosphorus availability to crops for maxi...

Integrated soil fertility and soil water conservation technologies are possible solutions to the low per capita food production in Sub-Saharan Africa (SSA). Nonetheless, the rate of adoption of these technologies by smallholder farmers has stagnated over the years despite being recommended. This has been attributed to the existence of wide communic...

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, the...

This study ascertained the socioeconomic determinants of farmers' knowledge on soil and water conservation technologies in Dry zones of Central Highlands of Kenya involving 400 farming households. Results showed that the majority of the farmers had inadequate knowledge on the use and benefits of soil and water conservation technologies. The socioec...

In Sub-Saharan Africa (SSA), acidic soil covers 29% of the total area. About 13% of the Kenyan total land area has acidic soils, widely distributed in croplands of the central and western Kenyan regions. The high soil acidity, coupled with soil nutrient depletion, negatively affects crop productivity in the region. We conducted an on-farm experimen...

Conservation agriculture practices involving zero tillage and residue retention are promising nutrient management strategies for soil health restoration. Despite their potential positive impact on soil fertility, improved crop yields and increased revenues for smallholder farmers; their effect on nitrogen inputs and crop growth is not clearly under...

Water harvesting technologies and soil conservation measures promote water-nutrient synergy and increase agricultural production in the dryland zones of sub-Saharan Africa. To alleviate water stress, soil fertility decline and reduce runoff, soil and water conservation measures are promising options whose impact on agricultural productivity has not...

Locally available organic inputs to soil, solely or in combination with inorganic fertilizers, are used to reverse declining soil fertility and improve soil organic matter content (SOM) in smallholder farms of most Sub-Saharan Africa (SSA) countries. Soil organic matter characterization can indicate soil organic input, carbon (C) sequestration pote...

Degraded landscapes and soil water stress are long-standing problems to smallholder agriculture in the drylands. Despite the important roles of zai technology in restoring degraded landscapes and improving the agricultural productivity, the technology is yet to be adopted to its fullest extent. This can be attributed to gender-linked disparities in...

Crop productivity in most smallholder farming systems in Sub-Saharan Africa experience low use of soil amendment resources, low and erratic rainfall, frequent dry spells, and droughts. Rain-fed agriculture has a high crop yield potential if rainfall and soil nutrient input resources are utilized effectively. Thus, in 2011, we set up an on-farm expe...

Determination of biologically active components of the soil organic matter, such as soil microbial biomass carbon (C) and nitrogen (N) can be used as indicators for variations in soil productivity due to changes in soil management. Soil agronomic management practices bring about changes in the physical and chemical properties of the soil, resulting...

Soil acidity and phosphorus deficiency are some of the constraints hampering agricultural production in tropical regions. The prevalence of soil acidity is associated with phosphorus (P) insufficiency and aluminum saturation. We conducted a two-seasons experiment to evaluate soil phosphorus availability and exchangeable aluminum in response to phos...

Integrated Soil Fertility Management (ISFM) practices are widely recognized as crucial interventions but knowledge-intensive technologies for farmers in Sub-Saharan Africa (SSA). Very few studies have synthesized the knowledge gaps between smallholder practices and recommended ISFM packages. A farm survey was therefore carried out in Runyenjes sub-...

Integrated Soil Fertility Management (ISFM) practices are widely recognized as crucial interventions but knowledge-intensive technologies for farmers in Sub-Saharan Africa (SSA). Very few studies have synthesized the knowledge gaps between smallholder practices and recommended ISFM packages. A farm survey was therefore carried out in Runyenjes sub-...

Phosphorus is a critical nutrient for plant growth. Several agronomic practices have been promoted to improve soil fertility and crop productivity in Western Kenya. Yet, despite their benefits, a dearth of knowledge exists on their long-term effects on soil microbial biomass and phosphorus solubilizing microbial species (PSMs) abundance especially...

A major constraint to crop production in Sub-Saharan Africa is nutrient deficiency, especially phosphorus (P)deficiency. Phosphorus plays a crucial role in photosynthesis but is usually deficient in acidic soils since it is converted to less available forms, affecting crop yields. There is a need to improve phosphorus availability to crops for maxi...

Decline in soil fertility is one of the major constraints to sustainable crop production and profitability. To meet the increasing demand for the growing population the issue of low soil fertility needs to be addressed. An on-farm experiment was established to evaluate the effect of interaction between NPK fertilizers and minimum tillage on soil fe...

Dryland ecosystems have always been prone to relatively high vegetation and general environmental degradation; translating to changes in soil physical and chemical properties and massive carbon losses. Despite their vast surface area, Carbon sequestration therein still remains low. However, this low carbon means they are less saturated and therefor...

In sub‐Saharan Africa (SSA), few studies have quantified greenhouse gas (GHG) emissions following application of soil amendments, for development of accurate national GHG inventories. Therefore, this study quantified soil GHG emissions using static chambers for two maize cropping seasons (one full year) of four different soil amendments in the cent...

Inadequate and poorly distributed rainfall and declining soil fertility have led to low crop productivity in most smallholder farms in sub-Saharan Africa. As a result, there has been a renewed quest for sustainable and resource-use efficient agricultural production practices. Zai pit technology is a practice that has the potential to alleviate wate...

Aims: To evaluate the effects of phosphate rock and organic inputs on soil organic carbon and acid phosphatase activity. Study Design: The experiment was laid in Randomized Complete Block Design with seven treatments replicated thrice. Place and Duration of Study: The study was conducted at Kigogo Primary school in Meru South Sub-county, Tharaka Ni...

In Sub-Saharan Africa, agricultural production has been on the declined mainly due to low soil fertility exacerbated by climate variability as a result of rise in global atmospheric greenhouse gas (GHG) emissions. Several soil fertility amendments have been developed, experimented, adopted and found to improve both yields and general soil health. H...

Organic farming has been proposed as a solution to foster agricultural sustainability and mitigate the negative environmental impacts of conventional farming. This study assessed N losses and soil surface N balances in conventional and organic farming systems in a sub-humid and semi-humid (Chuka and Thika) sites in Kenya. Nitrate–N (NO3⁻–N) leached...

To match Nitrogen (N) supply to crop N demand, it is essential to understand N release and uptake patterns in different farming systems and crops. To assesses the dynamics of N released in organic and conventional systems and potential synchrony and asynchrony in crop N uptake, a study was conducted over three cropping seasons (potato, maize and le...

Current demand for soybean in Kenya is higher than production, and the deficit is filled through importation from neighboring Countries. Despite the high demand, production and adoption remain low. The study sought to determine factors influencing the decision to adopt soybean by smallholder farmers, assess acreage under soybean, and its production...