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Full-Text Articles in Soil Science

Soil Property Responses To Push-Pull Cropping In East Africa, Grace Mercy Amboka, Mattias Jonsson, Celina Apel, David Meinhof, Adomas Liepa, Frank Chidawanyika, Andargachew Detebo, Felipe Librán-Embid, Emily A. Martin, Ingolf Steffan-Dewenter, Marcell K. Peters, Jie Zhang, Michael Thiel, Michael Otim, James Mugisha, Ghebremedhin Belay Bahta, Fredah Maina, Alice Murage, Benjamin Feit, A. Sigrun Dahlin May 2026

Soil Property Responses To Push-Pull Cropping In East Africa, Grace Mercy Amboka, Mattias Jonsson, Celina Apel, David Meinhof, Adomas Liepa, Frank Chidawanyika, Andargachew Detebo, Felipe Librán-Embid, Emily A. Martin, Ingolf Steffan-Dewenter, Marcell K. Peters, Jie Zhang, Michael Thiel, Michael Otim, James Mugisha, Ghebremedhin Belay Bahta, Fredah Maina, Alice Murage, Benjamin Feit, A. Sigrun Dahlin

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Push-pull technology is increasingly promoted in sub-Saharan Africa, particularly for pest management and enhancing crop productivity. However, its influence on soil properties remains understudied, despite its potential implications for soil health and sustainable soil fertility management. This study examines soil properties in push-pull and conventional non-push-pull cropping systems. Soil samples were collected from push-pull and conventional plots in Ethiopia, Kenya, Rwanda, and Uganda. We examined the associations between soil physicochemical properties and cropping systems, along with key components of push-pull, namely Desmodium coverage and plot age, and manure and mineral fertiliser application. Overall, there were a few differences in soil …


Maize Yield Stability Under Organic And Conventional Farming Systems In Sub-Humid Agro-Ecozones Of Central Kenya, Milka Kiboi, David Bautze, Felix Matheri, Amritbir Riar, Andreas Fliessbach Sep 2025

Maize Yield Stability Under Organic And Conventional Farming Systems In Sub-Humid Agro-Ecozones Of Central Kenya, Milka Kiboi, David Bautze, Felix Matheri, Amritbir Riar, Andreas Fliessbach

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Maize (Zea mays L.) is the main staple crop and is important to the food security and livelihoods of people globally. We evaluated the effects of organic and conventional farming systems on maize grain yield and temporal yield stability under different external input levels in a long-term experiment (2007–2022) at two sites in Kenya. We implemented four farming systems: organic high (Org-High), conventional high (Conv-High), organic low (Org-Low), and conventional low (Conv-Low) in a randomized complete block design. Growth indicators for maize, height, stem diameter, and grain yield were higher in high input systems, but grain yield stability was not. …


Contribution Of Different Frass Fertilizer Products On Enhanced Growth, Yield And Nutrient Quality Of Broccoli [Brassica Oleracea], Noella Kagehi, Dennis Beesigamukama, Chrysantus M. Tanga, Mathew P. Ngugi, Sevgan Subramanian, Fathiya M. Khamis Jan 2025

Contribution Of Different Frass Fertilizer Products On Enhanced Growth, Yield And Nutrient Quality Of Broccoli [Brassica Oleracea], Noella Kagehi, Dennis Beesigamukama, Chrysantus M. Tanga, Mathew P. Ngugi, Sevgan Subramanian, Fathiya M. Khamis

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Vegetables are crucial for food security and income, but in developing countries their production is hindered by low soil fertility. Although the insect frass fertilizer is a potential solution, its use is constrained by limited product choices. Unlike conventional fertilizers, which are available in different forms, the insect frass fertilizer is mostly available in solid form. Here, we evaluated the effects of different black soldier fly frass fertilizer (BSFFF) products on broccoli [Brassica oleracea] growth, yield, and nutritional profiles. Solid, liquid BSFFF, chitin-fortified solid BSFFF, chitin-fortified liquid BSFFF, and commercial organic fertilizer (Safi) were applied at rates equivalent to 250 …


Modeling Integrated Soil Fertility Management For Maize Production In Kenya Using A Bayesian Calibration Of The Daycent Model, Moritz Laub, Magdalena Necpalova, Marijn Van De Broek, Marc Corbeels, Samuel Mathu Ndungu, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Rebecca Yegon, Wycliffe Waswa, Bernard Vanlauwe, Johan Six Aug 2024

Modeling Integrated Soil Fertility Management For Maize Production In Kenya Using A Bayesian Calibration Of The Daycent Model, Moritz Laub, Magdalena Necpalova, Marijn Van De Broek, Marc Corbeels, Samuel Mathu Ndungu, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Rebecca Yegon, Wycliffe Waswa, Bernard Vanlauwe, Johan Six

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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 and rigorously tested for accuracy. Here, we present a Bayesian calibration of DayCent, using data from four long-term field experiments in Kenya in a leave-one-site-out cross-validation approach. The experimental treatments consisted of the addition of low- to high-quality organic resources, with and without mineral nitrogen fertilizer. We assessed the potential …


Insect Frass Fertilizer As A Regenerative Input For Improved Biological Nitrogen Fixation And Sustainable Bush Bean Production, Agnes Chepkorir, Dennis Beesigamukama, Harun I. Gitari, Shaphan Y. Chia, Sevgan Subramanian, Sunday Ekesi, Birachi Eliud Abucheli, Jean Claude Rubyogo, Theodore Zahariadis, Gina Athanasiou, Aikaterini Zachariadi, Vasileios Zachariadis, Abdou Tenkouano, Chrysantus M. Tanga Jan 2024

Insect Frass Fertilizer As A Regenerative Input For Improved Biological Nitrogen Fixation And Sustainable Bush Bean Production, Agnes Chepkorir, Dennis Beesigamukama, Harun I. Gitari, Shaphan Y. Chia, Sevgan Subramanian, Sunday Ekesi, Birachi Eliud Abucheli, Jean Claude Rubyogo, Theodore Zahariadis, Gina Athanasiou, Aikaterini Zachariadi, Vasileios Zachariadis, Abdou Tenkouano, Chrysantus M. Tanga

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Bush bean (Phaseolus vulgaris L.) production is undermined by soil degradation and low biological nitrogen fixation (BNF) capacity. This study evaluated the effect of black soldier fly frass fertilizer (BSFFF) on bush bean growth, yield, nutrient uptake, BNF, and profitability, in comparison with commercial organic fertilizer (Phymyx, Phytomedia International Ltd., Kiambu, Kenya), synthetic fertilizer (NPK), and rhizobia inoculant (Biofix, MEA Fertilizers, Nairobi, Kenya). The organic fertilizers were applied at rates of 0, 15, 30, and 45 kg N ha−1 while the NPK was applied at 40 kg N ha−1, 46 kg P ha−1, and 60 kg K ha−1. The fertilizers …


Waste To Value: Global Perspective On The Impact Of Entomocomposting On Environmental Health, Greenhouse Gas Mitigation And Soil Bioremediation, Dennis Beesigamukama, Chrysantus M. Tanga, Subramanian Sevgan, Sunday Ekesi, Segenet Kelemu Dec 2023

Waste To Value: Global Perspective On The Impact Of Entomocomposting On Environmental Health, Greenhouse Gas Mitigation And Soil Bioremediation, Dennis Beesigamukama, Chrysantus M. Tanga, Subramanian Sevgan, Sunday Ekesi, Segenet Kelemu

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The innovative use of insects to recycle low-value organic waste into value-added products such as food, feed and other products with a low ecological footprint has attracted rapid attention globally. The insect frass (a combination unconsumed substrate, faeces, and exuviae) contains substantial amounts of nutrients and beneficial microbes that could utilised as fertilizer. We analyse research trends and report on the production, nutrient quality, maturity and hygiene status of insect-composted organic fertilizer (ICOF) generated from different organic wastes, and their influence on soil fertility, pest and pathogen suppression, and crop productivity. Lastly, we discuss the impact of entomocomposting on greenhouse …


Nitrogen Budgets And Nitrogen Use Efficiency As Agricultural Performance Indicators In Lake Victoria Basin, Winnie Ntinyari, Joseph Gweyi-Onyango, Mekonnen Giweta, James Mutegi, Benson Mochoge, Generose Nziguheba, Cargele Masso Oct 2022

Nitrogen Budgets And Nitrogen Use Efficiency As Agricultural Performance Indicators In Lake Victoria Basin, Winnie Ntinyari, Joseph Gweyi-Onyango, Mekonnen Giweta, James Mutegi, Benson Mochoge, Generose Nziguheba, Cargele Masso

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Too little nitrogen (N) is a threat to crop productivity and soil fertility in sub-Saharan Africa (SSA). Nitrogen budgets (NB) and nitrogen use efficiency (NUE) are critical tools for assessing N dynamics in agriculture and have received little or no attention in the region. Data were collected from smallholder farmers clustered into two categories, farmers applying and farmers not applying N fertilizers. NB were calculated using the Coupled Human and Natural Systems (CHANS) model approach for field and farm spatial scales. The results showed spatial variabilities in NB and NUE at the field level (maize and rice) across all the …


Understanding Factors Influencing Wheat Productivity In Ethiopian Highlands, J. Kihara, B. Gurmessa, L. Tamene, T. Amede, R. Sommer Feb 2022

Understanding Factors Influencing Wheat Productivity In Ethiopian Highlands, J. Kihara, B. Gurmessa, L. Tamene, T. Amede, R. Sommer

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Increasing yields in farmer fields is a priority to address increasing food demands. The study was conducted within four wheat-growing areas in Ethiopia: Debre Birhan, Hosaina, Sinana and Maychew. The objectives were to identify (1) best-bet soil fertility management options based on agronomic performance and economic evaluation and (2) key yield-reducing factors in farmer fields based on an agronomic survey among 55 participating farmers. Two types of on-farm experiments were conducted: researcher-managed trials that tested combinations of nutrients, including micronutrients, organic resources or both over two cropping seasons and farmer-managed trials comparing 'improved practice' against 'farmer's practice'. Fertilizer treatment affected …


Nitrogen Use Efficiency Trends For Sustainable Crop Productivity In Lake Victoria Basin: Smallholder Farmers' Perspectives On Nitrogen Cycling, Winnie Ntinyari, Joseph Gweyi-Onyango, Mekonnen Giweta, Benson Mochoge, James Mutegi, Generose Nziguheba, Cargele Masso Jan 2022

Nitrogen Use Efficiency Trends For Sustainable Crop Productivity In Lake Victoria Basin: Smallholder Farmers' Perspectives On Nitrogen Cycling, Winnie Ntinyari, Joseph Gweyi-Onyango, Mekonnen Giweta, Benson Mochoge, James Mutegi, Generose Nziguheba, Cargele Masso

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Nitrogen Use Efficiency (NUE) is one of the established metrics for benchmarking management of Nitrogen (N) in various systems. Numerous approaches to calculateNUEexist, making it difficult to compare the performances of systems depending on the methodology used. This study adopted the conceptualized framework by European Union Nitrogen Expert Panel (EUNEP) to calculateNUE values for cereal crops to determine future trends for the first time in the Lake Victoria region. Data were collected through in-person interviews among maize and rice smallholder farmers within the Lake Victoria region. Atotal of 293 observations were recorded. Collected data on yield andNfertilizer were used to …


Potential Of Entomocomposting Toward Soil Pathogen Suppression, Dennis Beesigamukama, María Gómez-Brandón, Chrysantus Mbi Tanga Jan 2022

Potential Of Entomocomposting Toward Soil Pathogen Suppression, Dennis Beesigamukama, María Gómez-Brandón, Chrysantus Mbi Tanga

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Waste accumulation and microbial pollution are key environmental challenges in most developing countries. Land filling, the commonest waste disposal method, is not sustainable due to land scarcity and point source pollution. Thus, a large fraction of organic wastes is not properly disposed, yet the conventional methods of waste recycling are less effective. The degradation of waste using insect life stages (entomocomposting) has emerged as a novel tool that is fast, affordable, and sustainable in recycling organic wastes with maximum pathogen suppression. This bioconversion process also generates an organic fertilizer with potential to enhance soil remediation and provide additional benefits on …


Performance Of Black Soldier Fly Frass Fertiliser On Maize (Zea Mays L.) Growth, Yield, Nutritional Quality, And Economic Returns, C. M. Tanga, D. Beesigamukama, M. Kassie, P. J. Egonyu, Changeh J. Ghemoh, Kiatoko Nkoba, S. Subramanian, A. O. Anyega, S. Ekesi Jan 2022

Performance Of Black Soldier Fly Frass Fertiliser On Maize (Zea Mays L.) Growth, Yield, Nutritional Quality, And Economic Returns, C. M. Tanga, D. Beesigamukama, M. Kassie, P. J. Egonyu, Changeh J. Ghemoh, Kiatoko Nkoba, S. Subramanian, A. O. Anyega, S. Ekesi

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Although the black soldier fly frass fertiliser (BSFFF) is globally recognised as a promising and potential high-quality organic fertiliser, there is inadequate information on its impact on the growth performance and nutritional status of maize. Furthermore, no information exist on their combination with mineral fertiliser (NPK) as well as economic impact on maize production. This study evaluated the comparative impact of BSFFF, NPK and commercial organic fertiliser (Evergrow®) on growth, nitrogen use efficiency, yield, nutritional quality, and profitability of maize under greenhouse conditions. The treatments included: (1) sole application of BSFFF, conventional compost of brewers’ spent grain (BSG), Evergrow, and …


In Situ Nitrogen Mineralization And Nutrient Release By Soil Amended With Black Soldier Fly Frass Fertilizer, Dennis Beesigamukama, Benson Mochoge, Nicholas Korir, Changeh J. Ghemoh, Sevgan Subramanian, Chrysantus M. Tanga Dec 2021

In Situ Nitrogen Mineralization And Nutrient Release By Soil Amended With Black Soldier Fly Frass Fertilizer, Dennis Beesigamukama, Benson Mochoge, Nicholas Korir, Changeh J. Ghemoh, Sevgan Subramanian, Chrysantus M. Tanga

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Although black soldier fly frass fertilizer (BSFFF) is effective on crop performance, information on nitrogen (N) mineralization and nutrient release capacity of soils amended with BSFFF is lacking. This study utilized field incubation experiments to investigate the ammonification, nitrification, microbial populations, and quantities of nutrients released by soils amended with BSFFF and commercial organic fertilizer (SAFI) for a period equivalent to two maize cropping seasons. For the control treatment, no BSFFF or SAFI was added. Results indicated that most of the N in BSFFF amended soils was available in the ammonium form, while soils treated with SAFI had higher nitrate …


Perennial Legume Intercrops Provide Multiple Belowground Ecosystem Services In Smallholder Farming Systems, Laurie E. Drinkwater, Charles A.O. Midega, Rachel Awuor, Dickens Nyagol, Zeyaur R. Khan Oct 2021

Perennial Legume Intercrops Provide Multiple Belowground Ecosystem Services In Smallholder Farming Systems, Laurie E. Drinkwater, Charles A.O. Midega, Rachel Awuor, Dickens Nyagol, Zeyaur R. Khan

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Soil degradation is a major underlying cause of poverty and malnutrition in smallholder agrarian communities across the globe. Legume diversification, through polyculture or intercropping, is a strategy that increases yields and income while improving family nutrition. However, the potential for these legume-cereal intercrops to restore soil functions in smallholder fields remains uncertain, with many studies failing to detect increases in soil organic matter (SOM). In sub-Saharan Africa, smallholders typically grow maize either intercropped with short-lived annual food legumes or as a monoculture. Recently, a novel maize system which includes perennial legumes in the genus Desmodium as intercrops, known as “push-pull” …


Black Soldier Fly-Composted Organic Fertilizer Enhances Growth, Yield, And Nutrient Quality Of Three Key Vegetable Crops In Sub-Saharan Africa, Abel O. Anyega, Nicholas K. Korir, Dennis Beesigamukama, Ghemoh J. Changeh, Kiatoko Nkoba, Sevgan Subramanian, Joop J.A. Van Loon, Marcel Dicke, Chrysantus M. Tanga Jun 2021

Black Soldier Fly-Composted Organic Fertilizer Enhances Growth, Yield, And Nutrient Quality Of Three Key Vegetable Crops In Sub-Saharan Africa, Abel O. Anyega, Nicholas K. Korir, Dennis Beesigamukama, Ghemoh J. Changeh, Kiatoko Nkoba, Sevgan Subramanian, Joop J.A. Van Loon, Marcel Dicke, Chrysantus M. Tanga

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Worldwide, French beans (Phaseolus vulgaris L.), tomato (Solanum lycopersicum L.), and kales (Brassica oleracea L. var. acephala) are considered economically important food crops. There is a rapid decline in their yield due to severe soil degradation. Thus, high commercial fertilizer inputs are crucial, though they remain expensive and inaccessible to resource poor farmers. We investigated the comparative performance of composted black soldier fly frass fertilizer (BSFFF), conventionally composted brewer's spent grain (BSG), commercial organic fertilizer (Evergrow), and mineral [nitrogen, phosphorus, and potassium (NPK)] fertilizer on growth, yield, N use efficiency, and nutritional quality (crude protein, crude fiber, crude fats, ash, …


Farm‐Scale Assessment Of Maize–Pigeonpea Productivity In Northern Tanzania, E. Mugi-Ngenga, S. Zingore, L. Bastiaans, N. P.R. Anten, K. E. Giller Jun 2021

Farm‐Scale Assessment Of Maize–Pigeonpea Productivity In Northern Tanzania, E. Mugi-Ngenga, S. Zingore, L. Bastiaans, N. P.R. Anten, K. E. Giller

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Little is known about productivity of smallholder maize–pigeonpea intercropping systems in sub-Saharan Africa. We conducted a survey of 277 farm households in Northern Tanzania to assess socio-economic factors, field management characteristics, and their association with productivity of maize–pigeonpea intercrops. On each farm, crop assessments were focused on a field that the farmer identified as most important for food supply. Variables associated with yields were evaluated using linear regression and regression classification. Biomass production ranged between 1.0 and 16.6 for maize, and between 0.2 and 11.9 t ha−1 for pigeonpea (at maize harvest). The corresponding grain yields ranged between 0.1 and …


Intercropping Desmodium And Maize Improves Nitrogen And Phosphorus Availability And Performance Of Maize In Kenya, Pierre Celestin Ndayisaba, Shem Kuyah, Charles Aura Odhiambo Midega, Peter Njoroge Mwangi, Zeyaur Rahman Khan Apr 2021

Intercropping Desmodium And Maize Improves Nitrogen And Phosphorus Availability And Performance Of Maize In Kenya, Pierre Celestin Ndayisaba, Shem Kuyah, Charles Aura Odhiambo Midega, Peter Njoroge Mwangi, Zeyaur Rahman Khan

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Low levels of nitrogen (N) and phosphorus (P) in soils in sub-Saharan Africa (SSA) limit maize (Zea mays) production in smallholder farms. We tested the hypothesis that desmodium (Desmodium intortum (Mill.) Urb.), a fodder legume, and food legumes commonly grown with maize in Western Kenya avail N and P and improve the performance of maize in intercrops. We measured available N and P in 15 cm topsoil at 4, 8 and 12 weeks after planting (WAP), and corresponding maize shoot weight in three seasons: 2017 long rains (LR), 2017 short rains (SR), and 2018 LR at Thomas Odhiambo Campus of …


Socio-Economic Predictors, Soil Fertility Knowledge Domains And Strategies For Sustainable Maize Intensification In Embu County, Kenya, Monicah Wanjiku Mucheru-Muna, Mildred Achieng Ada, Jayne Njeri Mugwe, Franklin Somoni Mairura, Esther Mugi-Ngenga, Shammie Zingore, James Kinyua Mutegi Feb 2021

Socio-Economic Predictors, Soil Fertility Knowledge Domains And Strategies For Sustainable Maize Intensification In Embu County, Kenya, Monicah Wanjiku Mucheru-Muna, Mildred Achieng Ada, Jayne Njeri Mugwe, Franklin Somoni Mairura, Esther Mugi-Ngenga, Shammie Zingore, James Kinyua Mutegi

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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 small-holder practices and recommended ISFM packages. A farm survey was therefore carried out in Runyenjes sub-County of Embu to determine factors influencing the quality of ISFM knowledge considering inorganic fertilizer, organic manure, integrated soil inputs, and improved maize seeds. One hundred small-scale maize farmers were systematically sampled in Embu County, Kenya, using a cross-sectional survey design. The most significant factors shaping the quality of ISFM knowledge (p < 0.05) included gender, age, household size, land under maize, off-farm earnings, maize yield, members involved in farming, farming experience, education level, and farm size. Farmers recorded lower knowledge scores for technical ISFM themes including soil liming, soil testing, fertilizer types, fertilizer functions, curing of organic manure, compost manure management, crop spacing, combination ratios for integrated inputs, and the labor and cost-benefit implications of integrated inputs, revealing important ISFM knowledge gaps. High-quality knowledge of blended fertilizers and DAP use was associated with increased soil testing and soil liming knowledge, respectively. Multivariate analysis of ISFM knowledge items provided a high-quality understanding of the structure of ISFM knowledge among farmers in Embu County, which is useful in developing future ISFM dissemination strategies. Humic nitisol, Fertilizer, ISFM strategies, ISFM knowledge quality, improved seeds, manure


Assessing And Understanding Non-Responsiveness Of Maize And Soybean To Fertilizer Applications In African Smallholder Farms, Dries Roobroeck, Cheryl A. Palm, Generose Nziguheba, Ray Weil, Bernard Vanlauwe Jan 2021

Assessing And Understanding Non-Responsiveness Of Maize And Soybean To Fertilizer Applications In African Smallholder Farms, Dries Roobroeck, Cheryl A. Palm, Generose Nziguheba, Ray Weil, Bernard Vanlauwe

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Use of mineral fertilizers is essential to enhance crop productivity in smallholder farming systems of Sub-Saharan Africa, but various studies have reported ‘non-responsiveness’ where application of inorganic fertilizers does not lead to satisfactory yield gains. This phenomenon is not well defined nor are its extent and causes well understood. In order to close these knowledge gaps, we assessed the effects of commonly recommended nitrogen (N), phosphorus (P) and/or potassium (K) fertilizer inputs on maize grain and soybean production on farmer fields across prevalent land slope and/or soil texture gradients (2 × 2 matrix) in four agroecosystems over two growing seasons. …


Science-Based Decision Support For Formulating Crop Fertilizer Recommendations In Sub-Saharan Africa, Jairos Rurinda, Shamie Zingore, Jibrin M. Jibrin, Tesfaye Balemi, Kenneth Masuki, Jens A. Andersson, Mirasol F. Pampolino, Ibrahim Mohammed, James Mutegi, Alpha Y. Kamara, Bernard Vanlauwe, Peter Q. Craufurd Apr 2020

Science-Based Decision Support For Formulating Crop Fertilizer Recommendations In Sub-Saharan Africa, Jairos Rurinda, Shamie Zingore, Jibrin M. Jibrin, Tesfaye Balemi, Kenneth Masuki, Jens A. Andersson, Mirasol F. Pampolino, Ibrahim Mohammed, James Mutegi, Alpha Y. Kamara, Bernard Vanlauwe, Peter Q. Craufurd

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In sub-Saharan Africa, there is considerable spatial and temporal variability in relations between nutrient application and crop yield, due to varying inherent soil nutrients supply, soil moisture, crop management and germplasm. This variability affects fertilizer use efficiency and crop productivity. Therefore, development of decision systems that support formulation and delivery of site-specific fertilizer recommendations is important for increased crop yield and environmental protection. Nutrient Expert (NE) is a computer-based decision support system, which enables extension advisers to generate field- or area-specific fertilizer recommendations based on yield response to fertilizer and nutrient use efficiency. We calibrated NE for major maize agroecological …


Soil Quality And Phosphorus Status After Nine Years Of Organic And Conventional Farming At Two Input Levels In The Central Highlands Of Kenya, C. Von Arb, E. K. Bünemann, H. Schmalz, M. Portmann, N. Adamtey, M. W. Musyoka, E. Frossard, A. Fliessbach Mar 2020

Soil Quality And Phosphorus Status After Nine Years Of Organic And Conventional Farming At Two Input Levels In The Central Highlands Of Kenya, C. Von Arb, E. K. Bünemann, H. Schmalz, M. Portmann, N. Adamtey, M. W. Musyoka, E. Frossard, A. Fliessbach

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Under temperate climate conditions, organic farming systems show improved soil quality compared to non-organic systems, whereas little long-term research on the impact of organic farming on soil quality has been conducted in sub-Saharan Africa. Within the system comparison (SysCom) project, two long-term field experiments were set up in 2007 in the sub-humid Central Highlands of Kenya to compare organic and conventional farming at two input levels (high input systems with recommended rates of nitrogen (N), phosphorus (P) and pesticides and with irrigation vs. rain-fed low input systems with low N, P and pesticides), with a similar design at both sites. …


Learning From The Soil's Memory: Tailoring Of Fertilizer Application Based On Past Manure Applications Increases Fertilizer Use Efficiency And Crop Productivity On Kenyan Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore Apr 2019

Learning From The Soil's Memory: Tailoring Of Fertilizer Application Based On Past Manure Applications Increases Fertilizer Use Efficiency And Crop Productivity On Kenyan Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore

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The large uncertainty in yield response to fertilizer application within smallholder cropping systems in sub-Saharan Africa (SSA) limits efforts aimed at intensifying crop production based on increased fertilizer application. We assessed the key field-scale cause of variability in maize (Zea mays) grain yield response to fertilizer nitrogen (N), phosphorus (P) and potassium (K) in the Sidindi area of Western Kenya based on past manure application, distance from the homestead, and clay and silt contents. We used data from nutrient omission trials conducted on 23 farms over seven consecutive cropping seasons covering the period 2013–2016, without changing treatments or plot location. …


Integrated Soil Fertility Management Sequences For Reducing Climate Risk In Smallholder Crop Production Systems In Southern Africa, Hatirarami Nezomba, Florence Mtambanengwe, Jairos Rurinda, Paul Mapfumo Jul 2018

Integrated Soil Fertility Management Sequences For Reducing Climate Risk In Smallholder Crop Production Systems In Southern Africa, Hatirarami Nezomba, Florence Mtambanengwe, Jairos Rurinda, Paul Mapfumo

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Climate change, increased climate variability and poor soil fertility are major bio-physical constraints to cropping on smallholder farms in southern Africa. We used the Agricultural Production Systems sIMulator (APSIM) to assess maize yield response to integrated soil fertility management (ISFM) rotational sequences of low-quality organic resources, nitrogen-fixing green manure and grain legumes, and mineral fertilizers under baseline (1960–2005) and projected (2040–2069) climates. APSIM was also employed to evaluate the response of maize yield to the ISFM sequences under a combination of a changing climate, and typical sowing dates and mineral fertilizer application rates for smallholder households of varying resource endowment. …


Reducing Losses But Failing To Sequester Carbon In Soils – The Case Of Conservation Agriculture And Integrated Soil Fertility Management In The Humid Tropical Agro-Ecosystem Of Western Kenya, Rolf Sommer, Birthe Katharina Paul, John Mukalama, Job Kihara Feb 2018

Reducing Losses But Failing To Sequester Carbon In Soils – The Case Of Conservation Agriculture And Integrated Soil Fertility Management In The Humid Tropical Agro-Ecosystem Of Western Kenya, Rolf Sommer, Birthe Katharina Paul, John Mukalama, Job Kihara

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Agriculture is a global contributor to greenhouse gas emissions, causing climate change. Soil organic carbon (SOC) sequestration is seen as a pathway to climate change mitigation. But, long-term data on the actual contribution of tropical soils to SOC sequestration are largely absent. To contribute to filling this knowledge gap, we measured SOC in the top 15 cm over 12 years in two agronomic long-term trials in Western Kenya. These trials include various levels – from absence to full adoption – of two widely promoted sustainable agricultural management practices: Integrated Soil Fertility Management (ISFM; i.e. improved varieties, mineral fertilizer and organic …


Strong Spatial-Temporal Patterns In Maize Yield Response To Nutrient Additions In African Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore Dec 2017

Strong Spatial-Temporal Patterns In Maize Yield Response To Nutrient Additions In African Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore

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Large variability in crop responses to macronutrient application at various spatial scales present challenges for developing effective fertilizer recommendations for crop production in smallholder farming systems of sub-Saharan Africa. We assessed maize yield responses to nitrogen (N), phosphorus (P) and potassium (K) application and evaluated relationships between crop responses to N, P and K application and soil analysis data. Nutrient omission trials were conducted on 23 farms located in Sidindi, Western Kenya, selected to be representative of the main soil and management factors in maize based systems in Siaya County. Treatments included a control and PK, NK, NP and NPK …


Profitability Of Diammonium Phosphate Use In Bush And Climbing Bean-Maize Rotations In Smallholder Farms Of Central Burundi, Marie Chantal Niyuhire, Pieter Pypers, Bernard Vanlauwe, Generose Nziguheba, Dries Roobroeck, Roel Merckx Oct 2017

Profitability Of Diammonium Phosphate Use In Bush And Climbing Bean-Maize Rotations In Smallholder Farms Of Central Burundi, Marie Chantal Niyuhire, Pieter Pypers, Bernard Vanlauwe, Generose Nziguheba, Dries Roobroeck, Roel Merckx

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Soil fertility decline is a major constraint to bean (Phaseolus vulgaris L.) and maize (Zea mays) production in the Central Highlands of Burundi. Nutrient sources, specifically fertilizers, are paramount to increasing the production in the regions. Hence, improving fertilizer use efficiency is considered as a key factor towards sustainable intensification. The use of grain legumes with low harvest indices, such as climbing beans, are assumed to improve soil fertility and fertilizer use efficiency. This study compares the rotational effects of bush and climbing bean varieties on maize and evaluates the profitability of diammonium phosphate (DAP, 18–46-0) fertilizer in the bean-maize …


Determinants Of Integrated Soil Fertility Management Technologies Adoption By Smallholder Farmers In The Chinyanja Triangle Of Southern Africa, Powell Mponela, Lulseged Tamene, Gift Ndengu, Ruth Magreta, Job Kihara, Nelson Mango Dec 2016

Determinants Of Integrated Soil Fertility Management Technologies Adoption By Smallholder Farmers In The Chinyanja Triangle Of Southern Africa, Powell Mponela, Lulseged Tamene, Gift Ndengu, Ruth Magreta, Job Kihara, Nelson Mango

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Integrated Soil Fertility Management (ISFM) technologies have proven to be viable options for improving land productivity and increasing yield. However, adoption of the set of complementary technologies that are required in ISFM is quite variable and studies tend to focus on single technologies. In this study we used cluster analysis to group technologies and ordered probit to determine the probability of multiple technology adoption. The result show that usage of ISFM in the Chinyanja Triangle (Southern Africa) is grouped into 3 technological sets based on complementarities. The set of nutrient dense technologies of inorganic fertiliser, compost and animal manure (ISFMset3) …


Understanding Variability In Crop Response To Fertilizer And Amendments In Sub-Saharan Africa, Job Kihara, Generose Nziguheba, Shamie Zingore, Adama Coulibaly, Anthony Esilaba, Vernon Kabambe, Samuel Njoroge, Cheryl Palm, Jeroen Huising Aug 2016

Understanding Variability In Crop Response To Fertilizer And Amendments In Sub-Saharan Africa, Job Kihara, Generose Nziguheba, Shamie Zingore, Adama Coulibaly, Anthony Esilaba, Vernon Kabambe, Samuel Njoroge, Cheryl Palm, Jeroen Huising

All Peer-Reviewed Publications

Improved understanding of soil fertility factors limiting crop productivity is important to develop appropriate soil and nutrient management recommendations in sub-Saharan Africa. Diagnostic trials were implemented in Kenya, Malawi, Mali, Nigeria and Tanzania, as part of the African Soils Information Service (AfSIS) project, to identify soil fertility constraints to crop production across various cropping systems and soil fertility conditions. In each country, one to three sites of 10 km × 10 km were included with each site having 12-31 field trials. The treatments tested included a control, an NPK treatment, three treatments in which the N, P and K nutrients …


Integrated Soil Fertility Management: Aggregate Carbon And Nitrogen Stabilization In Differently Textured Tropical Soils, R. M. Gentile, B. Vanlauwe, J. Six Dec 2013

Integrated Soil Fertility Management: Aggregate Carbon And Nitrogen Stabilization In Differently Textured Tropical Soils, R. M. Gentile, B. Vanlauwe, J. Six

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Soil organic matter is important to improve and sustain soil fertility in tropical agroecosystems. The combined use of organic residue and fertilizer inputs is advocated for its positive effects on short-term nutrient supply, but the effect of the integrated use on long-term stabilization of soil organic C and N is still unclear. We conducted a 1.5-y soil incubation experiment with maize (Zea mays) residue and urea fertilizer to examine the stabilization of C and N in four Sub-Saharan African soils differing in texture (sand, sandy loam, clay loam, and clay). The inputs were enriched with 13C and 15N in a …


Pushing The Envelope? Maize Production Intensification And The Role Of Cattle Manure In Recovery Of Degraded Soils In Smallholder Farming Areas Of Zimbabwe, Leonard Rusinamhodzi, Marc Corbeels, Shamie Zingore, Justice Nyamangara, Ken E. Giller Jun 2013

Pushing The Envelope? Maize Production Intensification And The Role Of Cattle Manure In Recovery Of Degraded Soils In Smallholder Farming Areas Of Zimbabwe, Leonard Rusinamhodzi, Marc Corbeels, Shamie Zingore, Justice Nyamangara, Ken E. Giller

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Soil fertility decline is a major constraint to crop productivity on smallholder farms in Africa. The objective of this study was to evaluate the long-term (up to nine years) impacts of nutrient management strategies and their local feasibility on crop productivity, soil fertility status and rainfall infiltration on two contrasting soil types and different prior management regimes in Murehwa, Zimbabwe. The nutrient management strategies employed in the study were: a control with no fertiliser, amendments of 100kg Nha-1, 100kg N+lime, three rates of manure application (5, 15 and 25tha-1) in combination with 100kg Nha-1, and three rates of P fertiliser …


Participatory Evaluation Of Integrated Pest And Soil Fertility Management Options Using Ordered Categorical Data Analysis, Hugo De Groote, Esther Rutto, George Odhiambo, Fred Kanampiu, Zeyaur Khan, Richard Coe, Bernard Vanlauwe Jun 2010

Participatory Evaluation Of Integrated Pest And Soil Fertility Management Options Using Ordered Categorical Data Analysis, Hugo De Groote, Esther Rutto, George Odhiambo, Fred Kanampiu, Zeyaur Khan, Richard Coe, Bernard Vanlauwe

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Maize is becoming the major food crop around Lake Victoria. Major constraints to its production are Striga, stem borer, and declining soil fertility. Innovative integrated technologies have been developed: the 'push-pull' system (intercropping with Desmodium and surrounded by Napier grass), soybean and Crotalaria rotations, and imidazolinone-resistant (IR) maize seed. In 12 demonstration trials in four villages in Siaya and Vihiga districts (Kenya) and two villages in Busia (Uganda) in 2003 and 2004, 504 farmers evaluated all cropping systems and a mono-cropped continuous maize, each cropped with IR or local maize, and supplemented or not with fertilizer, totaling 16 treatments. Farmers …