Browsing by Author "Mangale, N."
Now showing 1 - 8 of 8
- Results Per Page
- Sort Options
Item The Effects of Some Soil Fertility Improvement Technologies on the Chemical Characteristics of a Sandy Soil and Yields of Two Maize Varieties(2013) Mangale, N.; Mzingirwa, A.M.; Kenya Agricultural Research Institute, NARL- Kabete,Low and declining soil fertility has been shown to be the fundamental root cause of low food per capita in sub-Saharan Africa (SSA). Coastal Kenya is therefore not an exception. Soil fertility improving technologies have therefore been developed in the region to increase crop yields and reduce food poverty levels in coastal Kenya. The long-time effects of these technologies on the environment or their sustainability have however not been evaluated. This study carried out on a sandy soil classified as Acrisol to Luvisol therefore looked at the long-time effects of four (4) soil fertility improving technologies The study was conducted at KARI's Regional Research Center (RRC)-Mtwapa with Pwani hybrid 1 and 4 (PH 1 & 4) maize varieties were the test crop. The experiment was conducted for a period of 6 seasons or 3 years. Continuous use of inorganic fertilizers (DAP and CAN) lowered the soil's cation exchange capacity (CEC), pH and organic matter (OC) content while extractable P was increased. Total nitrogen (N) does not seem to be a good parameter to measure the effect of inorganic fertilizers on soil N levels. Since soil OC is necessary for a soil to have a good workability and increased CEC, the results appear to confirm farmers' observations that continuous use of inorganic fertilizers adversely affects soil physical characteristics (hard to till). The other 3 technologies resulted in increased soil. CEC, phosphorus (P) levels and OC content. The soil pH either remained the same or was slightly increased by the 3 soil improving technologies. Therefore the 3 soil improving technologies boosted or sustained the soil chemical characteristics which are vital for sustained crop productivity. Pwani hybrid 4 grain yields decreased with seasons reaching levels almost similar to those of PH 1 in the final season. On the other hand, PH 1 yields remained the same except during the first season where inadequate rainfall lowered them. The continued decrease in yields of PH 4 with successive seasons even when soil fertility improving technologies are used calls for further investigation on the nutrition of the maize variety. Nutrients needs of PH 1 are shown to be adequately supplied by the 4 technologies used.Item Farm-Level Agricultural Resilience and Adaptation to Climate Change Extension Manual(Kenya Agricultural and Livestock Research Organization, 2019-12) Okoti, M.; Esilaba, A.O.; Ketiem, P.; Mangale, N.; Muli, B.M.; Nyongesa, D.; Otipa, M.; Mutisya, D.; Too, A.; Njiru, E.; Muthiani, E.; Finyange, P.; Ndanu, A.; Wasilwa, L.; Kenya Agricultural and Livestock Research OrganizationClimate change and variability is acknowledged as a global phenomenon with potentially far-reaching implications to many economic sectors. It is characterized by increased recurrence of droughts, floods, rainfall variability (pattern, timing and intensity), increased mean surface temperature and famine that threaten millions of people, crops and livestock systems. The developing countries and the poor in society are highly vulnerable to impacts of climate change despite the minimal contribution (less than 10%) to the annual global carbon dioxide emissions. The increasingly observed weather risks threaten the agricultural production systems and food security conditions for majority of population in Kenya. Farmers who largely practice subsistence farming for livelihoods are characterized by degraded soils, small farm sizes, and low crop yields. Therefore, sustaining farmers’ agricultural growth and minimizing climate related shocks is crucial in building farmers and food production system resilience. Agricultural adaptations to climate change need to be resilient to deal with stresses and disturbances. These adaptations can either be technological, institutional or policy interventions to help farmers build resilience to current and future climate related shocks as well as mitigating greenhouse gas (GHG) emissions.Item Field And Laboratory Research Manual For Integrated Soil Fertility Management In Kenya(Kenya Soil Health Consortium, 2016-05) Mangale, N.; Muriuki, A.; Kathuku-Gitonga, A.N.; Kibunja, C.N.; Mutegi, J.K.; Esilaba, A.O.; Ayuke, F.O.; Nguluu, S.N.; Gikonyo, E.W.; Kenya Agricultural and Livestock Research OrganizationIn Kenya research efforts have generated numerous Integrated Soil Fertility Management (ISFM) technologies with potential for increasing food production and rural incomes (Jama et al., 2000; Lekasi et al,. 2001; TSBF, 2005; Salasya, 2005; Ojiem, 2006; AGRA, 2007; Misiko, 2007; Okalebo, et al., 2007; WAC, 2008; FAO, 2009; Rockstrom et al., 2009). However, these technologies have had limited impact on smallholder farmers’ fields. The gap between research and application of ISFM guidelines is wide and evidenced by the low uptake and utilization of recommended ISFM technologies by smallholder farmers. Reasons for this unfortunate scenario include incoherent and conflicting recommendations for ISFM technologies because generators of ISFM technologies and innovations hardly collaborate and/or share their research outputs with each other or with end users. This also results in many inappropriate technology recommendations that confuse target farmers and lower technology adoption. These are the major reasons why farmers have been unable to realize the full benefits of the potential productivity gains possible from growing improved crop varieties, although adoption of these varieties is now widespread in the country (Rukandema, 1984; Omiti et al., 1999). Although it is evident that appropriate use of ISFM can transform agriculture, the level of production with ISFM in Kenya has remained low. Part of the reason for low production ISFM can be traced to poor research. Successful ISFM research with a potential of increasing food production and incomes is best driven by appropriate field and laboratory research methods. In Kenya different laboratories use different methods to analyze for the same elements, often generating varying results for the same soil and plant samples. For example there are more than three methods for determination of soil and plant phosphorus levels used in different laboratories viz: Infra-red spectroscopy (IR), Bray II, Olsen, Mehlich I, II and III and the Truog methods. Recommendations based on the variable results from these methods are difficult to validate for reliability. Often this may lead to confusion and generation of wrong fertilizer recommendations leading to inappropriate use of farm inputs, soil acidification, low crop yields, low adoption, food insecurity and low household incomes. The Kenya Soil Health Consortium (KSHC) has developed this manual of field and laboratory methods through consultation with the major national, regional and international research and learning institutions to guide implementation of agricultural research in Kenya. This protocol highlights among others; the process of research formulation, process of project implementation, field research methodology and approaches, plants-soil sampling and analysis, soil chemical analysis methods, fertilizer recommendation and use efficiency, and data management. The protocol is intended to act as a reference material and as a guide for future agricultural research and development in Kenya. This protocol is of great benefit to a wide range of stakeholders involved in agricultural research, agricultural extension, capacity building, and agricultural policy development.Item Harmonized Fertilizer Recommendations For Optimal Maize Production In Kenya(Kenya Soil Health Consortium, 2016-10) Mangale, N.; Muriuki, A.; Kathuku-Gitonga, A.N.; Mutegi, J.K.; Kenya Agricultural and Livestock Research Organization -NARL ; International Plant Nutrition Institute (IPNI)The fundamental importance of agriculture in the development of Kenya’s economy cannot be underscored. Agriculture is the backbone of Kenya’s economy contributing 26% and 27% of the gross domestic product (GDP) annually directly and indirectly respectively. It also accounts for 65% of total exports and provides 18% and 60% of formal and total employment respectively. It is estimated that a 1% increase in the sector results in a corresponding 1.6% GDP growth in the overall economy. Evidence from a broad range of research impact studies show that returns on investment (ROI) from agricultural research in Kenya are two to three times higher than from all the other investments combined. Investments in agricultural research are therefore paramount to economic growth since the benefits it produces are widely and more equitably distributed. However, per capita food production in Kenya has continued to decline in spite of the successful introduction of new crop varieties, associated fertilizer and pesticide packages coupled with excellent research outcomes. Natural disasters (increased incidences of floods and droughts due to climate change), a high incidence of pests and diseases and degradation of the soil resource base among others have been cited as the main reasons for the decline. Degradation of the soil resource base is directly linked to poor land management including land use without installation of appropriate erosion control measures and exportation of nutrients from farms through the crop and indirectly through animal products without adequate replenishment of the removed nutrients (Bationo et al 1997; Sanchez, et al 1997 & Sanchez, 2002) The agricultural sector in Kenya is dominated by smallholder farmers who account for about 75% of the country’s total output. Under smallholder farming systems, soil fertility has been maintained through application of farmyard manure and inclusion of grain legumes into the cropping systems. The rapidly increasing population has put great pressure on land (land holding per household in arable Kenya zones is estimated at less than 0.5 ha) making farming intensification the only alternative option. One of the most significant policy challenges is to find innovative ways of managing food insecurity and household incomes through improvement in crop germplasm, soil fertility inputs and sound agronomic practices.Item Harmonized Fertilizer Recommendations for Pulses in Smallholder Farming Systems of Kenya(Kenya Agricultural and Livestock Research Organization, 2017-12) Mangale, N.; Kathuku-Gitonga, A.N.; Esilaba, A.O.; Nyongesa, D.; Kenya Agricultural and Livestock Research OrganizationProduction of pulses in East Africa dates back many years. The pulses (grain legumes) are beans, cowpeas, pigeon peas, green grams, dolichos lablab, chickpeas and lentils. These crops are grown in the Eastern Africa region in varying hectareage, depending on preferences and adaptation to agro-ecological zones. Cowpeas, chick peas, pigeon peas and green grams are grown in lower, drier and warmer areas. Beans and dolichos are grown in the medium rainfall areas of the region while lentils are grown in the cooler regions (Karanja, 2016). Pulses are grown in both mono-cropping and intercropping systems in Kenya. Most common crop combinations in intercropping systems include: maize-beans, maize cowpea, maize-pigeon pea, maize-Soya bean, maize-dolichoslablab, sorghum cowpea, millet-pulses, sugar cane-pulses and rice-pulses (Chui and Nadar 1984; Nadar 1984; Mangale 1989; Matusso et al., 2012; Karanja, 2016). This cropping practice aims to match efficiently crop demands to the available growth resources and labour. The efficient use of available growth resources in a given piece of land and eventually maximizing productivity is the primary advantage of intercropping crops of different height, canopy structure, rooting ability, and nutrient requirements (Matusso et al., 2012). Many studies on intercropping have shown that legumes-cereal intercropping is an important productive and sustainable system due to its resource facilitation and significantly enhancing crop productivity as compared to that of monoculture crops (Matusso et al., 2014). In an effort to improve food security, intercropping cereals with legumes plays an important role by providing a farmer with both carbohydrates and proteins for their dietary needs. Apart from nutritional composition of component crops in an intercropping, it has been also reported that intercropping improves soil fertility through biological nitrogen fixation, increases soil conservation through greater ground cover than sole cropping (Ofori and Stern, 1987; Matussoet al., 2014; Hailu Gebru, 2015; Nyoki and Ndakidemi 2016), and provides better protection against crop pests and diseases than when grown in monoculture (Ofori and Stern, 1987; Matusso et al., 2014; Hailu Gebru, 2015).Item KCEP–CRAL Soil and Fertility Management Trainer of Trainers’ Manual(Kenya Agricultural and Livestock Research Organization, 2019-04) Esilaba, A.O.; Mangale, N.; Kathuku-Gitonga, A.N.; Njiru, E.; Muindi, E.M.; Nyongesa, D.; Okoti, M.; Mutuma, E.; Kenya Agricultural and Livestock Research OrganizationThe agriculture sector in Kenya directly contributes 26 per cent of the Gross Domestic Product (GDP) and another 27 per cent of GDP indirectly through linkages with other sectors. However, growth in this sector is constrained by, among other factors, declining soil fertility and deteriorating soil health. Soil management strategies center on: acquisition of appropriate knowledge on soils, their utilization and maintenance of their fertility for sustainable improved crop productivity. This module is intended to familiarize participants on the importance of soil management and recognition that healthy and fertile soils are essential for crop productivity and value chains.Agricultural productivity in Kenya is generally low despite the high demand from the increasing population. Yields of the major staple crops, maize and beans, obtained by farmers are well below the research potential yields and this is attributed to various problems including low soil fertility resource base (low soil organic carbon, nitrogen, phosphorous, potassium and some micro-nutrients) and poor land and water management. Such poor management results in loss of soil nutrients estimated at 21% of nitrogen, 8% phosphorous and 45% Muriate of Potash per year per hectare. Soil fertility management is therefore crucial for farmers to realize potential yields and improve households and national food and nutrition security.Item Overcoming Soil Acidity Constraints Through Liming and Other Soil Amendments in Kenya: A Review(East African Agricultural and Forestry Journal, 2022) Esilaba, A.O.; Mangale, N.; Kathuku-Gitonga, A.N.; Kamau, D.M.; Muriuki, A.W.; Mbakaya, D.; Zingore, S.Food production in Kenya is constrained by low and declining soil health resulting from low soil fertility and increasing widespread soil acidity, coupled with emerging climate change effects leading to recurrent food and nutrition insecurity. The major food production areas with high crop yield potential in the country are greatly affected by soil acidity due to continuous cropping, loss of organic carbon, nutrient leaching and inappropriate use of fertilizers. While use of organic and inorganic fertilizers, improved seed varieties and crop protection have received much research attention, liming as one way of improving soil health and crop production has not received similar attention. Consequently, potential yield of hybrid crops remains constrained. Soil acidity is mainly ameliorated by applying lime or other acid‐neutralizing materials, which neutralize the acidity, raises soil pH, increases the availability of plants’ nutrients and adds calcium and magnesium to the soil. It also improves the environment for beneficial soil microorganisms thus enhancing rapid breakdown of organic materials in the soil and releasing nutrients for growing plants. Soil buffer capacity determines the amount of lime per unit of soil volume needed to alter soil pH. Soils with low Cation Exchange Capacity (CEC) respond rapidly to liming than soils with high CEC. But the low-CEC soils have a high capacity for rapid leaching of the added bases, thus a quicker return to original acidity unless additional liming is done. Over-liming is recommended for soils which have low CEC, such as sand which is deficient in buffering agents such as organic matter and clay. There is therefore need for appropriate attention to to ameliorate soil acidity in order to maintain good soil health for food and nutrition security. A meta-analysis of a desk study supported by field experiment was carried out in areas viewed as most affected by soil acidity. The aim of the study was to evaluate amendments that can be used for alleviating soil acidity in acidic soils. The results showed that extensive work has been done in Western and Rift valley regions of Kenya targeting soil acidity alleviation and few studies in the coastal and eastern regions due to perception that these areas do not have acidic soils. Among the soil acidity amendments, use of lime and organic sources showed positive crop response and increased yields when applied in acidic soils.Item Potassium Nutrient Status and Management in Kenyan Soils for Increased Productivity(East African Agricultural and Forestry Journal, 2022) Kathuku-Gitonga, A.N.; Esilaba, A.O.; Mangale, N.; Wasilwa, L.; Okoti, M.; Nyongesa, D.; Kamoni, P.T.; Waruru, B.K.; Muya, E.M.; Thuranira, E.; Mutisya, D.; African Plant Nutrition Institute (APNI) ; Kenya Agricultural and Livestock Research Organization (KALRO), Kabete & KatumaniNitrogen, phosphorus and potassium are regarded as the main basic nutrients necessary for plant growth and production and their functions are interrelated. Potassium is necessary for regulation of plant cells, for the production of proteins and enzymes. It improves crop's disease and pests' resistance, and it increases crop yield and plays a significant role in enhancing crop quality. Potassium deficiency inhibits protein production even when nitrogen is abundant. The objective of the study was to determine status of potassium in selected Kenyan soils and responses to applied potassium fertilizers. Studies were carried out in Kenya through laboratory soil analysis, meta-data analysis and fertilizer response studies. Soils were collected in the trial sites and analyzed using wet chemistry method. For meta-analysis, published materials were collected, collated, digitized and harmonized. Benefit cost ratios were calculated for each technology to ascertain its profitability. The soil analysis results showed that potassium, nitrogen, organic carbon and zinc were deficient. The meta-analysis results showed that, limited research studies had been conducted on potassium in Eastern, Coast and Rift Valley regions of Kenya. The most economical potassium responses were recorded under application of 60 kg K/ha, although the yields were not profitable. However, the fertilizer response studies showed increased crop yields on addition of potassium fertilizer up to 40 kg K/ha. Hence lower rates of potassium (less than or equal to 40 kg K/ha) are recommended to offset and maintain adequate potassium levels in the soil for optimal crop production and income. Nevertheless, soil analysis is key before any fertilizers are added to soils.
