PREP-PAC: a nutrient replenishment product designed for smallholders in western Kenya

Woomer, Paul L.; Okalebo, J. R.; Maritim, H.K.; Obura, Pamela; Mwaura, Francis; Nekesa, P; Mukhwana, Eusebius J.

doi:10.1016/s0167-8809(03)00187-7

Cited by 13 publications

(8 citation statements)

References 11 publications

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“…Positive economic returns to investment from individual PREP-PAC inputs and their combinations are reported elsewhere (Obura et al 1999, Woomer et al 2003a). …”

Section: Testing the Effectiveness Of Components Of Prep-pacmentioning

confidence: 62%

Available technologies to replenish soil fertility in East Africa

Okalebo

Othieno

Woomer³

et al. 2006

Nutr Cycl Agroecosyst

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Low inherent soil fertility in the highly weathered and leached soils largely accounts for low and unsustained crop yields in most African countries. But in particular, the major nutrients, nitrogen (N) and phosphorus (P), are commonly deficient in these soils. This scenario of nutrient depletion is reflected in food deficits and hence the food aid received continuously, specifically in sub-Saharan Africa. Undoubtedly, substantial efforts have been made in the continent to replenish the fertility of degraded soils in attempts to raise crop yields, towards self-sufficiency and export. Such efforts consist of applications of both organic and inorganic resources to improve the nutrient status of soils and enhanced nutrient uptake by crops, provided that soil moisture is adequate. Overall, positive crop responses to these materials have been obtained. Thus in the East African region, maize (staple) yields have been raised in one growing season from below 0.5 t/ha without nutrient inputs, to 3-5 t/ha from various nutrient amendments at the smallhold farm level. However, in spite of the positive crop responses to nutrient inputs, farmers are generally slow to adopt the soil fertility management technologies. In this paper we review the impact of some technologies, focussing the use of nutrient resources of different characteristics (qualities) in relation to improved crop yields, with an overall goal to enhance technology adoption. Thus, inorganic resources or fertilizers often give immediate crop responses, but their use or adoption is rather restricted to large-scale farmers who can afford to buy these materials. Organic resources, which include crop residues, water hyacinth and agroforestry shrubs and trees, are widely distributed, but they are generally of low quality, reflecting the need to apply large quantities to meet crop nutrient demands. Moreover, most organics will add N mainly to soils. On the other hand, phosphate rocks of varying reactivity are found widely in Africa and are refined elsewhere to supply soluble P sources. The recently developed soil fertility management options in East Africa have targeted the efficient use of N and P by crops and the integrated nutrient management approach. Some people have also felt that the repackaging of inputs in small, affordable quantities, such as the PREP-PAC described in this paper, may be an avenue to attract smallhold farmers to use nutrient inputs. Nonetheless, crop responses to nutrient inputs vary widely within and across agroecozones (AEZs), suggesting specificity in recommendations. We highlight this observation in a case study whereby eight soil fertility management options, developed independently, are being tested side-

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“…Positive economic returns to investment from individual PREP-PAC inputs and their combinations are reported elsewhere (Obura et al 1999, Woomer et al 2003a). …”

Section: Testing the Effectiveness Of Components Of Prep-pacmentioning

confidence: 62%

Available technologies to replenish soil fertility in East Africa

Okalebo

Othieno

Woomer³

et al. 2006

Nutr Cycl Agroecosyst

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“…Reduced emergence due to pelleting is possible when clay is applied over sugar beet seeds (Durant and Loads, 1986) but macronutrient solution immersed seeds yielded with more in cereals (Woomer et al, 2003) and nutrient pelleted seeds accelerated growth and development (Konstantinov, 1983) which has not happened in our experiment with potato. There is a significant difference between A. nilotica pelleting alone with that of added nutrients treatments.…”

Section: Discussionmentioning

confidence: 66%

A method to use very small size potato (Solanum tuberosum L.) tubers as seed

Ravichandran¹,

Venkatasalam²,

Muthuraj³

et al. 2015

Afr. J. Plant Sci.

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Potato, being a vegetatively propagated crop, tubers of 30-60 g size is used as seed. Whereas, < 20 g size potato tubers are left in the soil itself after harvesting, as they are not suitable either for consumption or seed purpose. Seed pelleting technique is used to increase the tuber size and provide additional nutrient support. Two cultivars of potato (Solanum tuberosum L.) with five different treatments using left over under sized tubers (having radius of around 3.98 to 5.57 mm) were used for this experiment. During storage, weight loss was minimum in Acacia treatment (8.33%) and sprouting was not affected by Acacia and salicylic acid treatments. At the end of storage, phenol was high in Acacia treated tubers. These tubers were planted in the field. The time taken for 50% germination was similar in control (22.33 days), Acacia (22.33 days) and salicylic acid (22.67 days) treatments. Varietal differences were observed with the type of chemical used for pelleting. In general the yield obtained with Acacia leaf powder pelleting was more in both the cultivars.

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“…In smallholder farming, the key performance parameters of technology options to improve soil fertility and/or weed suppression are yield increase (Odendo et al, 2009) and sustainable use of available resources (Woomer et al, 2003) or economic feasibility (CIMMYT, 1988). In this study, variations in maize grain yield on a seasonal basis were mainly influenced by the unreliable amount of rainfall experienced during the short rainy seasons as compared to the long rainy season which had a 20-70% higher rainfall and better distributed during the crop growth.…”

Section: Agronomic Performance Of Technology Optionsmentioning

confidence: 99%

“…Organic manure-based options are a common practice in the region as animal manures and seeds of green manure crops are readily available . However, mineral fertilizers are often problematic because of their cost, the frequently untimely availability and the fact that no single P (or K)fertilizer is available in the markets of the region (Woomer et al, 2003). On the other hand, the extra land required for legume growth may worsen the already severe land shortages (0.5 ha per household), particularly in the subsistence farms where it is hardly affordable to set aside land for a crop that is not directly yielding food or income (Odendo et al, 2009).…”

Section: Technology Requirement Of Production Factorsmentioning

confidence: 99%

“…The frequently applied blanket recommendations do not consider the diverse socio-ecological situations (resource availability and resource base quality) facing farmers at household level (Tittonell et al, 2010) and the site-and system-specific niche environments for technology adoption . The use of mineral fertilizer is limited by cost and accessibility (Woomer et al, 2003) such that the few farmers using mineral fertilizers often do not apply the recommended rates, resulting to poor outputs . Organic-based technologies on the other hand, are either labour-(farm yard manure) or land-intensive (green manures) and the effectiveness often depends on season and soil attributes (Becker et al, 1994;Ngome et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

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Assessment of Technology Options Addressing Agricultural Production Constraints in Western Kenya

Mtei¹,

Ngome²,

Becker³

et al. 2013

GJAS

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Poor soil fertility and weed infestation are among major constraints facing agricultural production in Western Kenya. Recommended technologies differ in resource requirement and their effectiveness are seasonal site-specific. On-farm experiments were conducted during 2008/09 cropping seasons on two soil types of western Kenya using maize as a test crop. Seven technology options were assessed on agronomic performance, resource requirement, and economic returns. Maize grain yield differed between cropping seasons with generally higher yields during long rainy season, and across soil types with organic manure-based options performing better on Ultisol than on Alfisol. Response of soil parameters reflected the amount of added nutrients and soil type with strongest effect of added N on Alfisol and of added P on Ultisol. All options significantly reduced weed biomass in the maize fields in the long (>90%) than in the short rainy seasons (>50%). Green manure-based option required more labour while mineral fertilizer-based options required largest capital. The economic netbenefit varied between -112 and +892 € ha -1 with highest values in organic manure-based options during short rainy season and in mineral fertilizer-based options during long rainy season. This example illustrates the need to define sitespecific technology evaluation for successful targeting of technology options.

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PREP-PAC: a nutrient replenishment product designed for smallholders in western Kenya

Cited by 13 publications

References 11 publications

Available technologies to replenish soil fertility in East Africa

Available technologies to replenish soil fertility in East Africa

A method to use very small size potato (Solanum tuberosum L.) tubers as seed

Assessment of Technology Options Addressing Agricultural Production Constraints in Western Kenya

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