Occurrence of poorly responsive soils in western Kenya and associated nutrient imbalances in maize (Zea mays L.)

Njoroge, Ruth; Otinga, Abigael N.; Okalebo, J. R.; Pepela, Mary; Merckx, Roel

doi:10.1016/j.fcr.2017.05.015

Cited by 23 publications

(28 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We did not encounter non-responsive fields to NPK fertilization, in contrast to findings by earlier studies in western Kenya, and in the larger SSA region (Tittonell and Giller, 2013;Zingore et al, 2008;Njoroge et al, 2017a). The occurrence of such non-responsive soils has mainly been attributed to additional constraints of secondary and micronutrients following sustained cropping with no or insufficient nutrient inputs (Vanlauwe et al, 2015;Kihara et al, 2017;Njoroge et al, 2017a). Observed yields under NPK fertilization at low soil Mg and Ca availability however indicated no additional nutrient constraints beyond those of N, P and K in the clay rich soils of the study area, strongly contrasting to findings of Zingore et al (2008) for depleted sandy soils of Zimbabwe.…”

Section: Strong Yield Response To Balanced Fertilization In Nutrientcontrasting

confidence: 91%

“…Yields with NPK in the former control plots also matched those under long-term NPK in all three seasons of Phase 2-NOT (Table 5.3). We did not encounter non-responsive fields to NPK fertilization, in contrast to findings by earlier studies in western Kenya, and in the larger SSA region (Tittonell and Giller, 2013;Zingore et al, 2008;Njoroge et al, 2017a). The occurrence of such non-responsive soils has mainly been attributed to additional constraints of secondary and micronutrients following sustained cropping with no or insufficient nutrient inputs (Vanlauwe et al, 2015;Kihara et al, 2017;Njoroge et al, 2017a).…”

Section: Strong Yield Response To Balanced Fertilization In Nutrientcontrasting

confidence: 86%

“…Such distinct methodological differences are bound to invariably generate substantially different categorization of soils, with further expected differences in technological and policy recommendations. For example, in the study by Njoroge et al (2017a), 57% of 44 sites which showed a value cost ratio (VCR) of less than 2 following application of 100, 30 and 60 kg ha -1 of N, P and K respectively were classified as poorly non-responsive in the long rainy season of 2014. With mean maize grain yield response to NPK of 4.7 t ha -1 (Njoroge et al, 2017a), such classification raises a myriad of questions as one would expect that soils in this study are generally responsive.…”

Section: Quantification Of Non-responsive Soilsmentioning

confidence: 99%

“…There however appears to be a lack of consensus on the specific criteria for identifying such poor non-responsive and low responsive soils. Some studies in western Kenya have used observed maize yields with NPK fertilization as a measure of responsiveness , while others have used monetary returns to NPK fertilizer use as a measure of responsiveness (Njoroge et al, 2017a). Such distinct methodological differences are bound to invariably generate substantially different categorization of soils, with further expected differences in technological and policy recommendations.…”

Section: Quantification Of Non-responsive Soilsmentioning

confidence: 99%

See 3 more Smart Citations

Feed the crop, not the soil! : Explaining variability in maize yield responses to nutrient applications in smallholder farms of western Kenya

Kinyanjui

View full text Add to dashboard Cite

show abstract

Section: Strong Yield Response To Balanced Fertilization In Nutrientcontrasting

confidence: 91%

Section: Strong Yield Response To Balanced Fertilization In Nutrientcontrasting

confidence: 86%

Section: Quantification Of Non-responsive Soilsmentioning

confidence: 99%

Section: Quantification Of Non-responsive Soilsmentioning

confidence: 99%

See 2 more Smart Citations

Feed the crop, not the soil! : Explaining variability in maize yield responses to nutrient applications in smallholder farms of western Kenya

Kinyanjui

View full text Add to dashboard Cite

show abstract

“…The increasing food demand of this growing population requires agricultural intensification with efficient fertilizer use. Current fertilizer recommendations in SSA are often only specified to the level of a region, for instance, an agro-ecological zone (AEZ) or administrative district (e.g., Mowo and Mlingano 1993;FURP 1994;Schnier et al 1996). The fertilizer recommendations for these larger regions are commonly referred to as blanket fertilizer recommendations.…”

Section: Introductionmentioning

confidence: 99%

Fertilizer response and nitrogen use efficiency in African smallholder maize farms

Ichami

Shepherd

Sila

et al. 2018

Nutr Cycl Agroecosyst

View full text Add to dashboard Cite

Improving fertilizer recommendations for farmers is essential to increase food security in smallholder landscapes. Currently, blanket recommendations are provided across agro-ecological zones, although fertilizer response and nutrient use efficiency by maize crop are spatially variable. We aimed to identify factors that could help to refine fertilizer recommendation by analyzing the variability in fertilizer response (FR) and the agronomic nitrogen use efficiency (N-AE). A literature search for on-farm studies across Kenya and Sub-Sahara Africa (SSA), excluding Kenya, yielded 71 publications. The variability in FR was studied using a meta-analysis whereas key factors that influence FR and N-AE were studied with linear regression models. On average, the FR was 2, but it varied considerably from 1 to 28.5 (excluding outliers). In SSA, 18% of the plots were non-responsive plots with an FR \ 1. The main factors affecting N-AE for Kenya were P-Olsen, silt content, soil pH, clay and rainfall, whereas only soil pH, exchangeable K and texture were important for SSA. However, our study indicates that available data on soil, climate and management factors could explain only a small part (\ 33%) of the variation in FR and Electronic supplementary material The online version of this article (

show abstract

Factors driving cereal response to fertilizer microdosing in sub‐Saharan Africa: A meta‐analysis

et al. 2020

View full text Add to dashboard Cite

Fertilizer microdosing (FM) is being promoted in sub‐Saharan Africa (SSA) to boost crop productivity on smallholder farms. However, yield response variability is a barrier to adoption. We conducted a meta‐analysis to analyze the variability in cereal crop yield response to FM and to determine the main factors associated with this variability. Thirty publications pertaining to millet [Pennisetum glaucum (L.) R. Br.], sorghum (Sorghum bicolor L. Moench) or maize (Zea mays L.) were assessed. Factors analyzed were crop type, rainfall, soil texture, type and rate of fertilizer, and complementary practices. On average, FM improved millet, sorghum and maize crop yields by 68%. Yield response tended to increase with increasing rainfall and the largest yield gains were observed in medium‐textured soils (81%), as compared to light (61%) and heavy‐textured soils (30%). The combined application of N and P performed better than either element alone. Crop response tended to increase with increasing rates of N. In the case of P, this was true only on light textured‐soils. On medium‐textured soils, the response appeared independent of the rate of P. There was a synergetic effect of water conservation measures on the performance of FM, while combining FM with organic matter (OM) amendments decreased its performance. Results highlighted major trends in cereal crop response to FM that could be used to prioritize target areas. However, these may require additional, site‐specific field experiments, especially for factors for which little data is currently available.

show abstract

Occurrence of poorly responsive soils in western Kenya and associated nutrient imbalances in maize (Zea mays L.)

Cited by 23 publications

References 42 publications

Feed the crop, not the soil! : Explaining variability in maize yield responses to nutrient applications in smallholder farms of western Kenya

Feed the crop, not the soil! : Explaining variability in maize yield responses to nutrient applications in smallholder farms of western Kenya

Fertilizer response and nitrogen use efficiency in African smallholder maize farms

Factors driving cereal response to fertilizer microdosing in sub‐Saharan Africa: A meta‐analysis

Contact Info

Product

Resources

About