Impacts of Climate Variability and Soil Fertility Management Strategies on Maize Grain Yield on Ferrralsols in Coastal Western Africa

SUMMARYDeclining land productivity is a major problem facing smallholder farmers today in Sub-Saharan Africa, and as a result increase in maize grain yield has historically staggered behind yield gains that have been achieved elsewhere in the world. This decline primarily results from reduction in soil fertility caused by continuous cultivation without adequate addition of external nutrient inputs. Improved soil fertility management practices, which combine organic and mineral fertilizer inputs, can enable efficient use of inputs applied, and can increase overall system's productivity. The trials were established at two sites with different soil fertility status to determine the effects of various organic sources (Tithonia diversifolia, Mucuna pruriens, Calliandra calothyrsus and cattle manure) and their combinations with mineral fertilizer on maize grain yield, economic return and soil chemical properties. Drought spells were common during the peak water requirement periods, and during all the seasons most (90%) of the rainfall was received before 50% flowering. In good and poor sites, there was a significant (p < 0.001) effect of season on maize grain yield. Tithonia diversifolia recorded the highest (4.2 t ha−1) average maize grain yield in the poor site, while Calliandra calothyrsus gave the highest (4.8 t ha−1) average maize grain yield in the good site. Maize grain yields were lower in treatments with sole fertilizer compared with treatments that included organic fertilizers. The maize grain yields were higher with sole organics compared with treatments integrating organic and inorganic fertilizers. Soil pH increment was statistically significant in the sole manure treatment in good and poor sites (t-test, p = 0.036 and 0.013), respectively. In the poor site, magnesium increased significantly in the sole manure and manure + 30 kg N ha−1 treatments with t-test p = 0.006 and 0.027, respectively. Soil potassium was significant in the sole manure treatment (t-test, p = 0.03). Generally the economic returns were low, with negative net benefits and benefit cost ratio of less than 1. Inorganic fertilizer recorded the highest net benefit and return to labour (p < 0.001 and <0.01, respectively) in the good site. The treatments that had very high maize grain yields did not lead to improved soil fertility, thus there is need for tradeoffs between yield gains and soil fertility management when selecting agricultural production technologies.

Download Full-text

Legacy effects of soil fertility management on cereal dry matter and nitrogen grain yield of organic arable cropping systems

European Journal of Agronomy ◽

10.1016/j.eja.2020.126169 ◽

2021 ◽

Vol 122 ◽

pp. 126169

Author(s):

Johannes Wilhelmus Maria Pullens ◽

Peter Sørensen ◽

Bo Melander ◽

Jørgen Eivind Olesen

Keyword(s):

Soil Fertility ◽

Grain Yield ◽

Dry Matter ◽

Cropping Systems ◽

Legacy Effects ◽

Soil Fertility Management ◽

Fertility Management

Download Full-text

Biophysical and socio-economic tools for assessing soil fertility: A case of western hills, Nepal

Agronomy Journal of Nepal ◽

10.3126/ajn.v1i0.7536 ◽

2013 ◽

Vol 1 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

BP Tripathi ◽

JE Jones

Keyword(s):

Soil Fertility ◽

Management Practices ◽

Management Strategies ◽

Soil Management ◽

Cost Effective ◽

Integrated System ◽

Residue Management ◽

Soil Fertility Management ◽

Fertility Management ◽

Early Results

The middle mountain region of Nepal, which occupies some 30% of the total land, is the homeland of 45% of the total population, with agriculture being the main source of their livelihoods. Hill farming is primarily based on organic manure with livestock, forest and crops being major components of an integrated system. The aim of this study is to develop and promote improved methods for research and development organizations to identify cost-effective and appropriate soil fertility management strategies through; providing an improved understanding of the biophysical and socio-economic factors affecting the adaptability of sustainable soil management strategies in hillside systems, developing methodologies for evaluating soil fertility technologies and management systems for differently resource farmers in different farming systems, and strengthening the capability of local professionals in collaborating institutions to provide useful information to farmers. The work is placing emphasis on promoting cost-effective methods of soil fertility management, building on farmers' own knowledge and systems. Participatory techniques have been used for gaining a better understanding of fertility indicators, trends and existing soil management practices during 2000/01 in the western hills of Nepal. Farmers are now concerned that increasing amounts of chemical fertilizer at increasingly higher cost have to be applied, soils are becoming “harder” and production is declining. As a result farmers in four agro-ecological zones opted to either test methods for “improving” the quality of farm yard manure (FYM), or “improve” crop residue management. Early results show that through covering the FYM with black plastic sheets, yield increases of over 30% can be achieved. The use of participatory farm management techniques is providing a basis for local NGOs and farmers to evaluate their own experiments and develop soil fertility technologies and systems for their environments.DOI: http://dx.doi.org/10.3126/ajn.v1i0.7536 Agronomy Journal of Nepal (Agron JN) Vol. 1: 2010 pp.1-9

Download Full-text

Optimizing Soil Fertility Management Strategies to Enhance Banana Production in Volcanic Soils of the Northern Highlands, Tanzania

Agronomy ◽

10.3390/agronomy10020289 ◽

2020 ◽

Vol 10 (2) ◽

pp. 289 ◽

Cited By ~ 1

Author(s):

Akida I. Meya ◽

Patrick A. Ndakidemi ◽

Kelvin M. Mtei ◽

Rony Swennen ◽

Roel Merckx

Keyword(s):

Soil Fertility ◽

Management Strategies ◽

Farming Systems ◽

Animal Manure ◽

Cattle Manure ◽

Organic N ◽

Mineral Fertilizers ◽

Soil Fertility Management ◽

Fertility Management ◽

N Dose

Banana is an important crop in high altitude areas of Tanzania, grown widely both as a food staple and as the main source of income. However, its production is constrained by low soil fertility, a result of gradual nutrient mining by the crop. Currently, soil fertility management in banana-based farming systems in the country relies mainly on applications of animal manure. However, the amount of manure produced in most farms is not enough to replenish soil fertility due to the small number of animals kept by smallholder resource-poor farmers who are the major producers in the country. Field experiments were conducted at three sites with varying soil types and contrasting weather conditions along the altitudinal gradients on the slopes of the volcanic mountains of Kilimanjaro and Meru, northern Tanzania to (1) investigate the effect of mineral nitrogen (mineral N) fertilizer applications on the growth and yield of Mchare banana (Musa spp., AA, a traditional East African highland cooking banana sub-group), at the four levels of 0, 77, 153, and 230 kg N ha−1 year−1 as a starter strategy to improve the current soil fertility management strategies, and (2) evaluate the effect of the combined use of inorganic and organic N sources on growth and banana fruit production as an alternative strategy to manage soil fertility and minimize animal manure requirements. The treatment factors were trial sites (Tarakea, Lyamungo, and Tengeru) as the main factor and N fertilization strategies (as urea alone, sole cattle manure, and in combination with urea, sole common bean (Phaseolus vulgaris L.) haulms as well as in combination with urea) as a sub factor. Bean haulms and cattle manure were applied each year for two years. Fertilization at 153 kg N ha−1 year−1 derived solely from urea significantly (p < 0.001) resulted in high yield increment of up to 42% relative to the control. However, the increase was highest (52%) with the same N dose derived from cattle manure in combination with urea at 50% substitution. Sole bean haulms resulted in a smaller yield increment, the same as the lowest N dose from the sole urea fertilization treatment. The study concludes that soil fertility management in smallholder banana-based farming systems should not solely rely on animal manure and mineral fertilizers.

Download Full-text

Increased Maize Yields through the Transdisciplinary Process with Site Specific Fertilizer Recommendation in Small Holder Farms in Uasin Gishu County, Kenya

Journal of Experimental Agriculture International ◽

10.9734/jeai/2019/v34i130162 ◽

2019 ◽

pp. 1-10

Author(s):

Arusey Chebet ◽

Otinga A. Nekesa ◽

Wilson Ng’etich ◽

Ruth Njoroge ◽

Roland W. Scholz ◽

...

Keyword(s):

Soil Fertility ◽

Grain Yield ◽

Maize Yield ◽

Soil Testing ◽

Site Specific ◽

Maize Grain Yield ◽

Significant Difference ◽

Fertilizer Recommendations ◽

Maize Yields ◽

Maize Grain

The objective of this study was to evaluate the effects of site-specific fertilizer recommendations on maize yield using the transdisciplinary (TD) process. 144 farmers participated in the study for the two seasons. Experiments were laid on the farmers’ fields at four sites (Kapyemit, Kipsomba, Ngenyilel and Ziwa, in Uasin Gishu County) using Randomized Complete Block Design in a 3 x 2 factorial arrangement. Treatments included farmers who participated in the TD process (TD2) and those who did not (TD1) in using the interventions for soil fertility improvement which were farmer own practices (ST1); farmers who applied government recommendations (ST2), and site-specific fertilizer recommendations (ST3) which was based on soil testing results. The Data collected was the dry weights of maize which were measured at the end of the seasons and subjected to Analysis of Variance using Genstat 14th edition. Means separation was done using Fischer’s unprotected Least Significant Difference.. There was a significant effect on maize yields by soil testing and participation in TD process p = 0.01. The mean maize grain yield for season one was 5.43 ton ha-1 while for season two was 5.73 ton ha-1. Control farmers (TD1) maize grain yield of 5.27 ton ha-1, had a significant difference (p = 0.05) from the yield of participating farmers (TD2) who had 5.96 ton ha-1. Maize grain yield was increased by the application of site specific fertilizer recommendations which gave an overall mean of 6.57 ton ha-1 for season one and 6.56 ton ha-1 for season two. Following (ST3) recommendations and participation in the TD process, improved soil nutrient content thus maize yield increased. We recommend soil testing and consequent site-specific fertilizer recommendations for any initiative in managing soil fertility.

Download Full-text

SEQUENCING INTEGRATED SOIL FERTILITY MANAGEMENT OPTIONS FOR SUSTAINABLE CROP INTENSIFICATION BY DIFFERENT CATEGORIES OF SMALLHOLDER FARMERS IN ZIMBABWE

Experimental Agriculture ◽

10.1017/s0014479714000131 ◽

2014 ◽

Vol 51 (1) ◽

pp. 17-41 ◽

Cited By ~ 12

Author(s):

H. NEZOMBA ◽

F. MTAMBANENGWE ◽

R. CHIKOWO ◽

P. MAPFUMO

Keyword(s):

Soil Fertility ◽

Crop Yields ◽

Smallholder Farmers ◽

Mineral Fertilizers ◽

Soil Productivity ◽

Soil Fertility Management ◽

Management Options ◽

Integrated Soil Fertility Management ◽

Fertility Management ◽

Maize Grain

SUMMARYResearch has proved that integrated soil fertility management (ISFM) can increase crop yields at the field and farm scales. However, its uptake by smallholder farmers in Africa is often constrained by lack of technical guidelines on effective starting points and how the different ISFM options can be combined to increase crop productivity on a sustainable basis. A 4-year study was conducted on sandy soils (<10% clay) on smallholder farms in eastern Zimbabwe to assess how sequencing of different ISFM options may lead to incremental gains in soil productivity, enhanced efficiency of resource use, and increase crop yields at field scale. The sequences were primarily based on low-quality organic resources, nitrogen-fixing green manure and grain legumes, and mineral fertilizers. To enable comparison of legume and maize grain yields among treatments, yields were converted to energy (kilocalories) and protein (kg) equivalents. In the first year, ‘Manure-start’, a cattle manure-based sequence, yielded 3.4 t ha−1of maize grain compared with 2.5 and 0.4 t ha−1under a woodland litter-based sequence (‘Litter-start’) and continuous unfertilized maize control, respectively. The ‘Manure-start’ produced 12 × 106kilocalories (kcal); significantly (p< 0.05) out-yielding ‘Litter start’ and a fertilizer-based sequence (‘Fertilizer-start’) by 50%. A soyabean-based sequence, ‘Soya-start’, gave the highest protein production of 720 kg against <450 kg for the other sequencing treatments. In the second year, the sequences yielded an average of 5.7 t ha−1of maize grain, producing over 19 × 106kcal and 400 kg of protein. Consequently, the sequences significantly out-performed farmers’ designated poor fields by ~ fivefold. In the third year, ‘Soya-start’ gave the highest maize grain yield of 3.7 t ha−1; translating to 1.5 and 3 times more calories than under farmers’ designated rich and poor fields, respectively. In the fourth year, ‘Fertilizer-start’ produced the highest calories and protein of 14 × 106kcal and 340 kg, respectively. Cumulatively over 4 years, ‘Manure-start’ and ‘Soya-start’ gave the highest calories and protein, out-performing farmers’ designated rich and poor fields. Sunnhemp (Crotalaria junceaL.)-based sequences, ‘Green-start’ and ‘Fertilizer-start’, recorded the highest gains in plant available soil P of ~ 4 mg kg−1over the 4-year period. Assessment of P agronomic efficiencies showed significantly more benefits under the ISFM-based sequences than under farmers’ designated rich and poor fields. Based on costs of seed, nutrients and labour, ‘Soya-start’ gave the best net present value over the 4 years, while ‘Fertilizer-start’ was financially the least attractive. Overall, the ISFM-based sequences were more profitable than fields designated as rich and poor by farmers. We concluded that ISFM-based sequences can provide options for farm-level intensification by different categories of smallholder farmers in Southern Africa.

Download Full-text

Good soil management can reduce dietary zinc deficiency in Zimbabwe

CABI Agriculture and Bioscience ◽

10.1186/s43170-021-00057-4 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Muneta G. Manzeke-Kangara ◽

Edward J. M. Joy ◽

Florence Mtambanengwe ◽

Prosper Chopera ◽

Michael J. Watts ◽

...

Keyword(s):

Soil Fertility ◽

Zn Deficiency ◽

Soil Fertility Management ◽

Management Scenarios ◽

Fertility Management ◽

Zn Concentration ◽

Maize Grain ◽

Soil Zn ◽

Nutrient Resources ◽

Grain Zn Concentration

Abstract Background Dietary zinc (Zn) deficiency is widespread in sub-Saharan Africa (SSA) with adverse impacts on human health. Agronomic biofortification with Zn fertilizers and improved soil fertility management, using mineral and organic nutrient resources, has previously been shown to increase Zn concentration of staple grain crops, including maize. Here, we show the potential of different soil fertility management options on maize crops to reduce dietary Zn deficiency in Zimbabwe using secondary data from a set of surveys and field experiments. Methods An ex-ante approach was used, informed by published evidence from studies in three contrasting smallholder production systems in Zimbabwe. To estimate current Zn deficiency in Zimbabwe, data on dietary Zn supply from non-maize sources from the Global Expanded Nutrient Supply (GENuS) data set were linked to maize grain Zn composition observed under typical current soil fertility management scenarios. Results A baseline dietary Zn deficiency prevalence of 68% was estimated from a reference maize grain Zn composition value of 16.6 mg kg−1 and an estimated dietary Zn intake of 9.3 mg capita−1 day−1 from all food sources. The potential health benefits of reducing Zn deficiency using different soil fertility management scenarios were quantified within a Disability Adjusted Life Years (DALYs) framework. A scenario using optimal mineral NPK fertilizers and locally available organic nutrient resources (i.e. cattle manure and woodland leaf litter), but without additional soil Zn fertilizer applications, is estimated to increase maize grain Zn concentration to 19.3 mg kg−1. This would reduce the estimated prevalence of dietary Zn deficiency to 55%, potentially saving 2238 DALYs year−1. Universal adoption of optimal fertilizers, to include soil Zn applications and locally available organic leaf litter, is estimated to increase maize grain Zn concentration to 32.4 mg kg−1 and reduce dietary Zn deficiency to 16.7%, potentially saving 9119 DALYs year−1. Potential monetized yield gains from adopting improved soil fertility management range from 49- to 158-fold larger than the potential reduction in DALYs, if the latter are monetized using standard methods. Conclusion Farmers should be incentivized to adopt improved soil fertility management to improve both crop yield and quality.

Download Full-text