Declining Soil Fertility Research Articles

Linkages between Soil Acidity, Soil Plant Nutrients and Land Use on Ferralsols in Central Uganda

A study to examine the linkages between soil acidity, soil plant nutrients and land use on Ferralsols was carried out on smallholder farms in Central Uganda. The objective of the study was to assess the effect of soil pH on soil plant nutrient availability under the current land use. The study was carried out in Mpigi, Masaka, Wakiso, Mukono and Mubende districts representing Central Uganda. Soil samples were randomly collected from Coffee, Banana, soybean, common bean, maize and virgin fields in the five districts and the pH and plant nutrient analyzed accordingly. The analysis of variance (ANOVA) showed significant difference (p<0.01) on soil nitrogen, Calcium (p< 0.05) and Magnesium (p< 0.05). When treatment was assessed, the study showed significant difference (p< 0.01) on potassium. Besides, the study also showed high concentrations of Manganese (Mn) and Iron (Fe) in addition to very high sand and low silt and clay contents. The current land use for coffee production in Masaka district recorded the lowest soil pH (4.4) followed by annual fields (pH 4.60) in Mpigi. The highest soil pH (5.7) was recorded in banana fields in Mubende. The study also recorded very low to low N, P and K. Generally, the study observed rapid soil fertility decline in smallholder farms in the region.

Nanotechnology in Agriculture: Feeding the Future a Brief Review by Leonard Copping

The world faces a challenge. The global population is increasing while climate change is applying stress to traditional farming. As a result food security and sustainable agriculture is facing a challenge the likes of which it has never faced before. Failure to address it could result in catastrophe. But developments in nanotechnology could be about to help ease the impending crisis. Developments could see it improve crop yields without resorting to extensive land expansion or excessive use of agrochemicals as well as enabling more efficient resource management. If it delivers, the rewards could be significant for investors and mankind alike. According to a report by Insight Analytic, the global agricultural nanotechnology market size was valued at some $321.1 billion in 2022. It is predicted to reach $868.98 billion by 2031 with a CAGR of 11.94%. The report said: “The development of the global market will be fuelled by the merger of improved agricultural techniques with nanotechnologies over the next five years. Additionally, the benefits can lower threats, including air and ground pollution, soil acidification, eutrophication, declining soil fertility and biodiversity loss. With the global population’s growth, rising demand for crops with higher yields will further support the expansion of the industry.

Assembly and co-occurrence patterns of rhizosphere bacterial communities are closely linked to soil fertility during continuous cropping of cut chrysanthemum (Chrysanthemum morifolium Ramat).

Continuous cropping is known to have profound effects on the soil microbial community in different planting systems. However, we lack an understanding of how different years of continuous cropping affects rhizosphere soil bacterial community co-occurrence pattern and assembly processes in the cut chrysanthemum (Chrysanthemum morifolium Ramat.) field. We collected the soils from cut chrysanthemum rhizospheres with planting for 1 year (PY1) and continuous cropping for 6 years (CY6) and 12 years (CY12). Real-time quantitative PCR and flow cytometry (FCM) techniques were used to test the 16S rRNA gene copy number and bacterial cell count, respectively. The bacterial community structure was analysed by using high-throughput sequencing technology. The CY12 had a significantly decreased soil fertility index and rhizosphere bacterial living cell counts and gene copy numbers compared to CY6 and PY1 (P <0.05). The rhizosphere bacterial community dissimilarity increased as the continuous cropping years increased. Three main ecological clusters (modules #1, #2, and #3) were observed in the bacterial co-occurrence network across all samples, and only the relative abundance of module #1 (enriched in the CY12) was significantly correlated with soil fertility (P <0.05). Moreover, the rhizosphere bacterial community assembly was primarily governed by the deterministic process under 12 years of continuous cropping. Soil fertility decline correlates with ecological network modularization and the deterministic assembly process of the rhizosphere bacterial community of cut chrysanthemum during continuous cropping.

Factors affecting soil quality among smallholder macadamia farms in Malawi

Declining soil fertility limits smallholder macadamia productivity in Malawi. To reverse this trend, it is essential to apply organic and inorganic fertilisers in an efficient and effective manner. Yet, fertilizer recommendations for smallholder macadamia (Macadamia integrifolia) production in Malawi are not site-specific. Nutrient imbalances can occur if fertilisers are applied without a clear understanding of whether they are required or not. This may lead to yield losses, unnecessary costs, and other environmental issues associated with excess fertiliser application. To address this research need/ knowledge gap, our study examined the current soil fertility status among smallholder macadamia farms in Malawi. Specifically, the objective was to establish an evidence base for promoting soil fertility restoration interventions for smallholder macadamia production. One hundred and eighty nine soil samples at a depth of 0–15 cm were collected from sixty three smallholder macadamia farms belonging to the Highlands Macadamia Cooperative Union Limited members in central and southern Malawi. We found that the majority of the soils were sandy loams (52%), strongly acidic (mean pH ≤ 5.1), and deficient in essential nutrients required for the healthy growth of macadamia. The soils had an average low cation exchange capacity of 1.67 cmol ( +) kg−1, which is inadequate for macadamia cultivation. More than half of the sampled soils had very low organic matter content (≤ 1%). The low soil organic matter content, coupled with the sandy texture and high acidity, contributed to the observed low concentrations of essential nutrients and cation exchange capacity. Poor agronomic practices and inherent soil characteristics are responsible for this low soil fertility. Altogether, our findings underscore the urgent need to identify and implement more sustainable and effective soil nutrient management practices that help to improve the soil fertility of macadamia farms under smallholder systems.

UNLOCKING THE POTENTIAL OF AGRICULTURE WASTE AS A SOIL AMENDMENT ON GROWTH PERFORMANCE OF SWEET CORN (Zea Mays.)

The decline in soil fertility of agricultural land and the abundance of agricultural wastes is a major problem in the environment. To overcome these problems, agricultural wastes have the potential to serve as a beneficial product that provides sustainable agriculture. The use of agricultural wastes as soil amendments is a sustainable practice in improving soil quality and plant productivity. Therefore, this study was carried out to evaluate the potential of agricultural wastes and agriculture wastes-derived biochars as soil amendments toward sweet corn (Zea Mays.) growth performance. The study was conducted in the greenhouse for 75 days. A randomized complete block design with four treatments (oil palm empty fruit bunch (EFB), EFB biochar, decanter cake, corn cob and corn cob biochar) in combination with mineral soil and four replication was used during the study. Plant height, stem diameter, and number of leaves were assessed for each treatment. Results indicate that corn cob biochar significantly increased the sweet corn height and plant diameter by respectively 11.0% and 25.0% as compared to the control. An increase in the stem diameter by 10.0% due to the application of EFB was observed at 45 days compared to the other treatments. In conclusion, the agricultural waste which is corn cob biochar were observed to have the potential in enhancing the sweet corn (Zea Mays.) growth.

SISTEM AKUAPONIK DARI SUDUT KESIHATAN KEPADA MANUSIA: SATU KAJIAN LITERATUR

Aquaponic system, which combines aquatic animal farming and vegetable cultivation, is a beneficial aquaculture technology. The aquatic animal and plants used in this system mutually depend on each other to produce healthy products that are free from any harmful chemical usage. In conventional agriculture, which utilizes soil as the growing medium, there are a number of significant issues. These include soil pollution, a decline in soil fertility, the excessive use of toxins and chemicals, and issues regarding the cleanliness of the goods that are produced. It is indeed significantly different when compared to aquaponic systems that produce organic and non-hazardous products. Therefore, the objective of this paper is to clarify the use of aquaponic systems and the benefits that can be obtained from this system, especially in terms of human health. This method of writing applies a qualitative approach based on previous studies and research conducted through the collection of journals, scientific articles, theses, and pertinent literature discussing the advantages of aquaponic systems. The results of the writing indicate that aquaponic systems can provide health benefits from two perspectives: Islamic religious requirements and supported by findings from scientific studies. This system is found to be in line with the requirements of Islam and the goals of Shariah in preserving life, as the quality of maintenance and the water used in this system are free from pollutants and ensure the cleanliness of the produce. This is then supported by scientific studies showing that the plant yields produced by this system are not exposed to fish waste or harmful pathogens that could be detrimental to human health.

Sweet potato is a strategic root crop in Oceania: A synthesis of the past research and future direction

Sweet potato is an important food, industrial, and pharmaceutical crop worldwide and highly adapted to adverse ranges of agroclimatic conditions, making it one of the strategic crops under climate change. Despite the importance, sustainable crop production continues to be an issue because of the pressure put on land, the decline in soil fertility, the buildup of pests and diseases, and no standardized production practices. Production is highly mechanized in temperate regions, whereas, in the tropics, it is still a subsistence crop confined to subsistence farming systems. These issues are compounded by a lack of generically and agronomically improved genotypes adapted to wider agroecological zones with adaptive tolerance to existing and new stresses. In the recent past, significant progress has been made worldwide; however, the outcomes tend to be locality-specific, and cannot be extrapolated, needing decentralization of the current approaches. This review points out that the crop is a critical strategic crop in the Oceania region because of its ability to grow under adverse ranges of agroclimatic conditions and can produce a reasonable yield. The paper continues to emphasize the current trends in emerging modern technology that can be used to efficiently improve and enhance traits of agronomic importance and wider adaptivity. In addition, land use plans, farming systems, and cultural production practices need to be changed for sustainable production. The need for these is further strengthened by pointing out alternative strategies, e.g., using organic matter as a relatively cheap and readily available source of soil nutrients compared to inorganic fertilizers.

Algaeculture for agriculture: from past to future

The continuous growth of the world population has imposed major challenges on agriculture. Consequently, farmers generalized the overuse of synthetic fertilizers and pesticides to meet the global food demand. Although these products have helped many developing countries increase their crop yield, they have simultaneously resulted in many issues, mainly the decline of soil fertility and degradation of local ecosystems due to soil, water, and air contamination, combined with their non-renewable nature and increased costs. For agriculture to become more sustainable, the use of alternative biological products, with recognized beneficial effects on plant yield and health, must be expanded. In this context, microalgae and cyanobacteria are rich sources of nutrients and bioactive metabolites, which have been gaining attention from researchers and companies for their ability to improve plant nutrition, growth, and tolerance to stress. This review gives an overview of the research work that has been done in the last two decades, regarding the use of microalgae and cyanobacteria (blue-green algae) as biofertilizers, biostimulants, and biopesticides. This work identified trends and challenges and highlights the use of microalgae to recycle the nutrients from wastewater to improve plant productivity while reducing the fertilizer and water footprint for more sustainable agriculture practices.

Response of Maize (Zea mays L.) to Blend (Nitrogen, Phosphorus, Sulfur, Boron) and Potassium Fertilizers Rates at Boloso Sore Woreda, Ethiopia

Background: The declining soil fertility is a severe bottleneck for crop production in Ethiopia. The application of inorganic fertilizer helps to correct a site-specific nutrient deficiency. Methods: The research was conducted at Achura kebele Farmers Training Center (FTC) from December 2020 to July 2021. Soil samples and crop data were collected and analyzed by standard procedures. Result: The soil reaction revealed that the soil was moderately acidic (pH=5.68) and low in organic carbon, total nitrogen, available phosphorus, potassium, sulfur and boron. The result of this study indicated that the growth and yield of maize were significantly (P less than 0.05) affected by the combined effect of both blended (nitrogen, phosphorus, sulfur, boron) and potassium fertilizer rates. The highest grain yield (7200.9 kg ha-1) was found from NPSB, 200 kg ha-1 + K, 50 kg ha-1and the lowest was recorded from control.

Rhizobium as Biotechnological Tools for Green Solutions: An Environment-Friendly Approach for Sustainable Crop Production in the Modern Era of Climate Change.

Modern and industrialized agriculture enhanced farm output during the last few decades, but it became possible at the cost of agricultural sustainability. Industrialized agriculture focussed only on the increase in crop productivity and the technologies involved were supply-driven, where enough synthetic chemicals were applied and natural resources were overexploited with the erosion of genetic diversity and biodiversity. Nitrogen is an essential nutrient required for plant growth and development. Even though nitrogen is available in large quantities in the atmosphere, it cannot be utilized by plants directly with the only exception of legumes which have the unique ability to fix atmospheric nitrogen and the process is known as biological nitrogen fixation (BNF). Rhizobium, a group of gram-negative soil bacteria, helps in the formation of root nodules in legumes and takes part in the BNF. The BNF has great significance in agriculture as it acts as a fertility restorer in soil. Continuous cereal-cereal cropping system, which is predominant in a major part of the world, often results in a decline in soil fertility, while legumes add nitrogen and improve the availability of other nutrients too. In the present context of the declining trend of the yield of some important crops and cropping systems, it is the need of the hour for enriching soil health to achieve agricultural sustainability, where Rhizobium can play a magnificent role. Though the role of Rhizobium in biological nitrogen fixation is well documented, their behaviour and performance in different agricultural environments need to be studied further for a better understanding. In the article, an attempt has been made to give an insight into the behaviour, performance and mode of action of different Rhizobium species and strains under versatile conditions.

Soil salinity estimation in Shule River Basin using support vector regression model

AbstractSoil salinization is a progressive degradation process that spreads globally and leads to a decline in soil fertility. Assessing the scale of salinization is crucial for sustainable agricultural development and saline‐land rehabilitation. In this study, we proposed a support vector regression spatial (SVR‐S) model that utilizes spatial dependence information to predict soil salinity over the irrigation area of the Shule River Basin in northwestern China. To investigate the performance of the SVR‐S model, 50 soil samples were collected in the field. Semivariograms of soil salinity (measured as total salt content and ion concentrations) were constructed to measure spatial dependence. The SVR‐S model was compared with the original SVR model and the geographically weighted regression (GWR) model regarding the salinity prediction ability. The soil salinity in the experimental area demonstrated a strong spatial dependence pattern. The SVR‐S model delivered a better performance than the SVR‐O and GWR. SVR‐S showed a correlation coefficient R of 0.87 and a root mean square error (RMSE) of 1.83%, while the performance of SVR‐O (R = 0.75, RMSE = 3.32%) and GWR (R = 0.73, RMSE = 3.47%) was comparatively poor. Topographic indices integrating spatial information contributed the most to the estimation of salinity in the study area. This study provides a new approach to integrating spatial information for accurate soil salinity mapping.

Isolation, Molecular Characterization and Application of Aspergillus niger and Penicillium chrysogenum with Biofertilizer Potentials to Enhance Rice Growth

The use of chemical fertilizers has been associated with a persistent decline in soil fertility, which&nbsp;is also detrimental to soil health. Biofertilizers have been reported to be better alternatives to&nbsp;chemical fertilizers. In this study, the mycofertilizer potentials of the species Aspergillus and Penicillium were investigated. The fungi were isolated from the rice (Oryza sativa Linn) rhizosphere and identified using cultural and molecular methods. The fungal isolates were examined for protease synthesis, nitrogen fixation, cellulose breakdown, and phosphate solubilization using standard methods. The mycofertilizer potentials of the isolates were screened for in an in-situ experiment that was carried out in the greenhouse using a pot experimental method. Isolates that solubilized phosphate and also produced cellulase and protease were selected for the greenhouse experiment. Aspergillus niger and Penicillium chrysogenum proved to be the best candidates among the isolates. The results of the greenhouse pot experiment showed that after 30 days of planting, rice (O. sativa) in the control group had the best performance, but after 63 days of planting, the rice in the pot inoculated with both A. niger and P. chrysogenum had the best performance, followed by the plant inoculated with A. niger, while the plant in the control group had the least average growth. Plants in the test groups had significant growth compared to the plants in the control group. These isolates could be used in the production of mycofertilizer for the growth of grain crops that are known not to fix nitrogen.

Measuring integrated smallholder soil fertility management practices in Megech watershed, Tana sub-basin, Ethiopia

Nowadays, a combination of natural and man-made factors has led to a decline in the physical and chemical quality of the soil. In Ethiopia, declining soil fertility and quality that lead to low agricultural production are made worse by soil erosion and nutrient depletion. Adoption and implementation of integrated soil fertility management strategies have emerged as inevitabilities in terms of development in Ethiopia generally and in the Tana sub-basin of northwest Ethiopia specifically. This study was created to evaluate the Megech watershed's integrated smallholder soil fertility management methods' adoption factors, status, and scope. A total of 380 individual farmers were surveyed using a semi-structured questionnaire to gather primary data. Descriptive statistics and econometric estimating methods were combined in the study. The findings supported the use of inorganic fertilizer, tree planting, organic fertilizer, stone bunds, and soil bunds by households as the primary methods for managing soil fertility. The outcomes of the econometric model also show that households' adoption decisions for integrated soil fertility management practices are highly interdependent. Additionally, there were similar underlying factors that affected the status and intensity of implementing integrated soil fertility management practices. The research concluded that effective soil management policies and programs should be designed, and implemented by smallholder farmers, agricultural experts, research centers, and governmental and non-governmental organizations to improve the quality of soil for sustainable food production. Moreover, raising the affordability of financial services and strengthening smallholder farmers' access to education help to increase their income, which in turn encourages the use of integrated soil fertility management practices.

Soil water use efficiency under integrated soil management practices in the drylands of Kenya

Soil moisture scarcity and soil fertility decline in the drylands contribute to declining crop productivity. The possible synergistic effects of integrating soil & water conservation, and soil fertility management practices on soil moisture, and hence water use efficiency (WUE) in the drylands of Tharaka-Nithi County in Kenya was assessed. The experiment was laid in a three by three split plot arrangement, with four replications, for four cropping seasons. Minimum tillage with mulch, tied ridges, and conventional tillage formed the main plot factors. The sub-plot factors included animal manure plus fertilizer at 120, 60, and 30 N kg ha−1. There was significant improvement in soil moisture by 35 and 28% by minimum tillage with mulch and tied ridges, respectively, compared to conventional tillage. Manure plus fertilizer rates of 120 and 60 N kg ha−1 had significantly lower soil moisture by 12 and 10%, respectively than the 30 N kg ha−1 across the seasons. The WUE was significantly enhanced by 150 and 65% under minimum tillage with mulch and tied ridges, respectively, compared to conventional tillage. Compared with 30 N kg ha−1, the 120 N kg ha−1 and 60 kg ha−1 significantly enhanced the WUE by 66 and 25%, respectively. Across the seasons, the best treatment combination for improving WUE was minimum tillage with mulch at 120 N kg ha−1 rate of manure plus fertilizer.

SOIL PHYSICO-CHEMICAL PROPERTIES IN A SELECTIVELY LOGGED FOREST AT GUNUNG RARA FOREST RESERVE, SABAH, MALAYSIA

The tropical rainforest has various lists of crucial functions in forest productivity. However, unsustainable logging method has led to the decline of soil fertility in the forest. This study aimed to investigate the impacts of different logging methods on the soil’s physical and chemical properties at Gunung Rara Forest Reserve, Sabah, Malaysia. The logging treatments were supervised logging with climber cutting (SLCC) and conventional logging (CL), and a virgin forest (VF) was used as the control plot. The size for each plot was one hectare and each was replicated into four plots making the total plots 12. Soil sampling was done at four depths (0–10 cm, 10–20 cm, 20–50 cm, and 50–100 cm) for soil analysis and bulk density. The finding shows that the soil properties in the treatment plots were not significantly different from the untreated plot. The soil organic matter, total nitrogen, and total carbon decreased with soil depths. The soil in all study areas was found acidic, ranging from 4.12 to 4.46. The soil textures were clay, sandy clay loam, and sandy loam. The SLCC plot recorded a higher mean of soil organic matter (5.93–7.40%), total phosphorus (0.08–0.09 meq/100 g), and cation exchange capacity (5.69–7.05 meq/100 g) compared to other plots. This study highlights the importance of analysing the impact of different logging methods on the soil’s physicochemical properties.

A Review of Combined Use of Biochar with Nitrogen Fertilizer as an Instrument for Improving Maize Yield and Soil Fertility

The decline of soil fertility is one of the major problems around the world for producing crops and ensuring food security. Therefore, the review's objective was to examine how biochar and inorganic nitrogen fertilizers affect soil physicochemical characteristics, as well as maize production and growth parameters. Similarly, biochar is a product of the thermochemical decomposition of biomass produced under limited oxygen. It has potential benefits in agriculture, such as improving soil fertility, water retention. The nutrient composition of biochar produced is determined by the type of feedstock used and the pyrolysis conditions. A study showed that adding biochar and nitrogen fertilizer decreased soil bulk density and enhanced water-holding capacity and soil chemical properties like pH, nitrogen, phosphorus, potassium, organic carbon, calcium, ECEC, and base saturation. Moreover, the review reported that the addition of N fertilizer and biochar greatly promoted crop N uptake and N content, which then increased leaf photosynthetic efficiency, dry matter accumulation, and grain yields. The findings discovered that when the rate of biochar and nitrogen increased, crop productivity and soil properties also increased significantly. It is concluded that applying biochar along with nitrogen fertilizer increased maize crop productivity as well as soil attributes more than applying biochar and nitrogen fertilizer separately. Therefore, farmers and agricultural experts should consider incorporating these practices into their land management strategies to improve overall agricultural sustainability.

Analysis of adoption of conservation agriculture practices in southern Africa: mixed-methods approach

In southern Africa, conservation agriculture (CA) has been promoted to address low agricultural productivity, food insecurity, and land degradation. However, despite significant experimental evidence on the agronomic and economic benefits of CA and large scale investments by the donor community and national governments, adoption rates among smallholders remain below expectation. The main objective of this research project was thus to investigate why previous efforts and investments to scale CA technologies and practices in southern Africa have not led to widespread adoption. The paper applies a multivariate probit model and other methods to survey data from 4,373 households and 278 focus groups to identify the drivers and barriers of CA adoption in Malawi, Zambia, and Zimbabwe. The results show that declining soil fertility is a major constraint to maize production in Zambia and Malawi, and drought/heat is more pronounced in Zimbabwe. We also find gaps between (a) awareness and adoption, (b) training and adoption, and (c) demonstration and adoption rates of CA practices in all three countries. The gaps are much bigger between awareness and adoption and much smaller between hosting demonstration and adoption, suggesting that much of the awareness of CA practices has not translated to greater adoption. Training and demonstrations are better conduits to enhance adoption than mere awareness creation. Therefore, demonstrating the applications and benefits of CA practices is critical for promoting CA practices in all countries. Besides, greater adoption of CA practices requires enhancing farmers’ access to inputs, addressing drudgery associated with CA implementation, enhancing farmers’ technical know-how, and enacting and enforcing community bylaws regarding livestock grazing and wildfires. The paper concludes by discussing the implications for policy and investments in CA promotion.

Analytical Approach by Sorting of Manure for Farming and Electricity from Municipality Solid Waste

Waste operation and declining soil fertility are the main issues endured by all developing nations, like India. Currently, agrarian application of Municipal Solid Waste (MSW) is one of the most promising and cost effective options for managing solid waste. It's helpful in working current burning issues viz. soil fertility and MSW operation still there's always a implicit trouble because MSW may contain pathogens and poisonous adulterants. Thus important emphasis has been paid to composting of MSW in recent times operation of compost from MSW in agrarian land helps in upgrading the soil’s physico- chemical parcels. Piecemeal from that it also assists in perfecting natural response of cultivated land. Keeping the present situation in mind, this review critically discusses the current script, agrarian application of MSW compost and energy from part of soil microbes and soil microbial response on external solid waste compost operation.

Effects of wildfire, torrential rainfall and straw mulching on the physicochemical soil properties in a Mediterranean forest

With the effects of fire, weather and post-fire management on soil properties having been studied mostly individually, there is little understanding of the combined effects of wildfire, heavy storm and straw mulching. In this study, we evaluated the changes in soil properties following a high-severity fire, post-fire soil treatment using straw mulch, and a torrential storm in a forest stand in north-western Portugal. The main physicochemical properties of the soil were evaluated in different soil conditions: a) burnt and untreated, b) burnt and mulched areas, and c) unburnt sites on three survey dates 1) soon after wildfire, 2) after the rainstorm, and 3) one year after wildfire. We found that soil water repellency strongly increased ephemerally immediately after wildfire, decrease after the storm and disappeared after one year. Fire reduced the soil organic matter (by 50%, on average), total nitrogen (by 85–90%) and available phosphorous (by about 45%) at both the mulched and untreated sites, and this effect was not changed by the ensuing rainfall. In comparison to the unburnt sites, the pH increased in the burnt soils, and the electrical conductivity decreased. Finally, the dynamics of the major cations and minor elements were affected differently by the wildfire and rainfall under the different soil conditions. One year after the fire, the most notable changes compared to the unburnt soil were detected in magnesium, potassium and almost all the minor elements. Based on these findings, instructions were given to the land managers (aim to control soil hydrophobicity following wildfire, supply more soil organic matter to the soil to avoid a decline in soil fertility, and use alternative actions to straw mulching to control the soil chemistry) that were aimed at more effective post-fire management in severely burnt areas in Mediterranean forests.

Enhancing sustainable agri-food systems using multi-nutrient fertilizers in Kenyan smallholder farming systems

Persistent food insecurity in the global south has triggered calls for sustainable development worldwide. Moreover, more than a quarter of the world's population suffers from micronutrient deficiencies or hidden hunger. The population bulge, declining soil fertility and inadequate/inappropriate use of farm inputs in Sub-Saharan Africa place it in a precarious position. Multi-nutrient fertilizer blends have been mooted as a key innovation in closing yield gaps and boosting food and nutrition security. This study assessed the extent of multi-nutrient fertilizer blends utilization and yield response across agroecological zones and their on-farm profitability under Kenyan smallholder farmer conditions. We collected data through a detailed household survey conducted in eight counties in Kenya representative of high, medium, and low productivity zones using a sample of 1094 smallholder farmers. Multi-nutrient fertilizers increased maize yields significantly (P < 0.05), eliciting a 400% yield increase compared to the control and 108% greater maize yield than conventional fertilizers in the high potential zone. Conversely, at 3.7 t/ha conventional fertilizers elicited a significant (P < 0.05) yield response in Irish potatoes in the high potential areas. Multi-nutrient fertilizers increased on-farm profitability of crops, specifically for potato production systems where a benefit: cost ratio (BCR) of more than 2 was observed. Farmers may break even when they use multi-nutrient fertilizers on maize particularly in the low potential areas. Therefore, there is considerable potential for multi-nutrient fertilizers to increase crop productivity while being economically viable across agroecological zones and cropping systems. However, the uptake of multi-nutrient fertilizers among farmers is quite low across the country, except for small pockets where limited interventions have been carried out. This calls for sustained efforts to scale multi-nutrient fertilizers with a focus on clear messaging that stresses the need to apply appropriate rates of various nutrients including the secondary nutrients and micro-nutrients.