Integrated Soil Fertility Management Research Articles

Nitrogen and phosphorus mineralization and their corresponding monetary values under long‐term integrated soil fertility management practices

Nitrogen and phosphorus mineralization and their corresponding monetary values under long‐term integrated soil fertility management practices

Factors influencing small holder farmers adoption of climate SMART agriculture practices in Welmera Woreda, Central Ethiopia

Adoption of climate-smart agriculture practices are believed to have significantly lessened the devastating impact of climate change on agriculture. However, in countries like Ethiopia, the adoption and use level of climate-smart agriculture practices remains low. The understanding of farmers’ levels of CSA practice adoption and influencing factors is therefore crucial. The goal of the study is to evaluate the degree to which various CSA practices were being used in the study area, as well as adoption determinants. The study was conducted in Welmera district, Oromia, Ethiopia. Three kebeles were chosen from the district, and a random sample of 306 farmers was picked. We used a cross-sectional household survey, a focus group discussion, and interviews with key informants. A multivariate probit model was employed to investigate the factors influencing the adoption of multiple climate-smart agriculture practices. According to the result, conservation agriculture, integrated soil fertility management, and crop diversification are the most often used CSA practices. The results also revealed that male farmers outperformed female farmers in terms of crop diversity and improved animal feed and feeding practice adoption. The age of farmers has a considerable and unfavorable impact on their likelihood of adopting improved soil fertility management and crop diversification practices. However, it has a positive and considerable impact on the adoption of agroforestry practices. With regards to economic factors, having a relatively big farmland area considerably enhances the adoption of conservation agriculture, enhances soil fertility management and crop diversity, and improves livestock feed and feeding methods and post-harvest technology practice. Improved livestock feed and feeding are more likely to be used with higher farm income. Having a significant number of animals strongly promotes the adoption of conservation agriculture, and access to financial services positively impacts agroforestry, diversification of crops, and postharvest technology practice adoption. Furthermore, institutional factors including access to agricultural extension services and training were discovered to be important and beneficial for crop diversification; similarly, access to field day participation was discovered to have a significant and positive impact on the adoption of conservation agriculture and improved soil fertility management practices. It is critical to raise awareness about climate change among farmers and experts, as well as to incorporate location-specific CSA practices into agricultural programs.

Assessment of nutrient flows in maize-based farming system by smallholder farmers for sustainable production in Ikara, Kaduna State

Nutrient depletion is one of the major causes of decreased crop yield, and a threat to food security and sustainable crop production. NutMon- toolbox was used to determine nutrient flows and partial nutrient balances of maize-based smallholders’ farming system. Data was collected using structured questionnaire from 15 randomly selected farmers, with five farmers each in three villages. Composite soil samples were also taken from each of the three plots. At crop maturity, samples of crop products and residues were randomly taken from the selected fields. Nitrogen, P and K contents in soil and crop material was used to calculate nutrient flows and partial balances. Results obtained revealed that mineral fertilizer flow, averaged 349.20kg N yr-1 and 81.45kg K yr-1 and were lower than 376.65kg N yr-1 and 431.44kg K yr-1 organic input. However, phosphorus in mineral fertilizer (55.78kg P yr-1) was higher compared to phosphorus (51.06 kg P ha-1 yr-1) in organic input. Nitrogen, phosphorus and potassium for maize seeds and crop residue were all negative. The partial nutrient balances were positive 53.45kg N ha-1 yr-1 and 79.40kg K ha-1 but negative 1.10kg P ha-1 yr-1. Harvesting of crops for food, without incorporation of crop residue into the soil, were the most important sources of nutrient mining in smallholder production system. Integrated soil fertility management practices that favour the buildup of soil organic matter and use of animal manure should be encouraged through effective extension services at Ikara, Kaduna State, Nigeria.

Soil Fertility Assessment and Mapping under Different Land Use Types along Toposequence at Danka Watershed in Dinsho Districts of Bale Highland Oromia, Southeastern Ethiopia

Soil fertility assessment and mapping bases, to increase fertilizer usage efficiency, decision-makers, planners, and soil management in undulating slopes farming of Ethiopian highlands like Bale Highland. The study aimed to assess and map soil fertility status along toposequence under different land use types at the Danka watershed of Dinsho District Bale Highland, Southeastern Ethiopia. Following the initial reconnaissance field survey, 54 composite soil samples were prepared from the three land use types (natural forest, grazing, and cultivated) at three slope positions lower (0 - 10%), middle (10 - 15%), and upper (15 - 30%) at a soil depth of 0 to 20 cm. Finally, the laboratory results were interpolated using the IDW interpolation technique in ArcGIS software 10.5 for the soil fertility status map and further analyzed using R software 4.1.1 Version for mean separation. The study findings indicate that the soil texture class of the study was loam to clay loam, clay loam, and clay to clay loam at the upper, middle, and lower slope positions, respectively. The finding revealed that the values varied from 5.81 – 6.66, 2.07 – 6.25%, 0.13 – 0.71%, 2.83 – 17.56 gm/kg, and 14.04 -38.80 cmol (+)/kg) for the soil pH, organic matter, total nitrogen, available phosphorus, and CEC, respectively. In this study, most of the soil fertility status of the Danka watershed was as follows: natural forest > grassland > cultivated land use types and lower slope > middle slope > upper slope positions. In conclusion, the main factors contributing to the area's declining soil fertility status were monocropping, total crop residue removal, soil erosion, nutrient leaching, and inadequate soil management. The results of the current study offer the basis for the work of farmers, planners, decision-makers, and other agriculture-related stakeholders. Integrated soil fertility management with biophysical soil conservation measures is advisable for cultivated land at all slope positions. Further, a study on slope position-based crop response fertilizer rating for agricultural precision and ensuring food security is recommended in undulating fields of the Danka watershed.

Effects of Slope Position on Soil Physicochemical Properties of Cultivated Land Use Type in Danka Watershed of Dinsho District, Bale Highland, Oromia, Southeast Ethiopia

Quantify and understand soil nutrient loss under different undulating topography farming bases for site-specific management and targeted fertilizer application rates. The study aimed to assess the effect of slope positions on soil physicochemical properties at the Danka watershed of Dinsho District Bale Highland, Southeastern Ethiopia. Consequent to the reconnaissance survey, soil samples were taken from the cultivated land use type in three replications at three different soil depths (0-0, 20-40, and 40-60 cm) and three slope positions (upper, middle, and lower), analyzed follow standard laboratory procedure and further analyzed using R software 4.1.1 version. The results showed soil physicochemical properties were significantly (P ≤ 0.05) influenced by the interaction between slope positions and soil depth. The results of soil physical properties varied from 1.29 -1.73 g cm-3, 2.47 – 2.74 g cm-3, 47.80 - 36.75%, 10.78 – 15.11%, 12.76 – 18.16%, and 4.06 – 8.16% bulk density, particle density, total porosity, FC, PWP, and AWHC, respectively. Selected soil chemical properties varied from 5.91 - 6.45, 0.64 - 3.20%, 0.04 - 0.25%, 1.14 - 5.60 gm/kg, and 10.24 - 37.24 cmol (+)/kg) soil pH, organic matter, total nitrogen, available phosphorus, and CEC, respectively. The values of exchangeable bases were concentration increased from the upper slope position toward the lower slope position and with increased soil depth. Soil micronutrients were increased with increased slope and decreased with increased soil depth. The lowest slope position had relatively better soil nutrient contents than other slope positions. It is advised that integrated soil fertility management, biophysical soil and water conservation, and slope-based, site-specific fertilizer rating for advance agricultural precision and ensure food security.

Integrated Soil Fertility Management Practices for Coffee in Tanzania: A Review

Integrated Soil Fertility Management Practices for Coffee in Tanzania: A Review

Impact of integrated soil fertility management on maize yield, yield gap and income in northern Ghana

This paper analyzes the impact of integrated soil fertility management (ISFM) on maize yield, yield gap and net income in northern Ghana using an inverse-probability-weighted regression adjustment (IPWRA). In this study, ISFM is restricted to the adoption of crop rotation (CR), inorganic fertilizer (FT), and farmyard manure (MN) either in isolation or in combination. We find a synergy in yield gain (86.52 % increase in yield) and a decrease in yield gap (of 10.22 %) with the adoption of all three technologies as a package (CR+FT+MN). The joint adoption of all three technologies is also associated with a 51.29 % increase in net income from maize production and has a Benefit-Cost Ratio of 3.23.

Mineralogical compositions of soils under three geological formations in some parts of Ogun state, Nigeria and their agricultural potentials

Investigating the mineralogical compositions of soils under different geological formations becomes imperative for maximizing agricultural productivity and ensuring the long-term viability of agricultural practices. Therefore, studies were carried out on mineral compositions and diversities of soils developed over the Basement complex rock, Coastal plain sands and Ewekoro formations in Ogun state Nigeria. A total of nine profile pits (three per location) of 2 m × 1 m × 2 m size were dug in all the three locations. Soil samples were collected from the pedogenic horizons of each profile pits in replicates into a well labeled polyethylene bag. Using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) the mineral contents and their relative abundance, elemental compositions and morphologies of the fine sand, coarse silt and clay fractions of the soils at different topographic positions were identified, described and compared. Results obtained from XRD and SEM analyses exhibited similarities. The most abundant elements in the basement complex and Ewekoro pedon were oxygen, carbon and silicon whereas in the coastal plain sand pedon, oxygen, carbon and aluminum were the most abundant element. The presence of mixed-layer illite, mica, kaolinite, quartz, hematite, anatase, goethite, and chlorite at varying degrees was observed in the pedons developed on these geological formations, although kaolinite and quartz dominated the soil matrix. The mineralogical complexity of the pedons followed the order of basement complex > coastal plain sand > Ewekoro formation. Profiles developed on the Ewekoro formation exhibited the highest degree of weathering, as evidenced by their chemical properties and mineralogical compositions. The petrographic evaluation of the three geological formations revealed that all pedons were rich in quartz and exhibited varying degrees of mineral complexity and maturation. The overlapping and distinct characteristics among the geologies indicated different stages of weathering. By using the mineral maturity index, profiles developed over the basement complex rock and the coastal plain sand could be regarded as sub-matured and this could have contributed significantly to the native fertility of these soils and profiles from the Ewekoro formation were the most weathered. The use of Ewekoro formation for agriculture would necessitate significant investments in agro-inputs and sound principles of soil management through integrated soil fertility management.

Response of Garlic (Allium sativum L.) Yield to Combined Biochar, Lime, and Inorganic-Fertilizer Rates in the Case of Gimbi District, Western Ethiopia

Soil degradation due to acidity is a serious problem in western Ethiopia, which would lower soil productivity and crop production. Implementing integrated soil fertility management is the most efficient approach for enhancing agronomic efficacy and boosting crop output while addressing the issue of soil acidity. This experimental study aimed to investigate the effect of combined coffee husk biochar (CHB), soil test-based value lime (STV), and inorganic-fertilizer (NPSB-fertilizer) rates on the optimum yield of garlic in Gimbi district, western Ethiopia. The field experiment was conducted during the 2022 cropping season on two sites. The experiment comprised 14 treatments laid out in a randomized complete block design with three replicates. Application of integrated biochar, lime, and inorganic-fertilizer rates showed a highly significant impact (p <0.01) on the yield and yield components of garlic. The treatment unit with T11 ha−1 had the significantly highest total fresh biomass yield (TFBY) per plant for both Farm-1 (65.9 g) and Farm-2 (75.3 g). Bulb yield fresh weight per plant (BWp) was highest in treatments of T4 and T8 ha−1 in Farm-1 (27.7–28.1 g) and in treatments of T4 and T11 ha−1, in Farm-2 (31.4–31.6 g). Marketable bulb yield (MBY) was significantly highest in treatments; T4, T7, T8, and T11 ha−1 in Farm-1 (8.5–9.3 tons ha−1) and Farm-2 (10.1–10.5 tons ha−1). Therefore, by combining, the application of 10 tons of biochar (CHB) + 75% of lime (STV) + 75% of inorganic-fertilizer (NPSB-fertilizer) ha−1 in strongly acid soil, and 7.5 tons of CHB + 50% of STV + 50% of NPSB-fertilizer ha−1 rates in very strongly acid soil are recommended for garlic production in Gimbi district, western Ethiopia, and similar areas. In order to draw firm conclusions, future research on more sites is necessary because this study was logically limited to two sites.

Quantitative analysis of soil degradation in response to land use change in the Guinea savanna zone of Ghana

Soil degradation (SD) poses a significant challenge to tropical agricultural production systems due to its role in depleting soil nutrients. Recently, SD has threatened population growth by causing hunger and poverty among smallholder farmers in the Guinea savanna agro-ecological zone of Ghana. However, SD cannot be directly measured. Instead, assessment and modelling efforts rely on biological and physico-chemical indicators. This study sought to: (i) select a minimum dataset (MDS) using a multivariate statistical technique; (ii) identify SD processes, and evaluate the extent of degradation; and (iii) suggest strategies to monitor SD in the study area. Soil samples were collected using the Land Degradation Surveillance Framework (LDSF), specifically designed for sub-plot level (1000 m2) sampling. This scheme aligns well with the typical farm structure of smallholder farmers (<10 acres). Soil samples, taken from a depth of 0–20 cm, were analyzed to assess their physico-chemical properties. Principal component analysis (PCA) identified seven key SD processes: soil texture, pH, organic carbon (OC), total nitrogen (TN), available phosphorus (Av. P), base saturation (BS) and Effective Cation Exchange Capacity (ECEC). These identified processes lead to the loss of OC, deterioration of soil texture, reduction in soil nutrients, and increased soil acidity. There was a strong positive correlation (r = 0.70, p<0.05) between soil physical and chemical properties. PC1 explained 26.86% of the total variance, followed by PC2 at 15.31%, PC3 at 12.46%, and PC4 at 9.98%. Also, PC5, PC6, and PC7 accounted for 8.49%, 7.25% and 1.42% of the variance, respectively. The land-use systems we identified significantly affected the concentration of soil nutrients (p<0.001). In our computed Composite Soil Degradation Index (CSDI), CEC emerged as the most significant SD indicator with a weight of 0.328, followed by Si:CL ratio at 0.187. The results indicate that soil management activities should focus on increasing organic matter. Soil nutrient depletion primarily occurs through several processes. Land clearing and burning of organic materials during land preparation are primary causes. Furthermore, a total crop removal during harvest, inadequate manure application, and subsequent leaching and erosion aggravates SD, leading to nutrient-depleted soils. We conclude that the loss of nutrients, specifically CEC, OC, Ex. K and Av. P is the primary contributor to chemical SD. Therefore, implementing integrated soil fertility management (ISFM) strategies, such as applying organic (e.g., animal-based manures, green manure, crop residues, compost) and inorganic fertilizers (e.g., NPK + micronutrients) is crucial for increasing soil nutrient availability, enhancing SOM content, and promoting carbon sequestration in these farming systems. This study establishes a baseline for comparing and evaluating the effectiveness of land management interventions at the landscape level in northern Ghana. Consequently, soil nutrient management should be tailored to site-specific conditions, focusing on increasing the efficiency of N, P, K and micronutrient uptake by plants. Adopting such site-specific management strategies could significantly contribute to the sustainable intensification of agricultural production systems in the Guinea Savanna agro-ecological zone of Ghana.

Monitoring soil quality of different land use systems: a case study in Suha watershed, northwestern highlands of Ethiopia

The problem of soil quality degradation has been becoming more severe in the highlands of Ethiopia due to soil erosion; land use and land cover change, and poor land management. The level of soil quality degradation was not well known and documented in the study area and the results of this study could provide new information to improve soil conditions. The present study was conducted to evaluate soil quality in terms of its physical and chemical fertility under different land use types in the Suha watershed, northwestern highlands of Ethiopia. A total of 27 composite surface soil samples (0–30 cm) were collected from adjacently located land-uses in three replications from two elevation gradients. Standard procedures were followed to analyze selected soil physical and chemical quality indicators. The differences in the mean values of the parameters were tested using a two-way analysis of variance. In addition, Soil Quality Degradation Index was evaluated to see the direction and magnitude of change in soil quality indicators. The analysis of variance results revealed that soil quality indicators such as index of soil aggregate stability, organic carbon (OC), total nitrogen (TN), and C:N ratio were significantly decreased in the cultivated land use system compared to other land use systems. On the other hand, the content of available Phosphorus was significantly higher in the cultivated land. Soil quality deterioration index values were highly negative for SOC (− 71.3%) and TN (− 67.7%) in the cultivated land, followed by grazing land (SOM = − 35.5% and TN = − 27.7%). Aggregated Soil Quality Index values also indicated that the status of soil quality under cultivated fields is rated as low, grazing land as optimal, and forest land as high. Generally, results indicated that land use and cover changes had adverse effects on soil quality indicators. Hence, soil management strategies, mainly Integrated Soil Fertility Management which integrates soil and water conservation strategies, are required to alleviate the problem of soil quality deterioration and improve agricultural productivity.

Fertilizer use efficiency and economic viability in maize production in the Savannah and transitional zones of Ghana

Increasing fertilizer use is highly justified for sustainable agricultural intensification if yield response, fertilizer use efficiency (FUE), and economic viability of fertilizer application are high. Despite the increasing fertilizer application rates in Ghana, yields only marginally increased. Also, the recent fertilizer price hikes post COVID-19 revived concern for economic analysis of fertilizers. This study analyzed the FUE and economic viability of fertilizer use in maize production in Guinea/Sudan Savannah and Transitional/Deciduous zones of Ghana. Survey data from 2,673 farmers in the 2019, 2020, and 2021 production seasons were used. The average agronomic efficiency (AE), partial factor productivity (PFP), and value-cost ratio (VCR) of fertilizer use were 2.2 kg of grains per kilogram of fertilizer, 18.3 kg grains per kilogram of fertilizer, and 1.8 Ghana cedis of marginal yield per Ghana cedi spent on fertilizer, respectively. Fertilizer use was economically viable for only 28.1% of farmers with a VCR of 2 or higher, while 52.5% reached the break-even point with a VCR of at least 1. Various fertilizer formulations, including NPK plus sulfur, and adoption of integrated soil fertility management (ISFM) practices, particularly improved seeds, organic fertilizers, and minimum tillage, improved maize yield response to fertilizer and thus the FUE. These low efficiency and economic viability of fertilizer use are prevailing conditions in other sub-Saharan Africa (SSA) countries and these do not guarantee sustainable food security and improved livelihood of the farmers in the region. Ghana’s Ministry of Food and Agriculture (MoFA), together with relevant stakeholders, should provide guidance on ISFM and intensify farmer education through farmer associations to increase the adoption of ISFM. The local government should work with other relevant stakeholders to improve the market conditions within the agriculture sector, for instance, by linking farmers to city markets for favorable output prices.

Determinants of adoption of climate smart agricultural technologies in wheat production in Arsi Zone, Oromia Region of Ethiopia

AbstractClimate-resilient crop production requires the use of crop technology that can sustainably increase productivity, build resilience to climate change, and reduce greenhouse gas emissions. Despite countrywide initiatives that promote climate-smart agricultural technology (CSAT) adoption, the rate of adoption has been extremely low. Therefore, this study aims to identify factors that affect the adoption of CSATs in wheat production in the Arsi zone of the Oromia region of Ethiopia. Towards this, plot-level primary data were gathered from 628 plots that were managed by 422 randomly selected wheat-producing smallholder farmers in three selected districts of the Zone. Descriptive statistics and multivariate probit (MVP) model were used to analyze data. The major CSATs adopted for wheat production in the study area were improved wheat varieties (95%), integrated soil fertility management (85%), and irrigation (19%). The result of the MVP model revealed that farmers with higher levels of education, farming experience, and contact with extension workers, have credit access, have access to market information, have greater annual total income, and are closer to the nearest market center are more likely to adopt CSATs in wheat production. Therefore, it is recommended that to enhance the adoption of CSATs in wheat production, policymakers and other development partners should concentrate on the identified factors that were significantly associated with the decisions to adopt CSATs.

Ability of Nutrient Management and Molecular Physiology Advancements to Overcome Abiotic Stress: A Study on Sub-Saharan African Crops

Abiotic stress is a major cause of the declining crop yield worldwide, especially in tropical agricultural areas. Meeting the global food demand has become a serious challenge, especially in tropical areas, because of soil acidity, Al and Fe toxicity, drought and heat stress, and climate change. In this article, we reviewed several research and review papers from Google Scholar to list the different solutions available for the mitigation of abiotic stress, especially in tropical regions where several major crops, such as maize, sorghum, wheat, rice, soybean, and millet, are affected by abiotic stress and fertilizer input. In particular, Sub-Saharan Africa (SSA) has been affected by the low use of fertilizers owing to their high cost. Therefore, soil and plant researchers and farmers have developed many techniques to mitigate the effects of stress and improve the crop yield based on the agroecological zone and crop type. Nutrient management using chemical fertilizers alone or in combination with organic crops is a strategy recommended to cope with abiotic stress and increase the crop yield, particularly in developing countries. Notably, integrated soil fertility management has been effective in semi-arid areas under drought and heat stress and in subhumid and humid areas with high soil acidity and Fe toxicity in Africa. Recent advances in the molecular physiology of various crops considered a staple food in SSA have facilitated the breeding of transgenic tolerant plants with high yield. However, the feasibility and implementation of this technique in the African continent and most tropical developing countries are major issues that can be solved via adequate subsidies and support to farmers. This review can aid in the development of novel strategies to decrease hunger and food insecurity in SSA.

Soil bacterial community is influenced by long‐term integrated soil fertility management practices in a Ferralsol in Western Kenya

AbstractIntroductionSoil bacterial community structure, abundance and diversity, important in biogeochemical cycling, are influenced by several anthropogenic and edaphic factors. Numerous agronomic practices have been promoted to improve soil fertility and crop production in western Kenya, but little is known on their impacts on soil microbial diversity in the region.Materials and MethodsIn this study, conducted in 2019, we assessed the influence of various long‐term (17 years) agronomic management practices, involving application of farmyard manure (FYM) either sole or under different combinations with inorganic nitrogen (N), phosphorus (P) and potassium (K), using 12 treatments, on bacterial community composition, relative abundance and diversity. The bacterial community composition was assessed through amplicon sequencing on an Illumina Miseq platform conducted in MR DNA Laboratory, USA.ResultsThe soil bacterial community composition and diversity were predominantly higher under management practices with application of FYM, either sole or in combination with inorganic fertilisers compared to treatments with either sole NPK fertiliser or no input application. Certain bacterial taxa, involving Proteobacteria, Bacteroidetes, Nitrospirae, Fusobacteria, Nitrospinae and Actinobacteria predominated in management practices where FYM was added either solely or in combination with chemical fertilisers. In addition, several soil chemical parameters showed significant influences on bacterial composition, relative abundance and diversity indices. Soil pH, soil organic carbon (SOC), N, K, Ca, Mg, Cu, Zn, Fe and cation exchange capacity consistently showed strong positive correlation with numerous bacterial phyla. Bacterial phyla were significantly affected by treatments. Some bacterial phyla, like Chloroflexi and Acidobacteria, were mostly dominant in treatments applied with organic inputs but were depressed under carbon‐deficient treatments (no‐input control and sole NPK application treatments).ConclusionThis study revealed that long‐term agricultural management practices that seek to improve SOC content and nutrient availability also stimulated bacterial diversity and shifted bacterial composition.

Determinants of Adoption of Integrated Soil Fertility Management Practices among Coffee Producers in Mid – Northern Uganda

Determinants of Adoption of Integrated Soil Fertility Management Practices among Coffee Producers in Mid – Northern Uganda

Effect of integrated soil fertility management on water retention, productivity and physiological parameters of Alfalfa (Medicago sativa) without and under deficit irrigation

The use of subpar agricultural techniques in arid regions is causing depletion of fresh water reservoirs and soil fertility, which has serious implications for the environment and food productivity. Although numerous studies have examined the effects and benefits of biochar as a soil supplement, particularly on soil water holding capacity, plant productivity, and soil fertility, limited information exists on the effects of biochar at different doses with biocompost on the productivity and physiological parameters of alfalfa compared to conventional agricultural practices under water stress in the field. This field study at three repetitions aimed to investigate how biochar made from tomato waste and date seeds pyrolyzed at a temperature around 540 °C affects soil chemical composition, water retention capacity, photosynthesis, protein levels, enzymatic activity, productivity, maturity, and stomatal traits in alfalfa under and without deficit water compared to conventional agricultural practices based on manure and chemical fertilizer. The results showed that biochar significantly increased the water retention capacity, especially when mixed with biocompost. The highest water retention capacity was observed in the 6 % biochar 3 % biocompost and 6 % biochar 6 % biocompost treatments, which exceeded 0.7 g H2O/g dw. The high productivity and maturity were observed with manure at medium doses combined with chemical fertilizers and at high doses of munure alone, but these results were unstable with time and with the irrigation regime. On the other hand, the fluctuation of these data was minimal for the 3 % biochar 0 % biocompost treatment under and without water stress. In addition, the low dose treatment of manure with chemical fertilizers resulted in high levels of proteins, photosynthetic activities, and low enzymatic activities, indicating that this treatment is better adapted to stress conditions. The treatments with biocompost alone yielded low results on all the parameters studied. To conclude, incorporating biochar and biocompost, especially in synergistic combinations, enhances water retention capacity and sustains alfalfa productivity under both stressed and unstressed conditions. These findings suggest a promising alternative to traditional manure and chemical fertilizers, showcasing the potential of biochar-based strategies for resilient and sustainable agricultural practices.

Correction: Combining organic and mineral fertilizers as a climate-smart integrated soil fertility management practice in sub-Saharan Africa: A meta-analysis

Correction: Combining organic and mineral fertilizers as a climate-smart integrated soil fertility management practice in sub-Saharan Africa: A meta-analysis

Soil Fertility Status as Influenced by Slope Gradient and Land Use Types in Southern Ethiopia

Understanding the effects of land use types and slope gradients on the physicochemical properties of soil is essential for sustainable soil management. Therefore, this study was conducted at the Azit subwatershed of Gedebano Gutazer Welene Woreda, Southern Ethiopia, with the objectives to evaluate the effect of land use types, examine the interaction of land use and slope gradient, and evaluate the effect of slope gradient on selected soil physicochemical properties. A total of 27 soil samples using a simple random sampling technique with randomized complete block design from 3 land use types (cultivated, eucalyptus, and grazing lands) ×3 slope gradients (upper 10–15%, middle 5–10%, and lower 2–5% slopes) ×3 replications and depth (0–20 cm) were collected. Results indicated that most of the physicochemical properties of soils were significantly ( P &lt; 0.01 ) affected by land use and slope gradient. Silt and sand particles did not vary significantly ( P &gt; 0.05 ) among the land use types. The interaction effect of land use and slope was not significant ( P &gt; 0.05 ) for most of the soil properties except for organic carbon (OC). Results of data analysis also showed that soil fertility was low under cultivated and eucalyptus lands coupled with the upper slope gradient. Therefore, based on the study’s findings, it can be recommended that integrated soil fertility management practices, such as the addition of soil organic matter and appropriate use of inorganic fertilizers, need to be implemented to restore the lost soil fertility status on the cultivated land and ultimately increase agricultural productivity on a sustainable basis. Eucalyptus plantings should also gradually be replaced by those that assist the soil in restoring its fertility.

Influence of Farmyard Manure Application on Potential Zinc Solubilizing Microbial Species Abundance in a Ferralsol of Western Kenya

Zinc is an important nutrient for plant growth and development. Its availability is influenced by zinc solubilizing microbes (ZSMs). The effects of commonly promoted agronomic practices on the abundance of ZSMs are so far not well understood. In this study, conducted in 2019, we assessed the effects of farmyard manure (FYM) application, either sole or in combination with residue and/or inorganic fertilizer inputs, on ZSM community structure using 11 treatments in a long-term (17 years) integrated soil fertility management experiment located in Western Kenya. Bacterial and fungal community composition were evaluated by amplicon sequencing on an Illumina MiSeq platform. The results showed that putative ZSMs (i.e., the ZSMs generally considered to possess the zinc solubilizing capabilities) were clustered in two major clades based on either the application or no application of FYM. Sole application of FYM significantly (p &lt; 0.05) increased the abundance of several ZSMs under a maize–Tephrosia rotation. In addition, systems with the combined application of FYM with other inputs generally showed significantly increasing trends for some ZSMs under a maize–Tephrosia rotation. Moreover, the combined application of FYM and P rather than only P significantly increased the abundance of some ZSMs under maize monocropping systems. Furthermore, as well as affecting ZSM abundance, soil chemical variables involving soil organic carbon (SOC), total N and Olsen P significantly increased with FYM application. This study indicated that management practices such as the application of FYM that increase SOC, and other soil chemical parameters, also/concomitantly increase ZSM abundance. These results imply enhanced capacities for microbial-linked zinc availability with FYM application.