Fertilizer Management Research Articles

Enhancing soil quality for sustainable agricultural practices in Subak rice fields

Understanding the soil quality of Subak rice fields in Bali is crucial for maintaining agricultural sustainability. This study aimed to explore aspects of soil quality, identify limiting factors, and offer guidance on sustainable land management. Utilizing survey methods, laboratory analysis, and soil quality determination, soil samples were selectively collected from each land unit (LU). LU selection was based on overlays of Subak zonation, soil type, slopes, rainfall, and elevation using Geographic Information System (GIS) techniques. Key soil quality indicators were assessed, including bulk density, texture, porosity, moisture content, pH, organic carbon, cation exchange capacity, base saturation, and nutrients (N, P, K). Overall, soil quality in the study area is classified as good in all LUs, but with significant variations in Soil Quality Index (SQI) values, suggesting the need for tailored management recommendations. Limiting factors include soil texture, organic carbon content, total nitrogen, available phosphorus, and biomass C. Recommended soil management practices include single plow tillage and the application of manure, urea, and SP-36 fertilizer on paddy fields. This approach aims to enhance land productivity sustainably while upholding environmental conservation and the principles of Subak, which have historically maintained a balanced and sustainable agricultural ecosystem.

Residue management and overwinter survival in winter canola (Brassica napus L.)

Winter canola production in eastern Canada is a growing segment of the Canadian canola industry. Crop establishment and survival overwinter have been identified as two of the major challenges associated with the production of winter canola. Environmental conditions can interact with agronomic practices, including seeding date, plant population density, fertility and residue management, to influence stand establishment in autumn and overwinter survival. The objective of the current research was to evaluate the impact and interaction of preceding crop residue and tillage practices on the establishment, overwinter survival and yield of winter canola in southern Ontario. Winter canola was seeded following either winter wheat or soybean and using conventional, no-till or strip-till practices. Over the course of the three years of study, the annual decline in winter canola plant population density was influenced by the type of tillage practice used but not by the preceding crop. The overwinter decrease in plant population density was largest in no-till, followed by strip-till and finally conventional tillage. At physiological maturity, winter canola yields in reduced tillage practices (i.e., no-till and strip-till) were equivalent to those achieved utilizing conventional tillage practices. When grain yields were standardized as a function of the spring plant population density, the highest and lowest yield per plant coincided with the lowest and highest plant population densities and were observed in strip-till (14.2 g plant-1) and no-till (9.1 g plant-1), respectively. Results of this research have established that winter canola can be successfully produced in Ontario utilizing a range of tillage practices.

Nitrogen use efficiency of open-pollinated maize cultivars and topcrosses under low nitrogen soil

The study was conducted to evaluate the nitrogen utilization efficiency (NUE) of open-pollinated maize cultivars under low nitrogen soil conditions. It took place at the Lower Niger River Basin Development Authority in Ilorin, Nigeria, during the 2019 and 2020 cropping seasons. The nitrogen treatments (0, 45, and 90 kg N ha⁻1) were assigned as the main plots, while the genotypes were designated as sub-plots in a split-plot design. The NUE of open-pollinated varieties (OPVs) and Topcrosses significantly increased with the application of 45 kg of nitrogen per hectare compared to 0 kg. Similarly, the maize grain yield for both OPVs and Topcrosses ranged from 1.40 to 3.57 t ha⁻1 and from 1.07 to 2.64 t ha⁻1 across the two years with the application of 45 kg of nitrogen per hectare compared to 0 kg. With the exception of days to 50 % silking, all other traits tested exhibited a significant correlation with grain yield. A gene pool for tolerance to low nitrogen may have been present in the cultivars Dmr-Esr Y Cif 2 and Acr 95 Tze Comp 4C3, which combined well with other cultivars to produce high grain yield and NUE. Topcrosses, including Ev Dt-Y 2000 Str C0 × Tze-W Dt Str C4, Dmr-Esr Y Cif 2 × Acr 95 Tze Comp 4C3, Ak 95 Dmr-Esrw × Tzb Rel D4 CO-W, Dmr-Esr Y Cif 2 × Tze-W Dt Str C4, and Br 9922 Dmr Sr × Ev Dt-Y 2000 Str C0, also demonstrated strong potential for maize grain yield and NUE. This suggests that these crosses could serve as promising candidates for developing low nitrogen tolerance in maize for low nitrogen soil environments. A positive relationship between fertilizer levels, NUE, and grain yield indicates that proper nitrogen fertilizer management can enhance both NUE and the grain yield of maize genotypes. Genetic analysis revealed that both phenotypic coefficient of variation (PCV) and environmental variance (δ2p) were higher than genotypic coefficient of variation (GCV) and genetic variance (δ2g), suggesting that environmental influences were more significant than genetic factors for the tested traits. Consequently, improving these traits may be achieved by manipulating environmental conditions.

Impact of Integrated Soil Fertility Management Practices on the Welfare of Smallholder Farmers in Ethiopia

Impact of Integrated Soil Fertility Management Practices on the Welfare of Smallholder Farmers in Ethiopia

Soil properties and yield of mung bean [VIGNA RADIATA (L.) WILCZEK] as influenced by tillage and phosphorous fertilizer management on sandy loam soil in Chitwan, Nepal

Phosphorous application combined with a variety of tillage methods promotes the growth and development of mungbeans and sustainably improves soil health. A field experiment was conducted in Mangalpur, Nepal from February to May of 2021 and 2022 to investigate the impact of varying tillage practices and phosphorous doses on the growth, development, and yield of mung beans, while also analyzing changes in soil physicochemical properties on sandy loam soil. The research was conducted in a 2-factorial split-plot design with three replications. After completion of the study, the plant height (59.43 cm), nodule plant-1 (15.84), pod plant−1 (23.65), and seed yield (1087.76 kgha−1) were significantly higher when phosphorous was applied at 40 kgha−1 and 60 kgha−1. Among different tillage practices, significantly greater plant height (57.21 cm), nodule per plant (15.76), pod plant−1 (24.99), seed pod-1 (10.76), seed yield (1089.92 kgha−1), and 1000-seed weight (48.23 g) were observed in conventional tillage. P at 60 kgha−1 resulted in significantly higher total soil nitrogen (0.207 %) and available P (30.65 kgha−1). Similarly, for tillage practices, statistically higher total soil nitrogen (0.23 %) and available phosphorous (32.45 kgha−1) were observed in zero tillage practices. Furthermore, pH was seen to be significantly higher in conventional tillage (6.12) followed by strip (5.79). A combination of conventional tillage with 40 kgha−1 was observed better in short-term conditions however, for better growth and yield of mung bean and sustainable health of the soil, zero tillage with 40 kgha−1 phosphorous can be suggested for sandy loam soil and environmental conditions present in the study site in the long-term.

Straw management and fertilization improve soil aggregate stability by inducing biological binding agents and specific keystone genera

Improving soil aggregate stability through proper fertilization management is essential for crop growth. However, how different fertilization regimes affect soil aggregate stability driven by microorganisms and biological binding agents remains largely unexplored. For this purpose, we conducted a 9-year field experiment involving two soil textures (i.e., loam and clay soils) and five fertilization regimes (i.e., no fertilizer or crop straw return (CK), crop straw return (S), chemical fertilization (N), crop straw return with chemical fertilizer (SN), and crop straw return with chemical fertilizer and 20% nitrogen substituted with chicken manure (SNM)). Mean weight diameter (MWD) of soil aggregates, glomalin-related soil protein (GRSP) content, and microbial community composition were investigated. The SN and SNM treatments had similar MWD, which was 70.08–76.45% higher than the CK, and the S and N treatments had similar MWD, which was 20.35–34.76% higher than the CK, indicating better effects of SN and SNM on the improvement of the soil aggregate stability than the S or N treatment. High easily extractable GRSP and total GRSP contents contributed to the improved MWD. Meanwhile, some specific keystone genera identified from the keystone modules (co-occurring groups of soil biota including arbuscular mycorrhizal fungi, bacteria, and nonmycorrhizal fungi) were recognized as the important factors regulating the MWD, though the selected specific genera in the loam soil differed from the clay soil. Altogether, our results highlighted the fundamental role of the GRSP and selected specific keystone microbial taxa in improving the soil aggregate stability and provided a list of microbial taxa linking to MWD in different soils, which could be specifically targeted in specific soil.

Sustaining Soil Health in High Tunnels: A Paradigm Shift toward Soil-centered Management

This review was conducted to synthesize current knowledge, learn producer and Extension specialist perspectives, and identify gaps in understanding of the role of soil health in sustaining production in high tunnel (HT) systems. This synthesis includes findings from scholarly resources related to soil health in HTs, including research and Extension-based literature, perspectives from experienced HT producers and technical assistance providers, and the direct observations of a broad network of university research and Extension personnel working with HTs. Findings are intended to identify knowledge gaps and additional research and Extension resource needs of greatest priority to the HT producer community and technical assistance providers that support them at the time of publication. A review of 68 research articles and 58 Extension resources was conducted. Focus group interviews were conducted with small groups of experienced HT farmers in four regions of the eastern half of the United States, with in-depth farm case studies conducted in individual farmers in three of these regions. Growers across regions identified soil fertility management, soilborne diseases, soil compaction, and lack of consistency of soil analyses specific to HTs as the greatest soil-related challenges to HT production. Research and resources for technical assistance providers on mitigation strategies to remediate yield-limiting HT soil conditions, such as excessive soil salinity and high pathogen populations, were also lacking. As such, process-based research on techniques such as leaching, soil steaming, solarization, and anaerobic soil disinfestation in tunnels that consider short- and long-term costs, benefits, and effects on soil and plant productivity should be prioritized in the future when considering the impact of HT production on soil health. Interviews also indicated a need for networking opportunities for technical assistance providers across agencies (e.g., Natural Resources Conservation Service, Extension, nongovernmental organizations). Despite a high and increasing rate of adoption, there is currently a lack of information about maintaining HT systems. Given that HTs play a critical and growing economic role for specialty crop growers throughout the eastern United States, comprehensive intervention across the research–Extension spectrum to sustain productivity in HT systems is recommended.

Fertilizer management practices for cassava in acid dryland of Sukabumi Regency, West Java

The productivity of cassava in acid dryland is generally still low. Fertilization, land amelioration, and superior varieties are the main solutions for increasing cassava productivity. This research aimed to determine the response of high-yielding varieties and fertilization technology packages to the growth and yield of cassava in acid dryland of Sukaharja Village, Warung Kiara District, Sukabumi Regency, West Java. The contents of organic carbon, nitrogen, and magnesium of the soil is below the minimum threshold, so the application of N fertilizer, organic matter, and ameliorant is expected to increase plant growth. The research consisted of two treatment factors: two cassava varieties and three fertilization technologies. The treatments were arranged in a completely randomized split-plot experimental design with three replications with variety as the main plot and fertilization technology package as the subplots. The treatment effect was observed on the character of plant height, wet biomass weight, stem diameter, number of tubers, tuber length, tuber diameter, tuber weight (large and small) per plant, and tuber yield per plot to be converted per ha. Tuber quality was observed by observing water content, percent dry matter, and starch yield. The results showed that the fertilization technology package increased plant height, fresh biomass weight, stem diameter, large tuber weight per plant, and yield per hectare in both varieties. Differences in varieties and fertilization technology packages have no effect on starch levels.

Combining insitu rainwater harvesting and integrated nutrient management of organic manure improves soil moisture, fertility and crop yields in marginalized areas: A review

Soil moisture stress and infertility are major biophysical constraints which limit crop production and food security in marginalized areas. Marginal areas are mainly associated with low rainfall which is insufficient to support crops until maturity is reached. The use of insitu rainwater harvesting methods such as planting pits, tied ridges, mulching, Zai pits and half-moon can be a solution to reduce moisture stress. This alone cannot improve crop yields hence the need to use integrated nutrient management (INM) of animal manure, biofertilisers, mineral fertiliser and composts to improve soil fertility, structure and increase water retention ability. Combining rainwater harvesting with INM has the potential to mitigate effects of climate change, improve crop yields and meet food demand in marginal areas. Various nutrient sources used as INM can restore soil health, increase microbial population, nutrient mineralisation and improve soil quality. Use of biofertilisers in agriculture reduces soil toxicity, improve nutrient availability and create a conducive environment for crop growth and development. Integration of tied ridges with cattle manure and mineral fertiliser has the potential of increasing infiltration rates, reducing surface runoff and increase crop yields with 50-150% regardless of soil type. This chapter sought to come up review the effects of rainwater harvesting methods and INM on soil fertility, moisture stress and crop yields in marginalized areas.

Assessment of Poultry Manure and Inorganic Fertilizers Influences on the Growth and Yield of Maize (Zea mays L.)

Assessment of Poultry Manure and Inorganic Fertilizers Influences on the Growth and Yield of Maize (Zea mays L.)

LASSOCIATION MAIS-NIEBE ET LA RESTITUTION ORGANIQUE SONT-ELLESLE MOTEUR DUNE GESTION DURABLE DES SOLS A LOUEST DU BURKINA FASO ?

Are maize-cowpea associations and organic restitution the driving force behind sustainable soil management in western Burkina Faso? Soil fertility management is one of the key factors in the sustainability of cropping systems in western Burkina Faso. With this in mind, a study was carried out on the management of crop residues, fertilization and the inclusion of legumes in the cropping system. The aim was to determine the effects of mulching, insertion of cowpeas into the cropping system and organo-mineral fertilization on soil fertility. The experimental design was a strip split plot with 4 replications and three treatments corresponding to 3 crop residue management methods, 3 cropping systems with or without maize and cowpea, and 2 types of fertilization. Trials were conducted from the 2018 to 2020 cropping seasons. Soil moisture, the number of fungal and bacterial colonies and soil chemical characteristics were determined in 2020. The results show a significant increase in soil moisture on maize-wheat association plots of 9.28 and 8.58% for the 0-20 cm depth and 6.85 and 5.31% for the 20-40 cm depth respectively compared with pure maize and cowpea cultivation. For crop residue management and fertilization, soil moisture levels were identical for all treatments. Concerning soil micro-organisms, the results show that five (05) types of fungi were identified on the different treatments: Aspergillus flavus, Aspergillus niger, Fusarium moniliforme, Geotrichumcandidum and Trichoderma sp. The results obtained show no significant difference between treatments at the 5% threshold, either for fungi, bacteria or soil chemical characteristics. Consequently, the maize-cowpea association can be considered a sustainable soil fertility management practice in the western region of Burkina Faso. However, the choice between recycling crop residues by mulching and applying organo-mineral fertilizer must be determined by the farms themselves, according to their socio-economic reality.

Effect of Integrated nutrient management practices on nutrient uptake, yield and quality of improved black kavuni rice variety (CO57)

The rising demand for high-quality rice and rice products motivates farmers to produce traditional rice varieties. Rice production needs to be substantially increased with suitable nutrient management practices to meet the demand. Hence, the present study was carried out to evaluate the influence of integrated nutrient management practices on nutrient yield and quality of improved black kavuni rice. The research was conducted during the Early kar (April-August 2023) and Late samba (September - January 2023-24) seasons in a randomized block design (RBD) with three replications and twelve treatments consisting of N in equivalent basis with organic manure and inorganic fertilizers and one control. Based on an N equivalent basis, the required quantity of inorganic fertilizer, farmyard manure (FYM), vermicompost (VC) and poultry manure (PM) were applied to rice. Observations on nutrient uptake, yield and quality were recorded, and the data were analyzed using LSD at a 5% probability level for significance differences. The results revealed that higher nutrient uptake, yield and quality parameters of rice were recorded with 50% recommended dose of nitrogen through inorganic fertilizer + 50% recommended dose of nitrogen through VC + foliar spray of 0.5% ZnSO4 & 1% FeSO4 at tillering, panicle initiation (PI) and flowering stage (T11).

Enabling Precision Agriculture through a Web-Based Fertilization Management System for Nawungan Selopamioro Fruit Orchards

Precision Agriculture (PA) is an integrated farming system based on information and technology for managing agriculture to identify, analyze, and manage spatial and temporal diversity information in specific locations to obtain optimum and sustainable benefits while minimizing unwanted environmental impacts. Fertilization is one of the crucial phases in agricultural production process considering technical cultivation aspects, costs, and environmental impacts. The current fertilization process at Kebun Buah Nawungan Selopamioro (KBNS) is still conventional, so there is no standard rule in determining the fertilization dose. Therefore, a PA approach is needed to provide suitable fertilizer doses for agricultural production needs. This objective of this study was to develop of a web-based fertilizer management system, integrating with orchard management to enhance accessibility and decision-making. The system calculates fertilizer requirements by analyzing soil nutrient availability (N, P, K), cultivation area, crop type and age, and available fertilizer types. The development followed the waterfall methodology, encompassing stages from requirement analysis to system maintenance. The outcome is a web application that manages land assets, administrative activities, and fertilizer needs tailored to specific land blocks, crop characteristics, and nutrient inventories. Subsequent validation against field conditions ensures the accuracy of its recommendations. Although comprehensive testing confirmed a 100% success rate in functionality, the system currently operates within a limited scope of variables. Future enhancements are planned to incorporate broader agronomic factors, such as soil pH and texture, to augment the system's precision. Despite its limitations, this system represents a significant technological advance in precision agriculture, promising to improve fertilizer application efficiency and support sustainable farming practices.

Effect of Integrated Application of Vermicompost and Inorganic Fertilizers on Yield and Yield Components of Bread Wheat in Adami Tulu Jido Kombolcha District of East Showa Zone, Ethiopia

A field experiment was conducted at Adami Tulu Agricultural Research Center during 2022 cropping season to evaluate the responses of vermin compost and inorganic fertilizers on bread wheat (Triticum aestivum). The experiment consists of eight treatments: T1= Control (without fertilizer), T2=50% RNP+4t/ha VC, T3= 50% RNP+ 8t/ha VC, T4=100% RNP, T5= 4t/ha VC, T6= 8t/ha VC, T7= 100% RNP+ 4t/ha VC, T8=100% RNP+8t/ha VC. The result revealed that grain yield affected by combined application of these two fertilizes. There are gradual changes in some major soil parameters have statistically affected by combined application of vermin compost and inorganic fertilizer. Accordingly maximum grain yield (4596.3kg/ha) was recorded from T2 where 50% recommended NP+4t/ha VC where as the lowest grain yield (2109.3kg/ka) was from control plot. Lastly partial budget analysis was also calculated to determine best treatment combination for future farther use. Accordingly maximum net benefit (155,870.50ETB) was obtained from T2 where 50% recommended NP+4t/ha VC was combined. Therefore this treatment was used as best treatment combination for this area, for this crop, it needed for large scale soil fertility management and increasing land productivity.

Contribution of distinct components in divergent organic amendments to long-term accumulation of soil organic matter in agricultural soils: evidence from thermally assisted hydrolysis and methylation-GC/MS.

Although maintaining/improving soil organic matter (SOM) quantity through utilizing organic amendments (OAs) is a productive practice, information on OA components contributing to long-term SOM accumulation in agricultural soils remains meager. Hence, we examined soil samples from a long-term experiment with different fertilizer managements, including no fertilizer (NF), chemical fertilizer (CF) only (CF), bark compost plus CF (BC + CF), coffee residue compost plus CF (CRC + CF), cattle manure compost plus CF (CMC + CF), and cattle manure compost (CMC) or sewage sludge compost (SSC) alone at a higher application rate. SOM in those samples was physically fractionated into free particulate form (fSOM), free form occluded in aggregates (oSOM), weakly bound form (wSOM), and strongly bound form (sSOM). Analysis of structural components in OAs and SOM fractions using thermally assisted hydrolysis and methylation combined with gas chromatography/mass spectrometry (THM-GC/MS) revealed OA components that have contributed to long-term SOM accumulation in each treatment. The SSC was characterized by higher proportions of short-chain fatty acids (FAs; 50%) and other aliphatic compounds (22%). Correlation analysis suggested that these characteristics may be effective for greater C accumulation in the bulk soil and wSOM fraction. The proportion of lignin-derived phenols, e.g., 3,4-dimethoxybenzaldehyde (Vh) and 1,2-dimethoxy-4-(1,2,3-trimethoxypropyl)benzene, was high in CMC (43%), presumably vital for promoting C accumulations in the oSOM, wSOM, and sSOM fractions in the CMC treatment. The short-chain FAs in CRC and aromatic components in BC are likely important for contributing fSOM accumulation.

Optimizing Soil Fertility through Machine Learning: Enhancing Agricultural Productivity and Sustainability

Nowadays, the sustainability of agriculture and food security have an increasing importance on soil fertility. Soil fertility is defined as the capacity of a land to grow crops and its potential crop productivity. However, factors such as increasing population, climate change, land use changes and environmental pollution threaten soil fertility. These threats can result in problems such as erosion, soil salinisation and organic matter depletion. Soil fertility is critical for the long-term health of agriculture and food security. Artificial intelligence techniques used to determine and manage soil fertility analyse the minerals present in the soil as well as other factors. These analyses assess the amount of minerals present in the soil, the availability of nutrients and important parameters such as pH. This information guides farmers in selecting the most appropriate crops. Furthermore, the integration of Internet of Things (IoT) technologies allows real-time monitoring of minerals and nutrients in the soil and optimising irrigation and fertilisation processes based on this data. These developments have the potential to improve soil fertility management and increase agricultural productivity.

Determination of fertilizer requirement of Indonesian black rice in winter season under different plant spacing at Agro-ecological Zone-9 of Bangladesh

Indonesian black rice is quite popular for its highly nutritive value and profitable production. The distinct knowledge about optimum fertilizer doses and plant spacing contributes to its promising yield. The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, from December 2022 to May 2023 to find out the effect of fertilizer management and plant spacing on the growth and yield of Indonesian black rice in the winter season. The experiment was conducted with 5 treatments of fertilizer management viz., F1(70% of recommended doses); F2(80% of recommended doses); F3(90% of recommended doses); F4(100% of recommended doses) and F5(110% of recommended doses) with 4 plants spacing viz., S1(20 cm × 15 cm); S2(20 cm × 20 cm); S3(25 cm × 15 cm) and S4(25 cm × 20 cm). The experiment was laid out in a split-plot design where the fertilizer management was allocated in main plots and the plant spacing was distributed in sub-plots with three replications. The result revealed that the fertilizer doses and plant spacings along with the interaction effects significantly influenced the growth and yield parameters of Indonesian black rice. Regarding vegetative growth, plant height (79.3cm), total tiller plant-1(21.27cm), and total leaf number plant-1 (58.47) were maximal at 100% recommended dose of fertilizer(F4) at DAT 65. Similarly, S2(20 cm × 20 cm) had better result in crop growth and yield attributes. The interaction effects of the treatments showed significant impact on plant height, total tiller and leaf number where F4S2 gave satisfied results. The highest values for the yield parameters including the maximum number of grains panicle-1 (100.70), 1000-grain weight (28.33g), and grain yield (5.69g) were found from the combination treatment of F4S2. On the other hand, the lowest grain (3.68g) yield was found from F1S4. Therefore, observing the results of the experiment, the best consideration was F4S2 at Agro-ecological Zone-9 in the winter season for the desirable growth and yield of Indonesian black rice.

Yield performance of aromatic fine rice as influenced by nitrogen fertilization and weed control techniques

Nitrogen fertilization and weed management is the major concern to yield maximization of rice. The study was conducted to assess the influence of nitrogen and weed control to yield improvement of aromatic rice BRRI dhan34. The experiment included three nitrogen levels viz. 50, 100 and 150 kg N ha-1 as well as three weeding schedules viz. one hand weeding at 15 days after transplanting (DAT), two hand weeding at 15 and 30 DAT and three hand weeding at 15, 30 and 45 DAT. The experiment was conducted with randomized complete block design. The findings demonstrated important correlations between weeding techniques, nitrogen levels and yield components. When the crop was fertilized with 50 kg N ha-1 the highest numbers of total tillers hill-1 (8.53), effective tillers hill-1 (7.51), grains panicle-1 (128.0) and grain yield (3.97 t ha-1) were resulted. Regarding weeding practices, two manual weeding carried out at 15 and 30 DAT reported the highest numbers of effective tillers hill-1 (7.62), grains panicle-1 (128.1) and grain yield (4.10 t ha-1). The highest effective tillers hill-1 (8.33), the most grains panicle-1 (129.8), the grain yield (4.36 t ha-1) and straw yield (6.40 t ha-1) were found in two hand weeding at 15 and 30 DAT combined with 50 kg N ha-1 and the lowest grain yield (3.53 t ha-1) was obtained from one hand weeding given at 15 DAT along with 150 kg N ha-1. Therefore, the study demonstrated that BRRI dhan34 can be fertilized with 50 kg N ha-1 along with two hand weeding at 15 and 30 DAT to obtained higher yield.

Small-scale farmers perception, adaptation choices to climate change and existing barriers: Evidence from northern Ethiopia

Climate change continues to significantly impact agricultural production in Ethiopia that have encountered several environmental problems in recent decades. The study site is one of the areas vulnerable to climate change and influenced by climate variability. This study intends to identify small-scale farmers’ adaptation options, their perception and existing barriers in northern Ethiopia. It is based on an analysis of cross-sectional data collected from 193 randomly selected farm household heads. A multivariate probit model was employed to analyze the factors influencing farmers’ climate change adaptation choices. Constraint Facing Index (CFI) technique was also constructed to identify the existing barriers. The findings indicate that a significant number of farmers (91.2%) reported a trend toward rising temperatures. Similarly, 86.01% of the farmers indicated that the perceived rainfall trend has decreased. Adjusting planting dates (56.5%), integrated soil fertility management practices (47.7%), early maturing crop varieties (53.4%), terracing for soil and water conservation (54.9%), and income diversification (55.4%) were the most common climate change adaptation options practiced by farm households in the study area. Some of these adaptation options have significant and complementary relationships. The farmer’s choice of adaptation option was highly constrained by institutional factors and all these identified factors can be possibly addressed through a better institutional service provision system, for a better farm-level adaptation while considering demographic characteristics as well.

Vertical migration and leaching behavior of antibiotic resistance genes in soil during rainfall: Impact by long-term fertilization

The vertical migration and leaching behavior of antibiotic resistance genes (ARGs) during rainfall in soils subjected to long-term fertilization remain largely unclear. In this study, ARGs in vertical profiles (0−60 cm) and leachates from three soils (acidic, neutral, and calcareous) in a long-term (13 years) field fertilization experiment were monitored by high-throughput quantitative PCR after each rainfall event throughout an entire year. The results showed that, compared with unfertilized soils, long-term manure fertilization mainly promoted the vertical migration and leaching of aminoglycoside, beta-lactam, and multidrug resistance genes in the soil profiles. As a result, the annual cumulative loads of ARGs in leachates from the three soils with long-term manure fertilization were significantly increased compared to the controls and were in the order of acidic soil > neutral soil > calcareous soil. SourceTracker analyses revealed that manured soil was the predominant source of the ARGs in the soil leachate samples. Pseudomonas, Anaeromyxobacter, IMCC26256, and MND1 were identified as the dominant potential hosts responsible for the vertical migration and leaching of ARGs in the three soils. PiecewiseSEM analysis further showed that long-term manure fertilization affected the vertical migration of ARGs during rainfall mainly by altering soil properties (i.e., pH, soil organic carbon, and sand). Our results suggest that the ARGs in soils with long-term manure fertilization are a significant potential source of ARG pollution in groundwater, and the measures should be taken to mitigate the vertical migration and leaching of ARGs during rainfall.