Carbon footprint of mixed farming crop-livestock rotational-based grazing beef systems using long term experimental data

In the context of ever-growing demand for food and associated concerns regarding the environmental impacts of high-input agricultural systems, there is growing interest in mixed farm enterprises to deliver greater sustainability compared with mono-enterprise production systems. However, assessments of such systems are complex and require high-resolution data to determine the true value and interconnectivity across enterprises. Given the scarcity of information on mixed crop–livestock systems and the difficulties of its analysis, we perform life cycle assessment using temporally high-resolution data (2019–2022) from a long-term experiment in South America to evaluate the ‘cradle-to-farmgate exit’ greenhouse gas emissions intensities of four rotational crop–livestock systems. Systems evaluated were continuous cropping: 2 years of continuous cropping; short rotation: 2-year continuous cropping plus 2-year pasture; long rotation: 2-year continuous cropping followed by 4-year pasture; and forage rotation: continuous pasture. Emissions intensities for beef throughput were reported as kilograms of carbon dioxide equivalents (CO2-eq) per kilogram of liveweight gain (LWG) using the Intergovernmental Panel for Climate Change’s Sixth Assessment Report (AR6 2021) CO2 characterisation factors. Point estimate results were found to be 11.3, 11.8, 11.8 and 16.4 kg CO2-eq/kg/LWG for continuous cropping, short rotation, long rotation and forage rotation, respectively. Emission averages arising from crops, which were separated from animal-based emissions using economic allocation, were 1.23, 0.53 and 0.52 kg CO2-eq/kg for soybean, wheat and oat, respectively. The inclusion of soil organic carbon stock changes had notable effects on reducing each system’s emissions: by 22.4%, 19.2%, 25.3% and 42.1% under continuous cropping, short rotation, long rotation and forage rotation, respectively, when soil organic carbon was included. Given there are few life cycle assessment studies available on such mixed-enterprise ‘semi-circular’ systems, particularly with novel primary data, this study adds critical knowledge to agri-food-related sustainability literature by addressing environmental issues in complex production systems compared to extant and broad coverage of mono-enterprise systems

Evolution of Agricultural Extension in Zimbabwe - Emerging Technologies, Training Needs and Future Possibilities

Skills development needs of smallholder farmers have often been overlooked during the delivery of agricultural information due to a lack of curriculum reform and gaps between agricultural extension officers’ (AEOs) training and farmers’ changing needs. Recent evidence suggests that the greatest need for agricultural extension services is for new farmers and emerging agricultural technologies compared to well-established farmers and farming methods. On the contrary, lack of adequate extension skills has impeded the implementation and success of climate- and nutrient-smart agricultural technologies such as conservation agriculture and integrated soil fertility management in rainfed cropping systems. Here, we review the history of agricultural extension in Zimbabwe and the impacts of colonial heritage and restructuring on extension. We also present findings from recent research on AEO training and gaps in the curriculum. This research indicated that a gap in skills exists due to insufficient AEOs’ training in essential areas such as farm management, market access, emerging technologies (for example, mobile phones) and supporting the changing needs of farmers. We demonstrate an urgent need for agricultural extension systems in Zimbabwe to explore new models in the field that equip AEOs with adequate training and skills which meet the needs of new farmers and emerging agricultural technologies

Detecting the genetic variants associated with key culinary traits in Dioscorea alata

Quality attributes play a pivotal role in determining consumers’ acceptance and market value of food crops. Dioscorea alata is a major yam species for food security in tropical areas, but our understanding of the genetic factors underlying tuber culinary traits is limited. This study aimed at elucidating the genetic basis of key culinary attributes, including apparent dry matter content (DM), cooking time, boiled yam hardness, and moldability, through genome-wide association studies (GWAS). Phenotypic assessment revealed notable variations among the D. alata genotypes and significant correlations among the quality traits. The GWAS identified 25 significant associations distributed across 14 chromosomes. A total of 12, 1, 6, 6 single nucleotide polymorphisms were detected for cooking time, moldability, hardness and DM. Allele segregation analysis of the identified loci highlighted favorable alleles for short cooking time, good moldability, high hardness and DM content. Within a set of 42 putative candidate genes, we identified genes differentially expressed in tubers of genotypes with contrasting quality attributes. Our study offers valuable insights into the links between these key culinary traits and the underlying genetic basis in D. alata. These findings have practical implications for breeding programs aimed at enhancing the quality attributes of greater yam

Enriched soil amendments influenced soil fertility, herbage yield and bioactive principle of medicinal plant (Cassia angustifolia Vahl.) grown in two different soils

High cost of chemical fertilizers and poor nutrient content in conventional organic sources (manure, compost, charcoal etc.) can be addressed through development of enriched organic amendments. However, there is a need to evaluate enriched organic amendments as a potential alternative of chemical fertilizers. Therefore, an effort was made to prepare enriched organic amendments through blending distillation waste of aromatic plant biomass (DWB) with naturally available low-grade rock phosphate (RP) and waste mica (WM). Enrich compost (ENC) was produced from DWB in a natural composting process, blended with mineral powder, whereas biochar fortified mineral (BFM) was prepared by blending biochar, derived from DWB through hydrothermal reaction, with mineral powder. The main aims of the present study were to investigate the impacts of ENC and BFM applications on soil properties, and herbage yield and quality of a medicinal herb Senna (Cassia angustifolia Vahl.). The performances of ENC and BFM at two different rates (2.5 and 5 t ha−1) were compared with the application of conventional farmyard manure (FYM, 5 t ha−1) and chemical fertilizers (CF, NPK 60-40-20 kg ha−1) in two different soils in a pot experiment. Both, ENC and EBC improved soil quality and fertility by increasing soil organic carbon, available nutrients, microbial biomass and enzyme activity. The ENC and BFM increased total herbage yields by 21 and 16.3 % compared to FYM. In both soils, the CF treatment produced the maximum dry herbage yields (32.7–37.4 g pot−1), which however were comparable to ENC (31.9–33.7 g pot−1) and BFM (30.7–35.1 g pot−1) treatments. Bioactive compound (sennoside) production in senna was significantly improved by ENC and BFM compared to CF. The present study indicates that ENC and BFM could not only help to overcome the limitation of conventional FYM, but also have the potentials to substitute costly chemical fertilizers, particularly in medicinal plant cultivation

An agrogeophysical modelling framework for the detection of soil compaction spatial variability due to grazing using field-scale electromagnetic induction data.

Soil compaction is a regarded as a major environmental and economical hazard, degrading soils across the world. Changes in soil properties due to compaction are known to lead to decrease in biomass and increase in greenhouse gas emissions, nutrient leaching and soil erosion. Quantifying adverse impacts of soil compaction and developing strategies for amelioration relies on an understanding of soil compaction extent and temporal variability. The main indicators of soil compaction (i.e., reduction of pore space, increase in bulk density and decrease in soil transport properties) are relatively easy to quantify in laboratory conditions but such traditional point-based methods offer little information on soil compaction extent at the field scale. Recently, geophysical methods have been proposed to provide non-invasive information about soil compaction. In this work, we developed an agrogeophysical modelling framework to help address the challenges of characterizing soil compaction across grazing paddocks using electromagnetic induction (EMI) data. By integrative modelling of grazing, soil compaction, soil processes and EMI resistivity anomalies, we demonstrate how spatial patterns of EMI observations can be linked to management leading to soil compaction and concurrent modifications of soil functions. The model was tested in a dairy farm in the midlands of Ireland that has been grazed for decades and shows clear signatures of grazing-induced compaction. EMI data were collected in the summer of 2021 and autumn of 2022 under dry and wet soil moisture conditions, respectively. For both years, we observed decreases of apparent electrical resistivity at locations that with visible signatures of compaction such as decreased vegetation and water ponding (e.g., near the water troughs and gates). A machine learning algorithm was used to cluster EMI data with three unique cluster signatures assumed to be representative of heavy, moderately, and non-compacted field zones. We conducted 1D process-based simulations corresponding to non-compacted and compacted soils. The modelled EMI signatures agree qualitatively and quantitatively with the measured EMI data, linking decreased electrical resistivities to zones that were visibly compacted. By providing a theoretical framework based on mechanistic modelling of soil management and compaction, our work may provide a strategy for utilizing EMI data for detection of soil degradation due to compaction

MinION sequencing of fungi in Sub-Saharan African air, and a novel LAMP assay for rapid detection of the tropical phytopathogenic genus Lasiodiplodia

To date, there have been no DNA-based metabarcoding studies into airborne fungi in tropical Sub-Saharan Africa. In this initial study, 10 air samples were collected onto Vaseline-coated acrylic rods mounted on drones flown at heights of 15-50 metres above ground for 10-15 minutes at three sites in Ghana. Purified DNA was extracted from air samples, the internal transcribed spacer (ITS) region was amplified using fungal-specific primers, and minION third-generation amplicon sequencing was undertaken with downstream bioinformatics analyses utilizing GAIA cloud-based software (at genus taxonomic level). Principal Co-Ordinate analyses based on Bray-Curtis beta diversity dissimilarity values found no clear evidence for structuring of fungal air communities based on geographic location (east vs. central Ghana), underlying vegetation type (cocoa vs. non-cocoa) or height above ground level (15-23 m vs. 25-50 m). In Ghanaian air samples, despite the very short flight times, ~90 operational taxonomic units (OTUs) were identified in each sample, with no statistical differences in alpha diversity between air samples from different locations, vegetation types or height above ground. In Ghanaian air, fungal assemblages were skewed at the phylum taxonomic level towards the ascomycetes (53.7%) as opposed to basidiomycetes (24.6%); at the class level, the Dothideomyectes were predominant (29.8%) followed by the Agaricomycetes (21.8%). The most common fungal genus in Ghanaian air was cosmopolitan and globally ubiquitous Cladosporium (9.9% of reads). Interestingly, many fungal genera containing economically important phytopathogens of tropical crops were also identified in Ghanaian air, including Corynespora, Fusarium and Lasiodiplodia. Consequently, a novel loop-mediated isothermal amplification (LAMP) assay, based on translation elongation factor-1α sequences, was developed and tested for rapid, sensitive and specific detection of the fungal phytopathogenic genus Lasiodiplodia. The potential applications for improved tropical disease management are considered

Evolution of decreased sensitivity to azole fungicides in western European populations of Plenodomus lingam (cause of Phoma leaf spot / stem canker on oilseed rape)

Plenodomus lingam (Leptosphaeria maculans) and P. biglobosus (L. biglobosa) are related fungal pathogens causing Phoma leaf spot and stem canker, an internationally damaging disease of oilseed rape (Brassica napus) and other brassicas. In Europe, fungicides used for disease management are mainly sterol 14α-demethylase (CYP51) inhibitors (DMIs/azoles); quinone outside inhibitors (QoIs), and succinate dehydrogenase inhibitors (SDHIs) are also used. Decreased DMI sensitivity has emerged in Australian and eastern European P. lingam populations. Decreased sensitivity is mediated by promoter inserts in CYP51 resulting in target site overexpression. In the present study, based on in vitro sensitivity testing, we report decreased DMI (prothioconazole-desthio and mefentrifluconazole) sensitivity in modern western European isolates of P. lingam (collected 2022-23) compared to baseline historical (1992-2005) isolates. Around 85% of the modern western European P. lingam isolates collected, for which the CYP51 promoter region was sequenced, carried a promoter insert but target site alterations were not detected. Six different CYP51 promoter inserts were identified, with a 237 bp fragment of the Sahana transposable element most frequently detected. Inserts were typically associated with a 3 to 10 fold decrease in sensitivity to the DMIs tested. In contrast to P. lingam, PCR screening revealed that CYP51 promoter inserts were absent in modern western European P. biglobosus isolates (collected 2021-23). The combined data indicate P. lingam isolates lacking an insert were similarly (or slightly more) sensitive to the DMIs tested for P. biglobosus, whereas those carrying an insert were slightly less sensitive than P. biglobosus. No clear evidence for substantive sensitivity shifts to the QoI (pyraclostrobin) or SDHI (boscalid) fungicides tested was obtained for either Plenodomus species

Adoption of no-tillage alters the pools of SOM with various thermal stability and their chemical composition by changing their sources in Northeast China

The stability and chemical composition of SOM are related to the changes of the proportions of old and young SOM. However, there are few studies that investigated the effects of no-tillage (NT) on the stability, chemical composition, and sources of SOM. In this study, the effects of 9-years of NT on the contents of total, thermally labile and stable SOM, their chemical composition and the contributions from C3 and C4 plants were determined. Before application of NT, the field has been used for C4 maize cultivation under conventional tillage (CT) management about 80 years after initial C3 grassland reclamation. Soil samples were collected in the 0–20 cm soil profile. Under NT treatment, the contents of total SOC, thermally labile and stable SOC, and C4-SOC decreased with soil depths. However, they were greater in the 0–10 cm layers than that in the 10–20 cm layer under CT. The contents of C3-SOC showed no change with depths under both of tillage treatments. NT had greater contents of total SOC, C4-SOC, thermal-labile SOC, and C4-SOCthermal-labile than CT in the 0–5 cm layer, but lower in the subsoil layers. The contents of C3-SOCthermal-labile decreased in the 0–5 cm layer under NT. The alkyl-C and O-alkyl-C were the main fractions of thermal-labile SOM and aromatic-C was the dominant fraction of thermal-stable SOM. C4-SOC (young SOC) was significantly positively correlated with alkyl-C and O-alkyl-C and negatively correlated with aromatic-C. Our results indicated that: (1) compared with continuously CT, applying NT resulted in SOC accumulation in the surface layer, (2) more maize residue input increased the new thermally labile and stable SOM yet lead to decrease the C3-SOCthermal-labile under NT, (3) the contributions of C3 and C4-direved SOM determined the chemical compositions of various SOM pools

Data from: A conserved fungal Knr4/Smi1 protein is vital for maintaining cell wall integrity and host plant pathogenesis

Filamentous plant pathogenic fungi pose significant threats to global food security, particularly through diseases like Fusarium Head Blight (FHB) and Septoria Tritici Blotch (STB) which affects cereals. With mounting challenges in fungal control and increasing restrictions on fungicide use due to environmental concerns, there is an urgent need for innovative control strategies. Here, we present a comprehensive analysis of the stage-specific infection process of Fusarium graminearum in wheat spikes by generating a dual weighted gene co-expression network (WGCN). Notably, the network contained a mycotoxin-enriched fungal module that exhibited a significant correlation with a detoxification gene-enriched wheat module. This correlation in gene expression was validated through quantitative PCR. By examining a fungal module with genes highly expressed during early symptomless infection, we identified a gene encoding FgKnr4, a protein containing a Knr4/Smi1 disordered domain. Through comprehensive analysis, we confirmed the pivotal role of FgKnr4 in various biological processes, including morphogenesis, growth, cell wall stress tolerance, and pathogenicity. Further studies confirmed the observed phenotypes are partially due to the involvement of FgKnr4 in regulating the fungal cell wall integrity pathway by modulating the phosphorylation of the MAP-kinase MGV1. Orthologues of FgKnr4 are widespread across the fungal kingdom but are absent in other Eukaryotes, suggesting the protein has potential as a promising intervention target. Encouragingly, the restricted growth and highly reduced virulence phenotypes observed for ΔFgknr4 were replicated upon deletion of the orthologous gene in the wheat fungal pathogen Zymoseptoria tritici. Overall, this study demonstrates the utility of an integrated network-level analytical approach to pinpoint genes of high interest to pathogenesis and disease control

Evaluating Urban Land Resource Carrying Capacity With Geographically Weighted Principal Component Analysis - A Case Study in Wuhan, China

With the rapid urbanization in China, urban land resources gradually become the core of urban development. This study spatially evaluated the urban land resource carrying capacity (LRCC) with a case study of the built-up area in Wuhan from 2015 to 2020. Following an evaluation index system, five critical LRCC indicators, including population density, GDP per land area, plot ratio, building density, and road network density, were selected by an analytical hierarchical process. The synthesis of indicators, however, is usually challengeable due to homogeneous assumptions of traditional techniques. In this study, we adopted a local technique, geographically weighted principal component analysis, to calculate a comprehensive carrying pressure (CCP) concerning spatially varying contributions of each indicator on their synthesis across different geographic locations. On mapping these spatial outputs of the built-up area in Wuhan, the highest CCP was found in the central areas, where population size tends to be influential and the dominant variable in 62.69% of subdistricts. Furthermore, increased construction over the 5 years has led to an increased CCP in some of the peripheries of the built-up area, and 55.22% of subdistricts show rising changes. With the GWPCA technique, this framework works well in evaluating and analyzing urban LRCC from a new local perspective