Efforts have been made in recent years to improve knowledge about soil greenhouse gas (GHG) fluxes from sub-Saharan Africa. However, data on soil GHG emissions from smallholder coffee-dairy systems ...have not hitherto been measured experimentally. This study aimed to quantify soil GHG emissions at different spatial and temporal scales in smallholder coffee-dairy farms in Murang'a County, Central Kenya. GHG measurements were carried out for one year, comprising two cropping seasons, using vented static chambers and gas chromatography. Sixty rectangular frames were installed on two farms comprising the three main cropping systems found in the area: 1) coffee (Coffea arabica L.); 2) Napier grass (Pennisetum purpureum); and 3) maize intercropped with beans (Zea mays and Phaseolus vulgaris). Within these fields, chambers were allocated on fertilised and unfertilised locations to capture spatial variability. Cumulative annual fluxes in coffee plots ranged from 1 to 1.9kgN2O-Nha−1, 6.5 to 7.6MgCO2-Cha−1 and −3.4 to −2.2kgCH4-Cha−1, with 66% to 94% of annual GHG fluxes occurring during rainy seasons. Across the farm plots, coffee received most of the N inputs and had 56% to 89% higher emissions of N2O than Napier grass, maize and beans. Within farm plots, two to six times higher emissions were found in fertilised hotspots – around the perimeter of coffee trees or within planted maize rows – than in unfertilised locations between trees, rows and planting holes. Background and induced soil N2O emissions from fertiliser and manure applications in the three cropping systems were lower than hypothesized from previous studies and empirical models. This study supplements methods and underlying data for the quantification of GHG emissions at multiple spatial and temporal scales in tropical, smallholder farming systems. Advances towards overcoming the dearth of data will facilitate the understanding of synergies and tradeoffs of climate-smart approaches for low emissions development.
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•Smallholder coffee-dairy farms have low soil GHG emissions in Central Kenya.•The inherent complexity of smallholder systems challenge GHG measurements.•Stratification among farms, fields, and field locations can capture spatial variability.•Sampling should match seasonal events to account for temporal variability.•Fertilised spots in coffee plots registered the highest emissions during wet periods.
Mixed production systems, in which producers have some combination of perennial and annual crops, livestock, and/or fisheries, are the most common form of farming in low- and medium-income countries, ...and they are increasingly of interest in high-income countries as an adaptive approach to climate change. Diversification in mixed systems can buffer against the risks climate change poses to food production systems through increased livelihood resilience, food security, and multiple ecosystem services. Mixed systems can provide near-term, local and regional resilience as well as contributing to sustained resilience in the global food system. Evidence and cases from mixed crop-livestock systems, agroforestry, and integrated aquatics systems demonstrate the technical, cultural, and socio-economic benefits, challenges and barriers to implementation. Support for mixed systems, including context-specific financial mechanisms, knowledge sharing, and markets, could help advance the adaptation and mitigation benefits of mixed systems. Failure to consider the place and context-specific dynamics in implementing these systems can lead to maladaptive outcomes.
•Shading in agrosilvopastoral systems affects the daily pattern of animal behaviour.•Pastures in agrosilvopastoral contain less structural foraging deterrents.•High proportions of dead biomass ...increase selectivity and reduce feed intake rate.•Animal behaviour, feed intake and performance greatly influence water productivity.•Agrosilvopastoral systems enhance feed conversion efficiency and water productivity.
Environmental conditions and available forage on pastures greatly differ between different farming systems, which can affect the behaviour of grazing cattle. The interplay between environment-, forage-, and animal-related variables may affect the use of feed and water resources in grazing-based systems. Hence, our objectives were (i) to study the differences between grazing-based systems and seasons in environment- and pasture-related variables as well as the behaviour, feed intake, performance, and water productivity of Nellore heifers, and (ii) to understand the interrelationships between these variables. The measurements were performed in a conventional grazing system (CON), an integrated crop-livestock (ICL), and a crop-livestock-forestry (ICLF) systems in the Brazilian Cerrado during the rainy and dry seasons. Ambient temperature and relative air humidity were hourly measured in both seasons. Forage biomass and sward height were determined every month. Forage samples were taken to determine the proportions of alive leaves, alive stems, and dead plant material and to analyse their nutritive value. Forage intake, drinking water intake, and liveweight changes were quantified in 12 Nellore heifers per system and season. Feeding behaviour was recorded by chewing sensors on nine continuous days in each season. Drinking water intake was measured by water meters attached to drinking water troughs, whereby trial cameras at the troughs recorded the frequency of drinking events of individual animals. Feed conversion efficiency and water productivity were estimated. The ICLF reduced the exposure time to high ambient temperatures so that heifers even grazed during the hottest hours. Forage biomass in ICL and CON had greater proportions of stem and dead plant material than in ICLF. Forage intake rate was greater and grazing events were longer for animals in ICLF than those in CON, whereas the daily number of grazing events was greater in CON. Feed conversion efficiency and water productivity were greater in integrated systems than in CON. Amongst studied variables, thermal environment and forage canopy structure with its proportions of dead plant material are the main driving factors for animal behaviour, forage intake rate, and animal performance. These variables reduce feed conversion efficiency and water productivity in grazing cattle. Further research should analyse strategies for promoting thermal comfort for the animals, increasing the proportions of alive biomass, and enhancing the nutritional value of pastures for more efficient use of forage and water resources in grazing-based systems.
Mixed crop‐livestock farms (MCLF) integrate livestock and crops using their animals to graze crop residues and/or cover crops. MCLF are considered sustainable because grazing and the manure deposited ...by livestock enhance soil fertility and recycles farm nutrients. However, livestock manure may introduce enteric foodborne pathogens to the soil, which could contaminate fresh produce. Organic farmers in the United States follow the USDA National Organic Program (NOP) standards, which require 90 or 120 days between incorporating raw manure into the soil and harvest. Although not specifically addressed in NOP, organic farmers using grazing within production fields may also use this standard. The objectives of this study were to generate preharvest data to assess the die‐off of generic Escherichia coli (E. coli) in the soil, after cover crops were grazed by sheep; and assess the genetic relatedness of generic E. coli isolates between soil and sheep faecal samples. We conducted a repeated observational study to evaluate the persistence of generic E. coli, as an indicator of faecal contamination and surrogate for STEC, in the soil of two fields (A and B) on an organic MCLF. Results showed a 3.70 log10 reduction in mean generic E. coli concentration MPN in the soil of field A from the highest of 3.70 log10 MPN/g on 48 day postsheep grazing (DPS) to −0.70 log10 MPN/g on 139 DPS. Field B showed a 3.51 log10 reduction in mean generic E. coli concentration in the soil from the highest mean of 3.51 log10 MPN/g on 14 DPS to the lowest mean −0.35 log10 MPN/g on 112 DPS. STEC prevalence in the sheep flock was 4.17% (1/24). Closely related generic E. coli strains were found between soil and faecal samples. Developing research‐based waiting periods between grazing and harvest is important to inform best practices for farmers and food safety regulators.
Malnourishment continues to remain a challenge in developing countries. As the undernourished are largely smallholder farmers, it is widely assumed that farm diversification and mixed crop‐livestock ...agricultural systems can help alleviate this problem. However, empirical evidence in this context is limited. Hence, we use a two‐year panel's data from Laos to examine whether farm production diversity as well as a mixed crop‐livestock farming system improves household dietary diversity among smallholder farmer. The results from the fixed effects regression indicate that although farm production diversity does lead to a higher dietary diversity, the effect diminishes with continued farm diversification. The counterfactual analysis from the endogenous switching regression reveals that mixed crop‐livestock farming systems do not necessarily enhance dietary diversity. However, we further find that purchasing food from the markets plays an important role in enhancing the dietary diversity of rural smallholder farmers.
•Rule-based models can assess the added value for being flexible.•Technical changes can affect farm flexibility.•Management skills are needed for improving farm flexibility.•A challenge for research ...is to strengthen the different dimensions of flexibility.
African farmers have always been exposed to climatic and economic variability and have developed a range of coping strategies. Such strategies form part of flexible farm management, an ability that may prove very valuable in the face of future climate change and market dynamics. The generally low productivity of African smallholder farming systems is usually addressed by research and development institutions by a variety of solutions for improving farm performance. However, changes to the system may affect the flexibility of farms and thus their ability to cope with variability. We quantified the added value of being flexible and how this flexibility is affected by technical changes, such as composting and cattle fattening recurrently proposed and promoted by research and development institutions and projects. The study was conducted in two villages of the agro-pastoral area of Burkina Faso, where livestock, cereals and cotton are the main farming activities. A whole-farm simulation model was developed based on information gathered during focus group meetings with farmers and detailed individual monitoring of farmers' practices. The model simulates farmers' decision rules governing the management of the cropping and livestock farm components, as well as crop and livestock production and farm gross margin. Using the existing decision rules, current farm performance was simulated by assessing the cereal balance, the fodder balance and the whole farm gross margin. Then, by comparing the mean and the coefficient of variation of these indicators resulting from (a) the existing decision rules (baseline scenario) and (b) a set of less flexible rules (rigid scenario), the added value of flexible management was revealed. The adoption of composting practices allowed a slight increase in gross margin associated with a decrease in its between-year variability in comparison with conventional practices. Cattle fattening only led to a higher gross margin in the years with high rainfall and low input prices when no management practices were used to limit dependence on external input. This kind of technical change thus requires increased management agility by farmers to deal with climatic and economic variability. We conclude that assessing the impact of technical interventions not only in terms of productivity but also in terms of changes in flexibility is useful for a better understanding of potential adoption of technical changes.
Peste des petits ruminants (PPR) is a highly contagious and fatal disease of mostly domestic goats and sheep. First reported in Uganda in 2007, the extent of peste des petits ruminants virus (PPRV) ...exposure, geographical distribution and risk factors of its transmission and spread are not clearly understood. In this study, we used cluster random sampling methodology to select study villages from three districts representing three different production systems along Uganda's "cattle corridor". Between October and December 2022, 2520 goat and sheep serum samples were collected from 252 households with no history of PPR vaccination in the past one year. The household heads were interviewed to assess possible risk factors of PPRV transmission using a structured questionnaire. The serum samples were screened with a commercial competitive enzyme-linked immunosorbent assay (cELISA) for PPRV antibodies. The determined overall true seroprevalence of PPRV was 27.3% 95% CI: 25.4-29.1. The seroprevalence of PPRV antibodies in different production systems was 44.1% 95% CI: 40.6-47.7, 31.7% 95% CI: 28.4-35.0 and 6.1% 95% CI: 4.4-7.9 for pastoral, agropastoral and mixed crop-livestock production systems respectively. A mixed-effects multivariable logistic regression model revealed strong statistical evidence of association between female animals and PPRV antibody seropositivity compared to males OR= 2.45, 95% CI: 1.7-3.5, p < 0.001. The likelihood of being PPRV antibody seropositive significantly increased with increasing small ruminant age. Animals older than 3 years were more than three times as likely to be PPRV seropositive compared to animals aged under 1 year OR= 3.41, 95% CI: 2.39-4.85, p < 0.001. There was no statistical evidence of association between small ruminant species and PPRV antibody seropositivity (p = 0.423). Village flocks that interacted with neighboring flocks daily during grazing (IRR = 1.59, 95% CI: 1.19-2.13) and watering around swamps (IRR = 1.59, 95% CI: 1.19-2.13) were highly correlated with increased number of PPRV seropositive animals as compared to flocks that were more restricted in grazing and watered around other water sources other than swamps. Flocks from pastoral and agropastoral production systems were more than 10 times more likely to have seropositive animals than mixed crop-livestock flocks. Targeting PPR control interventions (vaccination and livestock movement control) to pastoral and agro-pastoral small ruminant production systems that are very prone to PPR incursions is recommended to prevent PPRV spread to low-risk smallholder mixed crop-livestock production systems.
Integrated crop-livestock systems (ICLS) can be an alternative to increase the productivity of agroecosystems by enhancing nutrient cycling via grazing animals. Despite the holistic approach that ...bears the designing of ICLS, fertilization practices are proceeded in a conventional crop basis, disregarding nutrient fluxes at the appropriate spatial and temporal dynamics. We argue that fertilization practices in ICLS must follow the same integrated approach. To test this, we compared a conventional crop fertilization strategy versus a system fertilization approach applied to two production systems being a conventional cropping system and ICLS. The conventional cropping system consisted of a soybean crop succeeded by a non-grazed Italian ryegrass cover crop. The ICLS model consisted of a soybean-Italian ryegrass rotation grazed by sheep. In the conventional crop fertilization strategy phosphorus and potassium were applied at soybean sowing and nitrogen at the Italian ryegrass establishment. The system fertilization consisted of the application of all nutrients during the Italian ryegrass establishment. Accordingly, treatments were fertilization strategies in a factorial framework with production systems randomly distributed in a complete block design with four replicates. Results indicated for the first time greater daily herbage accumulation rate (24%;
P
< 0.01) and total herbage production (18%;
P
< 0.05) in the system fertilization compared with conventional crop fertilization. Consequently, system fertilization allowed for greater stocking rates in the pasture phase (17%;
P
< 0.05). The ICLS presented greater equivalent soybean yield (
P
< 0.001), energy production (
P
< 0.01), and system productivity (
P
< 0.05) compared with the cropping system, regardless of fertilization strategies. Soybean yield was not affected by fertilization strategies or grazing. In conclusion, the adoption of system fertilization strategy and crop-livestock integration enhance the production without jeopardizing soybean grain yields, so that land use is optimized by a greater energy production per unit of nutrient applied.
Mixed crop–livestock (MC–L) farming has gained broad consensus as an economically and environmentally sustainable farming system. Working on a Charolais-area suckler cattle farms network, we ...subdivided the 66 farms of a constant sample, for 2 years (2010 and 2011), into four groups: (i) ‘specialized conventional livestock farms’ (100% grassland-based farms (GF), n=7); (ii) ‘integrated conventional crop–livestock farms’ (specialized farms that only market animal products but that grow cereal crops on-farm for animal feed, n=31); (iii) ‘mixed conventional crop–livestock farms’ (farms that sell beef and cereal crops to market, n=21); and (iv) organic farms (n=7). We analyse the differences in structure and in drivers of technical, economic and environmental performances. The figures for all the farms over 2 years (2010 and 2011) were pooled into a single sample for each group. The farms that sell crops alongside beef miss out on potential economies of scale. These farms are bigger than specialized beef farms (with or without on-farm feed crops) and all types of farms show comparable economic performances. The big MC–L farms make heavier and consequently less efficient use of inputs. This use of less efficient inputs also weakens their environmental performances. This subpopulation of suckler cattle farms appears unable to translate a MC–L strategy into economies of scope. Organic farms most efficiently exploit the diversity of herd feed resources, thus positioning organic agriculture as a prototype MC–L system meeting the core principles of agroecology.
Soil phosphorus (P) utilization may be affected by agricultural complexity, in particular when combining annual crops and livestock grazing on the same land area and at overlapping times. Our ...objectives were to qualify and quantify soil organic and inorganic P compounds using sodium hydroxide-ethylenediaminetetraacetic acid (NaOH-EDTA) extraction and 31P nuclear magnetic resonance spectroscopy (31P NMR) in response to increasing complexity with integrated crop-livestock systems (ICLS) in subtropical Brazil. Soil at a depth of 0–5cm was collected from three long-term (7 to 12years) cropping studies with and without ruminant grazing of cover crops. All sites were managed under no tillage, and treatments with livestock were managed with moderate grazing intensity. In these agro-ecosystems, grazing compared with no-grazing had greater soil P content as total and bioavailable orthophosphate and lower soil organic P and fewer monoesters, including inositol phosphates. Grazing increased P bioavailability and reduced recalcitrant organic P concentration in soil; therefore, cropping systems that integrate livestock (ICLS) can be a sustainable alternative to improve P use in farming systems of subtropical Brazil.
•Soil phosphorus composition was affected by agricultural complexity.•Greater agricultural complexity was achieved with grazing of winter cover crops.•Grazing of cover crops increased soil inorganic and bioavailable P content.•Grazing reduced soil organic P including myo- and scyllo-Inositol hexakisphosphate.
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