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La combinaison de différents systèmes de culture et de travail du sol avec différents génotypes au cours de plusieurs saisons de culture peut révéler des opportunités d'intensification durable (IS). L'objectif de cette étude était d'évaluer la performance de six génotypes de maïs en culture intercalaire avec labour de conservation (sans labour) - deux options prometteuses pour le SI. L'expérience a été menée sur trois ans (ou six saisons de culture) à la station de recherche de Kiboko, au Kenya, avec la culture de la sole et le labour des plaques de moulage comme systèmes de production de base. Les résultats ont montré que les génotypes et les systèmes de culture du maïs avaient un effet significatif sur le rendement, mais que l'effet du travail du sol n'était pas significatif. De plus, il n'y avait pas d'effets interactifs significatifs des facteurs testés sur le rendement du maïs. Le génotype de maïs CKH10085 avait le rendement le plus élevé de 7,7 t ha-1 en culture en solitaire, mais il a également enregistré la plus grande pénalité de rendement en raison de la culture intercalaire de 1,1 t ha-1. D'autre part, le génotype CKH10717 a maintenu le même rendement moyen de 7,1 t ha-1 dans les systèmes de travail du sol conventionnels et de conservation. Les génotypes commerciaux CKH10080 et CKH08051 étaient plus stables que les autres génotypes expérimentaux dans les conditions variables de croissance et de gestion. Ces deux génotypes sont de maturité intermédiaire et de tolérance à la sécheresse, deux attributs essentiels à l'amélioration de la production de maïs. Les cultures intercalaires ont réduit les rendements de maïs en raison de la concurrence accrue, par exemple, le rendement global de la culture de la sole était de 7,1 t ha-1 par rapport à 6,4 t ha-1 en cultures intercalaires ; ce qui représente une pénalité de rendement global de 0,7 t ha-1. Les différences de performance des génotypes de maïs ont révélé des possibilités de déploiement de génotypes pour réduire les risques ou maximiser le rendement, en fonction des circonstances biophysiques et de l'objectif de production de l'agriculteur. La combinación de diferentes sistemas de cultivo y labranza con diferentes genotipos a lo largo de varias temporadas de cultivo puede revelar oportunidades para la intensificación sostenible (IS). El objetivo de este estudio fue evaluar el rendimiento de seis genotipos de maíz en cultivos intercalados con labranza conservadora (sin labranza), dos opciones prometedoras para SI. El experimento se llevó a cabo durante tres años (o seis temporadas de cultivo) en la Estación de Investigación de Kiboko, Kenia, con el cultivo de lenguado y el arado de vertederos como sistemas de producción de referencia. Los resultados mostraron que los genotipos de maíz y los sistemas de cultivo tuvieron un efecto significativo en el rendimiento, pero el efecto de la labranza no fue significativo. Además, no hubo efectos interactivos significativos de los factores probados en el rendimiento del maíz. El genotipo de maíz CKH10085 tuvo el mayor rendimiento de 7,7 t ha-1 en el cultivo de lenguado, pero también registró la mayor penalización de rendimiento debido al cultivo intercalado de 1,1 t ha-1. Por otro lado, el genotipo CKH10717 mantuvo el mismo rendimiento medio de 7,1 t ha-1 tanto en sistemas de labranza convencional como conservadora. Los genotipos comerciales CKH10080 y CKH08051 fueron más estables que los otros genotipos experimentales en las condiciones variables de crecimiento y manejo. Estos dos genotipos son de madurez intermedia y tolerancia a la sequía, dos atributos críticos para mejorar la producción de maíz. Los cultivos intercalados redujeron los rendimientos de maíz debido a una mayor competencia, por ejemplo, el rendimiento general del cultivo de lenguado fue de 7,1 t ha-1 en comparación con 6,4 t ha-1 en cultivos intercalados; lo que representa una penalización de rendimiento general de 0,7 t ha-1. Las diferencias en el rendimiento de los genotipos de maíz revelaron oportunidades para desplegar genotipos para reducir el riesgo o maximizar el rendimiento, dependiendo de las circunstancias biofísicas y el objetivo de producción del agricultor. Combining different cropping and tillage systems with different genotypes across several cropping seasons can reveal opportunities for sustainable intensification (SI). The objective of this study was to assess the performance of six maize genotypes under intercropping with conservation tillage (no-till) - two promising options for SI. The experiment was carried out over three years (or six cropping seasons) at Kiboko Research Station, Kenya with sole cropping and mouldboard ploughing as baseline production systems. Results showed that maize genotypes and cropping systems had a significant effect on yield, but the effect of tillage was not significant. Moreover, there was no significant interactive effects of the tested factors on maize yield. The maize genotype CKH10085 had the highest yield of 7.7 t ha-1 under sole cropping yet it also recorded the largest yield penalty due to intercropping of 1.1 t ha-1. On the other hand, genotype CKH10717 maintained the same average yield of 7.1 t ha-1 in both conventional and conservation tillage systems. The commercial genotype genotype CKH10080 and CKH08051 were more stable than the other experimental genotypes under the variable growing and management conditions. These two genotypes are of intermediate maturity and drought tolerance, two critical attributes to improved maize production. Intercropping reduced maize yields due to increased competition, for example the overall yield of sole cropping was 7.1 t ha-1 compared with 6.4 t ha-1 under intercropping; representing an overall yield penalty of 0.7 t ha-1. The differences in performance of maize genotypes revealed opportunities to deploy genotypes to reduce risk or maximize yield, depending on the biophysical circumstances and the production objective of the farmer. يمكن أن يكشف الجمع بين أنظمة المحاصيل والحراثة المختلفة والأنماط الجينية المختلفة عبر العديد من مواسم المحاصيل عن فرص للتكثيف المستدام (SI). كان الهدف من هذه الدراسة هو تقييم أداء ستة أنماط جينية للذرة تحت الزراعة البينية مع حراثة الحفظ (بدون حراثة) - وهما خياران واعدان لـ SI. تم إجراء التجربة على مدى ثلاث سنوات (أو ستة مواسم زراعة) في محطة أبحاث كيبوكو، كينيا باستخدام الزراعة الوحيدة وحرث ألواح القوالب كنظم إنتاج أساسية. أظهرت النتائج أن الأنماط الجينية للذرة وأنظمة المحاصيل كان لها تأثير كبير على المحصول، لكن تأثير الحراثة لم يكن كبيرًا. علاوة على ذلك، لم تكن هناك آثار تفاعلية كبيرة للعوامل التي تم اختبارها على محصول الذرة. كان للنمط الجيني للذرة CKH10085 أعلى إنتاجية تبلغ 7.7 طن هكتار -1 تحت المحصول الوحيد، ومع ذلك فقد سجل أيضًا أكبر عقوبة على المحصول بسبب المحصول البيني البالغ 1.1 طن هكتار -1. من ناحية أخرى، حافظ النمط الجيني CKH10717 على نفس متوسط العائد البالغ 7.1 طن هكتار -1 في كل من أنظمة الحراثة التقليدية وأنظمة الحفظ. كان النمط الجيني التجاري CKH10080 و CKH08051 أكثر استقرارًا من الأنماط الجينية التجريبية الأخرى في ظل ظروف النمو والإدارة المتغيرة. هذان النمطان الوراثيان لهما نضج متوسط وتحمل للجفاف، وهما سمتان حاسمتان لتحسين إنتاج الذرة. قللت الزراعة البينية من غلة الذرة بسبب زيادة المنافسة، على سبيل المثال، كان العائد الإجمالي للمحصول الوحيد 7.1 طن هكتار -1 مقارنة بـ 6.4 طن هكتار -1 تحت الزراعة البينية ؛ مما يمثل عقوبة إنتاجية إجمالية قدرها 0.7 طن هكتار -1. كشفت الاختلافات في أداء الأنماط الجينية للذرة عن فرص لنشر الأنماط الجينية لتقليل المخاطر أو زيادة الغلة، اعتمادًا على الظروف الفيزيائية الحيوية وهدف الإنتاج للمزارع.

La combinaison de différents systèmes de culture et de travail du sol avec différents génotypes au cours de plusieurs saisons de culture peut révéler des opportunités d'intensification durable (IS). L'objectif de cette étude était d'évaluer la performance de six génotypes de maïs en culture intercalaire avec labour de conservation (sans labour) - deux options prometteuses pour le SI. L'expérience a été menée sur trois ans (ou six saisons de culture) à la station de recherche de Kiboko, au Kenya, avec la culture de la sole et le labour des plaques de moulage comme systèmes de production de base. Les résultats ont montré que les génotypes et les systèmes de culture du maïs avaient un effet significatif sur le rendement, mais que l'effet du travail du sol n'était pas significatif. De plus, il n'y avait pas d'effets interactifs significatifs des facteurs testés sur le rendement du maïs. Le génotype de maïs CKH10085 avait le rendement le plus élevé de 7,7 t ha-1 en culture en solitaire, mais il a également enregistré la plus grande pénalité de rendement en raison de la culture intercalaire de 1,1 t ha-1. D'autre part, le génotype CKH10717 a maintenu le même rendement moyen de 7,1 t ha-1 dans les systèmes de travail du sol conventionnels et de conservation. Les génotypes commerciaux CKH10080 et CKH08051 étaient plus stables que les autres génotypes expérimentaux dans les conditions variables de croissance et de gestion. Ces deux génotypes sont de maturité intermédiaire et de tolérance à la sécheresse, deux attributs essentiels à l'amélioration de la production de maïs. Les cultures intercalaires ont réduit les rendements de maïs en raison de la concurrence accrue, par exemple, le rendement global de la culture de la sole était de 7,1 t ha-1 par rapport à 6,4 t ha-1 en cultures intercalaires ; ce qui représente une pénalité de rendement global de 0,7 t ha-1. Les différences de performance des génotypes de maïs ont révélé des possibilités de déploiement de génotypes pour réduire les risques ou maximiser le rendement, en fonction des circonstances biophysiques et de l'objectif de production de l'agriculteur. La combinación de diferentes sistemas de cultivo y labranza con diferentes genotipos a lo largo de varias temporadas de cultivo puede revelar oportunidades para la intensificación sostenible (IS). El objetivo de este estudio fue evaluar el rendimiento de seis genotipos de maíz en cultivos intercalados con labranza conservadora (sin labranza), dos opciones prometedoras para SI. El experimento se llevó a cabo durante tres años (o seis temporadas de cultivo) en la Estación de Investigación de Kiboko, Kenia, con el cultivo de lenguado y el arado de vertederos como sistemas de producción de referencia. Los resultados mostraron que los genotipos de maíz y los sistemas de cultivo tuvieron un efecto significativo en el rendimiento, pero el efecto de la labranza no fue significativo. Además, no hubo efectos interactivos significativos de los factores probados en el rendimiento del maíz. El genotipo de maíz CKH10085 tuvo el mayor rendimiento de 7,7 t ha-1 en el cultivo de lenguado, pero también registró la mayor penalización de rendimiento debido al cultivo intercalado de 1,1 t ha-1. Por otro lado, el genotipo CKH10717 mantuvo el mismo rendimiento medio de 7,1 t ha-1 tanto en sistemas de labranza convencional como conservadora. Los genotipos comerciales CKH10080 y CKH08051 fueron más estables que los otros genotipos experimentales en las condiciones variables de crecimiento y manejo. Estos dos genotipos son de madurez intermedia y tolerancia a la sequía, dos atributos críticos para mejorar la producción de maíz. Los cultivos intercalados redujeron los rendimientos de maíz debido a una mayor competencia, por ejemplo, el rendimiento general del cultivo de lenguado fue de 7,1 t ha-1 en comparación con 6,4 t ha-1 en cultivos intercalados; lo que representa una penalización de rendimiento general de 0,7 t ha-1. Las diferencias en el rendimiento de los genotipos de maíz revelaron oportunidades para desplegar genotipos para reducir el riesgo o maximizar el rendimiento, dependiendo de las circunstancias biofísicas y el objetivo de producción del agricultor. Combining different cropping and tillage systems with different genotypes across several cropping seasons can reveal opportunities for sustainable intensification (SI). The objective of this study was to assess the performance of six maize genotypes under intercropping with conservation tillage (no-till) - two promising options for SI. The experiment was carried out over three years (or six cropping seasons) at Kiboko Research Station, Kenya with sole cropping and mouldboard ploughing as baseline production systems. Results showed that maize genotypes and cropping systems had a significant effect on yield, but the effect of tillage was not significant. Moreover, there was no significant interactive effects of the tested factors on maize yield. The maize genotype CKH10085 had the highest yield of 7.7 t ha-1 under sole cropping yet it also recorded the largest yield penalty due to intercropping of 1.1 t ha-1. On the other hand, genotype CKH10717 maintained the same average yield of 7.1 t ha-1 in both conventional and conservation tillage systems. The commercial genotype genotype CKH10080 and CKH08051 were more stable than the other experimental genotypes under the variable growing and management conditions. These two genotypes are of intermediate maturity and drought tolerance, two critical attributes to improved maize production. Intercropping reduced maize yields due to increased competition, for example the overall yield of sole cropping was 7.1 t ha-1 compared with 6.4 t ha-1 under intercropping; representing an overall yield penalty of 0.7 t ha-1. The differences in performance of maize genotypes revealed opportunities to deploy genotypes to reduce risk or maximize yield, depending on the biophysical circumstances and the production objective of the farmer. يمكن أن يكشف الجمع بين أنظمة المحاصيل والحراثة المختلفة والأنماط الجينية المختلفة عبر العديد من مواسم المحاصيل عن فرص للتكثيف المستدام (SI). كان الهدف من هذه الدراسة هو تقييم أداء ستة أنماط جينية للذرة تحت الزراعة البينية مع حراثة الحفظ (بدون حراثة) - وهما خياران واعدان لـ SI. تم إجراء التجربة على مدى ثلاث سنوات (أو ستة مواسم زراعة) في محطة أبحاث كيبوكو، كينيا باستخدام الزراعة الوحيدة وحرث ألواح القوالب كنظم إنتاج أساسية. أظهرت النتائج أن الأنماط الجينية للذرة وأنظمة المحاصيل كان لها تأثير كبير على المحصول، لكن تأثير الحراثة لم يكن كبيرًا. علاوة على ذلك، لم تكن هناك آثار تفاعلية كبيرة للعوامل التي تم اختبارها على محصول الذرة. كان للنمط الجيني للذرة CKH10085 أعلى إنتاجية تبلغ 7.7 طن هكتار -1 تحت المحصول الوحيد، ومع ذلك فقد سجل أيضًا أكبر عقوبة على المحصول بسبب المحصول البيني البالغ 1.1 طن هكتار -1. من ناحية أخرى، حافظ النمط الجيني CKH10717 على نفس متوسط العائد البالغ 7.1 طن هكتار -1 في كل من أنظمة الحراثة التقليدية وأنظمة الحفظ. كان النمط الجيني التجاري CKH10080 و CKH08051 أكثر استقرارًا من الأنماط الجينية التجريبية الأخرى في ظل ظروف النمو والإدارة المتغيرة. هذان النمطان الوراثيان لهما نضج متوسط وتحمل للجفاف، وهما سمتان حاسمتان لتحسين إنتاج الذرة. قللت الزراعة البينية من غلة الذرة بسبب زيادة المنافسة، على سبيل المثال، كان العائد الإجمالي للمحصول الوحيد 7.1 طن هكتار -1 مقارنة بـ 6.4 طن هكتار -1 تحت الزراعة البينية ؛ مما يمثل عقوبة إنتاجية إجمالية قدرها 0.7 طن هكتار -1. كشفت الاختلافات في أداء الأنماط الجينية للذرة عن فرص لنشر الأنماط الجينية لتقليل المخاطر أو زيادة الغلة، اعتمادًا على الظروف الفيزيائية الحيوية وهدف الإنتاج للمزارع.

Abstract Background The African continent is known for high entrepreneurial activity, especially in the agricultural sector. Despite this, the continent's economic development is below expectations, due to numerous factors constraining the growth and sustainability of agricultural SMEs. These constraints have been exacerbated by the COVID-19 pandemic. The purpose of this study was to understand the pathways through which the pandemic affected agri-SMEs, with specific focus on assessing the differentiated effects arising from the size of the agri-SME and the gender of the owner-manager. Methods Data was collected from over 100 agri-SMEs, ranging in size from sole proprietorships with one employee to agri-SMEs employing up to 100 people, in six African countries. Mixed methods were used to analyse the data with changes in business operations arising from changing market access, regimented health and safety guidelines and constrained labour supply assessed using visualisations and descriptive statistics. Logistic regression modelling was employed to determine the set of variables contributing to agri-SME business downturn during the COVID-19 pandemic. Results All surveyed agri-SMEs were negatively affected by COVID-19-associated restrictions with the size of the firm and gender of the owner-managers resulting in differentiated impacts. The smallest agri-SMEs, mainly owner-managed by women, were more likely to experience disruptions in marketing their goods and maintaining their labour supply. Larger agri-SMEs made changes to their business operations to comply with government guidelines during the pandemic and made investments to manage their labour supply, thus sustaining their business operations. In addition, logistic regression modelling results show that financing prior to the pandemic, engaging in primary agricultural production, and being further from urban centres significantly influenced the likelihood of a firm incurring business losses. Conclusions These findings necessitate engendered multi-faceted agri-SME support packages that are tailored for smaller-sized agri-SMEs. Any such support package should include support for agri-SMEs to develop sustainable marketing strategies and help them secure flexible financing that considers payment deferrals and debt moratorium during bona fide market shocks such as the COVID-19 pandemic.

Abstract Background The African continent is known for high entrepreneurial activity, especially in the agricultural sector. Despite this, the continent's economic development is below expectations, due to numerous factors constraining the growth and sustainability of agricultural SMEs. These constraints have been exacerbated by the COVID-19 pandemic. The purpose of this study was to understand the pathways through which the pandemic affected agri-SMEs, with specific focus on assessing the differentiated effects arising from the size of the agri-SME and the gender of the owner-manager. Methods Data was collected from over 100 agri-SMEs, ranging in size from sole proprietorships with one employee to agri-SMEs employing up to 100 people, in six African countries. Mixed methods were used to analyse the data with changes in business operations arising from changing market access, regimented health and safety guidelines and constrained labour supply assessed using visualisations and descriptive statistics. Logistic regression modelling was employed to determine the set of variables contributing to agri-SME business downturn during the COVID-19 pandemic. Results All surveyed agri-SMEs were negatively affected by COVID-19-associated restrictions with the size of the firm and gender of the owner-managers resulting in differentiated impacts. The smallest agri-SMEs, mainly owner-managed by women, were more likely to experience disruptions in marketing their goods and maintaining their labour supply. Larger agri-SMEs made changes to their business operations to comply with government guidelines during the pandemic and made investments to manage their labour supply, thus sustaining their business operations. In addition, logistic regression modelling results show that financing prior to the pandemic, engaging in primary agricultural production, and being further from urban centres significantly influenced the likelihood of a firm incurring business losses. Conclusions These findings necessitate engendered multi-faceted agri-SME support packages that are tailored for smaller-sized agri-SMEs. Any such support package should include support for agri-SMEs to develop sustainable marketing strategies and help them secure flexible financing that considers payment deferrals and debt moratorium during bona fide market shocks such as the COVID-19 pandemic.

In a number of African countries, the trophy hunting of large felids is an important revenue generator for landholders, governments and in some cases communities. The hunting of large felids is especially profitable but they are sensitive to harvest, as the killing of prime-aged, dominant males can lead to infanticide and lowered reproductive success. In an attempt to limit the negative impacts of trophy hunting on large felids, the scientific community has proposed a number of interventions, including age restrictions on the animals that may be hunted. Such interventions are theoretically complementary to trophy hunting, as hunters typically seek large trophies, and older animals are normally larger than younger ones in large felids. If trophy size results in an increase in trophy price, then interventions that improve average trophy size could confer elevated earnings. This is particularly true if such interventions increased the number of failed hunts such that the same tag can be sold more than once. However, if trophy size is not one of the most important factors determining the desirability of a hunt (which we judge by the price paid for a trophy hunt package), it may be more difficult to implement such schemes. It is therefore important to evaluate potential determinants of trophy hunt package price; and we examine that here for leopards (Panthera pardus) in Africa, at both the country and outfitter level. We show that Tanzania and Botswana have the most expensive package prices while South Africa has the cheapest packages. At the country level, we found no statistical relationships between package price and leopard trophy size (either through advertised website or Safari Club International (SCI) leopard trophy size), country GDP, relative hunt success, or quota size. Contrastingly, the number of charismatic species offered within a package and an index of outfitter reputation (as measured by total SCI trophy records) were positively associated with package price. Interestingly, SCI leopard trophy size was inversely correlated with package price. Our results suggest that hunters do not value leopard trophy size above other factors, which could hinder the implementation of more sustainable, age-based leopard hunting regulations.

In a number of African countries, the trophy hunting of large felids is an important revenue generator for landholders, governments and in some cases communities. The hunting of large felids is especially profitable but they are sensitive to harvest, as the killing of prime-aged, dominant males can lead to infanticide and lowered reproductive success. In an attempt to limit the negative impacts of trophy hunting on large felids, the scientific community has proposed a number of interventions, including age restrictions on the animals that may be hunted. Such interventions are theoretically complementary to trophy hunting, as hunters typically seek large trophies, and older animals are normally larger than younger ones in large felids. If trophy size results in an increase in trophy price, then interventions that improve average trophy size could confer elevated earnings. This is particularly true if such interventions increased the number of failed hunts such that the same tag can be sold more than once. However, if trophy size is not one of the most important factors determining the desirability of a hunt (which we judge by the price paid for a trophy hunt package), it may be more difficult to implement such schemes. It is therefore important to evaluate potential determinants of trophy hunt package price; and we examine that here for leopards (Panthera pardus) in Africa, at both the country and outfitter level. We show that Tanzania and Botswana have the most expensive package prices while South Africa has the cheapest packages. At the country level, we found no statistical relationships between package price and leopard trophy size (either through advertised website or Safari Club International (SCI) leopard trophy size), country GDP, relative hunt success, or quota size. Contrastingly, the number of charismatic species offered within a package and an index of outfitter reputation (as measured by total SCI trophy records) were positively associated with package price. Interestingly, SCI leopard trophy size was inversely correlated with package price. Our results suggest that hunters do not value leopard trophy size above other factors, which could hinder the implementation of more sustainable, age-based leopard hunting regulations.

AbstractProcess‐based models are useful for assessing the impact of changing management practices and climate on yields and greenhouse gas (GHG) emissions from agricultural systems such as grasslands. They can be used to construct national GHG inventories using a Tier 3 approach. However, accurate simulations of nitrous oxide (N2O) fluxes remain challenging. Models are limited by our understanding of soil‐plant‐microbe interactions and the impact of uncertainty in measured input parameters on simulated outputs. To improve model performance, thorough evaluations against in situ measurements are needed. Experimental data of N2O emissions under two management practices (control with typical fertilization versus increased clover and no fertilization) were acquired in a Swiss field experiment. We conducted a multimodel evaluation with three commonly used biogeochemical models (DayCent in two variants, PaSim, APSIM in two variants) comparing four years of data. DayCent was the most accurate model for simulating N2O fluxes on annual timescales, while APSIM was most accurate for daily N2O fluxes. The multimodel ensemble average reduced the error in estimated annual fluxes by 41% compared to an estimate using the Intergovernmental Panel on Climate Change (IPCC)‐derived method for the Swiss agricultural GHG inventory (IPCC‐Swiss), but individual models were not systematically more accurate than IPCC‐Swiss. The model ensemble overestimated the N2O mitigation effect of the clover‐based treatment (measured: 39–45%; ensemble: 52–57%) but was more accurate than IPCC‐Swiss (IPCC‐Swiss: 72–81%). These results suggest that multimodel ensembles are valuable for estimating the impact of climate and management on N2O emissions.