Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton(Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertili...Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton(Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cropping systems in two cotton-growing zones. Plough-based tillage plus incorporation of cover crop biomass(PTI), conservation agriculture with strip tillage(CA_ST), and conservation agriculture with no tillage(CA_NT) were compared with the reference plough-based tillage(PT). The objective was to identify morpho-physiological traits of cotton that increase yield in agroecological cropping systems. Our approach combined a field experiment and crop simulation model(CSM) of CROPGRO-Cotton to evaluate the effects of genotype(G) × environment(E) × management(M) interactions on seed cotton yield(SCY).Results Cultivars Tamcot_camde and Okp768 and simulated ideotypes performed best in CA systems. Increased seed mass, large and thick leaves, and later maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits also resulted in better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes designed could increase SCY in Benin.Conclusion A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good SCY in agroecological cropping systems. These results provide scientific evidence and useful knowledge for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.展开更多
Cadmium(Cd)is a toxic trace metal that occurs naturally in agricultural soils and can accumulate in the edible parts of crops,notably in cereal grains.This study investigated the extent to which sulfur(S)fertilization...Cadmium(Cd)is a toxic trace metal that occurs naturally in agricultural soils and can accumulate in the edible parts of crops,notably in cereal grains.This study investigated the extent to which sulfur(S)fertilization increases the availability of Cd in a calcareous(Calc)and a non-calcareous(Ncalc)soil.Changes in Cd availability and speciation were monitored over a 21-d incubation period,along with changes in pH and the concentrations of sulfate,nitrate,calcium,magnesium,aluminum(Al),manganese(Mn),and nickel(Ni)in the potassium nitrate(KNO_(3))extracts,after the addition at agronomic rates of three forms of S fertilizers:elemental S(S(0)),potassium sulfate(K_(2)SO_(4)),and ammonium sulfate((NH_(4))_(2)SO_(4)).Elemental S did not increase the Cd concentration in the KNO_(3)extracts of either soil due to its too limited oxidation to sulfates.The two sulfate fertilizers had contrasting effects on Cd concentration depending on the nature of the counter cation(K^(+)or NH_(4)^(+)).While K_(2)SO_(4)caused almost no change in Cd concentration in either soil,(NH_(4))_(2)SO_(4)increased Cd concentration in both soils.The nitrification of NH_(4)^(+)reduced soil pH,thereby increasing the concentrations of Cd,Al,Mn,and Ni in the Ncalc soil over time,as evidenced by the strong negative correlations between soil pH and the concentrations of these four elements in the KNO3 extract after 21 d.In the Calc soil,the mechanism of Cd concentration increase after(NH_(4))_(2)SO_(4)addition was more difficult to understand and could result from the proton-mediated alteration of Cd-bearing phases such as carbonates,following ammonia(NH_(3))volatilization.The relevance of these results for the S fertilization of cereals in Cd-contaminated soils is discussed.展开更多
Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems ...Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems of Central and South Cameroon, few have come out contribution of the structure of these traditional systems in the dynamics of the vegetation of these forest-savannah ecotones. The present contribution has the overall objective of demonstrating the structural efficiency of agroforests the dynamics of ecotone vegetation, but also in the conservation of biodiversity. To do this, a participatory analysis was carried out with 56 farmers distributed in the five villages of Makénéné. Botanical inventories supplemented socio-economic household surveys. The data collected was subjected to various analyzes (univariate test, analysis of variance, multivariate test, PCA, CAH). The results reveal that 55.2% of agroforests are less than 15 years old and those with an area greater than 1500 m<sup>2</sup> predominate (33%). They are mainly young with generally small surface areas. The horizontal structure reveals that the largest diameter classes are those of [20 - 30 cm[ and [10 - 20 cm[ with a very low rate of basal area. Agroforests with trees over 10 m high are dominant in five villages of Makénéné. Two types of structural profiles characterize the agroforestry flora of the area, namely intensive pluristratified home gardens on savannah and intensive pluristratified agroforests under forest-savannah transition vegetation. Principal Component Analysis (PCA) and Ascending Hierarchical Clustering (HAC) show three Agroforest Clusters each. The PCA distribution reveals that woody biomass (Y) is strongly correlated with tree diameter (DBH) and significantly with height (Cluster 2). The age (AAG) (Cluster 1) of these agroforests, on the other hand, remains independent of the density (DST) of these trees (Cluster 3). The agroforests in the Nyokon, Carrière and Mocksud villages are the most effective in terms of conserving woody diversity while the agroforests of the Kinding ndé and Nyokon villages are more efficient in the reforestation processes. These results could be considered as effective and quantifiable tools for the certification of numerous cash crops such as cocoa and coffee, which will make it possible to valorize this local knowledge in terms of scientific and in the development of various programs and writing of technical notes.展开更多
This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in...This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize.展开更多
Agroforestry ecosystems are constructed by simulating natural ecosystems, applying the principles of symbiosis in nature, and organizing multiple plant populations to coexist, while conducting targeted cultivation and...Agroforestry ecosystems are constructed by simulating natural ecosystems, applying the principles of symbiosis in nature, and organizing multiple plant populations to coexist, while conducting targeted cultivation and structural control scientifically. Rubber agroforestry complex ecosystems aim for sustainable development in terms of industry, ecology, resource utilization, and the livelihoods of producers. Rubber agroforestry complex ecosystems create a complex production structure system that integrates biology, society, and the economy through species combinations. Rubber trees and associated biological components coordinate with each other, mutually promote growth, and yield a variety of products for producers. Cultivation techniques and patterns of rubber agroforestry are essential components of these ecosystems. This study analyzes the production practices of rubber agroforestry complex cultivation, with a focus on the development and characteristics (complexity, systematicity, intensity, and hierarchy) of rubber agroforestry systems using a literature analysis and a survey approach. It explores the types and scales of complex planting, specifications and forms, and major effects of complex cultivation. This study identifies successful rubber agroforestry cultivation patterns and practical techniques, as well as the potential benefits of developing rubber agroforestry cultivation. It also points out the shortcomings in the development of complex planting, including an emphasis on production practices but insufficient theoretical research, a focus on production but inadequate attention to the market, and an emphasis on yield while overlooking the improvement of standards, brands, and added value. There are various complex patterns for young rubber plantations, but relatively fewer for mature plantations. Based on this analysis, this study suggests that future efforts should focus on in-depth research on interspecies and environmental interactions in rubber agroforestry ecosystems, clearly define key roles, accelerate the innovation of development patterns, and strengthen the foundation for development. It recommends promoting and demonstrating successful rubber agroforestry complex patterns and providing technical training, developing product branding for rubber agroforestry patterns, enhancing product value, expanding the application functions of rubber-forest mixed crop products, and establishing a stable and sustainable industry chain. This study provide practical experience and theoretical insights in rubber agroforestry complex systems from China the potential to enrich the knowledge of rubber agroforestry composite systems, provide practical experience to improve the operating income of smallholders, and even promote the sustainable development of rubber plantations.展开更多
In the light of its negative impacts on the environment and human health, conventional agriculture is currently facing new challenges;for example, reducing pesticide reliance, improving biodiversity, adapting to clima...In the light of its negative impacts on the environment and human health, conventional agriculture is currently facing new challenges;for example, reducing pesticide reliance, improving biodiversity, adapting to climate change and reconciling winegrowers with consumers, which require changes to be made to vineyard management. A shift towards more sustainable agriculture via the development of agroecological systems may be key to meeting these environmental, economic and social challenges. This study aimed to evaluate the performance of existing viticultural systems, as well as that of three new scenarios that we built to change conventional vine production systems and their related practices. The end aim is to adopt the principles of agroecology, and more virtuously, to ensure that vine production remains in line with societal expectations. First, thirty-eight different viticultural systems were chosen. Three realistic scenarios for changing these production systems were then built by working with stakeholders and incorporating the best practices that had been identified in the vineyard. Conventional practices were optimised in the first scenario and an agroecological approach was adopted for the other two scenarios: an Agroecological scenario (using synthetic chemicals) and an Agroecological-Bio scenario (organic system). All three scenarios were based on a combination of good practices which contribute to enhancing vineyard biodiversity, and which thus restore biological regulation and in turn reduce pesticides. The viticultural systems performances have been evaluated with a methodology involving multicriteria decision aid using ELECTRE Tri-C and ELECTRE III methods. Seven evaluation criteria were selected which covered socio-economic performance (economic profitability, workload and system complexity) and environmental performance (pesticide pressure, pesticide ecotoxicity, agroecological practices and pesticide drift). The best performances were achieved by the two agroecological scenarios, and this methodology can be adaptable to different production systems everywhere in different viticultural regions.展开更多
本研究旨在建立一种高效、快速、选择性测定食品中痕量汞的方法。通过溶剂热法及后续的巯基化修饰,成功制备了一种新型巯基功能化磁性介孔二氧化硅(Thiol-functionalized Magnetic Mesoporous Silica,记为mSS@Fe_(3)O_(4))吸附剂。将该...本研究旨在建立一种高效、快速、选择性测定食品中痕量汞的方法。通过溶剂热法及后续的巯基化修饰,成功制备了一种新型巯基功能化磁性介孔二氧化硅(Thiol-functionalized Magnetic Mesoporous Silica,记为mSS@Fe_(3)O_(4))吸附剂。将该吸附剂用于磁性固相萃取(MSPE),结合原子荧光光谱法(AFS),构建了一种分析食品中痕量汞的新方法。通过X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)等手段对材料进行了表征,证实了巯基已成功接枝到磁性介孔二氧化硅表面。系统优化了萃取过程中的关键参数,包括样品pH值、吸附时间、吸附剂用量、洗脱液组成和上样体积。结果表明,归因于材料的介孔结构和高比表面积,吸附平衡在1 min内即可达到,实现了对Hg^(2+)的快速富集。在最优条件下,该吸附剂对Hg^(2+)的理论最大吸附容量(qm)为67.89 mg/g;在回收率保持>90%时,最大上样体积为200 mL,预浓缩因子可达200。该方法具有较宽的pH值(1~13)适用范围和优异的抗基质干扰能力。方法线性范围为0.10~4.0μg/L(相关系数r=0.9996),方法检出限(MDL)为0.012μg/kg,对空白样品进行7次平行测定的相对标准偏差(RSD)为2.4%(n=7)。通过对国家标准物质和多种实际样品(草鱼、大米等)的加标回收实验,验证了方法的准确性和可靠性,回收率在94.0%~106%。该方法集快速、高效、高选择性与高灵敏度于一体,为食品中痕量汞的常规监测提供了有力的技术支持。展开更多
【目的】探究霍氏假单胞菌M11与巨大芽孢杆菌M28对土壤低肥力胁迫下玉米光合特性的调控作用及生理机制差异。【方法】开展盆栽试验,设置正常土壤对照(control check,CK)、低养分处理(low nutrient treatment,LNT)及低养分接种处理(M11+...【目的】探究霍氏假单胞菌M11与巨大芽孢杆菌M28对土壤低肥力胁迫下玉米光合特性的调控作用及生理机制差异。【方法】开展盆栽试验,设置正常土壤对照(control check,CK)、低养分处理(low nutrient treatment,LNT)及低养分接种处理(M11+LNT、M28+LNT)。于玉米抽雄期测定土壤养分、植株生长指标、气体交换参数、叶绿素荧光特性及快速叶绿素荧光诱导动力学(O-J-I-P chlorophyll a fluorescence transient,OJIP)曲线,于成熟期测定产量。【结果】M11显著提高了土壤有效磷、速效钾和有机质含量,降低了电导率;M28显著提升了土壤全氮含量。2种接种处理均能显著促进玉米生长,提高株高、叶面积、SPAD值及生物量;极显著提升净光合速率(net photosynthetic rate,P_(n))、气孔导度(stomatal conductance,G_(s))、蒸腾速率(transpiration rate,T_(r))和水分利用效率(water use efficiency,WUE),降低胞间CO_(2)浓度(intercellular CO_(2)concentration,C_(i))。荧光参数显示最小荧光(minimal fluorescence,F_(o))降低,最大光化学效率(maximum quantum yield of PSⅡ,F_(v)/F_(m))、实际光化学量子产量(actual quantum yield of PSⅡ,Φ_(PSⅡ))、表观光合电子传递速率(electron transport rate,ETR)、光化学淬灭系数(photochemical quenching,qP)和基于激发能压力的光化学淬灭系数(fraction of open PSⅡ centers based on excitation energy,qL)显著提高,非光化学淬灭系数(non-photochemical quenching,NPQ)无显著变化。OJIP曲线表明接种处理未出现K点,J点荧光降低,I点和P点荧光提高,相对可变荧光的差异动力学ΔV_(t)分析证实菌株同步优化光系统Ⅱ(photosystem Ⅱ,PSⅡ)供体侧与受体侧的电子传递,I−P相振幅增大表明光系统I(photosystem I,PSI)活性增强。快速叶绿素荧光诱导动力学分析(junction-intermediate-peak test,JIP-test)参数显示,接种处理显著提高了以吸收光能为基础的性能指数(performance index based on absorbed light energy,PI_(ABS))、以单位面积为基础的性能指数(performance index on a cross-section basis,PI_(CS))、捕获的激子将电子传递到电子传递链中超过Q_(A)的其他电子受体的概率(probability that a trapped exciton moves an electron into the electron transport chain beyond Q_(A),Ψ_(o))、电子传递的量子产额(quantum yield for electron transport,φ_(Eo))和单位反应中心捕获的用于电子传递的能量(electron transport flux per RC,ETo/RC),降低了单位反应中心耗散的能量(dissipated energy flux per cross-sectional area,DI_(o)/RC)和用于热耗散的量子比率(quantum ratio for dissipated energy,φ_(Do))。最终,M11和M28处理使玉米鲜重较LNT组分别显著提高30.61%和22.64%。干重分别提高26.68%和23.41%。【结论】M11主要通过提高土壤有效磷、速效钾含量直接优化能量代谢与气孔运动;而M28主要通过提升土壤全氮含量,侧重于稳定光合机构结构。二者共同保护光合机构完整性并优化光系统电子传递效率,显著增强了低肥力胁迫下玉米的光合性能与产量,为微生物菌剂在绿色增产中的应用提供了理论支持。展开更多
基金supported by the Benin Cotton Research Institute (IRC)the Cotton Interprofessional Association (AIC)+1 种基金the French Agricultural Research Centre for International Development (CIRAD)the TAZCO_(2) project (Transition Agroécologique des Zones Cotonnières du Bénin),which is funded by the Republic of Benin and the French Development Agency (AFD)。
文摘Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton(Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cropping systems in two cotton-growing zones. Plough-based tillage plus incorporation of cover crop biomass(PTI), conservation agriculture with strip tillage(CA_ST), and conservation agriculture with no tillage(CA_NT) were compared with the reference plough-based tillage(PT). The objective was to identify morpho-physiological traits of cotton that increase yield in agroecological cropping systems. Our approach combined a field experiment and crop simulation model(CSM) of CROPGRO-Cotton to evaluate the effects of genotype(G) × environment(E) × management(M) interactions on seed cotton yield(SCY).Results Cultivars Tamcot_camde and Okp768 and simulated ideotypes performed best in CA systems. Increased seed mass, large and thick leaves, and later maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits also resulted in better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes designed could increase SCY in Benin.Conclusion A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good SCY in agroecological cropping systems. These results provide scientific evidence and useful knowledge for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.
基金supported by the CNRS-INSU EC2CO program in the framework of the CADSOU project,by the Nouvelle Aquitaine Region in the framework of the ESTOCADE project,and by the French National Research Institute for Agriculture,Food and Environment(INRAE)The authors are grateful to Ms.Melike Emet(INRAE,UMR ISPA)and Ms.Sylvie Bussière(INRAE,UMR ISPA)for their help treating the samples,and to Ms.Francesca Degan(ARVALIS-Institut du végétal)and Ms.Séverine Piutti(INRAE,UMR LAE)for helpful comments.
文摘Cadmium(Cd)is a toxic trace metal that occurs naturally in agricultural soils and can accumulate in the edible parts of crops,notably in cereal grains.This study investigated the extent to which sulfur(S)fertilization increases the availability of Cd in a calcareous(Calc)and a non-calcareous(Ncalc)soil.Changes in Cd availability and speciation were monitored over a 21-d incubation period,along with changes in pH and the concentrations of sulfate,nitrate,calcium,magnesium,aluminum(Al),manganese(Mn),and nickel(Ni)in the potassium nitrate(KNO_(3))extracts,after the addition at agronomic rates of three forms of S fertilizers:elemental S(S(0)),potassium sulfate(K_(2)SO_(4)),and ammonium sulfate((NH_(4))_(2)SO_(4)).Elemental S did not increase the Cd concentration in the KNO_(3)extracts of either soil due to its too limited oxidation to sulfates.The two sulfate fertilizers had contrasting effects on Cd concentration depending on the nature of the counter cation(K^(+)or NH_(4)^(+)).While K_(2)SO_(4)caused almost no change in Cd concentration in either soil,(NH_(4))_(2)SO_(4)increased Cd concentration in both soils.The nitrification of NH_(4)^(+)reduced soil pH,thereby increasing the concentrations of Cd,Al,Mn,and Ni in the Ncalc soil over time,as evidenced by the strong negative correlations between soil pH and the concentrations of these four elements in the KNO3 extract after 21 d.In the Calc soil,the mechanism of Cd concentration increase after(NH_(4))_(2)SO_(4)addition was more difficult to understand and could result from the proton-mediated alteration of Cd-bearing phases such as carbonates,following ammonia(NH_(3))volatilization.The relevance of these results for the S fertilization of cereals in Cd-contaminated soils is discussed.
文摘Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems of Central and South Cameroon, few have come out contribution of the structure of these traditional systems in the dynamics of the vegetation of these forest-savannah ecotones. The present contribution has the overall objective of demonstrating the structural efficiency of agroforests the dynamics of ecotone vegetation, but also in the conservation of biodiversity. To do this, a participatory analysis was carried out with 56 farmers distributed in the five villages of Makénéné. Botanical inventories supplemented socio-economic household surveys. The data collected was subjected to various analyzes (univariate test, analysis of variance, multivariate test, PCA, CAH). The results reveal that 55.2% of agroforests are less than 15 years old and those with an area greater than 1500 m<sup>2</sup> predominate (33%). They are mainly young with generally small surface areas. The horizontal structure reveals that the largest diameter classes are those of [20 - 30 cm[ and [10 - 20 cm[ with a very low rate of basal area. Agroforests with trees over 10 m high are dominant in five villages of Makénéné. Two types of structural profiles characterize the agroforestry flora of the area, namely intensive pluristratified home gardens on savannah and intensive pluristratified agroforests under forest-savannah transition vegetation. Principal Component Analysis (PCA) and Ascending Hierarchical Clustering (HAC) show three Agroforest Clusters each. The PCA distribution reveals that woody biomass (Y) is strongly correlated with tree diameter (DBH) and significantly with height (Cluster 2). The age (AAG) (Cluster 1) of these agroforests, on the other hand, remains independent of the density (DST) of these trees (Cluster 3). The agroforests in the Nyokon, Carrière and Mocksud villages are the most effective in terms of conserving woody diversity while the agroforests of the Kinding ndé and Nyokon villages are more efficient in the reforestation processes. These results could be considered as effective and quantifiable tools for the certification of numerous cash crops such as cocoa and coffee, which will make it possible to valorize this local knowledge in terms of scientific and in the development of various programs and writing of technical notes.
文摘This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize.
文摘Agroforestry ecosystems are constructed by simulating natural ecosystems, applying the principles of symbiosis in nature, and organizing multiple plant populations to coexist, while conducting targeted cultivation and structural control scientifically. Rubber agroforestry complex ecosystems aim for sustainable development in terms of industry, ecology, resource utilization, and the livelihoods of producers. Rubber agroforestry complex ecosystems create a complex production structure system that integrates biology, society, and the economy through species combinations. Rubber trees and associated biological components coordinate with each other, mutually promote growth, and yield a variety of products for producers. Cultivation techniques and patterns of rubber agroforestry are essential components of these ecosystems. This study analyzes the production practices of rubber agroforestry complex cultivation, with a focus on the development and characteristics (complexity, systematicity, intensity, and hierarchy) of rubber agroforestry systems using a literature analysis and a survey approach. It explores the types and scales of complex planting, specifications and forms, and major effects of complex cultivation. This study identifies successful rubber agroforestry cultivation patterns and practical techniques, as well as the potential benefits of developing rubber agroforestry cultivation. It also points out the shortcomings in the development of complex planting, including an emphasis on production practices but insufficient theoretical research, a focus on production but inadequate attention to the market, and an emphasis on yield while overlooking the improvement of standards, brands, and added value. There are various complex patterns for young rubber plantations, but relatively fewer for mature plantations. Based on this analysis, this study suggests that future efforts should focus on in-depth research on interspecies and environmental interactions in rubber agroforestry ecosystems, clearly define key roles, accelerate the innovation of development patterns, and strengthen the foundation for development. It recommends promoting and demonstrating successful rubber agroforestry complex patterns and providing technical training, developing product branding for rubber agroforestry patterns, enhancing product value, expanding the application functions of rubber-forest mixed crop products, and establishing a stable and sustainable industry chain. This study provide practical experience and theoretical insights in rubber agroforestry complex systems from China the potential to enrich the knowledge of rubber agroforestry composite systems, provide practical experience to improve the operating income of smallholders, and even promote the sustainable development of rubber plantations.
文摘In the light of its negative impacts on the environment and human health, conventional agriculture is currently facing new challenges;for example, reducing pesticide reliance, improving biodiversity, adapting to climate change and reconciling winegrowers with consumers, which require changes to be made to vineyard management. A shift towards more sustainable agriculture via the development of agroecological systems may be key to meeting these environmental, economic and social challenges. This study aimed to evaluate the performance of existing viticultural systems, as well as that of three new scenarios that we built to change conventional vine production systems and their related practices. The end aim is to adopt the principles of agroecology, and more virtuously, to ensure that vine production remains in line with societal expectations. First, thirty-eight different viticultural systems were chosen. Three realistic scenarios for changing these production systems were then built by working with stakeholders and incorporating the best practices that had been identified in the vineyard. Conventional practices were optimised in the first scenario and an agroecological approach was adopted for the other two scenarios: an Agroecological scenario (using synthetic chemicals) and an Agroecological-Bio scenario (organic system). All three scenarios were based on a combination of good practices which contribute to enhancing vineyard biodiversity, and which thus restore biological regulation and in turn reduce pesticides. The viticultural systems performances have been evaluated with a methodology involving multicriteria decision aid using ELECTRE Tri-C and ELECTRE III methods. Seven evaluation criteria were selected which covered socio-economic performance (economic profitability, workload and system complexity) and environmental performance (pesticide pressure, pesticide ecotoxicity, agroecological practices and pesticide drift). The best performances were achieved by the two agroecological scenarios, and this methodology can be adaptable to different production systems everywhere in different viticultural regions.
文摘【目的】探究霍氏假单胞菌M11与巨大芽孢杆菌M28对土壤低肥力胁迫下玉米光合特性的调控作用及生理机制差异。【方法】开展盆栽试验,设置正常土壤对照(control check,CK)、低养分处理(low nutrient treatment,LNT)及低养分接种处理(M11+LNT、M28+LNT)。于玉米抽雄期测定土壤养分、植株生长指标、气体交换参数、叶绿素荧光特性及快速叶绿素荧光诱导动力学(O-J-I-P chlorophyll a fluorescence transient,OJIP)曲线,于成熟期测定产量。【结果】M11显著提高了土壤有效磷、速效钾和有机质含量,降低了电导率;M28显著提升了土壤全氮含量。2种接种处理均能显著促进玉米生长,提高株高、叶面积、SPAD值及生物量;极显著提升净光合速率(net photosynthetic rate,P_(n))、气孔导度(stomatal conductance,G_(s))、蒸腾速率(transpiration rate,T_(r))和水分利用效率(water use efficiency,WUE),降低胞间CO_(2)浓度(intercellular CO_(2)concentration,C_(i))。荧光参数显示最小荧光(minimal fluorescence,F_(o))降低,最大光化学效率(maximum quantum yield of PSⅡ,F_(v)/F_(m))、实际光化学量子产量(actual quantum yield of PSⅡ,Φ_(PSⅡ))、表观光合电子传递速率(electron transport rate,ETR)、光化学淬灭系数(photochemical quenching,qP)和基于激发能压力的光化学淬灭系数(fraction of open PSⅡ centers based on excitation energy,qL)显著提高,非光化学淬灭系数(non-photochemical quenching,NPQ)无显著变化。OJIP曲线表明接种处理未出现K点,J点荧光降低,I点和P点荧光提高,相对可变荧光的差异动力学ΔV_(t)分析证实菌株同步优化光系统Ⅱ(photosystem Ⅱ,PSⅡ)供体侧与受体侧的电子传递,I−P相振幅增大表明光系统I(photosystem I,PSI)活性增强。快速叶绿素荧光诱导动力学分析(junction-intermediate-peak test,JIP-test)参数显示,接种处理显著提高了以吸收光能为基础的性能指数(performance index based on absorbed light energy,PI_(ABS))、以单位面积为基础的性能指数(performance index on a cross-section basis,PI_(CS))、捕获的激子将电子传递到电子传递链中超过Q_(A)的其他电子受体的概率(probability that a trapped exciton moves an electron into the electron transport chain beyond Q_(A),Ψ_(o))、电子传递的量子产额(quantum yield for electron transport,φ_(Eo))和单位反应中心捕获的用于电子传递的能量(electron transport flux per RC,ETo/RC),降低了单位反应中心耗散的能量(dissipated energy flux per cross-sectional area,DI_(o)/RC)和用于热耗散的量子比率(quantum ratio for dissipated energy,φ_(Do))。最终,M11和M28处理使玉米鲜重较LNT组分别显著提高30.61%和22.64%。干重分别提高26.68%和23.41%。【结论】M11主要通过提高土壤有效磷、速效钾含量直接优化能量代谢与气孔运动;而M28主要通过提升土壤全氮含量,侧重于稳定光合机构结构。二者共同保护光合机构完整性并优化光系统电子传递效率,显著增强了低肥力胁迫下玉米的光合性能与产量,为微生物菌剂在绿色增产中的应用提供了理论支持。
