The rapidly growing demand for food, feed and fuel requires further improvements of land and water management, crop productivity and resource-use efficiencies.Combined field experimentation and crop growth modelling d...The rapidly growing demand for food, feed and fuel requires further improvements of land and water management, crop productivity and resource-use efficiencies.Combined field experimentation and crop growth modelling during the past five decades made a great leap forward in the understanding of factors that determine actual and potential yields of monocrops.The research field of production ecology developed concepts to integrate biological and biophysical processes with the aim to explore crop growth potential in contrasting environments.To understand the potential of more complex systems(multi-cropping and intercropping) we need an agro-ecosystem approach that integrates knowledge derived from various disciplines: agronomy, crop physiology, crop ecology, and environmental sciences(soil, water and climate).Adaptation of cropping systems to climate change and a better tolerance to biotic and abiotic stresses by genetic improvement and by managing diverse cropping systems in a sustainable way will be of key importance in food security.To accelerate sustainable intensification of agricultural production, it is required to develop intercropping systems that are highly productive and stable under conditions with abiotic constraints(water, nutrients and weather).Strategies to achieve sustainable intensification include developing tools to evaluate crop growth potential under more extreme climatic conditions and introducing new crops and cropping systems that are more productive and robust under conditions with abiotic stress.This paper presents some examples of sustainable intensification management of intercropping systems that proved to be tolerant to extreme climate conditions.展开更多
Root density distribution of plants is a major Indicator of competition between plants and determines resource capture from the solh This experiment was conducted in 2005 at Anyang, located in the Yellow River region,...Root density distribution of plants is a major Indicator of competition between plants and determines resource capture from the solh This experiment was conducted in 2005 at Anyang, located in the Yellow River region, Henan Province, China. Three cotton (Gossyplum hlrsutum L.) cultivars were chosen: hybrid Btcultlvar CRI46, conventional Btcultlvars CRI44 and CRI45. Six planting densities were designed, ranging from 1.5 to 12.0 plants/m^2. Root parameters such as surface area, diameter and length were analyzed by using the DT-SCAN Image analysis method. The root length density (RLD), root average diameter and root area Index (RAI), root surface area per unit land area, were studied. The results showed that RLD and RAI differed between genotypes; hybrid CRI46 had significantly higher (P 〈0.05) RLD and RAI values than conventlonal cultlvars, especially under low planting densities, less than 3.0 plants/m^2. The root area index (RAI) of hybrid CRI46 was 61% higher than of CRI44 and CRI45 at the flowering stage. The RLD and RAI were also significantly different (P = 0.000) between planting densities. The depth distribution of RAI showed that at Increasing planting densities RAI was Increasingly distributed in the soil layers below 50 cm. The RAI of hybrid CRI46 was for all planting densities, obviously higher than other cultivars during the flowering and boll stages. It was concluded that the hybrid had a strong advantage in root maintenance preventing premature senescence of roots. The root diameter of hybrid CRI46 had a genetically higher root diameter at planting densities lower than 6.0 plants/m^2. Good associations were found between yield and RAI In different stages. The optimum planting density ranged from 4.50 plants/m^2 to 6.75 plants/m^2 for conventional cultlvars and around 4.0-5.0 plants/m^2 for hybrids.展开更多
Intercropping increases crop yields by optimizing light interception and/or use efficiency.Although intercropping combinations and metrics have been reported,the effects of plant density on light use are not well docu...Intercropping increases crop yields by optimizing light interception and/or use efficiency.Although intercropping combinations and metrics have been reported,the effects of plant density on light use are not well documented.Here,we examined the light interception and use efficiency in maize-peanut intercropping with different maize plant densities in two row configurations in semiarid dryland agriculture over a two-year period.The field experiment comprised four cropping systems,i.e.,monocropped maize,monocropped peanut,maize-peanut intercropping with two rows of maize and four rows of peanut,intercropping with four rows of maize and four rows of peanut,and three maize plant densities(3.0,4.5 and 6.0 plants m^(-1) row)in both monocropped and intercropping maize.The mean total light interception in intercropping across years and densities was 779 MJ·m^(-2),5.5%higher than in monocropped peanut(737 MJ·m^(-2))and 7.6%lower than in monocropped maize(843 MJ·m^(-2)).Increasing maize density increased light interception in monocropped maize but did not affect the total light interception in the intercrops.Across years the LUE of maize was 2.9 g·MJ–1 and was not affected by cropping system but increased with maize plant density.The LUE of peanut was enhanced in intercropping,especially in a wetter year.The yield advantage of maize-peanut intercropping resulted mainly from the LUE of peanut.These results will help to optimize agronomic management and system design and provide evidence for system level light use efficiency in intercropping.展开更多
Intercropping is the planned cultivation of species mixtures on agricultural land.Intercropping has many attributes that make it attractive for developing a more sustainable agriculture,such as high yield,high resourc...Intercropping is the planned cultivation of species mixtures on agricultural land.Intercropping has many attributes that make it attractive for developing a more sustainable agriculture,such as high yield,high resource use efficiency,lower input requirements,natural suppression of pests,pathogens and weeds,and building a soil with more organic carbon and nitrogen.Information is needed which species combinations perform best under different circumstances and which management is suitable to bring out the best from intercropping in a given production situation.The literature is replete with case studies on intercropping from across the globe,but evidence synthesis is needed to make this information accessible.Meta-analysis requires a careful choice of metric that is appropriate for answering the question at hand,and which lends itself for a robust meta-analysis.This paper reviews some metrics that may be used in the quantitative synthesis of literature data on intercropping.展开更多
Intercropping is the cultivation of more than one crop species on a single parcel of land. Intercropping seeks toexploit species complementarities to capture more of the available light, water and nutrient resources, ...Intercropping is the cultivation of more than one crop species on a single parcel of land. Intercropping seeks toexploit species complementarities to capture more of the available light, water and nutrient resources, and thusincrease combined crop yield[1]. Intercropping is well known in China, where smallholder farmers practice a greatdiversity of species combinations to increase their yields[2]. Figure 1 illustrates intercropping as done by a farmer inGansu Province, China, who chose to combine wheat, soybean and maize. This three-way combination offersseveral species complementarities. First, the growing period of wheat ends earlier than that of soybean and maize,so the soybean and maize can use all the light, water and nutrient resources of the land after wheat harvest. With thewheat covering only around half of the area, the plants will still produce about 70% of the normal yield for wheatgrown as a sole crop, because the wheat has virtually no competition for resources early on, resulting in greatercapture of light, water and nutrient resources in the intercrop than in a sole crop[3]. Furthermore, soybean and maizehave a complementarity for nitrogen acquisition, with maize requiring nitrogen from soil, but soybean being able to fixit from the air. Therefore, this combination can reduce fertilizer requirements.展开更多
Plant species have different traits for mobilizing sparingly soluble phosphorus (P) resources,which could potentially lead to overyielding in P uptake by plant species mixtures compared to monocultures due to higher P...Plant species have different traits for mobilizing sparingly soluble phosphorus (P) resources,which could potentially lead to overyielding in P uptake by plant species mixtures compared to monocultures due to higher P uptake as a result of resource (P) partitioning and facilitation.However,there is circumstantial evidence at best for overyielding as a result of these mechanisms.Overyielding (the outcome) is easily confused with underlying mechanisms because of unclear definitions.We aimed to define a conceptual framework to separate outcome from underlying mechanisms and test it for facilitation and complementarity with respect to P acquisition by three plant species combinations grown on four soils.Our conceptual framework describes both mechanisms of complementarity and facilitation and outcomes (overyielding of mixtures or no overyielding) depending on the competitive ability of the species to uptake the mobilized P.Millet/chickpea mixtures were grown in pots on two calcareous soils mixed with calcium-bound P (CaP) and phytate P (PhyP).Cabbage/faba bean mixtures were grown on both acid and neutral soils mixed with P-coated iron (hydr)oxide (FeP) and PhyP.Wheat/maize mixtures were grown on all four soils.Rhizosphere carboxylate concentration and acid phosphatase activity (mechanisms) as well as plant P uptake and biomass (outcome) were determined for monocultures rhizosphere and species mixtures.Facilitation of P uptake occurred in millet/chickpea mixtures on one calcareous soil.We found no indications for P acquisition from different P sources,neither in millet/chickpea,nor in cabbage/faba bean mixtures.Cabbage and faba bean on the neutral soil differed in rhizosphere acid phosphatase activity and carboxylate concentration,but showed no overyielding.Wheat and maize,with similar root exudates,showed overyielding (the observed P uptake being 22%higher than the expected P uptake) on one calcareous soil.We concluded that although differences in plant physiological traits (root exudates) provide necessary conditions for complementarity and facilitation with respect to P uptake from different P sources,they do not necessarily result in increased P uptake by species mixtures,because of the relative competitive ability of the mixed species.展开更多
Intensive monoculture agriculture has contributed greatly to global food supply over many decades,but the excessive use of agricultural chemicals(fertilizers,herbicides and pesticides)and intensive cultivation systems...Intensive monoculture agriculture has contributed greatly to global food supply over many decades,but the excessive use of agricultural chemicals(fertilizers,herbicides and pesticides)and intensive cultivation systems has resulted in negative side effects,such as soil erosion,soil degradation,and non-point source pollution[1].To many observers,agriculture looms as a major global threat to nature conservation and biodiversity.As noted in the Global Biodiversity Outlook 4[2],the drivers associated with food systems and agriculture account for around 70%and 50%of the projected losses by 2050 of terrestrial and freshwater biodiversity,respectively[3].展开更多
基金国家重点基础研究发展计划项目(2006CB102005)国家科技支撑计划项目(2008BADA5B03)+1 种基金supported by the C.T.de Wit Research School for Production Ecology and Resource Conservation,Wageningen University“973”program of China(2006CB102005)
基金funded by the International Cooperation and Exchange of the National Science Foundation of China(31461143025,31210103906,51209220)the National Basic Research Program of China(973 Program,2011CB100405)the Special Fund for Agro-Scientific Research in the Public Interest,China(201003043)
文摘The rapidly growing demand for food, feed and fuel requires further improvements of land and water management, crop productivity and resource-use efficiencies.Combined field experimentation and crop growth modelling during the past five decades made a great leap forward in the understanding of factors that determine actual and potential yields of monocrops.The research field of production ecology developed concepts to integrate biological and biophysical processes with the aim to explore crop growth potential in contrasting environments.To understand the potential of more complex systems(multi-cropping and intercropping) we need an agro-ecosystem approach that integrates knowledge derived from various disciplines: agronomy, crop physiology, crop ecology, and environmental sciences(soil, water and climate).Adaptation of cropping systems to climate change and a better tolerance to biotic and abiotic stresses by genetic improvement and by managing diverse cropping systems in a sustainable way will be of key importance in food security.To accelerate sustainable intensification of agricultural production, it is required to develop intercropping systems that are highly productive and stable under conditions with abiotic constraints(water, nutrients and weather).Strategies to achieve sustainable intensification include developing tools to evaluate crop growth potential under more extreme climatic conditions and introducing new crops and cropping systems that are more productive and robust under conditions with abiotic stress.This paper presents some examples of sustainable intensification management of intercropping systems that proved to be tolerant to extreme climate conditions.
文摘Root density distribution of plants is a major Indicator of competition between plants and determines resource capture from the solh This experiment was conducted in 2005 at Anyang, located in the Yellow River region, Henan Province, China. Three cotton (Gossyplum hlrsutum L.) cultivars were chosen: hybrid Btcultlvar CRI46, conventional Btcultlvars CRI44 and CRI45. Six planting densities were designed, ranging from 1.5 to 12.0 plants/m^2. Root parameters such as surface area, diameter and length were analyzed by using the DT-SCAN Image analysis method. The root length density (RLD), root average diameter and root area Index (RAI), root surface area per unit land area, were studied. The results showed that RLD and RAI differed between genotypes; hybrid CRI46 had significantly higher (P 〈0.05) RLD and RAI values than conventlonal cultlvars, especially under low planting densities, less than 3.0 plants/m^2. The root area index (RAI) of hybrid CRI46 was 61% higher than of CRI44 and CRI45 at the flowering stage. The RLD and RAI were also significantly different (P = 0.000) between planting densities. The depth distribution of RAI showed that at Increasing planting densities RAI was Increasingly distributed in the soil layers below 50 cm. The RAI of hybrid CRI46 was for all planting densities, obviously higher than other cultivars during the flowering and boll stages. It was concluded that the hybrid had a strong advantage in root maintenance preventing premature senescence of roots. The root diameter of hybrid CRI46 had a genetically higher root diameter at planting densities lower than 6.0 plants/m^2. Good associations were found between yield and RAI In different stages. The optimum planting density ranged from 4.50 plants/m^2 to 6.75 plants/m^2 for conventional cultlvars and around 4.0-5.0 plants/m^2 for hybrids.
基金This research was funded by the National Key R&D Program of China(2016YFD0300202)the China Institute of Water Resources and Hydropower Research Team Construction and Talent Development Project(JZ0145B752017)+1 种基金the International Cooperation and Exchange of the National Science Foundation of China(31461143025)The work was partly funded by the European Union through the Horizon 2020 Program for Research and Innovation under grant agreement No.727217(ReMIX:redesigning European cropping systems based on species MIXtures).
文摘Intercropping increases crop yields by optimizing light interception and/or use efficiency.Although intercropping combinations and metrics have been reported,the effects of plant density on light use are not well documented.Here,we examined the light interception and use efficiency in maize-peanut intercropping with different maize plant densities in two row configurations in semiarid dryland agriculture over a two-year period.The field experiment comprised four cropping systems,i.e.,monocropped maize,monocropped peanut,maize-peanut intercropping with two rows of maize and four rows of peanut,intercropping with four rows of maize and four rows of peanut,and three maize plant densities(3.0,4.5 and 6.0 plants m^(-1) row)in both monocropped and intercropping maize.The mean total light interception in intercropping across years and densities was 779 MJ·m^(-2),5.5%higher than in monocropped peanut(737 MJ·m^(-2))and 7.6%lower than in monocropped maize(843 MJ·m^(-2)).Increasing maize density increased light interception in monocropped maize but did not affect the total light interception in the intercrops.Across years the LUE of maize was 2.9 g·MJ–1 and was not affected by cropping system but increased with maize plant density.The LUE of peanut was enhanced in intercropping,especially in a wetter year.The yield advantage of maize-peanut intercropping resulted mainly from the LUE of peanut.These results will help to optimize agronomic management and system design and provide evidence for system level light use efficiency in intercropping.
文摘Intercropping is the planned cultivation of species mixtures on agricultural land.Intercropping has many attributes that make it attractive for developing a more sustainable agriculture,such as high yield,high resource use efficiency,lower input requirements,natural suppression of pests,pathogens and weeds,and building a soil with more organic carbon and nitrogen.Information is needed which species combinations perform best under different circumstances and which management is suitable to bring out the best from intercropping in a given production situation.The literature is replete with case studies on intercropping from across the globe,but evidence synthesis is needed to make this information accessible.Meta-analysis requires a careful choice of metric that is appropriate for answering the question at hand,and which lends itself for a robust meta-analysis.This paper reviews some metrics that may be used in the quantitative synthesis of literature data on intercropping.
文摘Intercropping is the cultivation of more than one crop species on a single parcel of land. Intercropping seeks toexploit species complementarities to capture more of the available light, water and nutrient resources, and thusincrease combined crop yield[1]. Intercropping is well known in China, where smallholder farmers practice a greatdiversity of species combinations to increase their yields[2]. Figure 1 illustrates intercropping as done by a farmer inGansu Province, China, who chose to combine wheat, soybean and maize. This three-way combination offersseveral species complementarities. First, the growing period of wheat ends earlier than that of soybean and maize,so the soybean and maize can use all the light, water and nutrient resources of the land after wheat harvest. With thewheat covering only around half of the area, the plants will still produce about 70% of the normal yield for wheatgrown as a sole crop, because the wheat has virtually no competition for resources early on, resulting in greatercapture of light, water and nutrient resources in the intercrop than in a sole crop[3]. Furthermore, soybean and maizehave a complementarity for nitrogen acquisition, with maize requiring nitrogen from soil, but soybean being able to fixit from the air. Therefore, this combination can reduce fertilizer requirements.
基金supported by the National Key R & D Program of China (Nos. 2017YFD0200200 and 2017YFD0200202)Projects of International Cooperation and Exchanges NSFC (No. 31210103906)Wageningen University Sandwich Ph.D. Fellowship (The Netherlands)。
文摘Plant species have different traits for mobilizing sparingly soluble phosphorus (P) resources,which could potentially lead to overyielding in P uptake by plant species mixtures compared to monocultures due to higher P uptake as a result of resource (P) partitioning and facilitation.However,there is circumstantial evidence at best for overyielding as a result of these mechanisms.Overyielding (the outcome) is easily confused with underlying mechanisms because of unclear definitions.We aimed to define a conceptual framework to separate outcome from underlying mechanisms and test it for facilitation and complementarity with respect to P acquisition by three plant species combinations grown on four soils.Our conceptual framework describes both mechanisms of complementarity and facilitation and outcomes (overyielding of mixtures or no overyielding) depending on the competitive ability of the species to uptake the mobilized P.Millet/chickpea mixtures were grown in pots on two calcareous soils mixed with calcium-bound P (CaP) and phytate P (PhyP).Cabbage/faba bean mixtures were grown on both acid and neutral soils mixed with P-coated iron (hydr)oxide (FeP) and PhyP.Wheat/maize mixtures were grown on all four soils.Rhizosphere carboxylate concentration and acid phosphatase activity (mechanisms) as well as plant P uptake and biomass (outcome) were determined for monocultures rhizosphere and species mixtures.Facilitation of P uptake occurred in millet/chickpea mixtures on one calcareous soil.We found no indications for P acquisition from different P sources,neither in millet/chickpea,nor in cabbage/faba bean mixtures.Cabbage and faba bean on the neutral soil differed in rhizosphere acid phosphatase activity and carboxylate concentration,but showed no overyielding.Wheat and maize,with similar root exudates,showed overyielding (the observed P uptake being 22%higher than the expected P uptake) on one calcareous soil.We concluded that although differences in plant physiological traits (root exudates) provide necessary conditions for complementarity and facilitation with respect to P uptake from different P sources,they do not necessarily result in increased P uptake by species mixtures,because of the relative competitive ability of the mixed species.
文摘Intensive monoculture agriculture has contributed greatly to global food supply over many decades,but the excessive use of agricultural chemicals(fertilizers,herbicides and pesticides)and intensive cultivation systems has resulted in negative side effects,such as soil erosion,soil degradation,and non-point source pollution[1].To many observers,agriculture looms as a major global threat to nature conservation and biodiversity.As noted in the Global Biodiversity Outlook 4[2],the drivers associated with food systems and agriculture account for around 70%and 50%of the projected losses by 2050 of terrestrial and freshwater biodiversity,respectively[3].