Developments in soil biology and in methodsto characterize soil organic carbon can potentially delivernovel soil quality indicators that can help identifymanagement practices able to sustain soil productivityand envir...Developments in soil biology and in methodsto characterize soil organic carbon can potentially delivernovel soil quality indicators that can help identifymanagement practices able to sustain soil productivityand environmental resilience. This work aimed atsynthesizing results regarding the suitability of a range ofsoil biological and biochemical properties as novel soilquality indicators for agricultural management. The soilproperties, selected through a published literature review,comprised different labile organic carbon fractions [hydrophilicdissolved organic carbon, dissolved organic carbon,permanganate oxidizable carbon (POXC), hot waterextractable carbon and particulate organic matter carbon],soil disease suppressiveness measured using a Pythium-Lepidium bioassay, nematode communities characterizedby amplicon sequencing and qPCR, and microbialcommunity level physiological profiling measured withMicroResp™. Prior studies tested the sensitivity of each ofthe novel indicators to tillage and organic matter additionin ten European long-term field experiments (LTEs) andassessed their relationships with pre-existing soil qualityindicators of soil functioning. Here, the results of theseprevious studies are brought together and interpretedrelative to each other and to the broader body of literatureon soil quality assessment. Reduced tillage increasedcarbon availability, disease suppressiveness, nematoderichness and diversity, the stability and maturity of thefood web, and microbial activity and functional diversity.Organic matter addition played a weaker role in enhancingsoil quality, possibly due to the range of composition of theorganic matter inputs used in the LTEs. POXC was theindicator that discriminated best between soil managementpractices, followed by nematode indices based on functionalcharacteristics. Structural equation modeling showsthat POXC has a central role in nutrient retention/supply,carbon sequestration, biodiversity conservation, erosion control and disease regulation/suppression. The novelind展开更多
A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, Un...A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, University of Agriculture, Faisalabad. The experiment was laid out in RCBD (Randomized Complete Block Design), with split plot arrangement having three replications. The experiment was comprised of three tillage regimes (Minimum, Conventional and Deep) and three nitrogen levels viz: 100, 200 and 300 kg•ha<sup>-1</sup>. Urea was used as a source of nitrogen, sulphate of potash as a source of potassium and triple super phosphate as a source of phosphorous. The amount of phosphorous and potash was constant in all the treatments i.e. 125 kg•ha<sup>-1</sup> and 100 kg•ha<sup>-1</sup> respectively. Results of present study are summarized as yield parameters are significantly affected by different nitrogen levels and tillage regimes. Maximum number of plants at harvest (7.93), number of grain rows per cob (17.70), number of grains per row (34.31), number of grains per cob (678.58), and cob weight (187.50 g) were observed in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. 1000-grain weight (275.52 g), biological yield (15.66 t•ha<sup>-1</sup>), grain yield (6.16 t•ha<sup>-1</sup>) and dried stalk yield (9.91 t•ha<sup>-1</sup>) were observed maximum in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. Harvest index significantly affected by tillage regimes and maximum harvest index (39.58%) were recorded in deep tillage which was statistically at par with conventional tillage (38.83%). It was concluded that higher grain yield of maize can be obtained by deep tillage with the application of 200 kg•ha<sup>-1</sup> nitrogen application under the prevailing conditions of Faisalabad.展开更多
A well developed macropore network is advantageous in terms of transport processes regarding gas and water,as well as nutrient acquisition and root growth of crops.X-ray computed tomography provides a non-destructive ...A well developed macropore network is advantageous in terms of transport processes regarding gas and water,as well as nutrient acquisition and root growth of crops.X-ray computed tomography provides a non-destructive method to visualize and quantify three-dimensional pore networks.Geometrical and morphological parameters of the complex pore system such as connectivity,tortuosity,porosity and pore surface area would be very useful for modeling and simulation of transport and exchange processes by providing quantitative data on relevant soil structural features and their modification by soil management.The scope of this study was to analyze and quantify the development of soil structure in the subsoil depending on three different precrop species(alfalfa A,chicory C and fescue F),at three depths(45,60 and 75 cm)and cultivation periods(1,2 and 3 years).Furthermore,morphological(air-filled porosityθa,pore surface area)and geometrical(pore diameter,connectivity,continuity,tortuosityτ)parameters were gathered with X-ray CT and image analysis.From an experimental field trial(Germany)with a Haplic Luvisol as soil type samples were taken and investigated.Air-capacity(θa)was measured in the laboratory for the same cylinders and compared to the results derived by image analysis.Air-capacity was highest for alfalfa(3 years,75 cm).Tortuosity(τ)ranged between 1.3 and 4.38,while alfalfa(3 years)showed the highest value,which indicated structural development due to crack formation by enhanced root water uptake.Thus,an increase in accessible surface may improve water and nutrient supply for plants,whereas the highτvalues may assume that oxygen supply is limited.It was found that the interaction of gas-diffusivity and the calculated parameters should be further investigated in terms of limitations to plant growth.展开更多
基金the EU Horizon 2020 projectInteractive Soil Quality Assessment in Europe and China for agriculturalproductivity and environmental resilience (iSQAPER), grant number 635750(mediated through the Swiss State Secretariat for Education, Research andInnovation). The University of Ljubljana, University of Trier, UniversityMiguel Hernandez, and the long-term field experiment owners providedsamples and data, and Lijbert Brussaard, Ron de Goede, Else Biinemann-Konig and Paul Mader provided constructive feedback on earlier versions ofthe manuscript.
文摘Developments in soil biology and in methodsto characterize soil organic carbon can potentially delivernovel soil quality indicators that can help identifymanagement practices able to sustain soil productivityand environmental resilience. This work aimed atsynthesizing results regarding the suitability of a range ofsoil biological and biochemical properties as novel soilquality indicators for agricultural management. The soilproperties, selected through a published literature review,comprised different labile organic carbon fractions [hydrophilicdissolved organic carbon, dissolved organic carbon,permanganate oxidizable carbon (POXC), hot waterextractable carbon and particulate organic matter carbon],soil disease suppressiveness measured using a Pythium-Lepidium bioassay, nematode communities characterizedby amplicon sequencing and qPCR, and microbialcommunity level physiological profiling measured withMicroResp™. Prior studies tested the sensitivity of each ofthe novel indicators to tillage and organic matter additionin ten European long-term field experiments (LTEs) andassessed their relationships with pre-existing soil qualityindicators of soil functioning. Here, the results of theseprevious studies are brought together and interpretedrelative to each other and to the broader body of literatureon soil quality assessment. Reduced tillage increasedcarbon availability, disease suppressiveness, nematoderichness and diversity, the stability and maturity of thefood web, and microbial activity and functional diversity.Organic matter addition played a weaker role in enhancingsoil quality, possibly due to the range of composition of theorganic matter inputs used in the LTEs. POXC was theindicator that discriminated best between soil managementpractices, followed by nematode indices based on functionalcharacteristics. Structural equation modeling showsthat POXC has a central role in nutrient retention/supply,carbon sequestration, biodiversity conservation, erosion control and disease regulation/suppression. The novelind
文摘A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, University of Agriculture, Faisalabad. The experiment was laid out in RCBD (Randomized Complete Block Design), with split plot arrangement having three replications. The experiment was comprised of three tillage regimes (Minimum, Conventional and Deep) and three nitrogen levels viz: 100, 200 and 300 kg•ha<sup>-1</sup>. Urea was used as a source of nitrogen, sulphate of potash as a source of potassium and triple super phosphate as a source of phosphorous. The amount of phosphorous and potash was constant in all the treatments i.e. 125 kg•ha<sup>-1</sup> and 100 kg•ha<sup>-1</sup> respectively. Results of present study are summarized as yield parameters are significantly affected by different nitrogen levels and tillage regimes. Maximum number of plants at harvest (7.93), number of grain rows per cob (17.70), number of grains per row (34.31), number of grains per cob (678.58), and cob weight (187.50 g) were observed in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. 1000-grain weight (275.52 g), biological yield (15.66 t•ha<sup>-1</sup>), grain yield (6.16 t•ha<sup>-1</sup>) and dried stalk yield (9.91 t•ha<sup>-1</sup>) were observed maximum in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. Harvest index significantly affected by tillage regimes and maximum harvest index (39.58%) were recorded in deep tillage which was statistically at par with conventional tillage (38.83%). It was concluded that higher grain yield of maize can be obtained by deep tillage with the application of 200 kg•ha<sup>-1</sup> nitrogen application under the prevailing conditions of Faisalabad.
基金supported by the German Research Foundation(Deutsche Forschungsgemeinschaft DFG)within the framework of the research unit DFG‐FOR 1320.
文摘A well developed macropore network is advantageous in terms of transport processes regarding gas and water,as well as nutrient acquisition and root growth of crops.X-ray computed tomography provides a non-destructive method to visualize and quantify three-dimensional pore networks.Geometrical and morphological parameters of the complex pore system such as connectivity,tortuosity,porosity and pore surface area would be very useful for modeling and simulation of transport and exchange processes by providing quantitative data on relevant soil structural features and their modification by soil management.The scope of this study was to analyze and quantify the development of soil structure in the subsoil depending on three different precrop species(alfalfa A,chicory C and fescue F),at three depths(45,60 and 75 cm)and cultivation periods(1,2 and 3 years).Furthermore,morphological(air-filled porosityθa,pore surface area)and geometrical(pore diameter,connectivity,continuity,tortuosityτ)parameters were gathered with X-ray CT and image analysis.From an experimental field trial(Germany)with a Haplic Luvisol as soil type samples were taken and investigated.Air-capacity(θa)was measured in the laboratory for the same cylinders and compared to the results derived by image analysis.Air-capacity was highest for alfalfa(3 years,75 cm).Tortuosity(τ)ranged between 1.3 and 4.38,while alfalfa(3 years)showed the highest value,which indicated structural development due to crack formation by enhanced root water uptake.Thus,an increase in accessible surface may improve water and nutrient supply for plants,whereas the highτvalues may assume that oxygen supply is limited.It was found that the interaction of gas-diffusivity and the calculated parameters should be further investigated in terms of limitations to plant growth.
基金Challenge Program on Water & Food-Conservation agriculture for the dry-land areas of the Yellow River Basin(CPWFYRB200504)国家"十一五"科技攻关计划重大项目(2006BAC01A07)
