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comLinking flowering and reproductive allocation in response to nitrogen addition in an alpine meadow

Journal of Plant Ecology 2014年第3期7卷 231-239页

作者： Zhilong Zhang Kechang Niu Xudong Liu Peng Jia Guozhen Du State Key Laboratory of Grassland agroecosystems College of Pastoral Agriculture Science and TechnologyLanzhou University768 West Jiayuguan RoadLanzhouGansu 730020People’s Republic of China State Key Laboratory of Grassland agroecosystems School of Life SciencesLanzhou University222 Tianshui RoadLanzhouGansu 730000People’s Republic of China department of Biology Nanjing University22 Hankou RoadNanjingJiangsu 210093People’s Republic of China

Aims Plants can change in phenology and biomass allocation in response to environmental *** has been demonstrated that nitrogen is the most limiting resource for plants in many terrestrial *** studies have usually focused on either flowering phenology or biomass allocation of plants in response to nitrogen addition;how-ever,attempts to link flowering phenology and biomass allocation are still *** this study,we tested the effects of nitrogen addition on both flowering phenology and reproductive allocation in 34 common *** also examined the potential linkage between flowering time and reproductive allocation in response to nitrogen *** We conducted a 3-year nitrogen addition experiment in Tibetan alpine *** measured first flowering date and the repro-ductive allocation for 34 common plant species in control,low and high nitrogen added plots,***-way analysis of variance was used to examine differences of first flowering date and reproductive allocation among *** relationships between the change in species first flowering date and change in reproductive allocation in response to nitrogen addition were examined by calculating Pearson correlation *** Findings For most species,both first flowering date and reproductive alloca-tion significantly responded to nitrogen *** addition significantly delayed the first flowering date and reduced the repro-ductive allocation for all graminoid species,but accelerated flower-ing and increased reproductive allocation for most forb *** found that changes in first flowering date significantly negatively correlated with the changes in reproductive allocation over spe-cies in response to nitrogen,which indicated a positive relationship between flowering response and plant performance in reproductive *** that advanced their flowering time with nitrogen addition increased their reproductive allocation,whereas tho

关键词： alpine meadow flowering nitrogen addition reproductive allocation

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Short-Term Effect of Nitrogen Intensification on Aggregate Size Distribution, Microbial Biomass and Enzyme Activities in a Semi-Arid Soil Under Different Crop Types

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Pedosphere 2019年第4期29卷 483-491页

作者： Rajasekaran MURUGAN V. R. Ramakrishna PARAMA Beate MADAN R. MUTHURAJU Bernard LUDWIG department of Environmental Chemistry University of Kassel Nordbahnhof str. la Witzenhausen 37213 (Germany) department of Soil Science and Agricultural Chemistry University of Agricultural Sciences (GKVK) Bangalore 560065 (India) Organic Plant Production and agroecosystems Research in the Tropics and Subtropics University of Kassel Stein str. 19 Witzenhausen 37213 (Germany) department of Agricultural Microbiology University of Agricultural Sciences (GKVK) Bangalore 560065 (India)

There is a lack of quantitative assessments available on the effect of agricultural intensification on soil aggregate distribution and microbial properties. Here, we investigated how short-term nitrogen(N) intensification induced changes in aggregate size distribution and microbial properties in a soil of a hot moist semi-arid region(Bangalore, India). We hypothesised that N intensification would increase the accumulation of macroaggregates > 2 mm and soil microbial biomass and activity, and that the specific crop plant sowed would influence the level of this increase. In November 2016, surface(0–10 cm) and subsurface(10–20 cm) soil samples were taken from three N fertilisation treatments, low N(50 kg N ha-1), medium N(75 and 100 kg N ha-1 for finger millet and maize, respectively),and high N(100 and 150 kg N ha-1 for finger millet and maize, respectively). Distribution of water-stable aggregate concentrations,carbon(C) and N dynamics within aggregate size class, and soil microbial biomass and activity were evaluated. The high-N treatment significantly increased the concentration of large macroaggregates in the subsurface soil of the maize crop treatment, presumably due to an increased C input from root growth. Different N fertilisation levels did not significantly affect C and N concentrations in different aggregate size classes or the bulk soil. High-N applications significantly increased dehydrogenase activity in both the surface soil and the subsurface soil and urease activity in the surface soil, likely because of increased accumulation of enzymes stabilised by soil colloids in dry soils. Dehydrogenase activity was significantly affected by the type of crop, but urease activity not. Overall, our results showed that high N application rates alter large macroaggregates and enzyme activities in surface and subsurface soils through an increased aboveground and corresponding belowground biomass input in the maize crop.

关键词： agricultural intensification biomass input C and N dynamics large macroaggregate microaggregate N application small macroaggregate water-stable aggregates

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Yielding of Winter Triticale Varieties in Different Protection Levels in Two Sequence Systems

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Journal of Agricultural Science and Technology(B) 2016年第5期6卷 335-340页

作者： Ewa Adamiak Dagmara Szalczynska Jan Adamiak department of agroecosystems Faculty of Environment and Agriculture University of Warmia and Mazury in Olsztyn Plac Lodzki 3 10-719 Olsztyn Poland

Five-year trials （2011-2015） were accomplished in a continuous field experiment conducted at the Production and Research Station in Balcyny. The experiment was set up on a luvisol medium soil, derived from light loam with the objective of evaluating the response of two winter triticale varieties （Pigmej and Cyrkon） to cultivation without protection （O）, chemical weed control （H） and combined protection against weeds and fungi （HF）. Comparisons were made in two crop sequence systems： cultivation of winter triticale varieties in a 6-field crop rotation and cultivation in a 19-23-year-long monoculture. The results showed that the plant sequence system significantly differentiated the response of winter triticale varieties to the applied levels of field protection. Significantly higher grain yield gains of the winter triticale varieties in response to the application of herbicides or herbicides with fungicides were obtained in the monoculture than in the crop rotation. In the crop rotation, a higher increase in yields induced by the applied plant protection treatments was achieved by the variety Cyrkon. In the monoculture, the response of both varieties to the herbicides applied was nearly identical, while the combined application of herbicides and fungicides raised the yields of var. Pigmej higher than those of var. Cyrkon. Overall for the plant protection levels, var. Cyrkon yielded higher than var. Pigmej by 18.1% more in the crop rotation and by 26.9% in the monoculture. At the same time, var. Cyrkon demonstrated a weaker response to being grown in the monoculture than var. Pigmej did. The average yield of the former was reduced by 21.1%, whereas the latter yielded 26.6% less grain.

关键词： Winter triticale varieties crop rotation monoculture protection level.

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WATER USE IN HUMAN CIVILIZATIONS: AN INTERDISCIPLINARY ANALYSIS OF A PERPETUAL SOCIAL-ECOLOGICAL CHALLENGE

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Frontiers of Agricultural Science and Engineering 2021年第4期8卷 512-524页

作者： Andreas BUERKERT Kotiganahalli Narayanagowda GANESHAIAH Stefan SIEBERT Organic Plant Production and agroecosystems Research in the Tropics and Subtropics(OPATS) University of KasselSteinstrasse 19D-37213 WitzenhausenGermany School of Ecology and Conservation University of Agricultural Sciences(UASB)GKVKBengaluru 5600065India department of Crop Sciences University of GottingenVon-Siebold-Str.8D-37075 GottingenGermany

Since the onset of human societies, settlement patterns and social structures have been shaped by access to water. This review covers historical and recent examples from Cambodia, Central Asia, India, Latin America and the Arabian Peninsula to analyze the role of water resources in determining the rise and collapse of civilizations. Over recent decades increasing globalization and concomitant possibilities to externalize water needs as virtual water have obscured global dependence on water resources via telecoupling, but rapid urbanization brings it now back to the political agenda. It is foremost in the urban arena of poorer countries where competing claims for water increasingly lead to scale-transcendent conflicts about ecosystem services. Solutions to the dilemma will require broad stakeholder-based agreements on water use taking into account the available data on water resources, their current and potential use efficiency, recycling of water after effective treatment, and social-ecological approaches of improved governance and conflict resolution.

关键词： agroecology historical water use water footprint water governance urbanization

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Understanding bark thickness variations for Araucaria angustifolia in southern Brazil

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Journal of Forestry Research 2021年第3期32卷 1077-1087页

作者： Emanuel Arnoni Costa Veraldo Liesenberg César Augusto Guimaraes Finger AndréFelipe Hess Cristine Tagliapietra Schons Graduate Program in Forest Engineering Santa Catarina State University(UDESC)LagesSC 88520-000Brazil department of Forest Engineering Federal University of Uberlandia(UFU)Monte CarmeloMG 38500-000Brazil Graduate Program in Forest Engineering Federal University of Santa Maria(UFSM)Santa MariaRS 97105-900Brazil Graduate Program in agroecosystems Federal Technological University of Parana(UFTPR)Dois VizinhosPR 85660-000Brazil

This study aimed to understand bark thickness variations of Araucaria angustifolia(Bertol.)Kuntze trees growing in natural forest remnants in southern Brazil,and their relationship with quantitative and qualitative *** thickness must be accurately estimated in order to determine timber volume *** is an important variable for the sustainable management and conservation of araucaria *** spite of its importance and visibility,bark thickness variations have not been evaluated for this key species in southern Brazil.A total of 104 trees were selected,and their qualitative and quantitative attributes such as diameter at breast height(D_(BH)),height(H),crown base height(C_(BH)),crown length(C_(L)),social position(S_(P)),stoniness(S_(T)),position on the relief(P_(R)),vitality(V_T)and branch arrangement(B_(A))were *** trees were categorized into two groups:red bark or gray *** analysis and artificial neural networks(ANN)were used for modelling bark *** results indicate that:(1)bark thickness showed good correlation to D_(BH),with 0.76 as coefficient of determination(RS_P),0.540 as Mean Absolute Error(M_(AE))and 22.4 root-meansquare error in percentage(R_(MSE%));(2)the trend changed according to bark colour,with significant differences for the intersection(_0–Pr>F:p=0.0124)and slope(β_(1)–Pr>F:p=0.0126)of bark thickness curves between groups;(3)the highest correlation of bark thickness was found with:D_(BH)(ρ=0.88),H(ρ=0.58),C_(BH)(ρ=0.46),S_(P)(ρ=-0.52),and B_(A)(ρ=-0.32);(4)modelling with ANN confirmed high adjustment(R^(2)=0.99)and accuracy(R_(MSE%)=3.0)of the *** is an efficient and robust technique for the modelling of various qualitative and quantitative attributes commonly used in forest *** effective use of ANN to estimate araucaria bark in natural forests reinforces its potential,besides the possibility of application for other forest species.

关键词： Dendrometry attributes Crown characteristics Prediction models Bark factor Parana-pine

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Toward sustainable intensification of agriculture in sub-Saharan Africa

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Frontiers of Agricultural Science and Engineering 2020年第4期7卷 401-405页

作者： Andreas BUERKERT Eva SCHLECHT Organic Plant Production and agroecosystems Research in the Tropics and Subtropics(OPATS) University of Kassel37213 WitzenhausenGermany Animal Husbandry in the Tropics and Subtropics(AHTS) University of Kassel and University of Göttingen37213 WitzenhausenGermany

Across the African continent efforts to intensify agriculture have been limited to specific commodities,locations or particular production *** causes for the widespread failure to overcome low land and labor productivity while maintaining ecosystem services have often be analyzed but remain poorly understood.A socialecological system approach may help to better understand the complex nature of ecological disadvantages,postcolonial structures,limited connect between producers and consumer markets,low off-farm livelihood opportunities,partial underpopulation and lacking experience with the concept of sustainable production as a major impediment for sustainable intensification of the agricultural ***,recent success stories in agro-pastoral systems as well as urban vegetable and animal production and associated value chains in West Africa,and in intensive mixed-cropping systems of the Great Lakes Region show the potential of stakeholder-driven agricultural *** interpretation of these cases may provide lessons for a more widespread eco-intensification of smallholder agriculture in sub-Saharan Africa.

关键词： colonial heritage land use marketing property rights subsistence agriculture urbanization value chains

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Positive intercropping effects on biomass production are species-specific and involve rhizosphere enzyme activities: Evidence from a field study

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Soil Ecology Letters 2022年第4期4卷 444-453页

作者： Amit Kumar Evgenia Blagodaskaya Michaela A.Dippold Vicky M.Temperton Institute of Ecology Faculty of SustainabilityLeuphana University Lüneburg21335LuneburgGermany department of Soil Ecology Helmholtz Center for Environmental Research-UFZ Halle06120Halle(Saale)Germany Agro-Technology Institute RUDN University117198MoscowRussia Biogeochemistry of agroecosystems University of GoettingenBuesgenweg 237077GoettingenGermany

Less attention has been given to soil enzymes that contribute to beneficial rhizosphere interactions in intercropping ***,we performed a field experiment by growing faba bean,lupine,and maize in mono and mixed cultures in a moderately fertile *** measured shoot biomass and the kinetic parameters(maximal velocity(V max)and Michaelis-constant(K m))of three key enzymes in the rhizosphere:Leucine-aminopeptidase(LAP),β-1,4-N-acetylglucosaminidase(NAG),and phosphomonoesterase(PHO).Faba bean benefitted in mixed cultures by greater shoot biomass production with both maize and lupine compared to its expected biomass in ***,LAP and NAG kinetic parameters were less responsive to mono and mixed cultures across the crop *** contrast,both the V max and K m values of PHO increased in the faba bean rhizosphere when grown in mixed cultures with maize and lupine.A positive relative interaction index for shoot P and N uptake for faba bean showed its net facilitative interactions in the mixed ***,these results suggest that over-productivity in intercropping is crop-specific and the positive intercropping effects could be modulated by P *** argue that the enzyme activities involved in nutrient cycling should be incorporated in further research.

关键词： Enzyme kinetic parameters Phosphorus mobilization Nitrogen fixation Niche complementarity Biomass increase Relative interaction index

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Soil organic carbon stocks and belowground biomass in patches in heterogeneous grassland

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Grassland Research 2023年第4期2卷 279-288页

作者： Martin Komainda Eliana Mohn Klára Kajzrová Kilian Obermeyer Jan Titěra Vilém Pavlů Johannes Isselstein department of Crop Sciences Grassland ScienceGeorg-August-UniversityGöttingenGermany Faculty of Science Humanities and EducationTechnical University of LiberecLiberecCzechia department of Agroecology and Crop Production Faculty of AgrobiologyFood and Natural ResourcesCzech University of Life SciencesPrahaCzechia University of Vechta VechtaGermany Grassland Research Station Liberec Department of Weeds and Vegetation of AgroecosystemsCrop Research InstitutePrahaCzechia Centre of Biodiversity and Sustainable Land Use GöttingenGermany

Background:Selective grazing creates stable patches of contrasting sward height,thereby providing different growth conditions for the grass sward above and below ground and potentially affecting soil organic carbon(SOC)*** hypothesized that the presence of patches leads to greater spatial variability in belowground biomass(BGB)and SOC stocks than occurs between pastures managed under different stocking ***:A long-term grazing experiment consisting of three stocking intensities was used for this *** studied BGB,SOC,and soil total nitrogen(Ntot)stocks in the 0-15 cm soil *** diversity of plant species,soil bulk density,soil phosphorus,potassium,and magnesium contents were ***:There were no significant effects of patch or stocking intensity on BGB,SOC,and Ntot *** patches had a greater Shannon diversity than tall patches(p<0.05)and plant-available nutrients in soil correlated positively with sward height(p<0.05).Conclusions:We conclude from the current results and previous studies that higher plant species diversity with lower soil nutrient contents in short-patch areas and higher nutrient contents together with light competition in tall-patch areas might balance each other out with respect to BGB and SOC stocks.

关键词： grazing land roots seminatural grassland soil organic matter stocking rate

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Effect of Cultivation on Soil Organic Matter and Aggregate Stability

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Pedosphere 2005年第2期15卷 255-262页

作者： A.WILLIAMS P.VENEMAN department of Plant Soil and Insect Sciences University of Massachusetts MA 01003 (USA) department of Plant Amherst

Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980’s showed that loss of soil organic matter (SOM) and soil aggregate stability was standard features of non-sustainable land management in agroecosystems. In this study total soil organic carbon (SOC), particulate organic matter (POM), POM-C as a percentage of total SOC, and aggregate stability were determined for three cultivated fields and three adjacent grassland fields to assess the impact of conventional agricultural management on soil quality. POM was investigated using solid-state 13C nuclear magnetic resonance (NMR) to determine any qualitative differences that may be attributed to cultivation. Results show a highly significant loss in total SOC, POM and aggregate stability in the cultivated fields as compared to the grassland fields and a significant loss of POM-C as a percentage of total SOC. Integrated results of the NMR spectra of the POM show a loss in carbohydr

关键词： aggregate stability cultivation NMR particulate organic matter soil organic matter

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Impact of elevated CO2 and increased temperature on Japanese beetle herbivory

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Insect Science 2013年第4期20卷 513-523页

作者： Olivia K. Niziolek May R. Berenbaum Evan H. DeLucia department of Plant Biology Institute of Genomic Biology department of Entomology University of Illinois Urbana Illinois 61801USA

To examine how the major elements of global change affect herbivory in agroecosystems, a multifactorial experiment was conducted where soybeans were grown at two levels of carbon dioxide and temperature, including those predicted for 2050, under otherwise normal field conditions. Japanese beetles （Popillia japonica Newman） were enclosed on foliage for 24 h, after which the beetle survivorship, total and per capita leaf consumption, and leaf protease inhibitor activity were measured. The direct effect of temperature on beetle consumption and survivorship also was measured under controlled environmental conditions. No differences in total foliage consumption were observed; however, beetles forced to feed at elevated temperature in the field demonstrated greater per capita consmnption and reduced survivorship compared to beetles feeding at ambient temperature. Survivorship was also greater for beetles that consumed foliage grown under elevated CO2, but there were no interactive effects of CO2 and temperature, and no differences in leaf chemistry were resolved. Leaf consumption by beetles increased strongly with increasing temperature up to -37℃, above which increased mortality caused a precipitous decrease in consumption. An empirical model based on the temperature dependence of leaf consumption and flight suggests that the 3.5℃ increase in temperature predicted for 2050 will increase the optimal feeding window for the Japanese beetle by 290%. Elevated temperature and CO2 operating independently have the potential to greatly increase foliage damage to soybean by chewing insects, such as Popilliajaponica, potentially affecting crop yields.

关键词： carbon dioxide FACE (free-air concentration enrichment) Glycine max,herbivory Japanese beetles Popilliajaponica temperature dependence

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