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Symbiotic Behaviour Of Alfalfa Varieties Grown In Different Soils, C Scotti, S Gnocchi, M Carelli, P Rotili Jun 2024

Symbiotic Behaviour Of Alfalfa Varieties Grown In Different Soils, C Scotti, S Gnocchi, M Carelli, P Rotili

IGC Proceedings (1997-2023)

Six alfalfa (Medicago sativa) varieties were grown in two contrasting soils to study their symbiotic ability as estimated by nodule biomass and dry matter yield in presence of the natural population of rhizobia of soil. Varieties can be discriminated on the basis of total (year) nodule biomass; their ranking for nodule biomass was consistent in the different soil types although soils significantly influenced nodulation and dry matter yield.


Long Term Effects Of Liming A Basalt-Derived Soil, On Lucerene And Phalaris Production, K.M. F. Reed, J F. Chin Jun 2024

Long Term Effects Of Liming A Basalt-Derived Soil, On Lucerene And Phalaris Production, K.M. F. Reed, J F. Chin

IGC Proceedings (1997-2023)

Lime incorporated into a basalt-derived clay loam lowered exchangeable aluminium in soil. Soil pH was still elevated, 9 years after 2 t/ha of lime was incorporated. With lower rates of lime the density of lucerne plants declined. Lucerne yield more than doubled with lime. After six years, the area was sown to a phalaris-clover pasture. A 15% increase in the yield of phalaris was recorded from limed plots over the next three years. Despite this, 11 years after liming, herbage P concentrations increased with lime, from 0.28% to 0.35%.


Can Maize Influence The Dissolution Of Low Water Soluble Phosphorus Fertilizers?, S Sinaj, E Frossard Jun 2024

Can Maize Influence The Dissolution Of Low Water Soluble Phosphorus Fertilizers?, S Sinaj, E Frossard

IGC Proceedings (1997-2023)

The objectives of this study were to evaluate the respective importance of maize (Zea mays) and soil properties on the dissolution of two sparingly soluble P fertilizers. The surface horizon of an acidic and a calcareous soils were amended with Thomas’ slag or phosphate rock and were either incubated or cultivated with maize. Maize cultivation increased the rate of dissolution of both fertilizers in both soils. Its influence remained limited compared to fertilizer dissolution in the incubated acidic soil. In the calcareous soil, however, the presence of maize increased significantly the rate of fertilizer dissolution compared to that observed in …


Phosphorus Availability, Defoliation Tolerance, And Genetic Differentiation In White Clover, D F. Chapman Jun 2024

Phosphorus Availability, Defoliation Tolerance, And Genetic Differentiation In White Clover, D F. Chapman

IGC Proceedings (1997-2023)

The genetic composition of mixed populations of white clover growing in low fertility, grass-dominant hill pastures was estimated four and eight years after populations were established. Populations were based on an adapted ('Grasslands Tahora') or poorly adapted ('Grasslands Huia') cultivar, and received either no fertiliser, or 35kg P /ha /year. The P response curve of surviving plants was also determined, and compared with plants grown from 'standard' seedlines of the respective cultivars. Between years 4 and 8, the proportion of the populations constituted by plants true-to-type for the sown cultivar remained steady at 56 - 58% for Tahora, but fell …


Seasonal Variations Of Labile Soil Organic Carbon And Nitrogen Fertility In Grassland Soil In Tokyo, Japan, T Murata, H Tanaka, Y Kurokawa Jun 2024

Seasonal Variations Of Labile Soil Organic Carbon And Nitrogen Fertility In Grassland Soil In Tokyo, Japan, T Murata, H Tanaka, Y Kurokawa

IGC Proceedings (1997-2023)

We investigated seasonal variations of soil enzyme activities, soil inorganic N, soil microbial biomass N (BN) and soil total sugar C (TSC) during March to December in cattle-grazed pasture in Japan (Andisols). Dehydrogenase activity had three peaks in a year, on the other hand, phosphomonoesterase activity increased from spring (April) up to summer (August) but then gradually decreased toward winter. BN also showed a seasonal variation, which gradually increased from April to August, but in the end of August once decreased rapidly because of soil becoming dry. Soil inorganic N had three peaks which appeared after the appearance of dehydrogenase …


Reed Canarygrass (Phalaris Arundinacea L.) Response To Liquid Dairy Manure Or Fertilizer N, M P. Russelle, G W. Randall, P D. Clayton, M A. Schmitt, L J. Greub, C C. Sheaffer, R R. Kalton, D H. Taylor Jun 2024

Reed Canarygrass (Phalaris Arundinacea L.) Response To Liquid Dairy Manure Or Fertilizer N, M P. Russelle, G W. Randall, P D. Clayton, M A. Schmitt, L J. Greub, C C. Sheaffer, R R. Kalton, D H. Taylor

IGC Proceedings (1997-2023)

Livestock farmers face constraints in efficient manure management because of limited land availability, especially during the growing season, but reed canarygrass (Phalaris arundinacea L.) may provide a solution. We measured yield and apparent N removal of established reed canarygrass with surface-applied dairy manure slurry at three locations in the Upper Midwest, USA. Slurry was broadcast or banded at rates up to 375 m3 ha-1 (1190 kg N ha-1) in single or split applications and N fertilizer was applied at rates up to 448 kg N ha- 1 for comparison. Herbage was harvested three times per year. Nitrogen removal in …


The Influence Of Plant Density And Level Of Nitrogen Fertilization On The Production Of Eragrostis Curvula, P A. Pieterse, N F.G. Rethman, J Van Bosch Jun 2024

The Influence Of Plant Density And Level Of Nitrogen Fertilization On The Production Of Eragrostis Curvula, P A. Pieterse, N F.G. Rethman, J Van Bosch

IGC Proceedings (1997-2023)

The objective of this study was to determine whether plant density would have an influence on dry matter (CM) yield and to determine it’s interaction (if any) with levels of N fertilization. Plants on a broadcast establishment of lovegrass (Eragrostis curvula) were mechanically thinned, to leave 30 cm rows with spacing of 0.5 and 1 m. N fertilizer was applied in spring at levels equivalent to 0, 50, 100 and 150 kg N ha-1. The trial was conducted over three growing seasons. In the second and third years the DM yields with 100 and 150 kg N ha-1 on the …


Potassium Rates For Macrotyloma Axillare Growth, R A. Martim, F A. Monteiro, P.R. L. Portilho Jun 2024

Potassium Rates For Macrotyloma Axillare Growth, R A. Martim, F A. Monteiro, P.R. L. Portilho

IGC Proceedings (1997-2023)

The response of the tropical forage legume macrotiloma guata (Macrotyloma axillare (E. Mey) Verdc) to potassium rates was studied in a greenhouse experiment. The plants were grown in nutrient solution with seven potassium (K) rates, 0; 3.5; 7; 21; 35; 105 and 245 mg l-1 of solution, in randomized complete block design, with four replications. There was significant response of the legume to potassium rates. Considerations are made on the influence of these levels on plant dry matter yield in two harvests, root dry matter production and potassium and magnesium concentrations in the plant tissue.


Phosphorus Use Efficiency For Biomass Production Of Legume Species, A T. Ayala Torales, V A. Deregibus, P R. Moauro Jun 2024

Phosphorus Use Efficiency For Biomass Production Of Legume Species, A T. Ayala Torales, V A. Deregibus, P R. Moauro

IGC Proceedings (1997-2023)

The objective of the experiment was to identify traits associated with the production of plant biomass, and hence with P utilization efficiency, when legume species were fertilized. Red clover (Trifolium pratense) and narrowleaf birdsfoot trefoil (Lotus tenuis) were compared in a greenhouse experiment using phosphorus deficient soils. Three plants grew in pots fertilized with 0, 2, 4, 8, 15, 20, 30 and 40 ppm in soil, in a randomized experimental design. Harvest was made at 60 days from the sowing date. Leaf areas, shoot and root biomass, and tissue phosphorus contents were measured. Results showed that …


Phosphogypsum As A Source Of Nutrients For Bahiagrass, J E. Rechcigl, I S. Alcordo Jun 2024

Phosphogypsum As A Source Of Nutrients For Bahiagrass, J E. Rechcigl, I S. Alcordo

IGC Proceedings (1997-2023)

Phosphogypsum is a by-product of the manufacture of phosphoric acid from phosphate rock and is a potential source of sulfur and calcium for crops. There are currently more than 700 million Mg of phosphogypsum in Florida alone stacked in waste piles and an additional 30 million Mg produced annually. A 3-year study was conducted to determine whether addition of phosphogypsum to bahiagrass would increase production and quality. Results indicate that addition of up to 4.0 Mg/ha phosphogypsum increased bahiagrass yields, protein content, and in vitro digestibility of forage. This study has demonstrated that phosphogypsum can be used as an alternative …


A Review Of Centrosema Pascuorum (Centurion) Cvv. Cavalcade And Bundey As A Pasture Legume In The Ley Farming System Studies In North West Australia, K Thiagalingam, D Zuill, T Price Jun 2024

A Review Of Centrosema Pascuorum (Centurion) Cvv. Cavalcade And Bundey As A Pasture Legume In The Ley Farming System Studies In North West Australia, K Thiagalingam, D Zuill, T Price

IGC Proceedings (1997-2023)

Field experiments and commercial experience with the pasture legume Centrosema pascuorum (centurion) in the Katherine and Douglas Daly districts of the Northern Territory over the past ten years were reviewed. Results show that cultivars of this species (Cavalcade and Bundey) have good potential for improving both soil fertility and the quality of dry season forage (as hay or grazing) for cattle in mixed farming systems in the semi-arid tropics of north west Australia.


Influence Of N Fertilization Application And Regrowth On The Yields Of Grassland, J Tasi Jun 2024

Influence Of N Fertilization Application And Regrowth On The Yields Of Grassland, J Tasi

IGC Proceedings (1997-2023)

The effect of different levels of fertilization and regrowth periods on the quantity and quality and distribution of yields of eleven grassland species were studied in two plots in Hungary. The effect of the following variables were tested: regrowth period of 20 and 40 days; control, 100 and 200 kg N ha-1 and 11 grass and leguminous species.


Effect Of Plant Age And N And P Fertilization On Mineral Composition Of Andropogon Gayanus, D E. Morillo, A Caraballo, J Faria-Marmoll, L R. Mcdowell Jun 2024

Effect Of Plant Age And N And P Fertilization On Mineral Composition Of Andropogon Gayanus, D E. Morillo, A Caraballo, J Faria-Marmoll, L R. Mcdowell

IGC Proceedings (1997-2023)

Mineral concentrations of Andropogon gayanus Kunth, as affected by age of regrowth, 42 and 63 days (six and four cuttings); rate (kg/ ha/year) of N fertilizer, 0, 100 and 200, and of P2O5, 0 and 75, were evaluated on a sandy-loam Aridisol (pH 5.5) in Venezuela, using a split-split-plot experimental design with two replications. Forage mineral concentrations did not differ (P>0.05) among ages. Mean Ca, P, Mg, Na were: 0.20, 0.11, 0.10 and 0.029 %, and regarded as deficient for ruminants. Only K (1.21 %) was considered adequate. Mean Fe, Zn, Cu, Mn and Co were 57, 24, 2.7, …


Seasonality In The Response Of Perennial Grass-Clover Pastures To Phosphorus Fertiliser, A K. Metherell, A C. Mckenzie Jun 2024

Seasonality In The Response Of Perennial Grass-Clover Pastures To Phosphorus Fertiliser, A K. Metherell, A C. Mckenzie

IGC Proceedings (1997-2023)

Pasture dry matter yields from individual cuts of multi-year phosphorus (P) fertilizer field trials were analyzed for evidence of consistent seasonal trends in the response to P. The relative response to P was greatest in the late autumn - winter period, with the seasonal variation in relative yield being greater where soil fertility and mean annual relative yields were lowest.


Interaction Of Endomycorrhizal Fungi And Phosphate On Neonotonia Wightii, Lackey, V T. Paulino, O.M. A.A. Ghisi, M.A. C. Lucena, M J. Valarini, J C. Werner Jun 2024

Interaction Of Endomycorrhizal Fungi And Phosphate On Neonotonia Wightii, Lackey, V T. Paulino, O.M. A.A. Ghisi, M.A. C. Lucena, M J. Valarini, J C. Werner

IGC Proceedings (1997-2023)

This experiment was carried out in greenhouse condition, to study the effect of four phosphorus levels (20, 80, 140 and 200 kg of P2O5/ ha) with or without fungi mycorrhizal inoculation (Acaulospora longula + A. morrowae ). Five accessions of Neonotonia wightii (Wightii & Arn) Lackey (perennial soyabean) were studied: Malawi, Tinaroo, NO1264, NO409 and NO 250. The growth of Neonotonia was improved by the phosphorus fertilization.The effect of VAM inoculation was greater in the lower levels of P fertilization reducing its effect in the higher levels of P applied. The presence of soluble P induced higher N accumulation …


Effects Of Agropastoral Systems On Microbially Bound Phosphorus In Low P Acid Soils, A Oberson, D K. Friesen, C Morel, H Tiessen, E Frossard Jun 2024

Effects Of Agropastoral Systems On Microbially Bound Phosphorus In Low P Acid Soils, A Oberson, D K. Friesen, C Morel, H Tiessen, E Frossard

IGC Proceedings (1997-2023)

The effect of agropastoral systems replacing native savanna on microbially bound phosphorus (Pmic) in low P acid soils was investigated. Chloroform released P (PChl) was measured to estimate Pmic. In a long-term improved pasture experiment, PChl was higher in grass-legume (GL) than grass-only pasture (GO). Although the P balance was slightly higher in GO than in GL, available P contents followed the same trend as PChl suggesting that the presence of legumes enhances the maintenance of P fertility. In a rice-pasture system, PChl was higher than under rice monocrop indicating an effect of the cropping system on PChl that goes …


Potassium Release From Clays By Biosignal Of Grass Root Exudates, S Suzuki Jun 2024

Potassium Release From Clays By Biosignal Of Grass Root Exudates, S Suzuki

IGC Proceedings (1997-2023)

The objective of this study was to clarify that the root exudates of Italian ryegrass (Lolium multiflorum Lam.) expand the basal spacing of hydroxy potassium vermiculite (K-Vt) in the rhizosphere model with a clay-agar system, and to discuss that the action of the root exudates is regarded as a biosignal to release potassium ions from the interlayers of vermiculite clays.


Effect Of Slurry Application On Cell Wall Components And Silage Intake By Sheep Of Italian Ryegrass And Triticale, H Kawamoto, N Shimizu, R Uegaki, R Kobayashi Jun 2024

Effect Of Slurry Application On Cell Wall Components And Silage Intake By Sheep Of Italian Ryegrass And Triticale, H Kawamoto, N Shimizu, R Uegaki, R Kobayashi

IGC Proceedings (1997-2023)

The study was to elucidate the effect of application of slurry manure from dairy cows on chemical components, the rumen degradation characteristics and silage intake by sheep of Italian ryegrass (Lolium multiflorum Lam.) and Triticale ( rye-wheat hybrid). The amounts of application of slurry were 0, 50, 100 and 150 t/ha. The increasing level of slurry application resulted in a decrease of lower digestible cell wall and an increase of degradation rate. The silage of 150 t /ha treatment was significantly more consumed by sheep than the other treatments (p<0.05). The changes in cell wall components in both quantity and quality by the slurry application were advantageous to the increase of voluntary dry matter intake of the forage.


Different Response Of Lucerne (Medicago Sativa L.) Cultivars To P And Zn Fertilization And Susceptibility To Phosphorus-Induced Zinc Deficiency On Calcareous Soils, Gansu, China, Chen Wen, Graham Eagleton, Graeme Blair Jun 2024

Different Response Of Lucerne (Medicago Sativa L.) Cultivars To P And Zn Fertilization And Susceptibility To Phosphorus-Induced Zinc Deficiency On Calcareous Soils, Gansu, China, Chen Wen, Graham Eagleton, Graeme Blair

IGC Proceedings (1997-2023)

The three pot experiments were carried out at the Qingyang Research Station, Gansu, China to determine the yield response of P and Zn, and examine the effect of soil types on P and Zn requirement of the local and introduced lucerne cultivars in the establishment phase on calcareous soils. The results showed marked growth and dry matter yield benefit at lucerne establishment when P fertiliser was applied on both soils. There were no consistent difference among the three cultivars in response to added P. A significant shoot yield response to Zn was only recorded at high P supply in the …


Application Of N And P Fertilizers On Pasture Of Southern Italy: Effects On Forage Species, Production And Quality, D Ferri, G Convertini Jun 2024

Application Of N And P Fertilizers On Pasture Of Southern Italy: Effects On Forage Species, Production And Quality, D Ferri, G Convertini

IGC Proceedings (1997-2023)

The effects of N and P fertilization on the productive and qualitative characteristics of improved pastures in inside Southern Italy areas were investigated. The trial was carried out in two sites characterized by different altitude above sea level and soil properties; also previous fertilization treatments and botanical composition characteristics are significantly different. The N fertilization reduced negative effects of climatic variations (typical of these areas) on botanical composition of “Bella” grassland at lower altitude. On the contrary a more stable botanical composition assured good yields and quality of forage at “Li Foy” field (higher a.s.l.) because more regular weather conditions …


Sulphur And Phosphorus Responses Of Russell Lupin In Rangeland, P Jarvis, R J. Lucas, J.G. H. White Jun 2024

Sulphur And Phosphorus Responses Of Russell Lupin In Rangeland, P Jarvis, R J. Lucas, J.G. H. White

IGC Proceedings (1997-2023)

Russell lupin (Lupinus polyphyllus) was established by oversowing into low fertility, depleted tussock rangeland in 1990. The soil was low in phosphorus (P) and sulphur (S). P, (O, 12.5, 25 or 50 kg P /ha) and S (0 or 60 kg S/ha) were applied at sowing. In May 1994, a further 0 or 60 kg S /ha was applied as a sub-plot treatment. Lupin and grass dry matter (DM) was assessed in December 1995. Lupin did not grow in the absence of S. Lupin and grass responded to the additional S giving a maximum of 4.2 and 4.9 …


Raster Map For Prediction Of Heading Date Of Timothy By Nonparametric Dvr Method, T Saigusa, K Nakashima, N Noshiro, M Tsutsumi Jun 2024

Raster Map For Prediction Of Heading Date Of Timothy By Nonparametric Dvr Method, T Saigusa, K Nakashima, N Noshiro, M Tsutsumi

IGC Proceedings (1997-2023)

A system for making a raster map for predicting the heading date of timothy (Phleum pratense L.) at first cutting for every 1km2 plot was developed to supply information for smooth harvest of forage of good quality in a dairy farming area of Hokkaido. Daily mean air temperature for every 1km2 plot was estimated with data from a network of meteorological observatories and data base of the Japan Meteorological Agency. Day length could be calculated from latitude and calendar day. Using these two environmental factors, heading date of timothy at first cutting for each area was predicted by nonparametric DVR …


Long-Term Effects Of Co2 Enrichment And Temperate Increase On Forage Quality In A Temperate Grass, J F. Soussana, J M. Besle, I Chabaux, P Loiseau, P C. De Faccio Carvalho Jun 2024

Long-Term Effects Of Co2 Enrichment And Temperate Increase On Forage Quality In A Temperate Grass, J F. Soussana, J M. Besle, I Chabaux, P Loiseau, P C. De Faccio Carvalho

IGC Proceedings (1997-2023)

Perennial ryegrass swards were grown during two years at two N fertilizer supplies in elevated (700 ppm) or ambient atmospheric CO2 concentration at outdoor temperature and at + 3°C in elevated CO2. Elevated CO2 and temperature increase had only minor impacts on the digestibility and on the fiber composition of the cut material. On average, the water soluble carbohydrate concentration of the leaf laminae was doubled in elevated CO2, whereas a 3°C temperature increase reduced this concentration by 25 %.


Co2 Enrichment And Temperature Effects On Productivity Of Field-Grown Phalaris And Subterranean Clover, J M. Lilley, T P. Bolger, R M. Gifford Jun 2024

Co2 Enrichment And Temperature Effects On Productivity Of Field-Grown Phalaris And Subterranean Clover, J M. Lilley, T P. Bolger, R M. Gifford

IGC Proceedings (1997-2023)

Pure and mixed swards of Phalaris aquatica and Trifolium subterraneum were exposed to cool (ambient) and warm (cool +3oC) temperatures, at both 380 and 690 ppm CO2 concentrations in field temperature gradient tunnels for 5 months. In general, clover and the mixture had similar forage productivity in each treatment, while phalaris was less productive. Elevated CO2 increased clover production 40% in the monoculture and the mixture. Higher temperatures reduced clover regrowth at ambient CO2 and reduced the response to elevated CO2 in the monoculture but not in the mixture. In contrast, phalaris regrowth in the monoculture was not increased by …


Growth Response Of Australian Temperate Pasture Species To Co2 Enrichment, T P. Bolger, J M. Lilley, R M. Gifford, J R. Donnelly Jun 2024

Growth Response Of Australian Temperate Pasture Species To Co2 Enrichment, T P. Bolger, J M. Lilley, R M. Gifford, J R. Donnelly

IGC Proceedings (1997-2023)

Growth responses to a doubling of the atmospheric CO2 concentration for 15 species represented in temperate pastures of southern Australia were investigated in a glasshouse experiment. The final dry weight increase due to CO2 enrichment averaged 34% across species but varied widely. The variation in CO2 response was greater among species within botanical groups than it was among groups. The CO2 response of a number of ‘desirable’, but also a number of ‘undesirable’ species was greater than the mean response, suggesting that these species may increase their proportion in pastures as atmospheric CO2 rises. Our results do not support the …


Co2 Gas Fluxes In Grazing Pasture, T Oku, S Shibata, S Takahashi, M Shibayama Jun 2024

Co2 Gas Fluxes In Grazing Pasture, T Oku, S Shibata, S Takahashi, M Shibayama

IGC Proceedings (1997-2023)

CO2 gas fluxes in grazing pastures were measured directly by the eddy correlation method to determine whether grasslands function as carbon sinks or sources. Observations revealed daytime CO2 absorption fluxes to grassland and nighttime CO2 emission fluxes to atmosphere. In 1993, the daily amounts of CO2 absorbed by grassland were larger than those of CO2 emitted to the atmosphere during the measuring period in spite of a cool summer and consequently lower level of solar radiation. In 1994, we obtained reverse carbon budgets especially on very hot days, which resulted from a different fluctuation pattern of the CO2 gas fluxes. …


Elevated Co2 And Temperature Effects On Paspalum And Arachis Forages, K J. Boote, F B. Fritschi Jun 2024

Elevated Co2 And Temperature Effects On Paspalum And Arachis Forages, K J. Boote, F B. Fritschi

IGC Proceedings (1997-2023)

Long-term effects of elevated carbon dioxide (CO2) and elevated temperature on growth processes of bahiagrass (Paspalum notatum Flugge) and rhizoma peanut (Arachis glabrata Benth.) were evaluated. Forages were established and grown in 27-m long temperature-gradient greenhouses constructed over a natural field soil. Treatments were two CO2 levels, 350 or 700 vpm CO2, and four temperature sectors (0, 1.5, 3.0, and 4.5 °C above ambient). Shoot emergence, ground cover, leaf and canopy assimilation, rate of leaf appearance, and dry matter accumulation were measured. Increasing temperature accelerated plant establishment and increased early plant dry matter accumulation, leaf area, and leaf appearance rate. …


Productivity Of Orchardgrass In Japan Estimated By The Neural Network Method And The Effect Of An Increase In Co2 And A Rise In Temperature, H Sasaki, T Suyama, M Fukuyama Jun 2024

Productivity Of Orchardgrass In Japan Estimated By The Neural Network Method And The Effect Of An Increase In Co2 And A Rise In Temperature, H Sasaki, T Suyama, M Fukuyama

IGC Proceedings (1997-2023)

The purpose of this study is to estimate changes in the productivity of orchardgrass (Dactylis glomerata L.) resulting from an anticipated increase in CO2 and a rise in temperature. Productivity of orchardgrass is primarily determined by mean temperature and solar radiation. Accordingly, a growth model was established on this basis by using the neural network method. Maps of areas where productivity is depressed in the summertime were drawn based on calculations applying anticipated climatic changes to this model. The direct influence of the increase in CO2 density was also considered in making these maps. As a result, it was concluded …


Growth And Physiology Respond Differently To Elevated Co2 In Nad-Me And Nadp-Me C4 Grasses, D R. Lecain, J A. Morgan Jun 2024

Growth And Physiology Respond Differently To Elevated Co2 In Nad-Me And Nadp-Me C4 Grasses, D R. Lecain, J A. Morgan

IGC Proceedings (1997-2023)

Plants with C4 photosynthesis have one of three decarboxylation enzymes in their bundle sheath cells. Reports suggest that bundle sheath leakiness to CO2 is highest in the NAD-ME group, lowest in the NADP-ME group and intermediate in the PCK group. We investigated the hypothesis that growth and photosynthesis of three NADME grasses would respond more to elevated CO2 than three NADPME grasses. Contrary to our hypothesis, growth of NADP-ME grasses was greater under elevated CO2, while none of the NADME grasses had a significant response. Increased leaf non-structural carbohydrates were associated with greater growth responses of NADP-ME grasses, while none …


Nitrogen And Co2 Effects On Remobilization Of Root And Crown Reserves For Regrowth Following Defoliation, R H. Skinner, J A. Morgan, J D. Hanson Jun 2024

Nitrogen And Co2 Effects On Remobilization Of Root And Crown Reserves For Regrowth Following Defoliation, R H. Skinner, J A. Morgan, J D. Hanson

IGC Proceedings (1997-2023)

The effect of carbohydrate and nitrogen reserve remobilization during the first 4 d following defoliation on subsequent regrowth was studied under different soil nitrogen and atmospheric CO2 conditions. On a structural dry matter basis, elevated CO2 increased carbohydrate concentration without affecting total nitrogen in roots and crowns. High soil nitrogen had the opposite effect, increasing nitrogen concentration with no effect on nonstructural carbohydrates. Regrowth was significantly correlated with total nitrogen concentration at the time of defoliation. Carbohydrate concentration was not related to subsequent regrowth, nor was there a consistent correlation between carbohydrate or nitrogen remobilization and regrowth. No nitrogen remobilization …