Agricultural Science Commons^™

Nitrogen Budgets On A Pasture Under Combined Utilization Of Grazing And Cutting, Y. Kurokawa, S. Yamamoto, Y. Iijima, M. Kitagawa, F. Omata, S. Sakamoto, H. Tanaka, S. Suzuki, T. Shioya

IGC Proceedings (1977-2023)

Nitrogen budgets on a pasture being utilized for both grazing and cutting were investigated. A pasture containing tallfescue, orchard grass and white clover was divided into two areas: initially grazed (IA, 0.41ha) and grazed after cutting for hay (BA, 0.49ha). A herd of 4-5 cattle (heifers or steers of Japanese Black or Holstein) grazed at IA from 22 Apr. to 2 Jul. and grazed at both IA and BA from 3 Jul. to 21 Oct. 1999. The amount of N grazed from IA was 3 times higher than the sum of N of grazed herbage and harvested hay from BA. …

Effect Of Phosphatic Fertilizer Rates Level On Growth, Crude Protein Content And Nitrogen Fixation Ability Of Alfalfa At Sowing Year, Chang-Ho Kim, Hyo-Won Lee

IGC Proceedings (1977-2023)

The experiment was conducted to determine effects of phosphate fertilizers on growth characteristics, crude protein content and nitrogen fixation ability of alfalfa (Medicago sativa L) in the sowing year. Two rates of phosphate (200 and 400 kg/ha P) were applied to phosphorus -deficient native soil in Korea and samples were taken every 7 days from the 30th to the 93rd day. Number of branches, root length and dry matter weight at phosphate fertilizer level of 400kg in sowing year more increased than those at 200kg/ha. The number of nodules did not differ due to phosphate fertilizer rate. The crude …

Phosphorus Fertilizer Requirements For Temperate Dairy Pastures And Milk Production In South Eastern Australia, C. J. P. Gourley, I. Awty, M. O'Doherty, S. R. Aarons

IGC Proceedings (1977-2023)

Phosphorus (P) fertilizer is required to sustain productive pastures in Australia, yet optimum P fertility is poorly defined. A large farmlet study involving 10 herds was established in 1995 to determine the relationship between milk production and pasture response to four different P fertilizer rates, at three stocking rates. Pasture growth significantly increased with increasing P fertilizer rate. Cumulative milk production from pasture over 4 years, was significantly affected by P fertilizer, but responses diminished with increasing P rate. The results from this study will enable a better targeting of P fertility levels for profitable milk production from temperate dairy …

Responses To Nitrogen Fertilizer In Dairy Pastures With Differing Phosphorus Fertility In South Eastern Australia, C. J. P. Gourley, H. Frame, M. E. Hall

IGC Proceedings (1977-2023)

The application of nitrogen (N) fertilizer to temperate pastures is an increasingly popular management tool for boosting pasture production on dairy farms in Australia. However, limited information is available about N fertilizer responses that can be obtained from pastures with varying levels of phosphorus (P) fertility. A field experiment examining the initial and residual response of pasture growth to urea was carried out within a large dairy farmlet study, in October 1998. The four P fertility treatments (Olsen P values) ranged from 9 to 32 mg/kg. Dry matter yields increased with increasing N rates in all treatments, at both harvests. …

Comparison Of Nitrate Contents For Reed Canarygrass And Orchardgrass In Large Amounts Of Compound Fertilization, A. Fushimi, Y. Tamura, K. Matoba

IGC Proceedings (1977-2023)

Reed canarygrass (Phalaris arundinacea L.) could be an ideal candidate for manure application. We compared its growth, crude protein (CP) and nitrate N (NO³-N) content to that of orchardgrass (Dactylis glomerata L.) on different levels of nitrogen fertilization (3,10,15 and 20g N m^-2, applied from May 15 to September 15 after each monthly cutting. The dry weight (DW) of reed canarygrass increased significantly with increasing amounts of N nitrogen on July, August and September. However, orchardgrass only showed a significant increase in yield on September. The concentration of CP of reed canarygrass was significantly …

Modelling Nitrogen Uptake In Winter Oilseed Rape By Using Influx Kinetics Of Nitrate Transport Systems, S. Faure, P. Malagoli, P. Lainé, E. Le Deunff, F. Ledily, A. Ourry, J. Boucaud

IGC Proceedings (1977-2023)

A mechanistic model was proposed in order to predict nitrogen uptake by a culture of oilseed rape (Brassica napus L.), using independently measured characteristics of plants growing in hydroponic or under field conditions. Uptake kinetics of the different components (Constitutive and Inducible) of the Low and High Affinity Transport Systems of nitrate (CLATS, ILATS, CHATS and IHATS, respectively) were determined by ¹⁵NO₃^- labelling in controlled conditions. The use of kinetic equations of transport systems and the experimental field data from the INRA-Châlons rape databank allowed to model NO₃^- uptake during the plant growth cycle. …

Biological Interactions In Grassland Soils And Productivity, R. Cook, R. D. Bardgett, W. R. Eason, L. Skøt, K. J. Webb

IGC Proceedings (1977-2023)

This paper describes research on interactions between grassland plant species and soil microorganisms. Both parasitic and symbiotic microorganisms modify nutrient transfers between plants and soil. Experiments are described in which nematode infection of clover increased nitrogen transfer to companion ryegrass plants. Infection of clover enhanced activity of soil bacterial and fungal communities. Legume genotypes differing only in responses to symbionts (rhizobium and arbuscular mycorrhizal fungi) and pathogens are being developed for studies of gene expression during establishing and functional symbioses. Such plants can be used in experiments as defined perturbations that will provide information on the interactions and functions of …

Nitrogen Balances In High Rainfall, Temperate Dairy Pastures Of South Eastern Australia, Richard J. Eckard, D. F. Chapman, R. E. White, A. Smith, D. Chen, P. A. Durling

IGC Proceedings (1977-2023)

Nitrogen (N) fertilizer use on dairy pastures in south eastern Australia has increased exponentially over the past 15 years, causing increasing environmental concerns. Volatilisation, denitrification and leaching of N were measured for one year (1998-1999) in pastures receiving no N fertilizer (grass/clover), or 200 kg N/ha applied as urea (46%N) or ammonium nitrate (34.5%N). Nitrogen balances were calculated for each treatment.

Significantly more N was lost through volatilisation and denitrification when N was applied as urea compared to ammonium nitrate. Nitrate leaching losses were significantly greater with the application of N fertilizer, although the maximum loss was only 4.1 kg …

Heavy Metal And Contaminant Loading In The Oder River Floodplains And Consequences For Livestock Management, G. Schalitz, A. Behrendt

IGC Proceedings (1977-2023)

The predominately pristine lower Oder floodplains have experienced sedimentation and enrichment of heavy metals and contaminants since the start of industrialization in the region. With the creation of the German-Polish National Park, which included the flooded grassland area, intensive milk production has been prohibited. The objective of this research was to estimate the impact of the floodplain heavy metal and contaminant levels on the lower Oder region. Soil and plant content were analyzed for three transects according to accepted DIN methods. High content in soil did not consistently result in high plant contents; however, higher content levels were often observed …

Extended Daylength To Increase Fall/Winter Yields Of Warm-Season Perennial Grasses, P. Mislevy, T. R. Sinclair, J. D. Ray

IGC Proceedings (1977-2023)

Low forage production in fall/winter months is a severe limitation for dairy and beef cattle producers in the southeastern U.S. It was hypothesized that shrt daylengths during these months induce a physiological dormancy in grasses. Four grasses [Pensacola bahiagrass, Paspalum notatum Flugge; Tifton 85 and Florakirk bermudagrass, Cynodon dactylon (L.); Florona stargrass, C. nlemfuensis Vanderyst var. nlemfuensis] were subjected to extended daylengths during the winter/fall months in a field test. Pensacola bahiagrass and Tifton 85 bermudagrass showed especially dramatic increases in forage yield during the fall/winter season under the extended daylength. Genetic elimination of daylength sensitivity in these grasses …

Nitrogen Or Water Limitation To Grassland Growth During A Moderate Dry Season In The Humid Tropics, P. Cruz, M. Boval

IGC Proceedings (1977-2023)

The aim of this work was to compare the effects of nitrogen and water shortage on grassland production during a moderate dry season in a tropical humid environment. The results of two experiments carried out in Guadeloupe (FWI) have shown that during dry spells, the reduction in growth of natural grasslands based on Angleton grass (Dichantium aristatum) is more easily corrected by nitrogen fertiliser application than by irrigation. This shows that it is not the availability of water, but that of nitrogen, which is limiting the primary production of Angleton grass, stands. This result is less clear for …

Screening Brachiaria Introductions For Resistance To Spittlebugs (Homoptera: Cercopidae), José R. Valério, Cacilda Borges Do Valle, A. P. De Souza, M. C. M. Oliveira

IGC Proceedings (1977-2023)

Spittlebugs are the most evident and damaging pests of Signal grasses (Brachiaria) in tropical America. Damage caused by these insects can result in the complete loss of available forage, thereby reducing the carrying capacity of infested pastures. Host plant resistance is a low-cost method of controlling insects. High level of spittlebug resistance is found in the cultivar Marandu (B. brizantha), but it requires more fertile soils. Brachiaria germplasm provided by the International Center for Tropical Agriculture (CIAT) is available at National Beef Cattle Research Center of the Brazilian Agricultural Research Corporation (Embrapa Beef Cattle) and it …

Selection Of High Yielding And Anthracnose Resistant Stylosanthes For Brazil, India And China, N. White, S. Chakraborty, Celso D. Fernandes, M. J. Charchar, N. P. Melkania, C. R. Ramesh, B. Gangaiah, Guodao Liu, D. F. Cameron, J. W. Miles

IGC Proceedings (1977-2023)

Resistance to anthracnose, dry matter yield (DMY) and seed yield (SY) was assessed for germplasm and breeding lines of Stylosanthes in Brazil, India and China. Overall, Stylosanthes guianensis produced higher DMY than S. scabra, S. capitata and S. macrocephala at most sites in Brazil. Data from China suggest that there are high yielding anthracnose resistant S. guianensis lines that can reduce the reliance on CIAT 184. S. seabrana might also prove successful. S. seabrana in India produced the highest DMY and SY and it can form nodules with native Bradyrhizobium strains. Regional differences in resistance within accessions stress the …

Genetic Diversity In The Anthracnose Pathogen Infecting Stylosanthes In Brazil, India And China, P. Weeds, S. Chakraborty, Celso D. Fernandes, M. J. Charchar, C. R. Ramesh, Guodao Liu, S. Kelemu

IGC Proceedings (1977-2023)

This work aimed to determine the genetic diversity of Colletotrichum gloeosporioides infecting Stylosanthes spp. in Brazil, China and India. A total of 132 isolate originating from S. seabrana, S. macrocephala, S. capitata, S. scabra, and S. guianensis were used. Four major genetic groups were identified from an analysis of genetic diversity using selection-neutral DNA markers. Group 1 contained 20 isolates and this may represent a genotype that migrated from the center of diversity in Brazil and Colombia to Australia, Thailand and India. Group 2 consisted of 66 Brazilian isolates and group 3 had 19 isolates from …

Relationship Between Tree Density And Grass Dry Matter Yield In A Southern African Savanna, G. N. Smit

IGC Proceedings (1977-2023)

The investigation was carried out on a densely wooded area in the Mopani savanna of South Africa. Seven plots were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0 %) to plots thinned to the equivalent of 10 %, 20 %, 35 %, 50 % and 75 % of the leaf biomass of a control plot (100 %). The grasses responded positively to the tree thinning in terms of total dry matter yield. The yields between tree canopies were generally of the same order or higher than under tree canopies, with the yields where trees …

Seasonal Patterns Of Growth And Senescence In Cynodon Spp. Cv Tifton 85 Grazed Swards, L. F. M. Pinto, L. G. Barioni, S. C. Da Silva

IGC Proceedings (1977-2023)

Growth and senescence are very important determinants of grassland productivity and correspond to key features to be considered for grazing management purposes. The present study was carried out at ESALQ, Piracicaba, S.P., Brazil and evaluated growth and senescence as a function of sward surface height. Mathematical models generated revealed that a similar pattern of response occurred as described in the literature for temperate grass species. However, a seasonal variation in response curves for growth and senescence was also observed and could be related to climatic events. Highest herbage accumulation rates were observed within the range of 15 to 20 cm …

Yields And Sward Characteristics Of Timothy Cultivars Under Grazing, H. T. Kunelius, G. H. Dürr, K. B. Mcrae, S. A. E. Fillmore

IGC Proceedings (1977-2023)

Seven timothy (Phleum pratense L.) cultivars were evaluated over three pasture seasons under rotational grazing to 7 or 11 cm post-grazing heights and regrowth periods of four to seven weeks. There was a trend for the pasture type timothy cultivars to outyield Champ timothy (check). Dry matter yields were lower for the 7 cm than 11 cm post-grazing height. Although the overall cultivar x post-grazing height interaction was not significant (P > 0.05), there was variability in grazing tolerance among timothy cultivars. Yield of Kahu was maintained and vegetative tiller density of Kahu increased over the experimental period under 7 …

A Technique For Assessing Seed Survival Of New Pasture Legumes Following Grazing By Sheep, Caroline T. De Koning, P. E. Beale, A. J. Duncan, S. Hughes, K. Haskard

IGC Proceedings (1977-2023)

A technique for assessing the fate of seed grazed by sheep in small field plots was examined using the pasture species Trifolium michelianum cv. Paradana, Medicago truncatula cv. Mogul, Trifolium spumosum and Trigonella balansae. Trifolium spumosum lost the greatest proportion of seed from dry pasture residues (88% seed eaten), whereas Trigonella balansae, Paradana and Mogul lost 61%, 55% and 53% respectively. However, Trifolium spumosum and Paradana had high levels of seed in the faeces (56.8 kg/ha and 65.2 kg/ha respectively), whereas Mogul and Trigonella balansae had low levels (10.3 kg/ha and 11.0 kg/ha respectively). Mogul, due to it's …

Seasonal Growth Curves Of Perennial Ryegrass In Mexico, M. E. Z. Velasco, Alfonso Hernández-Garay, J. P. Pérez, V. A. González-Hernández

IGC Proceedings (1977-2023)

An experiment was established at Colegio de Postgraduados Research Station, Texcoco, México to evaluate the seasonal pattern of growth curve of perennial ryegrass (Lolium perenne) swards. Growth rate increases rapidly from a low level immediately after defoliation, and eventually reaches an equilibrium level as the amount of green leaf in the sward stabilize. The time required to reach this state varied according to the season of year, with the four seasons ranked in the order: spring (4 weeks) < summer (5 weeks) < autumn and winter (6 weeks). Once swards reached equilibrium, growth rates started to decline as a consequence of an increase in dead material and pseudostem. These increases were highest in spring and lowest in winter. The results of this study suggest that sward management to maximise herbage production and utilisation in ryegrass swards must be done once the highest green leaf mass is reached. In this trial, it was reached at 5, 6, 6 and 4 weeks in summer, autumn, winter and spring, respectively.

The Effects Of Planting Density On The Dry Matter Yield And The Overwintering Ability Of The Dwarf And Normal Napiergrasses In Two Years After Planting, Yasuyuki Ishii, M. M. Mukhtar, Sayan Tudsri

IGC Proceedings (1977-2023)

The objective of this study is to determine the optimum planting density in napiergrass (Pennisetum purpureum Schumach) among two dwarf varieties introduced from Thailand and two normal ones under three levels of density. Dwarf varieties showed lower plant height and mean tiller weight, and higher leaf area index (LAI) and leaf blade percentage. Crop growth rate was positively correlated with LAI, and net assimilation rate and canopy extinction coefficient (K) were negatively correlated with LAI in the second year, including all dwarf and normal varieties, while K tended to be lower in the dwarf varieties. With the increase in …

Light Interception And Dry Matter Yield In Grass/Legume Mixtures, H. A. Jönsson

IGC Proceedings (1977-2023)

The influence of grass variety on light interception and dry matter yield in a grass/clover mixture was studied. Two varieties of timothy (Phleum pratense L.) and five varieties of ryegrass (Lolium spp) as components in a mixture were compared during the spring period up to the first cut of the third harvest year. By replacing the timothy variety in the mixture both light interception and dry matter yield were significantly affected. The leaf orientation was thought to be a contributing factor with erect leaves intercepting less light. There were no significant differences neither in light interception nor …

Photosynthetic Light Response Of Tanzania Grass Under Four Levels Of Leaf Temperature, A. C. L. De Mello, P. M. Santos, Carlos G. S. Pedreira, M. Corsi, C. T. Dos S. Dias

IGC Proceedings (1977-2023)

The purpose of this paper is to establish photosynthetic light response curves for Tanzania grass (Panicum maximum Jacq.) under four leaf temperature levels. Photosynthetic rate was measured as a response to levels of photosynthetic photon flux density (PPFD) on the youngest fully expanded leaves of 12 representative tillers with an infra red gas analyzer. The effect of PPFD was tested for each leaf temperature level in a randomized complete block design. Photosynthetic light response curves were adjusted for each leaf temperature using a non-linear hyperbolic model. The maximum photosynthetic response was 25,59; 31,43; 34,57 and 27,53 µmol CO_{2 …}

Nonstructural Carbohydrate Reserves Of Temperate Perennial Grasses In Autumn Early Growth, Y. Tamura, K. Matoba, A. Fushimi, M. Moriyama

IGC Proceedings (1977-2023)

The objective of this study was to determine levels of nonstructural carbohydrate reserves of four temperate perennial grasses: Orchardgrass (Dactylis glomerata L.), Timothy (Phleum pratense L.), Perennial ryegrass (Lolium perenne L.), and Reed canarygrass (Phalaris arundinacea L.) in their early growth stages during the cool autumn temperatures in northern Japan. At the time of sampling, all grasses were in their vegetative stage, and Reed canarygrass was not forming rhizomes. Fructosan concentration in reed canarygrass roots (8.04%) was 22 times that of the leaf blade (0.36%) and twice that of the stem (3.40%); the concentration in reed …

Effect Of Cutting Height On Tiller Population Density And Herbage Biomass Of Buffel Grass, L. S. Beltrán, P. J. Pérez, G. A. Hernández, M. E. García, S. J. Kohashi, H. J. G. Herrera

IGC Proceedings (1977-2023)

The aim of this trial was to investigate the effect of different cutting heights on tiller population density and herbage biomass of Buffel grass (Cenchrus ciliaris L) grown in miniature swards in a greenhouse. Four treatments with five replicates: five cm, ten cm, and 20 cm cutting height, and control (without cut) were randomly allocated. Intensity of defoliation affected the cumulative herbage harvested; the ten cm cutting height was greater (404.1 g DM m^-2) than 5 cm (317.6 g DM m^-2) and 20 cm (263.9 g DM m^-2), respectively. Cumulative herbage harvested in …

Leaf Appearance Rate In Brachiaria Decumbens Grown In Nitrogen And Potassium Rates, M. D. C. Ferragine, F. A. Monteiro, S. C. Da Silva

IGC Proceedings (1977-2023)

A greenhouse experiment was carried out with Brachiaria decumbens Stapf. cv. Basilisk grown in nutrient solution. Five nitrogen rates (42; 140; 238; 336 and 434 mg/L) and three potassium rates (78; 234 and 390 mg/L) were studied in a factorial experiment, in a randomized complete block design, with four replications. Green leaf number was evaluated in six times in the first period of growth (27, 30, 33, 36, 39 and 42 days after transplanting) and nine times in the second period (45, 48, 51, 54, 57, 60, 63, 66 and 69 days after transplanting). Data was registered in three plants …

Morphogenesis And Defoliation Frequency Of Italian Ryegrass (Lolium Multiflorum) And Paspalum Urvillei In Lowland Under Three Levels Of P And K, Fernando L. F. De Quadros, A. G. S. Pigatto, D. G. Bandinelli, E. Marchezan, Marta G. Da Rocha

IGC Proceedings (1977-2023)

This trial was conducted to evaluate growth dynamics and defoliation frequency of Italian ryegrass (Lolium multiflorum) and Paspalum urvillei in a lowland area under three levels of P and K. Using randomization tests we observed that, in a general way, fertilizer treatments were not the determinant factors of leaf appearance and elongation rates for both species. Only the leaf appearance rate of Paspalum urvillei at 100 % of recommendation level and the elongation rate for Italian ryegrass, in the same treatment, was different. Probably other factors, like drainage, are contributing to these results. I. ryegrass phyllochron ranged from …

Variability In Herbage Mass And Chemical Composition Within A Timothy Sward, O. Niemeläinen, E. Miettinen, P. Virkajärvi, L. Alakukku, K. Hakala

IGC Proceedings (1977-2023)

Variability in herbage mass (HM) and chemical composition of timothy (Phleum pratense L.) sward was studied in a three-hectare field. The field, which was flat, was divided into twelve sections and a sampling site was randomly selected in each. The study was carried out in Sotkamo (64^o 01’N, 28^o22’E) research station in Finland. Snow depth and frost conditions were measured in winter and soil water content was monitored in the growing season at each sampling site. Observations on the crop included assessment of herbage ground cover and winter damage percentage, stand height and HM and analysis …

Effects Of Temperature, Nitrogen Fertilisation And Leaf And Tiller Age On Specific Leaf Area Of Brachiaria Decumbens, J. Busqué, M. Herrero

IGC Proceedings (1977-2023)

Signal grass (Brachiaria decumbens Stapf) micro-swards were grown under controlled environmental conditions at different temperatures and nitrogen fertilisation rates. Specific leaf area was responsive both to temperature and nitrogen, but did not change with the level of insertion of the leaf in the tiller. Senescing leaves had higher specific leaf area than old extended green leaves and these had higher values than new extended green leaves. Changes in specific leaf area were more related to changes in leaf area and more exactly to changes in leaf width.

The Use Of Cover Crops After A Maize Crop In The North Of Spain, D. Báez, M. Pinto, M. Rodríguez, G. Besga, J. M. Estavillo

IGC Proceedings (1977-2023)

This work intends to study N leaching losses in a field assay when crimson clover (Trifolium incarnatum) and italian ryegrass (Lolium multiflorum) was incorporated into the soil and quantify the their effect on N₂O, N total gaseous losses under controlled soil moisture and temperature conditions. Field assay: A split-plot design where main plot was the cover crop and the subplot was the rate of fertilizer (0 and 150 kg N ha^-1) applied to the subsequent maize crop. Laboratory assay: Residues of italian ryegrass and crimson clover were mixed with soil in containers, …

Multi-Year Application Of Dairy Slurry On Grassland: Effects On Crop, Soil Biota, Soil Nutrients, And N2O Emission, Shabtai Bittman, C. G. Kowalenko, D. E. Hunt, N. Patni, J. Paul, D. Raworth, J. Hountin, T. A. Forge, C. M. Monreal, O. Schmidt

IGC Proceedings (1977-2023)

The long-term effects of using manure as the principal nutrient source in intensive crop production systems are not well known. This paper reports on the effects of multi-year application of fertilizer or dairy slurry on a tall fescue (Festuca arundinacea Schreb.) sward. Slurry sustained greater grass yield than chemical fertilizer. Unlike fertilizer, slurry supplied 70 to 120 kg N/ha one year after application but little after one year; 4-years of manure applications built up the stable organic matter pool in the soil. Manure-N was less prone to leaching but more prone to N₂O emissions than fertilizer-N. Manured …