Weed Science Commons^™

Prediction Of Herbage Accumulation Of Cynodon Grasses By An Empirical Model Based On Temperature And Daylength, H. R. De Medeiros, Carlos G. S. Pedreira, N. A. Villa Nova, L. G. Barioni, A. C. C. Mello

IGC Proceedings (1977-2023)

The objective of this work was to estimate dry matter production of Cynodon grasses as a function of photothermal units (PU). Total PU values were calculated for the period from February 1 to April 24, 1996, from a location in southeastern Brazil. Regression analysis was run between PU and herbage production from a published data set on five Cynodon cultivars, with an r² of 0.9983. Differences between measured and estimated values were under 5%. Model testing using an independent data set on herbage dry matter production from grazed Cynodon pastures showed an overestimation, probably due to water deficit during …

Water Management For Establishment Of Alfalfa (Medicago Sativa L.), J. B. Rassini, E. J. A. Leme

IGC Proceedings (1977-2023)

This research was carried out in 1997, at the “Centro de Ciências Agrárias” of the “Universidade Federal de São Carlos”, in Araras, SP, Brazil, to evaluate the behavior of three growth stages (S₁ = initial vegetative stage, S₂ = full vegetative stage, and S₃ = reproductive stage) of the “Crioula” alfalfa cultivar, in the presence of four water levels (L₁ = 100%, L₂ = 80%, L₃ = 45-50% and, L₄ =20-25% of a sprinkler irrigation) in a field trial. Growth stages changed according to water levels, and S₂ stage was the most …

High Salinity Effects On The Components Of Relative Growth Rate In Rhodes Grass, E. Taleisnik, L. García Seffino, A. Córdoba, K. Grunberg, C. Arias, M. De Luca

IGC Proceedings (1977-2023)

Rhodes grass (Chloris gayana Kunth), is widely cultivated in the semiarid tropics and favored for its salt tolerance. Nevertheless, productivity decreases significantly under saline conditions, especially in tetraploid cultivars. The purpose of this work was to explore, in tetraploid cultivar Boma, the physiological causes for the observed salt-associated growth reduction. The effects of high salinity (200 mM NaCl) on the components of relative growth rate were analyzed in greenhouse experiments. An early reduction in leaf area expansion was observed, which later resulted in decreased dry matter accumulation. Plant leafiness was reduced by effects both on dry matter allocation to …

Evaluation Of Fertilizing Methods On The Establishment Of Pasture Species On Native Pasture By Direct Sowing, O. L. P. Oliveira, S. S. Gonzaga, J. O. N. Gonçalves, E. N. Muniz, T. M. S. Freitas, L. P. Grando

IGC Proceedings (1977-2023)

The experiment was carried out in the southern of Brazil, by direct sowing ryegrass (Lolium multiflorum), white clover (Trifolium repens), birds foot trifolium (Lotus corniculatus) and red clover (Trifolium pratensis) on native pasture. Herbicide Glyfosate was previously applied on this native pasture. The treatments were T1 -seed sowing in row with half fertilizer in row and half broadcasting; T2 – seed sowing in row with all fertilizer in row; T3 – seed sowing in row and all fertilizer broadcasting; T4 – seed and fertilizer broadcasting. The pasture was evaluated by two cuts …

Interactions Between The Effects Of Nitrogen, And Phosphorus, Potassium And Sulphur On Grass Production, J. D. Morton, L. C. Smith

IGC Proceedings (1977-2023)

The interactions between rates of nitrogen (N) and rates of phosphorus (P), potassium (K) or sulphur (S) on yield of ryegrass dominant swards were measured with no return of mown clippings in Southland, New Zealand. In the second year of the trial, the yield response to 176 kg N ha^-1 compared with no N increased only slightly with increasing soil Olsen P from 8 to 91 µg g^-1 soil. At 352 and 704 kg N ha^-1 there was a large increase in the yield response (from 5 to 9.4 and 11 t DM ha^-1 respectively) up …

Application Of Near Infrared Reflectance Spectroscopy (Nirs) For Macronutrients Analysis In Alfalfa (Medicago Sativa L.), A. Morón, D. Cozzolino

IGC Proceedings (1977-2023)

Near infrared reflectance spectroscopy was used to assess the mineral composition of alfalfa (Medicago sativa L.) as a tool for nutritional diagnosis. One hundred and ninety four (n = 194) samples of alfalfa from different locations representing a wide range of soils were used. Samples were reflectance scanned in a NIRS 6500 (NIRSystems, USA) instrument. The coefficients of determination (R²) of the regression estimate of the concentration of nitrogen, calcium, phosphorus, potassium, magnesium and sulphur and the errors in cross validation (SECV) were 0.93 (SECV: 1.6), 0.95 (SECV: 1.3), 0.93 (SECV: 1.9), 0.88 (SECV: 2.8), 0.82 (SECV: …

Phosphorus, Sulphur And Micronutrients On Grassland Improvement With White Clover (Trifolium Repens L.) On Basaltic Soils In Uruguay, A. Morón, D. F. Risso

IGC Proceedings (1977-2023)

Grasslands improvement with legumes is a promising technology for increasing forage quality and productivity on basaltic soils, but requires the correction of nutrient deficiencies. Phosphorus is a key element, but usual techniques of soil analysis are not good predictors. An experimental work was conducted in the northern region of the country. Evaluating the response of an improvement with white clover to P. Citric Acid showed a good association between soil P status and legume behavior. In addition there was a positive trend in forage production, in relation to S application, even though this effect was only significant in legume yield …

Effect Of Liquid Cattle Manure Application On The Botanical Composition Forage Dry Yield And Soil Chemical Characteristics In Mixed Pastures, J. K. Lee, W. H. Kim, D. E. Shin, S. Seo, G. J. Choi, E. S. Chung, G. J. Park

IGC Proceedings (1977-2023)

Many farmers apply liquid cattle manure on grassland, often in excess of crop N requirement, resulting in groundwater contamination. Our experiment was carried out to determine the effect of liquid cattle manure application on the botanical composition, forage dry yield and soil chemical characteristics in mixed pastures at the forage experimental field, National Livestock Research Institute, RDA, Korea. Five treatments consisting of no fertilizer, chemical fertilizer (210kg N/ ha), liquid cattle manure (40, 60 and 80 ton N/ ha) were arranged in a randomized complete block design with three replicates. No fertilizer treatment consistently had lower botanical composition rate of …

Nutrient Dynamics And Inventory In Tropical Grassland Ecosystem In Southern India, K. Karunaichamy, Kailash Paliwal

IGC Proceedings (1977-2023)

The present study was to ascertain the distribution of calcium (Ca), magnesium (Mg) and sodium (Na) in the different plant components and in the soil top 30 cm at Kalikesam in Western Ghats region of southern India. Magnesium concentration increased in the order: dead shoots > belowground > litter > aboveground live. Sodium concentration in live shoots was maximum in February (0.51%) and minimum in August (0.05%). Annually 8.94 g/m² Ca, 2.41g/ m² Mg and 2.30g/ m² Na was taken up by plants. The distribution of the three nutrients in plant/soil system indicated that the major portion of the nutrients …

The Effect Of Fermented Saw-Dust Pig Manure On Forage Mineral Contents And Soil Fertility In Cheju Volcanic Ash Soil, M. C. Kim, T. G. Kim

IGC Proceedings (1977-2023)

Studies were carried out to investigate the change of soil characteristics and pasture minerals as affected by fermented saw-dust pig manure(FSM) applied to mixed pasture of a brown volcanic ash soil during the period from October 1996 to October 1998. Pasture mixed with orchardgrass (Dactylis glomerata L.) and white clover (Trifolium repens L.) was treated with N 200kg/ha + P 300kg/ha +K 200kg/ha(T1), N 100kg/ha + 10 ton/ha FSM(T2), FSM 10 ton/ha(T3), 20ton/ha FSM(T4), 40ton/ha FSM(T5) or 80ton/ha FSM(T6). K and P contents of mixed pasture in the 3rd year after sowing increased significantly with increasing levels of …

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 …