Ammonia Losses By Volatilization From Coastcross Pasture Fertilized With Two Nitrogen Sources,
2021
Instituto Agronômico de Campinas, Brazil
Ammonia Losses By Volatilization From Coastcross Pasture Fertilized With Two Nitrogen Sources, H. Cantarella, L. De A. Corrêa, A. C. Primavesi, O. Primavesi, A. R. De Freitas, A. G. Da Silva
IGC Proceedings (1977-2023)
Ammonia losses by volatilization from five rates of urea or ammonium nitrate surfaceapplied to coastcross pasture, grown on a dark red latosol (Hapludox) in São Carlos, SP, Brazil, under tropical altitude climate, were measured. Volatilized ammonia was absorbed in traps placed on soil surface. The mean losses from urea applied after five successive cuttings of the grass were 15, 24, 34, and 40% for N rates of 25, 50, 100 and 200 kg N ha-1 per cutting, respectively.
Assessing The Effect Of N And P Supply On Dry Matter Yield Of Three Tropical Grasses,
2021
INRA, France
Assessing The Effect Of N And P Supply On Dry Matter Yield Of Three Tropical Grasses, O. Topall, C. Jouany, M. Duru, P. Cruz
IGC Proceedings (1977-2023)
The objectives are to study the effects of N and P supply and their interaction, on herbage dry matter yield and nutrient status of three tropical grasses. In order to estimate direct and indirect effects of P supply we express above-ground dry matter production as a function of the herbage nutrient status obtained from plant analysis. Results show that in absence of N, the significant increase in P nutrition status has only moderate consequences on herbage production and suggest that both N and P are limitant for herbage growth. P fertilization results in significant increase in dry matter yield only …
Mineral Acquisition And Utilization Strategy Of Three Tropical Forages At Different Phosphorus And Nitrogen Supply,
2021
Fundação de Apoio a Pesquisa Agropecuária e Ambiental, Brazil
Mineral Acquisition And Utilization Strategy Of Three Tropical Forages At Different Phosphorus And Nitrogen Supply, J. D. G. Santos Junior, Tsutomu Kanno, Manuel C. M. Macedo, M. R. Correa, L. G. Beretta
IGC Proceedings (1977-2023)
A glasshouse experiment was conducted to examine mineral acquisition and utilization strategies of Brachiaria decumbens (BD), Brachiaria brizantha (BB) and Panicum maximum (PM). The plants were grown under nine treatments resulted from the combination of three levels of phosphorus (0, 25 and 50 kgP/ha) and three levels of nitrogen (25, 150 and 300 kgN/ha). BD showed the lowest value of root weight and root length per pot, but the highest efficiency of P and N uptake (P and N uptake mg / unit root weight g). On the other hand, PM showed lower mineral uptake efficiency, but the highest mineral …
Sources And Rates Of Phosphorus In Improving Degraded Pasture In Brazilian West Amazon,
2021
Instituto de Zootecnia, Brazil
Sources And Rates Of Phosphorus In Improving Degraded Pasture In Brazilian West Amazon, Valdinei T. Paulino, N. L. Costa, C. R. Townsend, J. A. Magalhães, R. G. A. Periera
IGC Proceedings (1977-2023)
The effects of phosphorus sources (triple superphosphate – TSP, single superphosphate – SSP and partially acidulated rock phosphate – PARP) and rates (0, 50 and 100 kg/ha of P2O5 on dry matter (DM) yields and chemical composition of a degraded Brachiaria brizantha cv. Marandu pasture were evaluated in a cutting trial. Phosphorus fertilization, irrespective of sources and rates, showed an effective agronomic technique for pasture recuperation. The grass DM yields and potassium contents were significantly improved by phosphorus application, while weed DM yields were depressed. Irrespective of sources and rates, crude protein, phosphorus, and calcium contents were …
Implications Of Cover Crop Planting And Termination Timing On Rainfed Maize Production In Semi-Arid Cropping Systems,
2021
University of Nebraska–Lincoln
Implications Of Cover Crop Planting And Termination Timing On Rainfed Maize Production In Semi-Arid Cropping Systems, Alexandre T. Rosa, Cody Creech, Roger W. Elmore, Daran Rudnick, John L. Lindquist, Miguel Fudolig, Liberty E. Butts, Rodrigo Werle
Department of Agronomy and Horticulture: Faculty Publications
Despite the potential to increase soil organic matter, cycle soil nutrients, and suppress weeds, there is a concern that cover crops (CCs) soil water use negatively impacts subsequent crops in water-limited environments. Cover crop management practices such as planting and termination timing may mitigate the detrimental impacts of CCs in semi-arid cropping systems. To determine the effects of CCs under water-limited environments, we evaluated the total CC biomass produced in the fall and spring, soil water content during the subsequent maize growing season, weed density and biomass, crop residue, and soil nutrients at the maize V6 development stage, and maize …
Contributions Of Individual Cover Crop Species To Rainfed Maize Production In Semi-Arid Cropping Systems,
2021
University of Nebraska-Lincoln
Contributions Of Individual Cover Crop Species To Rainfed Maize Production In Semi-Arid Cropping Systems, Alexandre T. Rosa, Cody Creech, Roger W. Elmore, Daran Rudnick, John L. Lindquist, Liberty Butts, Italo K. Pinho De Faria, Rodrigo Werle
Department of Agronomy and Horticulture: Faculty Publications
Cover crop (CC) species selection can contribute to reducing soil penetration resistance (brassica species), improved soil nitrogen (N) cycling (legume species), and suppression of weeds (grass species). However, one of the main concerns about including CCs in water-limited environments is soil water use and the consequences to subsequent crops. To determine the effects of individual CC species under water-limited environments, we evaluated fall and spring CC biomass produced, and soil water and N content, penetration resistance, weed density and biomass during the maize growing season, and maize grain yield. The experiment was conducted under a winter wheat-maize-fallow rotation at two …
Understanding Shoot And Root Development,
2021
Massey University, New Zealand
Understanding Shoot And Root Development, C. Matthew, E. N. Van Loo, E. R. Thom, L. A. Dawson, D. A. Care
IGC Proceedings (1977-2023)
Shoot and root development of the grass tiller is presented as a series of events on the tiller axis. Leaf, tiller bud, true stem, and root development are successive events in the life cycle of a single phytomer and the tiller is a co-ordinated series of phytomers, successive phytomers being progressively more advanced than the previous phytomer. In reviewing the individual growth processes of leaf, tiller, true stem, and root formation, fundamental determinants of light and nutrient capture are examined and examples presented to illustrate the link between component processes, plant morphogenesis, and plant performance. An example of the application …
Ecophysiology Of Grasslands: Dynamic Aspects Of Forage Plant Populations In Grazed Swards,
2021
INRA, France
Ecophysiology Of Grasslands: Dynamic Aspects Of Forage Plant Populations In Grazed Swards, G. Lemaire
IGC Proceedings (1977-2023)
The aim of this paper is to review knowledge of the ecophysiological mechanisms influencing the dynamics of plant populations in grazed swards. Such an objective requires some definitions. Firstly, it is necessary to define “ecophysiology” as the study of the interactions between biological individuals (plants) with their own environment: how individuals perceive and react to any constraint and change of their environment, and how the functioning of plants as a population can modify their own environment. Such a definition implies a dynamic approach to pant population functioning as resulting from constant plant-plant interactions mediated by micro-environment modifications. In a grazed …
Bite Depth Penetration Patterns Of Dairy Cows Foraging On Complex Swards,
2021
Massey University, New Zealand
Bite Depth Penetration Patterns Of Dairy Cows Foraging On Complex Swards, W. M. Griffiths, J. Hodgson, G. C. Arnold
IGC Proceedings (1977-2023)
Sward height was the dominant cue used by dairy cattle to determine the depth of penetration on young vegetative swards. On more complex swards, bite depth penetration was controlled by variations in the depth of regrowth. Evidence showed that cattle grazed to the pseudostem:lamina interface, but sward height exerted a stronger effect on bite depth than pseudostem height. Modelling efforts to predict how the herbivore places bites in space in the vertical dimension across sward states are currently being restricted by the absence of detailed canopy structure descriptions. We argue that the contrast between strata is an important determinant of …
The Effect Of Progressive Grazing Of A Pasture On The Spatial Distribution Of Herbage Mass And Utilization By Cattle,
2021
University of Miyazaki, Japan
The Effect Of Progressive Grazing Of A Pasture On The Spatial Distribution Of Herbage Mass And Utilization By Cattle, Masahiko Hirata, S. Ogura
IGC Proceedings (1977-2023)
To develop an understanding of the spatially heterogeneous grazing of a pasture by large herbivores under progressive grazing, the herbage mass, herbage consumption and ingestive behavior by cattle were monitored daily at ninety-one 50 × 50 cm permanent locations in a bahiagrass (Paspalum notatum Flügge) pasture during a 6-day grazing period. With the progress of grazing, the mean pre-grazing herbage mass over the locations decreased. Responding to this, the mean number of visits and the mean rate of biting increased, and the mean residence time and the mean rate of defoliation decreased. The pre-grazing herbage mass became more heterogeneous, …
Nitrogen Response Efficiencies From Grazed Dairy Pastures Under Dry Conditions,
2021
Department of Natural Resources and Environment, Australia
Nitrogen Response Efficiencies From Grazed Dairy Pastures Under Dry Conditions, Frank R. Mckenzie, Joseph L. Jacobs
IGC Proceedings (1977-2023)
Experiments were conducted within a long-term nitrogen (N) fertiliser experiment under grazing. The objective was to examine N response efficiencies (kg dry matter (DM)/kg N) and herbage crude protein (CP) content to fertiliser N applied under dry soil conditions (gravimetric soil moisture content of 17% at 10cm; soil field capacity = 38% and wilting point = 11%) during autumn (April 1999) and late spring (November 1999) in southeastern Australia. Visually, N treated plots were greener in colour than control (no N) plots. No differences were recorded in primary or residual DM yields, N response efficiencies, and pasture growth rates between …
Effect Of Defoliation Frequency And Planting Density On Yield And Nutritive Value Of Coursetia Ferruginea (Hbk) Lavin,
2021
Universidad del Zulia, Mexico
Effect Of Defoliation Frequency And Planting Density On Yield And Nutritive Value Of Coursetia Ferruginea (Hbk) Lavin, H. J. Delgado Gómez, R. González Anciani, G. López, D. Urdaneta, L. Ramírez Avilés
IGC Proceedings (1977-2023)
The aim of the present study was to asses the influence of the frequency of defoliation and density of sowing on yield and nutritive value of Coursetia ferruginea. Three defoliation frequencies (6, 8 and 10 weeks) and three densities of planting (1 x 1 m, 1 x 1.5 m and 1 x 2 m) were evaluated. A randomized block design, in a split plot arrangement and four repetitions, was used. Frequency of defoliation has a strong significant (P< 0.01) effect on dry matter (DM) yield (13.6, 18.1 and 27.8 g DM/plant for 6, 8 and 10-week defoliation frequencies), plant height (63.5, 76.6 and 101.2 cm) and plant survival (71, 74 and 86%). Nutritive value was significantly (P< 0.05) affected by the frequency of defoliation. Mineral content was reduced as the defoliation interval increased. Density of planting did not affect (P> 0.05) any of the variables. It is concluded that, C. ferruginea is a forage shrub with potential to improve animal feed …
Leaf Elongation Rate Of Mediterranean And Temperate Tall Fescue Cultivars Under Water Deficit,
2021
INTA, Argentina
Leaf Elongation Rate Of Mediterranean And Temperate Tall Fescue Cultivars Under Water Deficit, Silvia G. Assuero, C. Matthew, Mónica G. Agnusdei
IGC Proceedings (1977-2023)
The leaf elongation rate of a temperate (Festuca arundinacea Schreb.) and a Mediterranean (F. arundinacea var. letourneuxiana) tall fescue cultivar in response to water deficit was studied in a glasshouse experiment. Plants of both cultivars were grown in the same containers and received water daily with gradation in intensity of water deficit achieved by varying the daily water ration per container. Leaf elongation rate (LER) was calculated for eight successive subperiods during the application of the water treatments. Under the high temperatures registered in this experiment, the Mediterranean cultivar showed lower LERs and tended to be less …
Prediction Of Herbage Accumulation Of Cynodon Grasses By An Empirical Model Based On Temperature And Daylength,
2021
Universidade de São Paulo, Brazil
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.),
2021
EMBRAPA, Brazil
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,
2021
INTA, Argentina
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,
2021
EMBRAPA, Brazil
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,
2021
AgResearch, New Zealand
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.),
2021
INIA, Uruguay
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,
2021
INIA, Uruguay
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 …
