Open Access. Powered by Scholars. Published by Universities.®

Agronomy and Crop Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

2023

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1501 - 1530 of 1788

Full-Text Articles in Agronomy and Crop Sciences

Modelling The Digestibility Decrease Of Three Grass Species During Spring Growth According To The Age Of The Grass, The Thermal Age And The Yield, M. E. Salamanca, R. Lambert, M. Gomez, A. Peeters Feb 2023

Modelling The Digestibility Decrease Of Three Grass Species During Spring Growth According To The Age Of The Grass, The Thermal Age And The Yield, M. E. Salamanca, R. Lambert, M. Gomez, A. Peeters

IGC Proceedings (1977-2023)

The nutritive value of forage changes during growth. For the protein content, a general evolution curve was found with the yield increase (Salette & Lemaire, 1984). The digestibility of the organic matter decreases during growth as cellulose and lignin content increase. Regrowth age is the main factor, which explains the digestibility decrease (Demarquilly & Jarrige, 1981). The crop age can be expressed in number of growth days but also in thermal age (cumulated temperature). We compared the digestibility change of three grass species during spring growth for two years as a function of yield increase, thermal age or number of …

Go to article

Visual Modelling Of Alfalfa Growth And Persistence Under Grazing, S. R. Smith Jr., L. Muendermann, A. Singh Feb 2023

Visual Modelling Of Alfalfa Growth And Persistence Under Grazing, S. R. Smith Jr., L. Muendermann, A. Singh

IGC Proceedings (1977-2023)

A ‘virtual’ alfalfa plant model was developed at the University of Manitoba in Canada as part of a comprehensive grazing research project. This model shows an alfalfa plant ‘growing’ on a computer screen and the plant’s response to grazing (similar to time-lapse photography). The original model was constructed by Singh (2005) to show the research potential of visually modelling alfalfa plant growth. The ability to visually ‘grow’ a plant on a computer screen also offers tremendous opportunities for teaching and extension. Detailed morphological measurements were used in the construction of Singh’s model, based on single plants subjected to the following …

Go to article

A New Agro-Meteorological Simulation Model For Predicting Daily Grass Growth Rates Across Ireland, R. P. O. Schulte Feb 2023

A New Agro-Meteorological Simulation Model For Predicting Daily Grass Growth Rates Across Ireland, R. P. O. Schulte

IGC Proceedings (1977-2023)

Grass growth rates and herbage yields depend on weather conditions, soil characteristics and grassland management and differ from year to year and from site to site. In the past, grass growth has been predicted using both mechanistic and statistical models. The accuracy of mechanistic models is commonly insufficient for practical application, while statistical models generally apply to one test site only (e.g. Han et al., 2003). In this paper a semi-empirical grass growth model is presented which is numerically accurate, but which can be applied to contrasting sites across Ireland at the same time.

Go to article

A Farmer-Based Decision Support System For Managing Pasture Quality On Hill Country, I. M. Brookes, D. I. Gray Feb 2023

A Farmer-Based Decision Support System For Managing Pasture Quality On Hill Country, I. M. Brookes, D. I. Gray

IGC Proceedings (1977-2023)

Despite considerable effort to promote formal feed budgeting in New Zealand, survey data suggests it is only adopted by 20% of farmers (Nuthall & Bishop-Hurley, 1999). Recent work (Gray et al., 2003) has identified that farmers may use a different approach - micro-budgeting - to manage feed. Rather than operate at a whole farm level, micro-budgeting focuses at the paddock level. This paper describes micro-budgeting as used by a high performing hill country sheep and cattle farmer to manage pasture quality over spring and a decision support model developed to help other farmers undertake this process

Go to article

Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management, L. Delaby, J. L. Peyraud, P. Faverdin Feb 2023

Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management, L. Delaby, J. L. Peyraud, P. Faverdin

IGC Proceedings (1977-2023)

The feeding of dairy cows at pasture presents many technical, economic and environmental advantages, while benefiting from a very favourable image. However, the management of grazed land is a complex game of strategy in which the farmer applies decisions in order to manage two unstable and uncertain fluxes of change: growth of grass and intake of the herd. Many tools (platemeter, etc.) and overall methods (local stocking rate references, farm cover, etc.) have been developed as aids to grazing management. Nevertheless, few decision-support systems are currently available that make it possible to anticipate and assess the consequences of a given …

Go to article

Understanding Livestock Grazing Impacts: A Decision Support Tool To Develop Goal-Oriented Grazing Management Strategies, S. J. Barry, K. Guenther, G. Hayes, R. Larson, G. Nader, M. Doran Feb 2023

Understanding Livestock Grazing Impacts: A Decision Support Tool To Develop Goal-Oriented Grazing Management Strategies, S. J. Barry, K. Guenther, G. Hayes, R. Larson, G. Nader, M. Doran

IGC Proceedings (1977-2023)

Managing grasslands in the western United States has become much more complex over the last few decades. A century ago the goal was to survive as a livestock producer, and grassland management involved using forage effectively and overcoming obstacles such as predators and shortages of water and feed. Today the successful grassland manager also needs to consider the diversity and health of the ecosystem as a whole. Livestock grazing can negatively and/or positively affect riparian areas, sensitive plants, and endangered wildlife. Since the impact on a specific factor will vary depending on the timing, intensity and class of livestock grazed, …

Go to article

Enhancing Grasslands Education With Decision Support Tools, H. G. Daily, J. M. Scott, J. M. Reid Feb 2023

Enhancing Grasslands Education With Decision Support Tools, H. G. Daily, J. M. Scott, J. M. Reid

IGC Proceedings (1977-2023)

We have successfully used Decision Support Tools (DST) relevant to the management of grazing enterprises to enhance problem solving skills of undergraduates in Australia. Tools such as GrassGro™ (Moore et al., 1997) and GrazFeed™ (Freer et al., 1997) are accessed from a central server by authorised users at many widely dispersed Universities across Australia using remote access to thin-client technology via an Internet portal. This has been supplemented with training for lecturers. Experience in developing appropriate teaching and learning materials and the reliable delivery of simulation software to many clients has enhanced learning outcomes at tertiary level. We …

Go to article

A Farmer Friendly Feed Budget Calculator For Grazing Management Decisions In Winter And Spring, M. Curnow, M. W. Hyder Feb 2023

A Farmer Friendly Feed Budget Calculator For Grazing Management Decisions In Winter And Spring, M. Curnow, M. W. Hyder

IGC Proceedings (1977-2023)

The Western Australian (WA) environment is Mediterranean with annual legume/grass pastures and a 6 month growing season. In autumn where over grazing can impact pasture establishment and in spring, prior to senescence, when under grazing can mean significant losses of efficiency are crucial times for grazing management. Pasture utilisation is typically low (25-35%) due to conservative stocking regimes; key to increasing productivity is increasing pasture utilisation (Grimm, 1998). Increased levels of productivity require farmer sophistication in the way they feed budget. To this end, satellite technology is being used to provide farmers in southern Australia with weekly estimates of pasture …

Go to article

Simulation Of Pasture Phase Options For Mixed Livestock And Cropping Enterprises, L. Salmon, A. D. Moore, J. F. Angus Feb 2023

Simulation Of Pasture Phase Options For Mixed Livestock And Cropping Enterprises, L. Salmon, A. D. Moore, J. F. Angus

IGC Proceedings (1977-2023)

In southern Australia, 50% of grain-producing farms also run beef and/or sheep enterprises. Legume pasture leys are used to replace soil nitrogen and manage crop disease risks. Deep-rooted perennials, predominantly lucerne (Medicago sativa), are replacing annual Trifolium subterraneum-based leys to increase pasture production. They also have the environmental benefits of limiting soil acidity, rising water tables and dryland salinity. After recent droughts depletion of soil water by lucerne has penalised wheat yields. Decision support tools can help farmers evaluate the long-term effects of grazed annual and perennial leys on animal and crop production at the whole farm …

Go to article

Grasscheck: Monitoring And Predicting Grass Production In Northern Ireland, P. D. Barrett, A. S. Laidlaw Feb 2023

Grasscheck: Monitoring And Predicting Grass Production In Northern Ireland, P. D. Barrett, A. S. Laidlaw

IGC Proceedings (1977-2023)

No abstract provided.

Go to article

Effect Of Strategy Of Forage Supplementation And Of Turnout Date In A Medium Stocking Rate System On The Main Characteristics Of Dairy Cows Grazing, P. Defrance, L. Delaby, J. M. Seuret, M. O'Donovan Feb 2023

Effect Of Strategy Of Forage Supplementation And Of Turnout Date In A Medium Stocking Rate System On The Main Characteristics Of Dairy Cows Grazing, P. Defrance, L. Delaby, J. M. Seuret, M. O'Donovan

IGC Proceedings (1977-2023)

Having a stocking rate of 2.9 cows per hectare of grassland (35 ares/cow) in Brittany offers many options for turnout date and forage supplementation strategies. For a farmer, knowing the consequences of the different options during the course of the grazing season makes grazing management decisions easier. As experiments on grazing management require considerable resources and are hardly generalisable, various spring scenarios have been tested using a dynamic decision support system, Pâtur’IN (Delaby et al., this volume).

Go to article

Grass Growth Profiles In Brittany, P. Defrance, J. M. Seuret, L. Delaby Feb 2023

Grass Growth Profiles In Brittany, P. Defrance, J. M. Seuret, L. Delaby

IGC Proceedings (1977-2023)

For farmers, knowing the local grass growth profile and the possible variations between years is very helpful in managing grazing. Indeed, the comparison with herd needs and anticipated farm cover change allows decisions to be made that will maintain the cover at the desired level. This paper proposes a ten-days grass growth profile corresponding to Brittany’s different conditions of soil, climate and pasture management.

Go to article

Using The Grassgro Decision Support Tool To Evaluate The Response In Grazing Systems To Pasture Legume Or A Grass Cultivar With Improved Nutritive Value, H. Dove, J. R. Donnelly Feb 2023

Using The Grassgro Decision Support Tool To Evaluate The Response In Grazing Systems To Pasture Legume Or A Grass Cultivar With Improved Nutritive Value, H. Dove, J. R. Donnelly

IGC Proceedings (1977-2023)

Decision support tools (DST) based on models of grazing systems allow the evaluation of changes in enterprise management on productivity and profitability. The Grassgro DST (Moore et al., 1997) uses historical weather data on a daily time step to simulate pasture growth and the resultant productivity of either grazing sheep or cattle. Different pasture species are represented within a parameter set that describes the response of pasture species to their environment. Manipulation of these parameters provides a means of evaluating, a priori, the likely responses of livestock production to ‘improved cultivars’. We report the results of simulations conducted …

Go to article

Ergot And Sterility In Bahiagrass: Genotypic And Environmental Effects On Seed Yield Potential, Javier Do Canto, Rafael Reyno, Hector Oberti, Marco Dalla Rizza, Daniel Real Feb 2023

Ergot And Sterility In Bahiagrass: Genotypic And Environmental Effects On Seed Yield Potential, Javier Do Canto, Rafael Reyno, Hector Oberti, Marco Dalla Rizza, Daniel Real

Grain and Other Field Crops Research Articles

Ergot disease (Claviceps paspali) and sterility have the potential to reduce seed yield in bahiagrass (Paspalum notatum Flüggé). Our objective was to determine the genotypic and environmental effects on seed yield, and the levels of ergot and sterility. Seventeen genotypes were evaluated in three locations across two years for seed yield, ergot severity, and total seed fractions (percentage of full seeds, ergot sclerotia and empty seeds). The percentage of full seeds and total seed yield were correlated (r = 0.52) but both were negatively correlated with the percentage of ergot sclerotia (r = −0.81 and −0.51). …

Go to article

Pasture Land Management System Decision Support Software, G. E. Groover, S. R. Smith, N. D. Stone, J. J. Venuto, J. M. Galbraith Feb 2023

Pasture Land Management System Decision Support Software, G. E. Groover, S. R. Smith, N. D. Stone, J. J. Venuto, J. M. Galbraith

IGC Proceedings (1977-2023)

Controlled or rotational grazing provides benefits to producers and society through profitable and sound management of grazing land and livestock. Pasture land management system (PLMS) is a decision support system developed to help university, government, and professionals provide technical pasture management assistance to beef and dairy producers. The PLMS focuses on the balance between seasonal forage supply and nutrient demand in a dairy or beef cattle operation. It allows users to explore and compare alternatives (dividing fields into multiple paddocks, changing stocking rates, and forage species) through a visual display and embedded simulation. Users enter a description of the farm …

Go to article

Forecast Of Herbage Production Under Continuous Grazing, K. Søegaard, J. Berntsen, K. A. Nielsen, I. Thysen Feb 2023

Forecast Of Herbage Production Under Continuous Grazing, K. Søegaard, J. Berntsen, K. A. Nielsen, I. Thysen

IGC Proceedings (1977-2023)

The utilization of pasture is very sensitive to oscillations in herbage growth. The farmer’s daily planning involves decisions on pasture use as well as on the amount and composition of supplement feeding. In this planning, expected daily growth rate is an important factor. Often the knowledge and experience about the growth rate is first available after changes in management should have been made. A different growth rate than expected should lead to changes in the grazing area or in the supplement feeding. Therefore, a simple model of grass/clover growth under grazing and irrigated conditions was developed. From spring 2004, the …

Go to article

A Decision Support Tool For Seed Mixture Calculations, B. P. Berg, G. Hutton Feb 2023

A Decision Support Tool For Seed Mixture Calculations, B. P. Berg, G. Hutton

IGC Proceedings (1977-2023)

Grassland species are normally seeded in mixtures rather than monocultures. In theory, seeding rates for mixtures are simply a sum of the amount of pure live seed (PLS) of each seed lot in the mix, an amount sufficient to ensure establishment and survival of each species. Mixtures can be complex because of the number of species used (especially in conservation and reclamation programs) and variations in seed purity and seed size. Soil limitations and seeding equipment settings need to be considered and in Canada, a metric conversion may be required. All these conditions make by-hand calculations of mixtures containing more …

Go to article

Risk-Efficiency Assessment Of Haying, A. J. Romera, J. Hodgson, S. T. Morris, S. J. R. Woodward, W. D. Stirling Feb 2023

Risk-Efficiency Assessment Of Haying, A. J. Romera, J. Hodgson, S. T. Morris, S. J. R. Woodward, W. D. Stirling

IGC Proceedings (1977-2023)

Pastoral livestock farms are complex, dynamic systems subject to many forms of external disturbance. Farm Management strategies are therefore typically designed to minimize system variation. The objective of this study was to explore the impacts of different haying policies, in terms of expected profit and risk, for cow-calf farms in the Salado Region of Argentina.

Go to article

Environmental Clustering Of New Zealand Dairy Herds, J. R. Bryant, N. López-Villalobos, J. E. Pryce, C. W. Holmes Feb 2023

Environmental Clustering Of New Zealand Dairy Herds, J. R. Bryant, N. López-Villalobos, J. E. Pryce, C. W. Holmes

IGC Proceedings (1977-2023)

Previous studies have found that milk yield (a proxy for feeding level) and temperature-humidity index (THI) are important factors in explaining genotype x environment (G x E) interactions, indicating differences between the abilities of genotypes to forage or consume concentrates effectively or to cope with thermal stress (Ravagnolo and Misztal, 2000; Zwald et al., 2003). The objective of this study was to quantify and cluster (CL) herd environments within New Zealand (NZ) based on production levels, a summer heat load index (HLI) and geographical location.

Go to article

Irish Dairy Farming: Effects Of Introducing A Maize Component On Grassland Management Over The Next 50 Years, A. J. Brereton, N. M. Holden Feb 2023

Irish Dairy Farming: Effects Of Introducing A Maize Component On Grassland Management Over The Next 50 Years, A. J. Brereton, N. M. Holden

IGC Proceedings (1977-2023)

Typical management of Irish dairy units is based on a low-cost spring-calving strategy with 90% of annual feed derived from grass grown on the farm. Almost 70% of feed is from grazed grass managed by rotational grazing, the remainder is conserved forage and concentrates. The objectives of the work were to examine how the management system has to be modified when part of the dairy unit land is allocated to maize silage instead of grass silage production, and to examine how climate change over the next 50 years will impact on grass and maize management within the production system.

Go to article

Autumn Root Reserves Of Lucerne Affected Shoot Yields During The Following Spring, D. J. Moot, E. I. Teixeira Feb 2023

Autumn Root Reserves Of Lucerne Affected Shoot Yields During The Following Spring, D. J. Moot, E. I. Teixeira

IGC Proceedings (1977-2023)

Frequent grazing affects shoot yield of lucerne (Medicago sativa L.) by limiting radiation interception (Teixeira et al., 2005b) and the accumulation of endogenous reserves (C and N) in perennial storage organs like crowns and taproots (Teixeira et al., 2005a). In temperate regions, the impact of low level of perennial reserves is particularly evident during early-spring, when lucerne regrowth resumes after an overwintering period. The analysis of lucerne yield can be fragmented into its yield components of plant population, shoots per plant and yield per shoot (Volenec et al., 1987). The objective of this research was to quantify …

Go to article

Lucerne Crown And Taproot Biomass Affected Early-Spring Canopy Expansion, E. I. Teixeira, D. J. Moot, A. L. Fletcher Feb 2023

Lucerne Crown And Taproot Biomass Affected Early-Spring Canopy Expansion, E. I. Teixeira, D. J. Moot, A. L. Fletcher

IGC Proceedings (1977-2023)

Leaf area index (LAI) quantifies canopy expansion in crops and is used in lucerne (Medicago sativa L.) simulation models to predict daily PAR interception (PAR i). This then drives yield through radiation use efficiency (RUE) (Gosse et al., 1984). In perennial crops, like lucerne, the level of biomass stored in crown and taproot may affect canopy expansion in subsequent regrowth cycles (Avice et al., 1997). In temperate regions the impact of this is likely to be greatest in early-spring, when low temperatures delay development. The objective of the current research was to identify whether contrasting levels of winter biomass in …

Go to article

Extending The Grazing Season With Turnips, P. Thomet, S. Kohler Feb 2023

Extending The Grazing Season With Turnips, P. Thomet, S. Kohler

IGC Proceedings (1977-2023)

A comparison of the actual feeding costs on 86 typical Swiss dairy farms confirmed that the production of hay and grass silage is very expensive with costs from the field to intake in the range of 20-25 Euro cents/kg of dry matter (DM). Options to extend the grazing season for dairy cows in the late autumn and early winter, and hence reduce winter feeding costs, would therefore be welcome (Penrose et al., 1996). The aim of the study was to compare the DM production potential of summer-seeded turnips with other brassicas and Italian ryegrass and to test whether dairy cows …

Go to article

Milk Production Performance Based On Grazed Grassland In Switzerland, P. Thomet, H. Menzi Feb 2023

Milk Production Performance Based On Grazed Grassland In Switzerland, P. Thomet, H. Menzi

IGC Proceedings (1977-2023)

A common feature of profitable dairy systems is the use of large amounts of low cost feed. One approach to improve the competitive ability of the dairy production therefore is to promote grazing (Dillon et al., 1995). A comparison of the actual feeding costs on typical Swiss dairy farms showed that hay and grass silage were four times and concentrates seven times more expensive than grazed grass. A maximum utilisation of grazed grass can be achieved with a seasonal production system, which synchronises the cow’s feed requirements with pasture growth. This strategy was implemented and consistently optimised on an …

Go to article

The Effect Of Inclusion Of A Range Of Supplementary Feeds On Herbage Intake, Total Dry Matter Intake And Substitution Rate In Grazing Dairy Cows, S. J. Morrison, D. C. Patterson, S. Dawson, C. P. Ferris Feb 2023

The Effect Of Inclusion Of A Range Of Supplementary Feeds On Herbage Intake, Total Dry Matter Intake And Substitution Rate In Grazing Dairy Cows, S. J. Morrison, D. C. Patterson, S. Dawson, C. P. Ferris

IGC Proceedings (1977-2023)

The milk production potential of dairy cows has increased substantially over the past two decades. This development presents new challenges for managing dairy cows during grazing, particularly where the objective is to maximise the proportion of energy in the diet derived from forage. The objective of the current study was to explore supplementation strategies to maintain high total forage intakes from grazed grass supplemented with alternative forage supplements in dairy cows during the grazing season. A second objective of the study was to examine the effect of supplement on substitution rate (SR) and milk yield response.

Go to article

White Clover Soil Fatigue: An Establishment Problem On Large And Intensive Dairy Farms, K. Søegaard, K. Møller Feb 2023

White Clover Soil Fatigue: An Establishment Problem On Large And Intensive Dairy Farms, K. Søegaard, K. Møller

IGC Proceedings (1977-2023)

In recent years a new constraint, clover soil fatigue, has appeared for the establishment of white clover (Trifolium repens) in Denmark. Increasing dairy farm size has led to more intensive use of clover in crop rotation schemes in the grazing areas located at convenient distances from stables. It has become common practice to establish new clover/grass in the fields just after ploughing clover/grass swards, and soil fatigue is becoming more common. On fatigued land the clover plants emerge, then become stunted and eventually disappear within the same year. The problem tends to cover the full field area. Obviously, …

Go to article

Effect Of Farm Grass Cover At Turnout On The Grazing Management Of Spring Calving Dairy Cows, M. O'Donovan, L. Delaby, P. Defrance Feb 2023

Effect Of Farm Grass Cover At Turnout On The Grazing Management Of Spring Calving Dairy Cows, M. O'Donovan, L. Delaby, P. Defrance

IGC Proceedings (1977-2023)

Early spring grazing is an objective for most Irish dairy farmers. If more grass is included in the diet of the cow in early lactation, the profitability of the farm system can be increased. Post turnout, dairy cow feeding management varies with the amount of farm grass cover (FC) available. Experiments on the consequences of different FC at turnout require large resources and all scenarios cannot be accounted for. Consequently, a decision support system, Pâtur’IN (Delaby et al., this volume), was used to describe the effects of various FC at turnout on grazing management in spring.

Go to article

What Supplementation Type For Spring Calving Dairy Cows At Grass In Autumn?, M. O'Donovan, E. Kennedy, T. Guinee, J. J. Murphy Feb 2023

What Supplementation Type For Spring Calving Dairy Cows At Grass In Autumn?, M. O'Donovan, E. Kennedy, T. Guinee, J. J. Murphy

IGC Proceedings (1977-2023)

In spring-calving herds the requirement for conserved forages for indoor feeding is very limited but these feeds may have a role to play as buffer feeds in the spring and autumn periods when grass supply is less than required or as alternatives to concentrates on pasture for cows in early lactation. The objective of this experiment was to compare alternative forages and concentrates as buffer feeds on pasture with spring-calving cows in the autumn.

Go to article

Manipulation Of Grass Growth Through Strategic Distribution Of Nitrogen Fertilisation, M. Stettler, P. Thomet Feb 2023

Manipulation Of Grass Growth Through Strategic Distribution Of Nitrogen Fertilisation, M. Stettler, P. Thomet

IGC Proceedings (1977-2023)

The objective of this study was to evaluate possibilities and limits of manipulating the grass growth of pastures by different nitrogen (N) application strategies with the aim to better synchronise grass supply and feed demand. In Switzerland, the use of N is strongly restricted by legislation. An efficient and well allocated N fertilisation is therefore important.

Go to article

A Comparison Of Three Systems Of Milk Production With Different Land Use Strategies, L. Shalloo, P. Dillon, J. J. Murphy Feb 2023

A Comparison Of Three Systems Of Milk Production With Different Land Use Strategies, L. Shalloo, P. Dillon, J. J. Murphy

IGC Proceedings (1977-2023)

Under the Luxemburg agreement FAPRI-Ireland (Breen & Hennessey 2003) projects that milk price will decrease by 5.0 to 5.5 c/l because of reductions in support for butter and skimmed milk powder. These changes mean that many dairy farmers need to reappraise their systems of milk production and consider necessary adjustments that will ensure viability in the longer term. The objective of this study was to model three different systems of milk production in scenarios where quota, cow numbers or land was restricted.

Go to article

First Prev Next Last