Physical Sciences and Mathematics Commons^™

Sustainable Intensification Of Livestock Systems Using Forage Legumes In The Anthropocene, José C. B. Dubeux Jr., D. M. Jaramillo, E. R. S. Santos, L. Garcia, L. M. D. Queiroz, K. R. Trumpp

IGC Proceedings (1997-2023)

Sustainable intensification of livestock systems implies greater efficiency in resource utilization resulting in greater output of products and other ecosystem services per unit of resource input. Strategies to improve resource use efficiency include diversification of plant and ruminant species with complementary resource use. Forages that have root systems with contrasting architecture and exploring different soil layers with complementary use of resource acquisition (e.g., nutrients, water) could enhance primary productivity. Belowground interactions with soil microbiota (e.g., mycorrhizae) is key to enhance resource utilization. Forages with complementary canopy characteristics that helps enhancing light interception and utilization could also lead to greater resource …

Short-Term Soil Organic Matter And Carbon Responses To Contrasting Grazing Intensities In Integrated Crop-Livestock Systems, Erick R. Da Silva Santos, Jose C. B. Dubeux, B. G. C. Homem, Cheryl L. Mackowiak, Lynn E. Sollenberger, D. Wright

IGC Proceedings (1997-2023)

Combining integrated crop-livestock systems under no-till management may improve soil organic matter (SOM) build up and improve soil C sequestration. Grazing cover crops appears as a possibility to combine crops and livestock in a farm system. Further SOM and soil C increase can be achieved by adding perennial grasses into crop rotations. However, the effect of grazing intensity in such systems are not fully understood. This 2-yr study investigated short-term effects of cropping system [winter cover crops-summer cotton (Gossypium hirsutum L.) and winter cover crops-summer bahiagrass (Paspalum notatum Flüggé) rotations], grazing intensity (no grazing, heavy, moderate, and light …

Effect Of Soil Nitrogen And Water Content On The Establishment Of A Lolium Perenne L. And Trifolium Repens L. Pasture, M. F. Alonso, Oscar A. Balocchi, I. Calvache, O. Martínez

IGC Proceedings (1997-2023)

Climate change has decreased rainfall in Southern Chile affecting the productivity of the grasslands that sustain the dairy and beef cattle industries. These grasslands are mainly mixtures of Lolium perenne L. and Trifolium repens L. Thus, we study the response on the establishment of a mixture of these two species to three levels of soil water content and two levels of nitrogen (N) fertilization. The trial was carried out in containers sowed in a complete randomized block´s design. Soil moisture measurements were taken daily. N fertilizations was applied at the establishment and every 60 days. Leaf appearance rate was measured …

Short-Term Versus Long-Term Effects Of Nitrogen Addition And Warming On Ecosystem N Dynamics In A Grass-Dominated Temperate Old Field, Benjamin F. A. Souriol

Electronic Thesis and Dissertation Repository

Increased atmospheric nitrogen (N) deposition and climate warming are both anticipated to influence the ecosystem N dynamics of northern temperate ecosystems substantially over the next century. Nevertheless, in field experiments with N addition and warming treatments, temporal scale can play an important role in determining the extent of treatment effects on N dynamics, and it is unclear to what extent the results of short-term studies can be extrapolated to responses over longer time scales. I compared the short-term versus long-term effects of N addition and warming on net N mineralization, N leaching, and N retention in a grass-dominated old field. …

Relationships Between Productivity, Quality And Traits In Seven Co-Occurring Grass Species, L. S. Pontes, Jean-François Soussana, P. Carrère, F. Louault, J. Aufrère, D. Andueza

IGC Proceedings (1997-2023)

The impacts of management options sometimes have dramatic effects on botanical composition which in turn affect yield and nutritive value. A functional analysis of vegetation response may help to understand and predict the impact of changes in grassland management in a more general way screening for plant traits that may control productivity and nutritive value.

Does Niche Complementarity Explain The Relationship Between Biodiversity And Ecosystem Functioning In Managed Grasslands?, Nina Buchmann, A. Kahmen

IGC Proceedings (1997-2023)

Niche complementarity was suggested to largely explain the positive relationship noted between plant diversity and productivity in some recent studies. This suggests that an increasing number of species exploits resources more efficiently and thus enhance ecosystem functions. This hypothesis, however, implies that niches occupied by different plant species are rather distinct so that niches from extinct or missing species stay unoccupied by the remaining species of an ecosystem. This experiment tested if plant species occupy different and distinct niches with respect to soil N uptake, being a possible functional explanation for the biodiversity ecosystem functioning relationship.

Sustainable Pastures For The High Altitude Andean Tropics Of Colombia, E. Cárdenas, L. Panizzo

IGC Proceedings (1997-2023)

Dairy production systems in the high altitude Andean region of Colombia (>2.600 m.a.s.l.) use large amounts of nitrogen (N) fertilisation. Due to the inefficient use of N by the grass, it contaminates surface and ground water resulting in the eutrophication of lakes and rivers. It contributes to increased atmospheric NOx, greenhouse gas and acid rain. Therefore, the effect of different species of grasses mixed with Lotus corniculatuson N soil balance was evaluated.

Seasonality Of Growth In Grass-Clover Swards Under Repetitive Nitrogen Application, M. Nassiri, A. Elgersma

IGC Proceedings (1997-2023)

The cohabitation of grass and clover is possibly due to asynchrony in their growth patterns, and to the beneficial effects of fixed nitrogen (N) on grass. Incompatibility of clover persistence with N fertilisation has been frequently reported (Nassiri and Elgersma, 2002). However, limited information is available regarding the effect of repetitive application of N in mixed swards. This research aims to study the balance between species in response to application of increasing rates of N throughout the growing season.

Effects Of Cattle Slurry, Their Solid And Liquid Fractions And Mineral N Fertilizers On Italian Ryegrass And Maize Forage Yield, H. Trindade, J. Coutinho, N. Moreira

IGC Proceedings (1997-2023)

Solid-liquid slurry separation techniques expand possibilities to improve slurry use efficiency and to reduce its negative environmental impact. These possibilities arise from the different behaviour of the two fractions concerning the release of nutrients, namely nitrogen (N), due to different C:N ratios (≈30 for the solid fraction and ≈7 for the liquid fraction).

The aim of this work was to evaluate the effect of cattle-slurry and their solid and liquid fractions applied at sowing time of Italian ryegrass (Lolium multiflorum cv. Andrea) and forage maize on crop dry matter (DM) yield. In the NW region of Portugal these two …

Nitrogen Balance And Soil Nitrates In Suckler Cow Pastures Fertilised With Mineral Fertiliser, Pig Slurry Or Cattle Compost, Isabelle Dufrasne, J. F. Cabaraux, L. Istasse, J. L. Hornick

IGC Proceedings (1997-2023)

A code of good practice was established by each European member state according to the EU Nitrate Directive. In Belgium, the nitrogen (N) inputs on pastures from slurry or compost are limited to 210 kg N/ha. Bigger quantities can be applied if the farmer follows a programme of additional measurements, including soil nitrate (NO₃) analysis. This investigation aimed to measure animal performance, N balance and soil NO₃ in pastures fertilised with mineral N, pig slurry or cattle compost, the pastures being grazed by Belgian Blue cows and their calves.

Mechanical Aeration And Liquid Dairy Manure: Application Impacts On Grassland Runoff Water Quality And Yield, T. J. Basden, S. B. Shah, J. L. Miller

IGC Proceedings (1997-2023)

Wet weather on heavy soils reduces oxygen availability in the root zone and reduces forage yields. Mechanical aeration can improve forage yield in these soil conditions. Research has shown that under certain conditions, mechanical aeration can increase yield by improving drainage and aeration (Davies et al., 1989); aeration can also increase depression, storage and infiltration thus reducing surface runoff and improving nutrient distribution in the root zone. Aeration on sloping, fertilised grassland can provide environmental (Douglas et al., 1995) and agronomic benefits. The objectives of this study were to evaluate the runoff water quality and agronomic impacts of …

Grazing Effects On Some Soil Characteristics In Lar Rangelands, S. A. Javadi, M. Jafari, Gh. Zahedi

IGC Proceedings (1997-2023)

Heavy grazing pressures jeopardise the sustainability of the ecosystem by reducing soil fertility (Dormaar et al., 1998). Different results have been reported of grazing intensities on soil chemical properties, which stem from climate, soil, vegetation, management and kind of animal (Dormaar et al., 1998; Javadi, 2003; Sanadgool, 2002).

Investigating The Role Of Plant Traits And Interactions In Emergent Wetland Nutrient Removal, Andrew Ryan Sample

Theses and Dissertations

Increasing wetland restoration in the Lower Mississippi Alluvial Valley has been identified as a method to reduce nutrient loading in the Gulf of Mexico. Wetlands have historically been used to treat water through processes facilitated by wetland plants, and relatively few species and plant traits have been identified as important in carrying out these processes. This study focuses on some of those species and traits and aims to identify species differences and plant traits that may be important for wetland nutrient mitigation. Chapter I provides background information on nutrient pollution, wetland biogeochemical mechanisms for nutrient sequestration, and the focal species …

Leaf Dry Matter Content Of Native Grassland Species Under Contrasting N And P Supply, P. Cruz, C. Jouany, Jérome M. Enjalbert, Michael Duru

IGC Proceedings (1997-2023)

The management of native grasslands - herbaceous vegetation with a broad diversity of flora and a large range of uses - must meet the requirements of environmental conservation and improvement of the quality of agricultural production. For this purpose we need tools for diagnosing the state of the vegetation in order to design, evaluate, and apply management practices to attain these objectives. These tools must be simple and quick to use and should not require botanical skills. Leaf dry matter content (LDMC) has been proposed as a good indicator of both fertility gradients and species preference for habitats (Cruz et …

Potentialities Of Near Infrared Spectroscopy To Assess Nitrogen, Phosphorus And Potassium Nutrient Status Of Grasslands In The Reunion Island, Philippe Lecomte, Vincent Blanfort, Michael Duru, P. Thomas, P. Grimaud

IGC Proceedings (1997-2023)

Controlled mineral fertilisation practices are an important component for sustainable management of grasslands. The assessment of available nutrients for plants and the general recommendations on the level of phosphorus and potassium to apply to grasslands are classically based on classical soil analysis and average regional levels. For nitrogen, mid or long term recommendations cannot easily be derived solely from soil composition, because it may be rapidly leached from the soil. Recent approaches tended to show that herbage plant N (Lemaire & Gastal, 1997), P, K (Duru & Huché, 1997) mineral analyses associated with actual biomass measurement could be useful for …

An Internet-Based Tool For Use In Assessing The Likely Effect Of Intensification On Losses Of Nitrogen To The Environment, N. J. Hutchings, B. M. Petersen, I. S. Kristensen, N. Detlefsen, M. S. Jørgensen

IGC Proceedings (1997-2023)

The EU Nitrates, Habitat and National Emissions Ceilings directives and the Kyoto Agreement mean that agricultural losses of NO₃, NH₃ and N₂O are under scrutiny by national and international environmental authorities. When farmers wish to intensify their operations, the authorities must then assess the likely environmental impact of the change in operation. The FARM-N internet tool was developed to help farmers and authorities agree how the farm will be structured and managed in the future, and to provide an objective assessment of the environmental losses that will result.

Nutrient Dynamics Of Freshwater Estuarine Sediments Disturbed By Dredging, Ryan Allan John Roekle

Theses and Dissertations

This study examined the nutrient environment of sediments in the Milwaukee River estuary and the dynamics of those nutrients during simulated disturbance experiments within the context of large-scale dredging remediation. Surface sediments were collected from throughout the Milwaukee estuary (including river, harbor, and nearshore stations) by PONAR, centrifuged to separate porewater (interstitial water) from solid material, and filtered to further isolate and stabilize dissolved material. Porewaters were analyzed for dissolved nutrients including ammoniacal nitrogen (AN), nitrate, nitrite, and soluble reactive phosphorus (SRP). Surface sediment porewaters within the estuary were often highly enriched in AN and SRP, which were often 10-2000x …

Cattle Overwintering Areas In Middle-European Conditions - Important “Point” Sources Of Nitrous Oxide Emissions, M. Šimek, J. Hynšt, P. Brůček, J. Čuhel, D. Elhottová, H. Šantrůčková, V. Kamír

IGC Proceedings (1997-2023)

Nitrous oxide (N₂O) emissions in grazed grasslands are strongly influenced by animal excreta (Fowler et al., 1997). In addition, soil compaction caused by animal traffic significantly influences soil physical conditions and thus directly or indirectly impacts on the microbial processes producing N₂O. In the Czech Republic pastures are mostly located in hilly and mountain areas. During the growing season, cattle are typically grazing, while during the winter the animals are concentrated near the animal house on a relatively small plot called an "overwintering area". The objective of this study was to estimate the fluxes of …

Effect Of Dairy Effluent On Turnip Nutritive Characteristics, Joe L. Jacobs, G. N. Ward, Frank R. Mckenzie

IGC Proceedings (1997-2023)

In southern Victoria, high summer temperatures and low rainfall lead to low pasture growth and a decline in nutritional value until rainfall commences in autumn. Annual forage crops such as turnips often are used to fill the summer feed gap. Jacobs & Ward (2003) observed that dairy effluent applied at low rates could improve turnip DM yields and crude protein content. Results from the first two years of a 3-year study comparing a range of effluent application rates on turnip leaf and root nutritive characteristics are reported.

Agronomic Value Of Mixture Of Perennial Rye-Grass Cultivars: Preliminary Results, W. G. Do Nascimento, F. Surault, J. C. Emile, Christian Huyghe

IGC Proceedings (1997-2023)

Mixtures of grass and legume species are commonly used in sown grasslands. Mixtures have been shown to be favourable for stable production over cycles and years due to a succession of species over time (Mosimann & Charles, 1996 ; Nie et al, 2004). However, little is known whether the genetic variation in pure stands has an influence on the agronomic value and its variation over seasons.

Perennial Grass Emergence And Establishment Using A Micro-Nutrient Seed Treatment, Charlie D. Clements, J. A. Young

IGC Proceedings (1997-2023)

Resource managers have become increasingly frustrated with restoration seeding failures in semi-arid and arid environments. In response to this frustration, some resource managers have attempted restoration seedings using non-conventional methodologies such as propriety seed treatments. The exact nature of these propriety treatments is often confidential, but they generally consist of either nutrient or micro-nutrient enrichment or inoculation with unspecified micro-organisms. One of the more popular propriety seed treatment used in Nevada, USA, is GERM-N-8®. This product is a suspension of nutrients (N 2%, P 14%, and K 3%) applied to dry seed. Resource managers often report excellent success using these …

Effect Of Dairy Effluent On Turnip Yields, Joe L. Jacobs, G. N. Ward, Frank R. Mckenzie

IGC Proceedings (1997-2023)

Dairy effluent is a significant point source in the pollution of waterways. Only 50% of dairy farms in the dryland regions of Victoria, Australia, have suitable dairy effluent systems of which only 25% are managed effectively (IRIS Research 2000). Despite many farmers viewing effluent as an undesirable waste, it contains relatively large amounts of agronomically valuable nutrients especially nitrogen (N) and potassium (K). Results are reported from the first two years of a three year study comparing turnip leaf and root dry matter (DM) responses to a range of dairy effluent rates.

The Input Of Forage Legumes In Sustainable Grassland Systems, Žydrė Kadžiulienė, L. Sarunaite

IGC Proceedings (1997-2023)

There is increased interest in sustainable grassland systems. One step towards sustainability is expansion of legume use, because of their potential to fix and transfer nitrogen (N) to subsequent crops. However, legumes can also have negative aspects, such as difficulties in establishment (Porqueddu et al., 2003), lack of persistence, N loss (Scholefield et al., 2002) and accumulation of soil borne disease agents (Kadziulis, 2001). The large variability within legume swards and between years in pastures and leys has encouraged us to search for possibilities to achieve stability of their inputs in sustainable grassland systems.

A Rapid Estimation Of Nitrogen Bound To Neutral Detergent Fibre In Forages By Near Infrared Reflectance Spectroscopy, Jérôme Bindelle, G. Sinnaeve, P. Dardenne, P. Leterme, A. Buldgen

IGC Proceedings (1997-2023)

Near infrared reflectance spectroscopy (NIRS) is widely used as a rapid method for the evaluation of the chemical composition or the nutritive value of foodstuffs (Givens et al., 1997). The determination of the neutral detergent fibre (NDF) bound N (NDF-N), which is highly variable in forages (Shayo & Udén, 1999), is expensive. The purpose of this study was to test the use of NIRS in the prediction of NDF-N in various forages.

The Effect Of Nitrogen Fertiliser And Season On The In Situ Degradability Of Irish Perennial Ryegrass In Cattle, V. Olsson, J. J. Murphy, F. P. O'Mara, K. O'Connell, J. Humphreys, F. J. Mulligan

IGC Proceedings (1997-2023)

In light of increasing environmental and economic pressure on agriculture to utilise resources more efficiently, protein feeding and its effects are fundamentally important. As grazed grass is the predominant feed in Irish dairy and beef cattle production systems, it is necessary to establish protein values for different grass varieties and cultivars fed. It is also important to investigate the extent of ruminal nitrogen (N) degradability for these grasses since this characteristic greatly influences environmentally damaging urinary N excretion.

Modelling Of Nitrogen Allocation And Partitioning Within Lucerne (Medicago Sativa) Shoot Tissues During Recovery From Defoliation: An Approach To Estimate Forage Production And Nitrogen Composition, F. Meuriot, A. Escobar-Gutiérrez, J-C. Avice, J-C. Simon, F. Lesuffleur, F. Gastal

IGC Proceedings (1997-2023)

Lucerne has been grown over centuries for forage. Its forage production is strongly correlated to the initial taproot and stubble N reserves (Avice et al., 1996; Meuriot et al., 2004). However, the influence of cutting management on the level of N storage and the contribution of these N reserves to forage production still remain unclear and need to be studied at the whole plant level. For this purpose, a deterministic model of N allocation within the different organs and partitioning within different biochemical N pools was developed for lucerne with high and low initial N status and cutting …

Urea Applied To Puccinellia-Based Pastures Increases Pasture And Sheep Production, M. L. Hebart, N. J. Edwards, A. D. Craig, E. A. Abraham, J. D. Mcfarlane, J. E. Hocking Edwards

IGC Proceedings (1997-2023)

In the 1950's large areas of native vegetation in the upper south east of South Australia (SA) were replaced with highly productive Hunter River lucerne. This maintained groundwater recharge at near pre-clearing levels. The area of lucerne was reduced dramatically in the late 1970's by a combination of lucerne aphids, wingless grasshoppers and drought. In 1981 severe flooding inundated large areas of the region, causing the saline groundwater to rise to the soil surface. Since that time, dryland salinity has been a feature of the local farming system and salt-tolerant pastures based on puccinellia (Puccinellia ciliata) were widely …

Effect Of Nitrogen On The Radiation Use Efficiency For Modelling Grass Growth, R. Lambert, A. Peeters

IGC Proceedings (1997-2023)

When nitrogen (N) is not at a sufficient level to permit maximum growth rate, dry matter production is reduced. Models of plant growth in relation to solar radiation intercepted by the crop have been largely used. According to these models, N deficiency can act on the leaf extension and thus on the quantity of radiation intercepted by the crop, but also by reducing the radiation use efficiency of the crop (RUE) (Bélanger, 1990). The effect of N on the RUE of ryegrass swards is determined and discussed.

Radiation Use Efficiency Of Ryegrass: Determination With Non Cumulative Data, R. Lambert, A. Peeters

IGC Proceedings (1997-2023)

The growth of a crop is generally described as biomass accumulation per unit time. Monteith (1977) developed a model of growth where biomass accumulation is related to solar radiation intercepted by the crop. This model has been largely used for different crops. The conversion factor between radiation absorbed or intercepted by the crop and the biomass production is called “radiation use efficiency” or “dry matter radiation quotient”. Radiation use efficiency (RUE) is usually calculated as the regression coefficient of the linear relationship between crop biomass measured repeatedly during growth and cumulated intercepted or absorbed solar radiation. Demetriades-Shah et al. …

The Effect Of Grassland Management On Bovine Nitrogen Efficiency, N. J. Hoekstra, R. P. O. Schulte, E. A. Lantinga, P. C. Struik

IGC Proceedings (1997-2023)

Nitrogen (N) losses through grazing bovines are at the heart of the current debate on environment and agriculture. N utilisation of grazing bovines is predominantly determined by the form and amount of energy and protein in their diet, which in Ireland consists mainly of grazed grass. The two main problems of grazed grass with respect to animal N utilisation are 1) the imbalance between total N content and energy content, and 2) the lack of synchronisation between the release of N and carbohydrates in the rumen. It was hypothesised that both the balance and synchronisation of N and energy in …