Agronomy and Crop Sciences Commons^™

An Overview Of The Physiology And Biochemistry Of N Reserves Mobilization In Forage Species, F Le Dily, A Ourry, J Boucaud

IGC Proceedings (1997-2023)

Recent works focusing on the physiological and biochemical events associated to perennial forages sustainability (re-growth after defoliation, winter survival), provided evidence that vegetative storage proteins (VSPs, ca proteins stored in remaining organs and specifically mobilized) were key organic compounds for shoot regrowth. Attempts to elucidate environmental conditions involved in VSPs deposit ability of different species are under progress today. In contrast, mechanisms of spring- or cut-induced proteolysis are investigated at a lesser extend. This contribution is an opportunity to summarize our knowledge of N-reserves mobilization and to set the question of VSPs breakdown regulation.

Intraspecific Competition In Lucerne And Relationships With Reserve Availability, Jean Christophe Avice, Alain Ourry, Gilles Lemaire, Jeffrey J. Volenec, Jean Boucaud

IGC Proceedings (1997-2023)

Below-ground reserves are thought to provide an indication of a forage potential for shoot regrowth after defoliation. The aim of this work was to re-evaluate the causal relationships existing between organic reserves (non-structural carbohydrates and N reserves) and shoot regrowth of alfalfa. The variations brought about by cultivar differences (cv Lodi or Europe), length of the previous regrowth period (30 or 45 d), or by intraspecific competition for light within a dense canopy, were studied. Field grown plants were harvested at weekly intervals, and separated as dominant, intermediate and suppressed plants. Shoot regrowth yield was determined and taproot were analyzed …

Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza

IGC Proceedings (1997-2023)

The nitrogen effects on Hyparrhenia diplandra were studied. Plants were grown on nutrient solutions of variable concentrations in nitrogen. The supplied nitrogen increased tillering, leaf production, lamina area, total dry matter accumulation and total nitrogen accumulation in lamina. A detailed examination showed that the effect on tillering was the main cause of the differences observed in dry weights between different treatments. The nitrogen supply elongated significantly the lamina and nitrogen deficiency increased its thickness; but this was not enough to compensate the loss of weight in lower nitrogen treatment. The lamina area as well as nitrogen accumulation in the lamina …

Nitrogen Use Efficiency Of Timothy Populations, G Belanger, C Murray, R Michaud, F Gastal, J E. Richards

IGC Proceedings (1997-2023)

The objective of this study was to determine the variability in N use efficiency among field-grown timothy (Phelum pratense L.) populations. Shoot biomass and N uptake were measured at the end of the spring growth cycle on six timothy populations fertilized with three N rates at two sites in Eastern Canada. The variability in shoot biomass among populations was similar under limiting and nonlimiting N conditions. The ranking of the populations, however, differed under limiting and non-limiting N conditions, and also between the two sites under limiting N conditions. The differences in shoot biomass among populations under highly N …

Tree Forages As Nitrogen Source For Ruminants In Sahelian Agro-Silvipastoral Systems, S T. Fall, B M. Doreau

IGC Proceedings (1997-2023)

Tree forages contribute up to 80% DM and 100% nitrogen content in the ruminants diet in the Sahel during the dry season. However, crude protein (CP) concentration in browse within a wide range and variation factors remain to be elucidated for better integration of browses in ruminants feeding systems. Variation factors of CP content and in vivo digestibility of four Sahelian browse species were investigated to appreciate the potential as nitrogen sources in Sahelian ruminant feeding systems. Seasonal variations in nitrogen content were evaluated in different plants part of A. raddiana, B. rufescens, B. aegyptiaca and G. senegalensis harvested in …

The Effects Of Tree Density On Pasture Production Under Acacia Melanoxylon, B S. Thorrold, I L. Power, M B. Dodd

IGC Proceedings (1997-2023)

Silvi-pastoral systems could contribute to greater total productivity and more sustainable land management of grazed pastures in New Zealand. Despite this potential, little is known of the interactions of tree species and environment on pasture growth. In this paper we report the effects of tree density on pasture yield in an Acacia melanoxylon silvi-pastoral system. The results show decreasing pasture yield with increasing tree density, although the extent of the reduction is less than would be expected under Pinus radiata. Results suggest that shade is the dominant factor causing yield decline in this study, while reduced N availability is …

Research Programme To Improve The Utilization Of Home-Grown Forages In The Netherlands, A.M. Van Vuuren, A H. Bosma, G J. Kaspers, J.J. M.H. Ketelaars, E.N. Van Loo, H J.P. Marvin, H Valk, G.W.J. Van De Ven

IGC Proceedings (1997-2023)

In The Netherlands a research programme has been initiated by the Ministry of Agriculture, Nature Management and Fisheries to increase the proportion of high-quality home-grown forage in rations for dairy cows. This should result in a more sustainable dairy husbandry by improving the efficiency of utilization of nitrogen and phosphorus from home-grown forages (mainly grass and maize) on farm level. Research disciplines involved are plant breeding, forage harvesting and conservation and nutrition.

Comparison Of Two Low-Input Cow/Calf Production Systems On Temperate Grassland, W. B. Bryan, Mata Padrino, E. Felton, E. C. Prigge, V. W. Temu, O. J. Gekara

IGC Proceedings (1997-2023)

Two systems of grass farming were compared in an eight-year experiment in West Virginia, USA. The grassland consisted primarily of cocksfoot (Dactylis glomerara L.), Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and red (Trifolium pretense L.) and white clover (T. repens L.). The objective was to compare two systems of beef cow calf production. The experiment was a randomized complete block with two replicated treatments. The grassland of treatment 1 (system 1) was overseeded with legumes, grazing started 1 wk earlier and continued 1 wk later than treatment 2 (system 2) and …

A Novel Technique To Label Cover Crop Biomass Using Stable Isotopes, L. M. D. Queiroz, José C. B. Dubeux Jr., Lynn E. Sollenberger, M. Wallau, D. R. S. Loures, M. A. Bernardini, I. L. Bretas, S. F. Novo, K. R. Trumpp, K. T. Oduor, J. D. Pereira Neto, M. Ruiz-Moreno

IGC Proceedings (1997-2023)

Stable isotopes can be used as tracers for carbon and nitrogen pathways being a great tool to track nutrients in integrated systems. The objective of this experiment was to understand the partitioning of 15N and 13C within cover crop plants when they were labeled with stable isotopes, using chambers under field conditions. Cover crops were planted at the University of Florida, North Florida Research and Education Center-Marianna, located in Marianna, FL. Treatments were four cover crops, in which one was considered a typical cover crop system and the other three consisted of an integrated crop-livestock system with or without the …

Herbage Accumulation And Mass In Massai Grass Plots Mixed With Forage Peanut And Fertilized With Nitrogen, Carlos A. B. Carvalho, M. O. Leal Junior, P. P. Carneiro, J. V. B. Ramos, N. Schultz, J. C. C. Almeida, A. J. Paiva

IGC Proceedings (1997-2023)

The objective of this work was to evaluate herbage accumulation and mass during the growing season of Massai grass mixed with peanut forage and fertilized with nitrogen. The work was carried out at Federal Rural University of Rio de Janeiro, Brazil, from 11/2021 to 03/2022. A randomized block experimental design was used, in plots of Massai grass Megathyrsus maximus, in a factorial arrangement, with seven replications. Four treatments formed by the combination of the presence or absence of Archis pintoi and nitrogen fertilization (0 and 50 kg ha^-1 of N). Canopy heights of the plots were evaluated weekly …

Application Of Fall Nitrogen Increased Spring Tall Fescue Yield, B. L. Hendrix, Christopher D. Teutsch, J. Duckworth

IGC Proceedings (1997-2023)

Late season nitrogen fertilization is a practice that has long been implemented in turfgrass production. This practice involves applying nitrogen from September through December and results in an extended green period in the fall without stimulating excessive shoot growth. The longer green period results in higher levels of carbohydrate reserves and enhanced root growth compared with a spring-summer fertilization program. In addition to these benefits, sods fertilized in late fall have been shown to green up two to six weeks earlier in the spring. Limited research has considered the impact of late fall nitrogen applications on grass growth in hayfields …

Chlorophyll And Mineral Dynamics Of Perennial Grass Species Found In Semi- Arid Rangelands Of South Africa, N. H. Msiza, K. E. Ravhuhali, H. K. Mokoboki, Sydney Mavengahama, L. E. Motsei

IGC Proceedings (1997-2023)

Minerals are essential for ruminants and are mostly provided by grass species. Their growth stage is vital in the supply of these minerals. Perennial grass species have been mostly undervalued, owing to the scarce information concerning their potential feeding value and little documentation about their potential nutritive value in different growth stages. This study was conducted to investigate the chlorophyll and mineral concentration of grass species at different growth stages under greenhouse conditions at the North-West University Experimental farm, North West province, South Africa. The soil, collected from different villages, was mixed and samples were drawn for chemical analysis before …

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 …

Optimizing Crop Productivity And Fertility Practices In Intermediate Wheatgrass, Roberta Bianchin Rebesquini

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The intensive management associated with many annual crops often includes recurring tillage, fertilization, and pesticide applications, which contribute to environmental concerns such as water pollution and soil erosion. Intermediate wheatgrass (Thinopyrum intermedium), recognized under the trade name Kernza®, is a perennial grass that can be managed to produce grain and biomass while providing desired environmental benefits such as soil conservation and nutrient cycling. There has been limited research on best management practices and crop productivity for this alternative dual-use crop in Nebraska. A field experiment was conducted beginning in 2021 to assess nitrogen (N), phosphorus (P), and potassium (K) management …

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).

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.

Evaluating Drill Interseeded Cover Crop Establishment And Nitrogen Impact In Irrigated Corn, Victor De Sousa Ferreira

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The adoption of cover crops as a strategy to improve soil health and cropping systems sustainability is on the rise in the United States. PRE herbicides with soil residual activity are widely applied in corn production systems to prevent early season weed development, crop-weed competition, and yield loss. When preemergence herbicides are applied in the field, the active ingredients remain in the soil rhizosphere for a period of time, killing weed seedlings as they emerge. However, PRE herbicides can also impact the establishment of interseeded cover crops. Greenhouse bioassay was conducted to evaluate the preemergence herbicide carry-over potential to interseeded …

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.