Sustainability Of Management Practices Of Mountain Pastures In Reunion Island (Indian Ocean),
2024
CIRAD EMVT
Sustainability Of Management Practices Of Mountain Pastures In Reunion Island (Indian Ocean), V Blanfort, P Thomas, G Balent, A Michon
IGC Proceedings (1977-2023)
The grazing systems are an essential component of these volcanic highlands (1000-2000m). Our investigations consist of building up diagnosis tools and decision rules for a sustainable control of these fragile grazed ecosystems composed of native and sown pastures. The use of a systemic approach allows us to analyse the interrelationship between the vegetation dynamic and the agricultural practices through three biological indicators which relate to one hundred paddocks in six cattle farms. Concerning the vegetation dynamics, it seems that some management practices lead to a nonreversable degradation stage. As regards the forage system, the measure of sward-height and estimation of …
Restoration Of Degraded Coastal Grasslands In The Falkland Island,
2024
Falkland Islands
Restoration Of Degraded Coastal Grasslands In The Falkland Island, J A. Kerr
IGC Proceedings (1977-2023)
In the Falkland Islands the coastal grasslands are the most valuable for wool production and important habitats for wildlife. Tussac grass (Parodiochloa flabellata Lam.) and sandy areas which support an Ammophilia - Elymus association have been degraded by overgrazing, burning and invasion by alien flora and fauna. Traditional approaches to restoration, mainly by replanting, have had limited success. Research on
Pathways For Losses Of Phosphorus For Rainfed Pastures In South Australia,
2024
CSIRO
Pathways For Losses Of Phosphorus For Rainfed Pastures In South Australia, J W. Cox, C A. Kirkby, D J. Chittleborough
IGC Proceedings (1977-2023)
This study showed that significant amounts of phosphorus (P) applied to grasslands in the Adelaide hills, South Australia move through kaolinitic clay subsoils. Large undisturbed soil cores were collected down a hillslope with soils and pasture typical of the Adelaide hills. Fertiliser was added to the surface of soil cores and catchment rainfall simulated. Leachate from the cores was measured daily and analysed for P. Results showed up to 34% of P applied to pastures on the upper-slopes, moves vertically through the subsoil clays mostly in the dissolved form. Elsewhere, < 1% of the applied P was lost. The subsoils where P movement was significant had high clay (44%) and iron oxide content (14%). These subsoils also had the greatest number of macropores (20% of pores > 5 mm). The results showed the importance of macropore flow …
Proximity Of Water Affects Grazing Distribution And Soil Nutrient Cycling,
2024
University of Missouri
Proximity Of Water Affects Grazing Distribution And Soil Nutrient Cycling, J R. Gerrish, P R. Peterson, F A. Martz
IGC Proceedings (1977-2023)
A three-year study was conducted to quantify the effects of travel distance to water on pasture utilization rate and soil nutrient gradients. A 64 ha unit was divided into 16 4 ha pastures having maximum travel distances ranging from 250 to 450 m. Temporal utilization rate (UR) and soil nutrient levels were determined at 30 m intervals beginning at the water source. Temporal UR significantly declined beyond 250 m in all pastures having travel distances exceeding 250 m while pastures with less than 250 m travel distance were uniformly grazed. Increased nutrient level gradients beginning within 60 m of water …
Grassland N Fertilization In Humid Tropics: Production, Organic Matter Decomposition And Uptake,
2024
CIRAD EMVT
Grassland N Fertilization In Humid Tropics: Production, Organic Matter Decomposition And Uptake, G Mandret, V Blanfort
IGC Proceedings (1977-2023)
Under tropical humid conditions at low altitudes in La Reunion island an experiment was conducted in 1995 to examine the effects of mineral and organic N fertilisation on regrowth of Chloris gayana . Mineral fertilisation stimulates the production of leaves for the first 20 days of regrowth. Dry matter production was increased of 181 % with the combination of manure plus ammonium nitrate and only 147 % with ammonium nitrate alone. The soil microbial biomass activity, measured after 50 days of regrowth, was increased of 31 % by application of manure, 41 % by ammonium nitrate and 50 % by …
Grasslands As A Comparative For Farming Practices' Influence On Carbon/Nitrogen Dynamics,
2024
North Dakota State University--Fargo
Grasslands As A Comparative For Farming Practices' Influence On Carbon/Nitrogen Dynamics, S A. Clancy, M E. Biondini, J C. Gardner
IGC Proceedings (1977-2023)
A remnant prairie was used for comparison of the soil as a natural resource among alternative and conventional farming systems. Beginning and ending biotic and abiotic characteristics were quantified directly. Carbon and N flow was calculated using CENTURY model. Carbon decay was not tied to the size of the soil organic matter pool (SOM), but to crop choice. Nitrogen decay was linked to the size of the SOM pool. Nitrogen fertilizer depressed the amount of N mineralized by soil biota. The alternative farming systems in North Dakota (no-till and green-manure fallow) more nearly mimic the ecosystem processes of the prairie …
Effects Of Sodium And Cadmium Application To Pasture On Mineral Leaching,
2024
University of Cambridge
Effects Of Sodium And Cadmium Application To Pasture On Mineral Leaching, P C. Chiy, C.J C. Phillips, E Zachou
IGC Proceedings (1977-2023)
Leaching of essential elements from pasture constitutes a significant loss of valuable nutrients, and the release of nitrates and toxic elements such as cadmium to ground water poses a risk to wildlife and consumers. Results are presented from two experiements on the effects of applying Na and Cd to perennial ryegrass (Lolium perenne) swards on the leaching of essential and toxic elements. Socium application increased Na and decreased K concentration in leached waters, and cadmium contamination increased the leaching of Na, K, Mg, Ca and P. The application of cadmium did not increase the cadmium concentration in leached …
Litter Decomposition And Nutrients Release During Decomposition In A Humid Grassland Of Northeastern India,
2024
Maniput University
Litter Decomposition And Nutrients Release During Decomposition In A Humid Grassland Of Northeastern India, P S. Yadava, N S. Thoudam
IGC Proceedings (1977-2023)
The litter decomposition and nutrient release of two dominant grass species Sporobolus indicus (L) R. Br., Leersia Hexandra SW. and mixed grasses was studies by litter bag technique in the humid grassland ecosystem at Imphal, Northeastern India. On ermination of experiment after 12 months, the shoots decomposed from 97.2 to 100% and the roots from 82.9 to 91.8% of different species. The rate of litter decomposition of shoots were higher than roots. The decomposition constant (K) also varied from species to species. It is positively correlated with soil moisture content during the study period. The initial nitrogen, lignin and lignin …
Nutrient Cycling For Pasture Fertilization Management Of Dairy Farms In The Basque Country (Northern Spain),
2024
Servicio de Investigacion y Mejora Agraria
Nutrient Cycling For Pasture Fertilization Management Of Dairy Farms In The Basque Country (Northern Spain), M Oyanarte, M Rodriguez, G Besga, M Domingo
IGC Proceedings (1977-2023)
The implementation of the European Agricultural Policy implies a new orientation for the management of dairy farms and, as a result, of pasture fertilization. It is important to develop a new methodology for the calculation of fertilizer recommendations. In order to do this, a model based on P and K nutrient cycles has been used and a computer program has been developed to calculate these cycles and estimate the following parameters: potential pasture yield, yield at the different cuttings, efficiency of excreta recycling in the pasture and efficiency of grass utilization, all these parameters being necessary for the calculation of …
Nutrient Leaching And Runoff In The Mediterranean Dairy Sheep Farming Systems,
2024
Centro di Studio sui Pascoli Mediterranei
Nutrient Leaching And Runoff In The Mediterranean Dairy Sheep Farming Systems, C Porqueddu, S Caredda, G Fara
IGC Proceedings (1977-2023)
Three years of research were carried out in Sardinia (Italy) to evaluate the environmental impact on the soil and water from intensification of the dairy sheep farming systems. An extensive rainfed system based on permanent pasture was compared with an intensive irrigated system based on a three year rotation (double cropping/lucerne). Runoff, soil erosion and nutrient losses were negligible. Nutrient losses by leaching had more important results with clear differences between forage crops. In terms of system losses, the differences were less marked.
Nitrogen Cycling In A Ley-Dominated Production System,
2024
Swedish University of Agricultural Sciences
Nitrogen Cycling In A Ley-Dominated Production System, B Fagerberg
IGC Proceedings (1977-2023)
N balance in a full-scale experiment with conventional and ecological farming systems at Öjebyn in northern Sweden was calculated with a nutrient flow model. Due to increased milk production there was a yearly increase in both N-input and output. Nfixation was on average twice as large in the ecological system. The farm N balance was increasingly positive in the conventional system and negative in the ecological. The soil N balance was more negative in the ecological system and less positive in the conventional system. Conclusions are: (1) ecological farming is possible without immediate DM yield reductions, but with negative effects …
The Relative Roles Of Livestock, Termites, Wild Animals And Human Beings In Nutrient Recycling In Nigeria,
2024
University of Ibadan
The Relative Roles Of Livestock, Termites, Wild Animals And Human Beings In Nutrient Recycling In Nigeria, S M. Liya, A A. Agboola
IGC Proceedings (1977-2023)
Primary production of savanna woodland and cropland vegetation in semi-humid tropical Nigeria was 990t/km2 and contained 8.0 t of nitrogen (N) and 1.4 t of phosphorus (P). Of this biomass livestock, termites and humans consumed 4, 29 and 6% respectively; 18% was burnt. Of the N and P stocks, livestock, termites and humans consumed 9 and 5%, 17 and 22%, and 10 and 9% respectively. The liveweights per km2 of livestock, termites and humans were 3.5, 10.0 and 2.3t respectively. Annual grass burning consumed 25% of N and 16% of P. The role of wild animals was negligible. About 2/3 …
Integrated Dairy Waste Management, Water Quality And Crop Utilization System,
2024
Land O Lakes
Integrated Dairy Waste Management, Water Quality And Crop Utilization System, D R. Ivers, P D. Clayton, R H. Beck, G W. Randall, L J. Greub, M A. Schmitt, W F. Wedin
IGC Proceedings (1977-2023)
Livestock-crop farmers have very limited opportunities to efficiently utilize manure in an environmentally safe manner during the cropgrowing season. In this study, dairy manure slurry was surfaceapplied over a two year period on reed canarygrass (Phalaris arundinacea L.), a perennial grass cover (living filter) at one location each in Iowa, Minnesota, and Wisconsin. Public and private (University and Cenex/Land O’Lakes) research and development capabilities were coupled to request and receive funding from a nationally-mandated program on water quality (United States Department of Agriculture). The primary objective was to study factors which impinge upon acceptable ground water quality using a …
Nitrogen Cycling In Pasture Grazed By Lactating Dairy Cows,
2024
USDA, Agricultural Research Service
Nitrogen Cycling In Pasture Grazed By Lactating Dairy Cows, M P. Russelle, L D. Satter, T Dhiman, V R. Kanneganti
IGC Proceedings (1977-2023)
Increasing use of intensive rotational grazing for livestock production in the USA raises questions about the potential for nitrate-N (NO3- N) leaching losses. In grazing experiments with lactating dairy cows at two sites in the Upper Midwest, we monitored milk production, soil NO3-N concentration, and NO3-N leaching. Dietary supplementation increased milk yield, but there was no measurable impact on NO3-N leaching losses. Leaching volumes and NO3-N losses were small on these silt loam soils, even directly under urine patches. The results suggest that NO3-N leaching is not likely to be a problem on fine-textured soils in the Upper Midwest under …
Groundwater Concentrations Of Non-Nitrogen Nutrients Under A Medium Fertility Pasture System,
2024
USDA, Agricultural Research Service
Groundwater Concentrations Of Non-Nitrogen Nutrients Under A Medium Fertility Pasture System, L B. Owens, R W. Van Keuren, W M. Edwards
IGC Proceedings (1977-2023)
The purpose of this multi-year study was to determine concentrations and transport of non-nitrogen nutrients in groundwater under a medium fertility pasture system. Rotationally grazed grass pastures received 56 kg N/ha annually as NH4NO3 for a 5-yr period. A topsoil pH of 6.0 and available P and K levels of 28 and 168 kg/ha, respectively, were maintained. Concentrations of P, K, Na, Ca, Mg, and Cl were measured in water from springs draining each paddock. Nutrient concentrations did not vary greatly on a monthly basis but there some increases during the second 5-yr period when annual N fertilizer rates were …
Monitoring The Movement Of N And S Through The Soil Plant Animal System Under Degraded And Perennial Pastures,
2024
University of New England Armidale
Monitoring The Movement Of N And S Through The Soil Plant Animal System Under Degraded And Perennial Pastures, Chen Wen, R.D B. Lefroy, G J. Blair, J M. Scott
IGC Proceedings (1977-2023)
An experiment was carried at Armidale, NSW, Australia, to test the hypothesis that pastures dominated by the perennial grass phalaris (Phalaris aquatica) together with white clover (Trifolium repens) can optimize nutrient cycling and minimize nutrient leakage in comparison with one where the perennial grass has been lost through prior overgrazing (‘degraded’). The concentrations of mineral nitrogen present as ammonium and nitrate indicated limited opportunities for N leaching under either perennial or ‘degraded’ pastures in this environment. The high S content in the 40-60 cm soil layer indicates some movement of S under both ‘degraded’ and perennial …
Can Forages Reduce Nitrate Leaching Losses From Mixed Cropping Rotations In New Zealand?,
2024
Crop & Food Research
Can Forages Reduce Nitrate Leaching Losses From Mixed Cropping Rotations In New Zealand?, G S. Francis, K M. Bartley, F J. Tabley
IGC Proceedings (1977-2023)
The objective of this two-year experiment was to determine the ability of forages grown as winter cover crops to reduce nitrate leaching losses after temporary leguminous pastures were ploughed. In both years, cover crops reduced cumulative leaching losses compared with bare fallow and were most effective when sown early in the autumn. When large amounts of residues with relatively low N concentrations were incorporated in the soil in the spring, there was extensive net N immobilisation that suppressed the yield of the following wheat test crop. When cover crops were grazed, the N consumed by sheep as herbage was returned …
Use Of Novel Incubation Technique To Measure N2 On 0/N2 Following Surface Or Injected Application Of Slurry,
2024
Institute of Grassland and Environmental Research
Use Of Novel Incubation Technique To Measure N2 On 0/N2 Following Surface Or Injected Application Of Slurry, D Scholefield, D Chadwick, J.M B. Hawkins
IGC Proceedings (1977-2023)
Measurements of N2O and N2 efflux were made following surface or injected application of slurry to a wet, fine-textured pasture soil. Intact blocks of the slurry applied soil were incubated in a laboratory system that permitted replacement of the original N2 in soil atmosphere with He, and thus the detection and estimation of N2 arising from denitrification. Following application at a rate equivalent to 112 kg N ha-1, 7.2 and 13.4 kg N ha-1 were lost from surface applied and injected slurry, respectively, during a 40 d period at 15 oC. Peak efflux of N2O occurred after about 20 d …
Nitrogen Leaching From Dairy Pastures In The Northeast United States,
2024
USDA, Agricultural Research Service
Nitrogen Leaching From Dairy Pastures In The Northeast United States, W L. Stout, G F. Elwinger, S L. Fales, L D. Muller, R R. Schnabel, W E. Priddy
IGC Proceedings (1977-2023)
While intensive grazing has the potential to increase dairy farm profitability in the Northeast United States, the uneven recycling of N through feces and urine can increase NO3 - leaching. We measured NO3 - leaching loss from urine and feces beneath N-fertilized orchardgrass using 60 cm diameter by 90 cm deep drainage lysimeters. Mean NO3-N levels in leachate beneath these areas were 3.8, 6.5, 93.5, 110 and 139 mg l-1 for the control, feces, and spring, summer and fall applied urine. Extrapolation of the leaching data over a grazed landscape indicates that a grazing intensity for a 180-day grazing season …
The Effect Of Forages On Soil Structure In New Zealand Mixed Cropping Rotations,
2024
Crop & Food Research
The Effect Of Forages On Soil Structure In New Zealand Mixed Cropping Rotations, G S. Francis, F J. Tabley, K M. Bartley
IGC Proceedings (1977-2023)
The objective of this experiment was to determine the rate and extent of changes in soil structural conditions under a range of forage plants and management practices. During the first experimental phase (years 1-6), the rate of soil structural improvement was slow even in the most effective treatment, with the greatest changes apparent in the surface soil (0-10 cm). Plants that produced the greatest aboveground dry matter and root mass were the most effective at improving soil structure, especially when annual tillage was avoided. In the second phase of the experiment (year 7), a spring wheat test crop was grown …
