Digital Commons Network^™

Nitrous Oxide Emissions From Grassland In Manawatu, New Zealand, R A. Carran, J P. Evans

IGC Proceedings (1977-2023)

Nitrous oxide (Np) is a minor component of the atmosphere which acts as a potent greenhouse gas and also causes ozone depletion. Soil bacteria are the most important agents of N2O production, but both the New Zealand and the international data on N2O emission rates from soils are very poor at present. In order to help define the possible range of emission ranges from pasture soils· we selected sites with characteristics that would make then "high" or "low" emitters of N2O. The "high" emission site was a fine-textured, fertile but poorly drained flood plain soil. The "low" emission site was …

Development Of Plants Resistant To Insect Pests Using Gene Manipulation, D.W R. White, D R. Biggs, M T. Mcmanus, C R. Voisey, J T. Christeller, A H. Broadwell, E.P J. Burgess, C N. Chilcott, P J. Wigley, P G. Mcgregor

IGC Proceedings (1977-2023)

Damage to pasture plants caused by insect pests reduces the supply of feed for grassland animal production. In addition, the use of chemical insecticides for the control of pasture pests is undesirable for reasons of high cost and possible damage to the environment. One way to overcome these limitations is 10 utilize a recent development. in plant molecular biology which has seen the incorporation of cloned genes that confer insect _pest resistance into crop plants. To date, the most widely used genes for this purpose are those coding for insecticidal proteins from the bacterium Bacillus thuringiensis, and for inhibitors …

Implications Of A Doubling In Ambient Carbon Dioxide Levels Of Herbage Quality In Perennial Ryegrass And White Clover, H Clark, C C. Bell, P.C D. Newton, B D. Campbell

IGC Proceedings (1977-2023)

Digestibility (DMD) and crude protein (CP) percentage in leaf and stem of 4 cultivars each of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) grown at 3 day/night temperatures (12f7, 18/ 13, 28/23°C) and 2 CO2 concentrations (35 0 or 700 ppm) was estimated using near infrared reflectance spectroscopy (N[RS). Differences between cultivars in DMD and CP were small and non-significant. Higher temperatures reduced DMD andCP in both species. DMD was unaffected by CO2 concentration in either species. The higher concentration of CO2 reduced leaf and stem CP by 14.6 and 10% respectively in white clover …

Volatile Constituents Of Tall Fescue Varieties In Relation To Palatability, Aldo Tava, Nicola Berardo, Miriam Odoardi

IGC Proceedings (1977-2023)

The chemical composition of the essential oil of tall fescue (Festuca arundinacea Schreb,), a poorly palatable species, was analysed by GC and GC-MS. The major components identified were alcohols, aldehydes and esters. The qualitative and quantitative differences detected among 6 cultivars of different geographical origin suggest the most abundant compounds may play a role in the grazing preference exhibited by animals.

Partitioning Of Major Elements Concentrations In Grasses Into Four Cell Fractions Based On Enzymatic Solubility, Suguru Saiga, Takanori Akiyama, Moegi Saski, Kiyoshi Watanabe

IGC Proceedings (1977-2023)

To investigate availability of major elements to animals, N, P, K, Ca and Mg of plant dry matter were partitioned into 4 cell fractions based on enzyme solubility. When the elemental concentration of forage was compared, Dactylis glomerata was higher in K (1.69%), Festuca aru11dinacea in N (2.35%), K (1.68%) and Mg (Q.341 %) and Lolimum perenne in N (2.54%), P (0.224%) and Ca (0.457%). When compared between plant parts, concentrations of all elements.were higher in leaf than in stem, especially P, Ca and Mg. As a result of partitioning, more than 85% of P, K and Mg resided …

Improvement Of The Feeding Value Of Senescent Grass Pastures By Molecular Genetic Manipulation, G D. Bonnett, K R. Stevenson, R J. Simpson

IGC Proceedings (1977-2023)

Senescent grass pasture has low feeding value end is the major limitation to animal productivity during summer in annual environments. The loss of fructan from the stems of temperate grasses as they senesce contributes significantly to the decline in feeding value of the grass, Temporary retention of fructan during senescence achieved by treating grass with a herbicide increases both the feeding value of the grass and the productivity of animals grazing the modified pasture. We have identified an enzyme responsible for initiating the loss of fructan from stems of Lolium rigidum. It has been purified, characterized and will be used …

Modeling The Effects Of Climate Variability And Climate Change On A Pastoral Farming System, R J. Martin, D B. Baird, M J. Salinger, P R. Van Gardingen, D G. Mccall

IGC Proceedings (1977-2023)

A simulation model was used to investigate the pasture and animal production and gross margins of a typical all sheep permanent pasture farm in South Canterbury, New Zealand, using 60 years of current climate data, and also a climate change scenario. The model was run on a fixed management system at different stocking rates with and without destocking during feed shortages. Mean annual pasture production was 8060 kg/ha, with a coefficient of variation of 22%. Destocking enabled more stock to be carried on average, with higher, but rh.ore variable, returns. A climate change scenario of a 75% increase in CO2' …

Effects Of Defoliation Height And Time Of Initital Defoliation On Regrowth Components In A Poa Pratensis- Dominated Sward, B E. Frankow-Lindberg

IGC Proceedings (1977-2023)

Two experiments on swards dominated by Poa pratensis L. were conducted in 2 climatically contrasting (wann/dry and cold/wet) years. There were either 4 or 3 initial defoliation dates in spring and 3 defoliation heights (2, 6 and 10 cm). Regrowths were harvested 4 weeks after the initial defoliation. The swards received a total of 80 kg/ha nitrogen split into 2 dressings. Regrowth characteristics, based on samples cut to ground level, depended on weather conditions. The yield of vegetative shoots was affected most by shoot size, which in turn was determined by initial defoliation date, in the dry year. In the …

Effect Of Management On Leaf Growth And Senescence Of Three Contrasting Grass Species, B M. Butler, J Hodgson

IGC Proceedings (1977-2023)

The innuence of continuous grazing management on leaf extension, leaf senescence and tiller density of 3 grass species with contrasting tillering rates, tiller size and growth habit was examined. Perennial ryegrass (Lolium perenne L. cv. Grasslands Nui), tall fescue (Festuca arundinacea Schreb, cv. Grasslands Roa) and Yorkshire fog (Holc,,s la11allls L. cv. Massey Bnsyn) were maintained in as near a steady state as possible at sward heights of 3-10 cm. The balance between leaf extension and senescence, and tiller density resulted in net extension per unit area being generally greatest at sward heights of- 5.5 cm in Yorkshire fog and …

Applications Of Random Amplified Polymorphic Dna (Rapd) Markers In Plant Biology, Gail M. Timmerman, John A. Mccalum

IGC Proceedings (1977-2023)

RAPDs are a new class of molecular marker based on PCR amplification of genomic DNA using random sequence primers. Their value for studying plant genomes has been clearly demonstrated in the short lime they have been in use. Uses of RAPD markers include genome mapping, lagging of genes, studying genetic diversity, identifying cultivars and analysing parentage. RAPDs should prove to be as applicable to the study of animal genomes ns they have for plant genomes, It is important that researchers using or planning to use this type of molecular marker be aware of two possible drawbacks of RAPDs. Since RAPDs …

A Traditional Exporter's Perspective Of Trade Reforms, N R. Mitchell

IGC Proceedings (1977-2023)

The agriculture and trade policies which governments commonly have pursued over the last three decades, particularly governments in the large developed countries, have had a major impact on world patterns of production and trade in livestock and livestock products. This has been especially so for milk and dairy products where government involvement in markets has been most pervasive. One effect has been that the comparative advantages derived from the production of livestock products based on pasture feeding of animals \lave been suppressed or overridden. Reform of the international trading system for agricultural products now being developed in the GATT, and …

Impact Of Changing Trade Opportunities On Livestock Production In Developing Countries, J K. Camoens

IGC Proceedings (1977-2023)

For the lesser developed countries (LDCs) and advanced countries (ACs), the paper identifies the determinants of "free" trade, analyses protectionism, examines the global trade picture with respect lo "free" trade, relates trade to production and the structure of demand, and finally predicts the impact of trade reforms. The analysis concludes that: (i) trade policies per se do not impact in any significant manner on domestic production or imports in the LDCs since world trade constitutes a small fraction of production; (ii) demand, and hence supply, of animal products are determined primarily by GNP, income distribution and price; (iii) grassland farming …

Development Of Grain-Saving, High Efficiency Pasture Animal Industry, Han Gui Qing

IGC Proceedings (1977-2023)

Grain-saving, high efficiency pasture-sustained (GSHEPS) animal industry, with its final purpose of profitable industry, is forage-orientated. This is a new fonn of operation based on advanced feeding management.

Effects Of Applied Nitrogen And Rest Period On Forage Production And Silage Quality, L Juan Carlos Dumont, A Francisco Lanuza

IGC Proceedings (1977-2023)

An experiment to analyse the effect of nitrogen (N) fertiliser and rest period initiation for silage making on permanent pasture was carried out. N fertiliser increased forage production, crude protein, neutral detergent fibre and ammonia-N. Shortening the intervals, by delaying the initiation of resting period, increased forage quality with only marginal decreases in dry matter (DM) production. Resting periods from the second week of September and cutting at the end of October or first week of November was appropriate in the Osorno area of Chile. The use of 60 kg N/ha is recommended. Two-cutting system must be considered in order …

Change In Botanical Composition, Dry Matter Yield And Forage Quality Of Grassland After Five Seasons Of Extensification, W Kuhbauch, J Schellberg

IGC Proceedings (1977-2023)

Extensification of grassland management in Germany has 2 major objectives (I) to reduce the surplus of crop and animal products, and (2) to diminish unwanted side effects against the environment from intensive production systems. Some of the programmes on offer require a reduced number of cuttings and grazings per season, including a very late first cut of the sward and a reduction of nitrogen fertiliser. In a 5-yenr experiment at the grassland research station Rengen, Eifel-mountain-range, Germany, extensification of this type on productive grassland sites created an unbalanced botanical composition and, with nitrogen applied, a major portion of quackgrass in …

Efficiency Of Different Implements For Pasture Interseeding, J A. Josifovich

IGC Proceedings (1977-2023)

Pasture renovation with grasses and legumes appears to be a good practice to increase primary and secondary production. Trials were planted in 6 locations in Buenos Aires province, Argentina, 2 in Pergamino and 4 200 and 300 km south east of Pergamino, to evaluate 3 different implement combinations: a) rigid chisel coulter, b) spring tooth heavy duty coulter, with teeth 30 cm apart followed by spring tooth cultivators, and c) spring tooth heavy duty coulter 30 cm used twice in the same direction. The species sown were: fescue (Festuca arundinacea Schreb.), brome (Bromus uniolides H.B.K.), chicory (Cichoriu, intybus …

Role Of Mixed Animal Type Grazing In Range Preservation And Increasing Animal Product Output, T Nolan, J Connolly, C Sall

IGC Proceedings (1977-2023)

fhe work was part of a research programme to a) evaluate the role of mixed animal type grazing in increasing production, b) explain any; benefits obtained and c) develop improved whole grazing ecosystems in temperate and semi-arid areas. Its specific ai was to improve domestic food production from range grazing livestock and to preserve or improve native range resources. This paper discusses some recent results from the Senegalese Sahel related to· animal preferential and differential selection, animal performance and the role of mixed grazing in improving the relationships between them to secure the objectives stated. The use of these results …

Effect Of Grass-White Clover Mixtures On Steer Performance And Sward Characteristics In Atlantic Canada, H T. Kunelius, P Narasimhalu

IGC Proceedings (1977-2023)

Pasture production in winter cold regions such as Atlantic Canada is limited by the availability of winter hardy and productive grass and legume species, Perennial ryegrass (Lolium perenne L.), meadow fescue (Festuca prarensis Huds.) and timothy (Phleum pratense L.) grown in binary mixtures with white clover (Trifolium repens L.), and naturalised pasture consisting of Poa spp., Agrostis spp. and white clover, were compared under grazing, Steers were used to graze the swards from 16-26 cm down to 8 or 11 cm post-grazing surface heights, Dry matter intake was higher for natural pasture than for sown pastures, …

Range Management: Optimizing Forage Production And Qualityy, J E. Danckwerts, N M. Tainton

IGC Proceedings (1977-2023)

Range management involves optimising forage production and quality, both in the short term and in the long term. In the short term, temporal climatic variability, stocking rate, grazing system, fire, animal type. and spatial variability, inter alia, strongly, influence forage production and quality. On the other hand, long-term optimisation requires prevention of range deterioration. The nature of this process seems to be profoundly different between humid and arid rangelands, at least in tropical and subtropical zones. In the former, changes are relatively predictable, overgrazing resulting in gradual deterioration. In the latter, change is event driven, providing the grazier with …

Livestock Production Systems In The Cameroon Sahelo-Sudanian Region, E Tedonkeng Pamo, R D. Pieper

IGC Proceedings (1977-2023)

The Sahelo-Sudanian region of Cameroon extends from 7° to 13° N. The region receives 400-1000 mm rainfall and is covered by a complex mosaic of. vegelation and plant communities. Animal production has always been a cornerstone of the economy of this region. The range use system of the region is extensive. The major problem faced by pastoralists has been a compression of their range not only by the northward-moving cultivation, but also by the southward moving desertification. Various grazing melhods have been suggested but none have yet been implemented, and nomadism and transhumance remain the major production systems. Analysis of …

Reduction Of Nutrient Losses For Dairy Farms, With Emphasis On Nitrogen, W Luten, D J. Den Boer

IGC Proceedings (1977-2023)

Recently the Dutch government presented several policy papers in which standards are given for maximum allowed emissions to air, groundwater and surface water. Depending on the farm situation an optimum combination of measures in relation to housing, slurry storage, slurry and fertiliser application, and composition of the ration can be taken. In general a better use of nutrients from animal manure by applying slurry with low emission techniques in the growing season and a reduction of the stocking rate by a higher milk production per cow are the most effective and cheapest measures to reach these targets. There is a …

A Preliminary Discussion Of The Management And Administration Of Yunwu Mountain Natural Grassland Reserve In China, Zhao Zhiyi, Yang Ailian

IGC Proceedings (1977-2023)

The advantages and problems encountered in the establishment of a grassland reserve are described. The conflicts between local farmers' requirement to feed and water livestock and the conservation strategy of natural grassland are discussed.

Big Geospatiotemporal Data Approaches To Monitoring And Mitigating Environmental Impacts In Agriculture, Olatunde D. Akanbi, Vibha S. Mandayam, Erika I. Barcelos, Arafath Nihar, Yinghui Wu, Jeffrey Yarus, Roger H. French

Student Scholarship

This research explores the application of geospatial techniques for global agricultural monitoring, integrating satellite imagery and soil data to assess crop health and soil conditions. Our approach provides actionable insights to improve agricultural productivity and sustainability, addressing food security challenges through advanced machine learning models.

Root Lesion And Burrowing Nematodes And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Nematodes are common soil pests that feed on the roots of a wide range of crops in all agricultural areas of Western Australia, resulting in significant crop yield loss. Root lesion nematode can be managed but not eradicated.

This factsheet summarises the biology of the root lesion nematode (RLN, Pratylenchus spp.) and burrowing nematode (Radopholus spp.) species that damage Western Australian (WA) crops, and their diagnosis and management.

Roly Poly And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Roly poly, also known as prickly saltwort or tumbleweed (Salsola australis), is a native species found throughout Australia. The dead plants can break off at ground level, forming the ‘tumbleweeds’ seen in movies.

Like most summer weeds, roly poly uses soil moisture and nutrients that would otherwise be available to the following crop. The time taken to clear uncontrolled plants can delay seeding.

Livestock will graze the young plants; however, they will not eat the mature plants and are injured by the prickly leaves.

Open Groundwater Drains In Wa, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Open groundwater drains are excavated channels with sloping floors and sides and open levees, designed to intercept and drain surface (usually fresh) and groundwater (usually saline in WA) from agricultural land. These drains are most effective where the channel is dug below a water table in soils that allow good lateral drainage.

DPIRD recommends leveed groundwater drains in most cases. These should form part of a whole farm and whole catchment integrated water and salinity management program. Information on this page is a guide only. It is highly recommended that landholders considering the construction of open drains seek expert advice …

Temporal Dynamics Of Coastal Sediment Characteristics: A Comparative Study On Pre- And Post-2004 Tsunami Event Along The Nagoor - Poompuhar Stretch, Tamil Nadu, Yamini S

Theses and Dissertations

Tsunamis represent some of the most devastating natural events for coastal regions, as exemplified by the 26th December 2004 Great Indonesian Earthquake triggered a massive tsunami across the Bay of Bengal and Indian Ocean, causing extensive destruction in various countries, including India. This study addresses a significant gap in the literature by focusing on the detailed sedimentological aspects of coastal dynamics. Specifically, it examines the pre-tsunami (December 2004), post-tsunami (January 2005), and recent (December 2022) sediment characteristics along a 35 km stretch of the Coromandel coast from Poompuhar to Nagoor.

Eight stations were selected for sampling: Poompuhar, Chinnankudi, Kuttyandiyur, Chandrapadi, …

Foraging Strategies Of Ruminant Livestock On Intensively Managed Grasslands: Potential And Constraints, I J. Gordon, C Lascano

IGC Proceedings (1977-2023)

All grazed swards exhibit heterogeneity in the spatial (horizontal and vertical) dispersion of species/biomass. A herbivore foraging at random within such a heterogeneous environment would ingest less nutrients than wou Id one which exploited the heterogeneity on offer through selective grazing. The suite of decision-making processes involved in the selective grazing we observe is termed the animal's foraging strategy. On first observation, intensively managed sown swards appear to offer little opportunity for a herbivore to exhibit a foraging strategy; however, opporlunities do exist and there is empirical evidence that herbivores foraging on sown swards tend to have a diet higher …

Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming

IGC Proceedings (1977-2023)

We review the evolutionary (species-specific) and ecological (individual behavioural) strategies of African grazing ungulates. The contexts considered are free-ranging wild ungulates, traditional livestock pastoralism and extensive commercial ranching. Particularly successful are (1) buffalo, able to digest grass fibre effectively in mesic grasslands; (2) wildebeest, exploiting semi-arid grasslands through migration; (3) megaherbivores (elephant, hippopotamus and white rhinoceros) utilising a wide range of vegetation components. Species-specific adaptations include body size and metabolic rate, digestive efficiency and passage rate, oral and dental anatomy, water dependence and detoxification capacity. Species overlap in grass species se'lected, with dietary differences apparent in grass height favoured, and …

Comparison Of Animal Gains Using Perennial Pastures Exclusively Or Combined With Chicory-Oats-Clover Temporary Winter Pastures, J A. Josifovich

IGC Proceedings (1977-2023)

The increment of winter forage availability using short-rotation pastures could be an interesting way to increase winter carrying capacity. The producer could make good use of higher spring grass production. Sowing oats, rye or chicory alone is quite common in the Argentine Pampa. to evaluate the efficiency of these short-rotation winter pastures a 3 year trial was carried out at Pergamino Experiment Station. The treatments were: a) perennial pastures, 100% of the surface, b) perennial pastures 75%, and chicory-clover 25%, with 2 replications of 3 ha each. The pastures were, for. class II soils, fescue (Festrlca aru11dinacea Schreb.) cv. El …