The Paired-Paddock Model as an Agent for Change on Grazing Properties Across Southeast Australia

From the mid 1970s to the mid 1990s the low productivity of wool and beef producing farms in the high rainfall zone (\u3e550 mm annual rainfall) in south east Australia has been a major contributing factor to the difficulties faced by farmers in this region. This was despite research from the Long-term Phosphate Experiment at Hamilton in south west Victoria indicating that there is considerable potential to increase the productivity and profitability of wool production (Saul, 1994). By implementing the productive pasture technology (PPT) that involves increased rates of fertiliser on pastures containing productive species and increased stocking rates to utilise the extra pasture grown (Trompf & Sale, 2000), gains in excess of $A200/ha on a gross margin basis can be regularly achieved. However wool and beef producers were reluctant to adopt the technology. In 1993 the Grassland\u27s Productivity Program (GPP) was initiated to assist producers to develop skills and gain confidence in their ability to manage more productive pastures on their farms. In brief, groups of 4-6 farmers were assisted by an experienced facilitator to compare current management practice in one paddock with PPT in an adjacent paddock. Over 500 wool and beef producers in south east Australia have been exposed to the paired-paddock model, firstly in the GPP from 1993 to 1997 and more recently in the Triple P Program. This paper reports on the effectiveness of the paired-paddock model in assisting pastoral producers to adopt PPT

The development of freshwater science in Britain, and British contributions abroad, 1900-2000

This article outlines the development of freshwater science between 1900 and 2000 and in particular traces British contributions, both to a deepened knowledge of specifics and to their interrelation as environmental and ecological science. The author provides a selected bibliography of important publications relevant to the topic of the article

Nitrogen and phosphorus limitation of phytoplankton growth in New Zealand lakes: Implications for eutrophication control

We examine macronutrient limitation in New Zealand (NZ) lakes where, contrary to the phosphorus (P) only control paradigm, nitrogen (N) control is widely adopted to alleviate eutrophication. A review of published results of nutrient enrichment experiments showed that N more frequently limited lake productivity than P; however, stoichiometric analysis of a sample of 121 NZ lakes indicates that the majority (52.9%) of lakes have a mean ratio of total nitrogen (TN) to total phosphorus (TP) (by mass) indicative of potential P-limitation (>15:1), whereas only 14.0% of lakes have mean TN:TP indicative of potential N-limitation (<7:1). Comparison of TN, TP, and chlorophyll a data between 121 NZ lakes and 689 lakes in 15 European Union (EU) countries suggests that at the national scale, N has a greater role in determining lake productivity in NZ than in the EU. TN:TP is significantly lower in NZ lakes across all trophic states, a difference that is driven primarily by significantly lower in-lake TN concentrations at low trophic states and significantly higher TP concentrations at higher trophic states. The form of the TN:TP relationship differs between NZ and the EU countries, suggesting that lake nutrient sources and/or loss mechanisms differ between the two regions. Dual control of N and P should be the status quo for lacustrine eutrophication control in New Zealand and more effort is needed to reduce P inputs

Seed Rain of a Native Pasture under a Range of Grazing and Fertiliser Regimes

In recent years, deferred grazing (no defoliation of pastures for a period generally from spring to late summer or autumn) has been widely adopted to rejuvenate degraded native pastures in marginal land classes such as steep hill country in western Victoria, Australia. One of the important features of deferred grazing is the increase of seed production over summer and autumn, which could potentially lead to natural regeneration and improved groundcover by pasture plants (Nie et al. 1999). While increasing seed numbers in the soil seed bank following deferred grazing were reported (Nie and Mitchell 2006), there has been little research on seed production during deferred grazing in this environment. This study aimed to investigate the seed rain (the fall to the ground of wind-dispersed seeds) of native pastures under various deferred grazing and fertiliser regimes. Seed population and composition in the soil seed bank are important contributors to the productivity, botanical composition and persistence of permanent pastures

Long Term Effects of Liming a Basalt-Derived Soil, On Lucerene and Phalaris Production

Lime incorporated into a basalt-derived clay loam lowered exchangeable aluminium in soil. Soil pH was still elevated, 9 years after 2 t/ha of lime was incorporated. With lower rates of lime the density of lucerne plants declined. Lucerne yield more than doubled with lime. After six years, the area was sown to a phalaris-clover pasture. A 15% increase in the yield of phalaris was recorded from limed plots over the next three years. Despite this, 11 years after liming, herbage P concentrations increased with lime, from 0.28% to 0.35%

Do forage legumes have a role in modern dairy farming systems?

peer-reviewedIntensification in New Zealand dairy farming systems has placed greater pressure on clover performance and fitness and has highlighted the need to develop clover cultivars that are better adapted to intensive grazing systems. Increased stocking rates and increased use of nitrogen fertiliser have put enormous pressure on the contribution of clover to modern dairy systems. Future innovations such as semi-hybrid cultivars offer the potential to improve the competitiveness of legumes with nitrogen-fertilised forage grasses. Similarly, advances in condensed tannin research suggest that significant animal performance gains can be achieved in conjunction with reduced environmental impact. In order to capture these benefits, dairy farmers will need to reassess their grazing management to ensure that legumes can be maintained at economically useful levels. Novel grazing management systems that optimise the benefits provided by the grass and legume components need to be used in future dairy farming systems. Forage legumes, and especially white clover, have an important role to play in modern dairy systems

Low water-soluble superphosphate fertiliser for pasture production in south-western Australia

Single superphosphate is derived from chemically treating rock phosphate into relative proportions of monobasic, dibasic and tribasic calcium phosphate to produce a commonly used source of phosphorus fertiliser for pasture systems. The leaching of phosphorus on susceptible soil types contributes to eutrophication and environmental damage. By modifying the chemistry of single superphosphate to match a soils phosphorus binding index and rainfall conditions, pasture dry matter yield can be maintained and leaching of phosphorus significantly reduced

The short term effects of a fire fighting foam and fire retardant on selected flora from Australia\u27s Southwest

Chemical fire suppressants arc used extensively throughout Australia\u27s Southwest to contain and suppress wildfires. Despite several studies being conducted into their effects on terrestrial vegetation in North America and Eastern Australia, where a variety of significant effects were found, no such investigation has been carried out in Australia\u27s Southwest. This study examined the short-term effects of a fire fighting foam and fire retardant on selected flora from Australia\u27s Southwest. Various concentrations of fire fighting foam and fire retardant were applied to seeds and seedlings of several native species. Native species were chosen for their high abundance and widespread distribution throughout Australia\u27s Southwest. Seed germination was assessed over 28 days for the number of germinants, whilst the seedlings were assessed on numerous growth characteristics over a ten-week period. Both the fire fighting foam and fire retardant treatments significantly reduced the germination of all seven species. Greater concentrations resulted in reduced seed germination. Both the 3.0% foam and 3.0% fire retardant treatments showed no sign of germination within the study period. The effect of the fire fighting foam on some native seedlings was significant, yet significant differences were inconsistent throughout the species examined and the variables applied. The fire retardant was far more influential on the growth characteristics measured and significantly affected all seven species. Significant responses included increases and decreases in biomass and improved and reduced plant health. From these results. it was determined that the use of fire retardants to control and suppress wildfires should be avoided where possible. The use of fire fighting foams between 0.1% and 0.4% foam concentrate is recommended as an ecologically sound and effective fire suppressant tool

Report of the 2004 Workshop on In Situ Iron Enrichment Experiments in the Eastern and Western Subarctic Pacific

Foreword 1. BACKGROUND AND OBJECTIVES (pdf, 0.1 Mb) 2. 2004 WORKSHOP SUMMARY (pdf, < 0.1 Mb) 2.1. What have we learned from the enrichment experiments? 2.2 What are the outstanding questions? 2.3 Recommendations for SEEDS-II 3. EXTENDED ABSTRACTS OF THE 2004 WORKSHOP 3.1 Synthesis of the Iron Enrichment Experiments: SEEDS and SERIES (pdf, 0.5 Mb) Iron fertilization experiment in the western subarctic Pacific (SEEDS) by Atsushi Tsuda The response of N and Si to iron enrichment in the Northeast Pacific Ocean: Results from SERIES by David Timothy, C.S. Wong, Yukihiro Nojiri, Frank A. Whitney, W. Keith Johnson and Janet Barwell-Clarke 3.2 Biological and Physiological Responses (pdf, 0.2 Mb) Zooplankton responses during SEEDS by Hiroaki Saito Phytoplankton community response to iron and temperature gradient in the NW and NE subarctic Pacific Ocean by Isao Kudo, Yoshifumi Noiri, Jun Nishioka, Hiroshi Kiyosawa and Atsushi Tsuda SERIES: Copepod grazing on diatoms by Frank A. Whitney, Moira Galbraith, Janet Barwell-Clarke and Akash Sastri The Southern Ocean Iron Enrichment Experiment: The nitrogen uptake response by William P. Cochlan and Raphael M. Kudela 3.3 Biogeochemical Responses (pdf, 0.5 Mb) What have we learned regarding iron biogeochemistry from iron enrichment experiments? by Jun Nishioka, Shigenobu Takeda and W. Keith Johnson Iron dynamics and temporal changes of iron speciation in SERIES by W. Keith Johnson, C.S. Wong, Nes Sutherland and Jun Nishioka Dissolved organic matter dynamics during SEEDS and SERIES experiments by Takeshi Yoshimura and Hiroshi Ogawa Formation of transparent exopolymer particles during the in-situ iron enrichment experiment in the western subarctic Pacific (SEEDS) by Shigenobu Takeda, Neelam Ramaiah, Ken Furuya and Takeshi Yoshimura Atmospheric measurement by Mitsuo Uematsu 3.4 Prediction from Models (pdf, 0.3 Mb) Modelling iron limitation in the North Pacific by Kenneth L. Denman and M. Angelica Peña A proposed model of the SERIES iron fertilization patch by Debby Ianson, Christoph Voelker and Kenneth L. Denman 4. LIST OF PARTICIPANTS FOR THE 2004 WORKSHOP (pdf, < 0.1 Mb) APPENDIX 1 Report of the 2000 Planning Workshop on Designing the Iron Fertilization Experiment in the Subarctic Pacific (pdf, 1 Mb) APPENDIX 2 Terms of Reference for the Advisory Panel on Iron fertilization experiment in the subarctic Pacific Ocean (pdf, < 0.1 Mb) APPENDIX 3 Historical List of Advisory Panel Members on Iron fertilization experiment in the subarctic Pacific Ocean (pdf, < 0.1 Mb) APPENDIX 4 IFEP-AP Annual Reports (pdf, 0.1 Mb) APPENDIX 5 PICES Press Articles (pdf, 0.6 Mb) (194 page document