ORCID Profile
0000-0002-0078-4154
Current Organisations
CSIRO Agriculture and Food
,
CSIRO
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Publisher: Elsevier BV
Date: 05-2012
Publisher: Elsevier BV
Date: 05-2012
Publisher: Elsevier BV
Date: 2012
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/WR10194
Abstract: Context Rodents cause yield losses of 10–15% in irrigated lowland rice crops in Vietnam, with farmers spending a lot of time and money trying to control them. Despite this, there is little understanding about the optimal timing of rodent control and the level of reduction required to maximise rice crop yields. This is compounded by the ability of rice crops to compensate for damage, and farmers applying control at the wrong time. Aims We explored the optimal timing and intensity of rodent control required to increase yields of irrigated lowland rice crops in the Mekong Delta, Vietnam. Methods We developed a system analysis framework using the rice model APSIM-Oryza validated against a hand-clipped field experiment, linked with a rodent population model and field data on rodent damage rates in rice crops. A range of intensities of reduced feeding rates and timing were explored in simulated scenarios. The responses were examined over three rice crop seasons in An Giang province, Mekong Delta, Vietnam. Key results The rice crop model was benchmarked, validated and shown to adequately compensate for rodent damage. Highest yield losses occurred in the third rice crop (16% yield loss). A one-off rodent control action at the booting stage of the rice crop with 50% control effectiveness achieved a 5% yield increase. The community trap barrier system (CTBS) with 30% control effectiveness achieved a 5% yield increase. Conclusions The modelling demonstrated the importance of rodent management timing and that control should be applied before the onset of the rodent breeding season, which normally starts at maximum tillering or booting stages. Implications We conclude that modelling can improve pest management decisions by optimising timing and level of effectiveness to achieve yield increases.
Publisher: Elsevier BV
Date: 08-2020
Publisher: CSIRO
Date: 2016
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/SR19162
Abstract: Key soil parameters, organic matter, soil pH and plant nutrients determine the capacity of a soil to sustain plant and animal productivity. Conservation agriculture (CA) and crop ersification or intensification may change these soil parameters positively or negatively, which eventually affect long-term sustainability. We monitored these key soil properties (at depths of 0–15 and 15–30 cm) under CA-based sustainable intensification practices: zero-till (ZT), and crop residue retention, and crop rotations on Inceptisols and Entisols in the Eastern Ganga Alluvial Plains from 2014 to 2017. The rainfall of this sub-tropical region is 1273–3201 mm. Soil organic carbon (C) ranged within 0.46–1.13% and generally followed (positive) rainfall gradients. At all sites, the soil under ZT tended to have higher organic C than conventional tillage (CT). Soil pHH2O ranged within 5.7–7.8 across the region. At all sites, soil pH generally decreased under ZT compared to CT. This was most marked at some acidic soil sites where pH decreased by up to 0.4 units the lower the initial soil pH, the higher was the decrease in pH under ZT practice. In contrast, the reverse trend was observed for soil organic C. Partial nutrient balances for N, P and K in rice–wheat and rice–maize systems were positive for N and P (& kg ha–1) but negative for K (up to 90 kg ha–1) under both tillage practices more so under ZT practice even though crop residues were retained. Changes under ZT provide an opportunity to maintain soil organic C. However, remediation measures such as liming and efficient use of fertilisers are required for long-term sustainability of the farming systems in this agriculturally important region of South Asia.
Publisher: Springer Science and Business Media LLC
Date: 29-03-2021
DOI: 10.1038/S41598-021-86206-1
Abstract: Enhancing crop production, particularly by growing a crop in the typically-fallow dry season is a key strategy for alleviating poverty in the Ganges delta region. We used a polder water and salt balance model to examine the impact of several crop management, salt management and climate change scenarios on salinity and crop evapotranspiration at Dacope and Amtali in Bangladesh and Gosaba in India. A key (and unsurprising) finding is that salt management is very important, particularly at the two drier sites, Dacope and Gosaba. Good salt management lowers salinity in the shallow groundwater, soil and water storage ponds, and leads to more irrigation. Climate change is projected to alter rainfall, and this in turn leads to modelled increases or decreases in runoff from the polders, and thence affect salt concentrations in the soil and ponds and canals. Thus, the main impacts of climate change are through the indirect impacts on salt concentrations, rather than the direct impacts of the amount of water supplied as rainfall. Management practices to remove salt from polders are therefore likely to be effective in combatting the impacts of projected climate change particularly at Dacope and Gosaba.
Publisher: Elsevier BV
Date: 03-2015
Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 03-2015
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 10-2015
Publisher: CSIRO
Date: 2021
DOI: 10.25919/F2GC-SF22
Publisher: Elsevier BV
Date: 12-2002
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 2013
Publisher: Elsevier BV
Date: 10-2018
Publisher: CSIRO
Date: 2021
DOI: 10.25919/FE7C-DG81
Publisher: Elsevier BV
Date: 12-2012
Publisher: Elsevier BV
Date: 08-2022
Publisher: Springer Science and Business Media LLC
Date: 20-06-2018
Publisher: Elsevier BV
Date: 07-2017
Publisher: Science and Education Publishing Co., Ltd.
Date: 07-02-2014
DOI: 10.12691/AEES-2-1-4
Publisher: MDPI AG
Date: 13-11-2022
Abstract: The Indo Gangetic Plain (IGP) is a food basket of South Asia and is considered a hotspot for air pollution due to persistently high emissions of anthropogenic aerosols. High levels of aerosols in the IGP not only affect the health of people but also the health of the natural system and the climate of the region. Aerosol effects on crop production in the IGP is an emerging area of interest for policymakers and the scientific community due to their possible effect on the food security and livelihood of millions of people in the region. To investigate the effect of anthropogenic aerosols on wheat production in the eastern IGP, we used a calibrated and validated Agricultural Production System Simulator (APSIM) model at nodes in Bangladesh, India and Nepal, 2015–2017. The effects of anthropogenic aerosols on wheat production were examined by running the APSIM model under three conditions: firstly, the condition with anthropogenic aerosols, using the observed meteorological data secondly, the condition without anthropogenic aerosols, considering only the radiative effect of anthropogenic aerosols (adding the reduced radiation due to anthropogenic aerosols on the observed data) thirdly, the condition without anthropogenic aerosols, considering the radiation as well as temperature effects (by adding the reduced solar radiation and temperature due to anthropogenic aerosols on the observed data). The study revealed that, on average, anthropogenic aerosols reduced the wheat grain yield, biomass yield, and crop evapotranspiration by 11.2–13.5%, 21.2–22%, and 13.5–15%, respectively, when considering the 2015–2017 seasons at the target sites of eastern IGP. The study also showed an average reduction of more than 3.2 kg per capita per annum of wheat production in the eastern IGP due to anthropogenic aerosols, which has a substantial effect on food security in the region. Moreover, the loss of wheat grain yield due to anthropogenic aerosols in the eastern IGP is estimated to be more than 300 million USD per annum during the study period, which indicates a significant effect of anthropogenic aerosols on wheat production in the eastern IGP.
Publisher: Wiley
Date: 03-2010
Publisher: CSIRO
Date: 2021
DOI: 10.25919/JWZN-4888
Publisher: Elsevier BV
Date: 05-2021
Publisher: Springer Science and Business Media LLC
Date: 13-06-2015
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 02-2017
Publisher: CSIRO
Date: 2015
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 2022
Publisher: Cambridge University Press (CUP)
Date: 25-05-2011
DOI: 10.1017/S0376892911000130
Abstract: Worldwide, irrigation development has affected pre-existing natural habitats and created novel aquatic habitats, and future changes in management will continue to influence flood-dependent vegetation and fauna. Irrigated agriculture has had a profound influence on native bio ersity in the Riverina region of temperate Australia. Current irrigation practices provide large amounts of water to the landscape in the form of constructed wetland habitats: irrigation channels, impoundments and flooded crop-growing areas. Flooded rice bays support many species of native wetland plants, and 12 of the 14 species of frog recorded in the region. All constructed habitats provide a food resource for waterbirds, but not breeding habitat. While a species of tortoise benefits from the provision of constructed habitats, terrestrial reptiles and mammals are most abundant in remaining native vegetation. The climate is predicted to become increasingly hot and dry, with a reduced and more variable supply of irrigation water, thus placing increasing stress on farming and on natural ecosystems. The predicted reduction of constructed aquatic habitats may affect the native species using them, but may not have a major adverse impact on bio ersity regionally because the species recorded in constructed habitats tend be abundant and widespread, and such species also occur in natural wetland habitats. Sensitive species that depend on native vegetation persisting in reasonable amounts and in good condition are at greater risk. In the Riverina, the remaining native vegetation should be managed to protect and improve its condition, including appropriate managed inundation events for flood-dependent communities. The landscape should be managed to provide the best context for the function and health of existing vegetation including moderating the effects of soil disturbance, fertilizers and herbicides. The impacts of changed irrigation practices should be mitigated through managed flooding of remnant vegetation. In countries with more evolved, traditional rice-growing systems than the Riverina, there will be greater emphasis on bio ersity coexistence with cultivation. Nonetheless, in all settings there is value in jointly considering the role of both natural and constructed habitats in bio ersity research and conservation.
Publisher: Springer Science and Business Media LLC
Date: 19-03-2009
Publisher: Elsevier BV
Date: 12-2020
Publisher: Wiley
Date: 17-12-2014
DOI: 10.1111/GCB.12758
Abstract: Predicting rice ( Oryza sativa ) productivity under future climates is important for global food security. Ecophysiological crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties associated with crop models remain largely unquantified. We evaluated 13 rice models against multi‐year experimental yield data at four sites with erse climatic conditions in Asia and examined whether different modeling approaches on major physiological processes attribute to the uncertainties of prediction to field measured yields and to the uncertainties of sensitivity to changes in temperature and CO 2 concentration [ CO 2 ]. We also examined whether a use of an ensemble of crop models can reduce the uncertainties. In idual models did not consistently reproduce both experimental and regional yields well, and uncertainty was larger at the warmest and coolest sites. The variation in yield projections was larger among crop models than variation resulting from 16 global climate model‐based scenarios. However, the mean of predictions of all crop models reproduced experimental data, with an uncertainty of less than 10% of measured yields. Using an ensemble of eight models calibrated only for phenology or five models calibrated in detail resulted in the uncertainty equivalent to that of the measured yield in well‐controlled agronomic field experiments. Sensitivity analysis indicates the necessity to improve the accuracy in predicting both biomass and harvest index in response to increasing [ CO 2 ] and temperature.
Publisher: Springer Science and Business Media LLC
Date: 11-2017
DOI: 10.1038/S41598-017-13582-Y
Abstract: The CO 2 fertilization effect is a major source of uncertainty in crop models for future yield forecasts, but coordinated efforts to determine the mechanisms of this uncertainty have been lacking. Here, we studied causes of uncertainty among 16 crop models in predicting rice yield in response to elevated [CO 2 ] (E-[CO 2 ]) by comparison to free-air CO 2 enrichment (FACE) and chamber experiments. The model ensemble reproduced the experimental results well. However, yield prediction in response to E-[CO 2 ] varied significantly among the rice models. The variation was not random: models that overestimated at one experiment simulated greater yield enhancements at the others. The variation was not associated with model structure or magnitude of photosynthetic response to E-[CO 2 ] but was significantly associated with the predictions of leaf area. This suggests that modelled secondary effects of E-[CO 2 ] on morphological development, primarily leaf area, are the sources of model uncertainty. Rice morphological development is conservative to carbon acquisition. Uncertainty will be reduced by incorporating this conservative nature of the morphological response to E-[CO 2 ] into the models. Nitrogen levels, particularly under limited situations, make the prediction more uncertain. Improving models to account for [CO 2 ] × N interactions is necessary to better evaluate management practices under climate change.
Publisher: Elsevier BV
Date: 11-2016
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/AR04249
Abstract: Summer crops grown during the summer fallow in a Mediterranean-type climate have the potential to produce out-of-season biomass and grain, increase water use, and reduce deep drainage. The potential effects of growing grain sorghum on components of the water balance, sorghum biomass and grain production, and yield of subsequent wheat crops were investigated by simulation using APSIM and long-term climate data from the Esperance district. Sorghum was simulated as part of 3 systems: (1) as an opportunity crop following wheat harvest, (2) as a fallow replacement after pasture removal and before entering a cropping phase, or (3) as a fallow replacement after a failed or waterlogged winter crop. Simulations were conducted for the period 1957–2003 at Myrup (mean annual rainfall 576 mm), Scaddan (408 mm), and Salmon Gums (346 mm). Sorghum was assumed to have a similar rooting depth to wheat. In order to gain confidence in using APSIM for these investigations, tests were initially conducted against field data involving summer and winter crops in sequence and measurements of soil water dynamics. Data sets also varied in summer rainfall, species (forage sorghum, grain sorghum, Japanese millet), and soil type (deep sand, and medium and shallow duplex). Overall, the simulations showed that incorporation of a sorghum crop increased transpiration by 10–30 mm/year, made the soil profile drier by a similar amount at wheat sowing, and consequently reduced deep drainage by 3–25 mm/year, depending upon cropping system and location. Long-term average drainage results were dominated by large episodes in wet years. The increased transpiration from the summer crop, although reducing drainage in wet years, could not eliminate drainage. Following wheat yields were reduced by an average of 200–400 kg/ha, corresponding to a reduction of 10% at wetter and 30% at drier locations. In the 2 fallow replacement systems, sorghum biomass was produced in nearly every simulated season. However, averaged over all seasons, sorghum grain production was much less reliable comprising only 10–20% of biomass. In the opportunity system, sorghum produced biomass in only 1 in 3 seasons at Salmon Gums and Scaddan and 1 in 2 at Myrup. Grain was produced in 1 in 5 seasons at all 3 locations, underlining the riskiness of this opportunity niche for summer crops in the Esperance district. Although summer cropping was shown to result in modest reductions in deep drainage, it also comes at a cost to wheat production. The largest effects on drainage and most reliable biomass production were seen in the systems where the summer crop was grown following pasture removal or a failed (waterlogged) winter crop. This research has also shown that recent farmer and researcher experiences of summer cropping are likely to be more favourably biased towards prospects for summer cropping than indicated by long-term simulations because of their longer-term perspective.
Publisher: CSIRO
Date: 2021
DOI: 10.25919/JVJ5-KK38
Publisher: Elsevier BV
Date: 07-2017
Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 03-2018
Publisher: Wiley
Date: 27-11-2017
DOI: 10.1002/JSFA.8683
Publisher: Elsevier BV
Date: 02-2019
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 03-2017
Location: Australia
Location: Australia
Start Date: 2015
End Date: 2013
Funder: Australian Centre for International Agricultural Research
View Funded ActivityStart Date: 2015
End Date: 2016
Funder: Department of Foreign Affairs and Trade, Australian Government
View Funded ActivityStart Date: 2010
End Date: 2015
Funder: Australian Centre for International Agricultural Research
View Funded ActivityStart Date: 2011
End Date: 2013
Funder: Australian Centre for International Agricultural Research
View Funded ActivityStart Date: 2015
End Date: 2020
Funder: Australian Centre for International Agricultural Research
View Funded Activity