Posts tagged Soil
Factors to consider when draining rice (February 2015)


This NSW DPI Primefact sheet is and overview of the guidelines to take into consideration when considering draining rice. The fact sheets covers areas such as the variety selection and time of sowing, the water management after flowering. It covers the key factors such as field layout, crop nitrogen, time when crop maturing , sowing methods, time of draining, grain development stages soil types and who and where to contact for further information. 

Read More
Improving rice water use efficiency - Direct Drilling of rice and Precision Farming (June 2014)


Water use efficiency is a driving factor for the Australian rice industry. Australian rice farmers grow rice in one of the driest continents in the world, achieving some of the world’s highest yields per hectare and water use efficiency per kilogram produced (Dunn & Pal Singh, 2013). In recent years, the availability of water for agricultural production has been reduced significantly as a result of government policy. Australian rice farmers are also under constant scrutiny to justify their water usage, so need to develop new technologies and practices. Historically Australia is one of the few countries to establish a rice crop by flying rice seed into a flooded bay. The majority of the countries visited establish their crops by drilling seed into the soil and establish by flushing. In Australia, this technique could be more broadly adopted with significant savings in water use and input costs.

Read More
Managing rice snails with copper sulphate - RIRDC Project PRJ - 005685 (2013)


Snails in rice crops are becoming a more significant problem for growers because of increased levels of repeat cropping aimed at maximising water use efficiency. Repeat cropping allows dormant snails to survive in the soil. Research on copper sulphate aimed at gaining product registration and ensuring its ongoing availability for snail control has shown that its variable performance relates strongly to soil type. Higher application rates are needed to the water above soils rich in dissolved organic carbon.  Even above soils low in dissolved organic carbon, biologically active copper concentrations fall dramatically within an hour of application.  Although soil testing could allow copper application rates to be ‘fine-tuned’ for individual fields, finding alternative chemicals unaffected by soil type should be a higher priority.

Read More
Can irrigation be sustainable - Link (2006)

This journal article discusses the issues associated with salinisation in irrigation areas.  This paper applies a whole of system-water balance to compare irrigation in three semi-arid regions suffering from similar sustainability issues: Rechna Doab (RD), Pakistan; the Liuyuankou irrigation system (LIS), China; and Murrumbidgee irrigation area (MIA), Australia. The major issues seen in these areas are soil salinity, water resources and ground water management. Data used to compare these different regions were climate and soils, available water and components of water balance. The project also examined the history of water resource development in each region. The paper concludes with these systems are dependent on direct or indirect use of groundwater. It compares the results from each region and the possible acceleration rate of salininsation. The paper expresses the need to quantify regional-water quality trends, downstream environmental impacts and the trade-off between yield reduction and direct regional groundwater use by crops in these systems. It also believes a need to radically rethink sustainability of food production, rational pricing and sharing of water and commodities. Thus justifying investment that will maintain and enhance ecosystem function within irrigated catchments. As the paper states that under present operational conditions, none of the three systems discussed in this paper is sustainable. 

Read More
Growing rice with less water (2006)

The Australian rice industry is a world leader in yields, quality and marketing. Water supply is fast becoming its greatest limitation. Can we find a rice growing system that will grow more rice per megalitre?  This Nuffield study overviewed work in several countries that is attempting to adopt aerobic and alternate-wet-and-dry (AWD) rice systems to increase water use efficiency.  The application of such systems in Australian rice growing has potential to lead to a 15–30% increase in water use efficiency, from evaporation savings.  Success of aerobic or AWD systems in Australia would require the rice industry to assess and adopt aerobic germplasm, refine AWD nitrogen management, consider Clearfield™ technology for broadleaf weed control and redefine rice soil suitability for AWD systems

Read More
Quantifying climate and management impacts on watertables and soil salinity (2005)

This CRC report describes the development of a surface-groundwater interaction model for the Murrumbidgee Irrigation Area (MIA) in Southern NSW. Rising  watertable and salinisation have threatened the viability of the MIA and this work is part of management strategies to ensure the sustainability of the area. The project presents the Hydrogeology and Soils of the MIA, conceptual model, model calibration, model results, prediction of groundwater levels, spatial distribution of groundwater levels, model performance, water balance of the Murrumbidgee Irrigation Area. Six scenarios are also presented including the analysis of dry conditions continued for next 25 years, relatively wet conditions continued for the next 25 Years, 50% and 75% reduction in rice area, partial and full reduction in seepage from channels, regional groundwater trends. The result of the investigation include the model being calibrated and used to simulate possible management scenarios. The authors states that as with any model there is a need to keep the model updated. It is also advisable to use it with other tools such as SWAGMAN Farm to convey modelling results and help determine sustainable irrigation levels on a year to year basis. The model is ready to formulate different land and water management options and to help determine on farm actions required to meet regional targets. 

Read More