Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 7637 IREC Farmers' Newsletter No. 195 ­ – Rice R&D 2016 fodder, garden mulch products l  detailed cost benefit and life cycle analysis of small scale on-farm gasification technologies for single enterprise energy production and how to overcome impediments to investment because of rapidly evolving overseas technologies, possibly through state government initiatives l  understanding the sustainability of continued straw removal versus burning and its impacts on productivity and the additional nutrient inputs that may be required to offset this removal l  understanding agronomic and carbon sequestration benefits of rice straw derived soil amendments l  development of rice varieties that may offer enhanced amorphous silicon nanoparticles l  development of specific technologies that allow the easy culturing of microorganisms that produce high value omega oils. Conclusion Despite research endeavours across a multitude of stakeholders, practical solutions that are economically viable for the management of rice straw at a level that accommodates the majority of farm businesses, other than burning, is not yet available for Australian rice growers. A co-ordinated effort between several closely-located industries that may reduce investment risk and overcome issues of scale and variations in feedstock quantity and composition is required. RIRDC Project PRJ-009170 Alternative management of rice straw Acknowledgments Funding from RIRDC, CSIRO Sustainable Agriculture Flagship and Deakin University is gratefully acknowledged. Dr John De Majnik is thanked for his support throughout and especially in the final stages. Thank you to Andrew Bomm and Neil Bull (Australian Ricegrowers’ Association) and Russell Ford and Antony Vagg (Rice Research Australia) for providing industry information. Further information Wendy Quayle M: 0417 436 775 E: [email protected] l At times, even responsible burning can present problems, consequently there is a need for the rice industry to explore alternative ways of managing rice straw. Photo: MALCOLM TAYLOR Burning compared with removal and retention A N important aspect of straw management for farmers is how it impacts on soil nutrient balance and longer-term soil fertility, as well as weed, pest and disease control. The chemical composition of rice straw and ash gives an indication of the nutrients and trace elements that are lost or remain, according to whether straw is removed completely from the field or burnt (Table 1). There have been claims that burning causes almost complete loss of nitrogen, about 25% of phosphorus, about 20% of potassium and 5–60% of sulphur. If straw is continually transported off farm on an annual basis then greater amounts of potassium may need to be applied. Generally, however, if the straw is burnt rapidly in situ, phosphorus, potassium, sulphur, calcium, magnesium and silicon losses may be relatively low since these elements tend to remain in the ash and will be retained in the soil. However, these elements may be in a different chemical form with potential changes in availability to plants. Burning versus straw removal also causes changes in soil moisture and hydraulic conductivity through heat and compaction. Table 1. Nutrient removal by rice grain, rice straw and burning rice straw Nutrient removal (kg nutrient/tonne) Nitrogen Phosphorus Potassium Magnesium Calcium Silicon Rice grain 10.5 4.6 3.0 1.5 0.5 2.1 Rice straw 7.0 2.3 17.5 2.0 3.5 11.0 Burning 7.0 0.6 3.5 1.0 2.9 0.2 Source: Dobermann and Fairhurst, Best Crops International, 2002