Grains Research & Development Corporation
Corporate in Canberra

Improving the effectiveness of furrow sowing in water repellent soils. Improved tools that are old by grain growers and advisers to improve nutrient use efficiency. Soil water repellence restricts and diverts water infiltration into the soil, which impacts on seed germination, nutrition, crop pasture, weed establishment and grain and livestock production as well as inducing increased risk of wind and water erosion. Furrow sowing originally using winged points or sweep points was introduced to water repellent sands to improve crop establishment by moving repellent sand to the ridges, which could then harvest water into the furrow where the seed was sown. However, with some knife points and press wheel systems in water repellent sand it has been noted by growers and researchers that sometimes the furrow remains parched while the ridges are wet. The research projects Novel solutions for managing non wetting soils and Delivering agronomic strategies for water repellent soils aim to increase knowledge about soil amelioration techniques and explore management techniques promoting better strategies for water repellent soils. Delivering agronomic strategies for water repellent soils Existing agronomic options are available to manage water repellent soils, including furrow sowing, spreading and incorporating clay wealthy subsoil, use of soil wetting agents and alternative land use options. Some knife point seeding systems allow water repellent sandy soil to flow into the begin furrow with the seed and fertilizer reducing establishment. Modifying the seeding system and use of banded in furrow wetting agents may produce opportunities to improve the win of furrow sowing on water repellent soils. Historically furrow sowing was introduced to water repellent sand plain soils to harvest water into the furrow where the seed was sown which improved crop establishment. Further improvement of water entry into repellent soil in the furrow may also be achieved by using a banded soil surfactant in the furrow. Brief term soil water repellence mitigation options, such as improved furrow sowing and use of banded soil wetting agents, offer a relatively low cost way of improving crop establishment and performance across all the water repellent soils in a seeding program. Lengthy term soil water repellence amelioration options, such as clay spreading or delving, rotary spading and moldboard sloughing, are more costly and generally only applied to relatively insignificant parts of the cropping program each year. Six research trials have been established over the final 3 years. Impact of seeding point type and banded wetting agent on crop establishment and yield on low water repellence surface soil in a relatively wet growing season (252mm). Banding wetting agents in the bottom of the furrow, after the press wheels, to assist water entry into the seed zone is an efficient use of surfactants as relatively low volumes of 12 La are required, thereby reducing the cost. Water repellence, furrow sowing, soil wetting agents, soil inversion, rotary spading, clawing. The following Grower Groups are collaborating with Department of Agriculture and Food Western Australia as segment of the projects Novel solutions for managing non wetting soils and Delivering agronomic strategies for water repellents soils funded by GRDC. To improve the efficacy of furrow sowing on water repellent soils a number of approaches involving modifying aspects of the design and configuration of the knife point seeding system have been identified including: Using a banded wetting agent applied to the bottom of the furrow behind the sowing press wheel to improve water entry into the furrow. Soil wetting agents confine surfactants that reduce the surface tension of water and improve water entry into repellent soil. Liming may be qualified to diminish the severity of water repellence in acidic soils and improve crop germination, establishment and productivity. In those soils where spading or sloughing results in an increase in topsoil clay content, such as occurs with the deep loamy sands the water repellence amelioration benefits should end longer. The impact of these tools on improved establishment and increased shoot and hence stubble biomass may under a succeeding zero till, packed stubble retention system provide more opportunities for water entry through biological pathways such as intact stubble, root systems and plant crowns in the lengthy term.