Lucerne - Professor Derrick Moot_default

Introduction to Lucerne Research

• Focus on Lucerne (Medicago sativa), agronomy, and comprehensive grazing management strategies developed over the last twenty years at Lincoln University.

• Highlighted interest due to the underutilization of Lucerne in New Zealand for grazing purposes despite its benefits.

• Research is aimed at addressing significant challenges in New Zealand's agricultural sector and developing effective grazing management practices tailored specifically for Lucerne, enhancing both productivity and sustainability.

Early Experiments

• Initial experiments were meticulously designed to compare the yield and quality of various dryland pasture types in New Zealand, taking place across diverse climatic regions (from Central Otago to Hawke's Bay).

• Key pastures included:

  • Lucerne, known for its high forage value and ability to improve soil quality.

  • Ryegrass and white clover, serving as the control group due to their widespread use.

  • Coxfoot combined with subclover, balancer clover, and Caucasian clover, assessing their viability as alternatives.

• This extensive experiment was funded by Beef and Lamb New Zealand, with observations collected over a nine-year period to capture long-term trends and results.

Yield and Performance Results

• Lucerne significantly outperformed other pasture types, with an impressive average yield of about 17 tonnes per hectare over the entire duration of the experiment.

• Notably, the second year of Lucerne growth faced challenges due to heavy snowfall, which impacted production levels.

• Comparative analysis revealed that other pastures suffered declining yields:

  • Ryegrass and white clover yields dropped from 10.5 tonnes to 6.5 tonnes by the final year.

  • Throughout the study, the Coxfoot and subclover combination maintained a consistent yield of around 9 tonnes, showcasing better resilience.

Long-term Management Insights

• Long-term observations indicated that ryegrass pastures exhibited a notable decline in sown species, losing approximately 10% annually, particularly influenced by pest infestations and adverse drought conditions.

• In contrast, Coxfoot pastures endured a loss of only around 3% annually, demonstrating greater geographical and environmental adaptability.

• Strong emphasis on the integration of Lucerne and Coxfoot within dryland grazing systems was recommended to optimize forage quality, improve animal health, and enhance overall farm productivity.

Water Usage and Dry Matter Production

• Comprehensive analysis of water usage across different pasture types revealed:

  • Grass pastures utilized an average of 13 kg of dry matter per millimeter of water, indicating lower efficiency.

  • Grass-clover combinations yielded approximately 20 kg of dry matter per millimeter, largely benefiting from the inclusion of Coxfoot and subclover.

  • Lucerne excelled in this area, surpassing other varieties with nearly 30 kg of dry matter per millimeter of water, underscoring its higher efficiency and productivity, especially crucial during high-demand periods in the spring.

Soil Health and Cultivation Practices

• Successful establishment of Lucerne necessitates deep, well-draining soil to support taproot development, which is essential for moisture and nutrient uptake.

• An ideal soil pH level for Lucerne cultivation is between 6 to 7, which is crucial for its growth and nitrogen fixation.

• Adoption of inoculated seeds, particularly for ensuring effective nitrogen fixation, is recommended with a planting depth of 10 to 25 mm to support early establishment.

• Direct drilling methods are preferred to conserve moisture, with autumn sowing being viable only in warmer regions of the North Island to minimize risks from colder weather.

Weed Management and Soil Improvement

• Effective management of weeds, particularly annual grasses that threaten pasture integrity, is crucial for maintaining the health and productivity of Lucerne.

• Cultivation practices such as lime application are vital for increasing soil pH and reducing toxic aluminum levels, which adversely affect root development. For example, targeted lime application raised soil pH from 5.2 to approximately 6, substantially enhancing crop resilience and performance.

Grazing Management Strategies

• Understanding critical grazing timings within the seasonal cycle is essential. Early lambing or setting stock on Lucerne should be avoided to prevent damage to the growing plants.

• It's vital to recognize the growth dynamics of Lucerne:

  • Spring represents the season of peak growth, as nutrients are remobilized from underground reserves to support leaf and stem development.

  • Grazing in August is typically optimal at heights around 10-15 cm to ensure quality feed is provided.

  • Allowing longer grazing periods in the autumn supports replenishing the underground reserves, setting the stage for robust spring growth.

Animal Management Considerations

• Awareness of health issues, such as red gut and bloat risks when grazing Lucerne, is paramount; therefore, provision of sufficient fiber is crucial to balance diets.

• Regular vaccination schedules for clostridial diseases and close monitoring of cobalt levels are necessary to prevent deficiencies that could undermine livestock health.

• Implementing mixed grazing strategies is recommended to optimize pasture utilization and ensure overall animal wellbeing.

Case Study: Bonavirie Farm Transformation

• Case study on Doug Avery's Bonavirie Farm illustrates a remarkable transformation following the implementation of Lucerne grazing strategies.

• Significant increases were recorded in lambing percentages and live weights sold, with profitability enhanced dramatically from $317 to $792 per hectare.

• This case highlights sustainable farming practices that emphasize economic balance, environmental stewardship, and social resilience.'

Conclusion

• Emphasis on the continuous improvement of grazing management techniques and pasture quality through Lucerne implementation can dramatically enhance agricultural outcomes.

• Urging the adoption of region-specific strategies to amplify pasture water use efficiency is essential to address the growing global demand for meat.

• Acknowledgment of support from Beef and Lamb New Zealand, Lincoln University, and other organizations dedicated to sustainable farming research and development.