MASH Makes has been conducting a multi-season field trial to assess the long-term impact of a single biochar application on crop yields. Now in its seventh season, the positive results continue.

This long-term trial alternates between soybean and chickpea each season. This allows us to observe how biochar performs across different crops and conditions over time. The most recent chickpea harvest allowed us to evaluate the continued residual impact of biochar in the soil. Even after several cropping cycles and no repeat applications, biochar-treated plots continued to outperform untreated controls.

While many soil inputs lose their effectiveness after one or two seasons, biochar behaves differently. Even after multiple cropping cycles, the residual effect of biochar remains clearly visible in the field.

Over time, biochar slowly spreads through the soil and mixes deeper into the ground. Even as it moves, the crops in this trial continue to respond positively. This suggests that biochar is helping improve the soil in ways that benefit plants season after season.  

Yield response after seven seasons

Results from the latest chickpea harvest show continued gains:

• 2 tonnes/acre: 18% increase in yield
• 4 tonnes/acre: 33% increase in yield

These results reinforce a pattern observed throughout the trial: plots receiving higher biochar application rates consistently show the strongest yield responses.

Looking deeper into the soil

Soil samples have already been collected from the trial plots and will now be analysed to evaluate changes in soil characteristics and to better understand how biochar continues to influence soil health over time.

Key takeaways after seven seasons

• One-time biochar application delivers multi-season benefits
• Yield improvements continue years after the initial application
• 4 t/acre applications produce the largest yield gains

Long-term trials like this help demonstrate that biochar can support sustained improvements in soil health and farm productivity, even in challenging agricultural environments.

Our biochar research spans multiple crops in pot and field studies. Learn more about it on our biochar research page.