When does no-till yield more? A global meta-analysis

Flashcards reviewing key findings from a meta-analysis on the effects of no-till agriculture on crop yields, considering various crop and environmental factors.

What are the goals of no-till agriculture?

Reduce soil erosion, decrease input costs, and sustain long-term crop productivity

What crop categories matched conventional tillage yields in no-till systems?

Oilseed, cotton, and legume crop categories

Which cereal crops experienced the smallest and largest negative impacts from no-till?

Wheat (-2.6%) had the smallest, while rice and maize (-7.5% and -7.6%) had the largest negative impacts.

Under what conditions did no-till perform best?

Rainfed conditions in dry climates

What happened to yields in the first 1–2 years following no-till implementation?

Yields declined for all crops except oilseeds and cotton.

How long did it take for no-till yields to match conventional tillage yields?

3–10 years, except for maize and wheat in humid climates

How were no-till yields affected by nitrogen fertilizer?

Reduced by 12% without N fertilizer and 4% with inorganic N addition

What is the global imperative that has been set forth?

To produce more with less

What are the three crop management principles of conservation agriculture?

Minimum soil disturbance (including no-till), crop rotation, and residue retention/permanent soil cover

What are the environmental and economic benefits of no-till implemented as the core principle of CA?

Conserves soil resources, improves soil quality, reduces production costs, and increases profitability

What are the main reasons for no-till adoption?

Economic benefits and reduced soil erosion

Why might no-till practices reduce crop productivity?

Potential for soil waterlogging, cooler soil temperatures, compaction affecting root growth, or altered soil fertility requirements

What were the objectives of the meta-analyses?

Evaluate the influence of crop and environmental variables on no-till productivity and identify factors contributing to no-till yield gaps.

What is the most important factor influencing the overall yield response to no-till?

Crop category

How did no-till affect yields in tropical latitudes?

Reduced yields the most (-15.1%)

Which three variables were the most important for maize?

Duration, residue management, and aridity

Which three variables were the most important for wheat?

Aridity, irrigation, and N rate

What is the effect of residue retention and crop rotation?

The negative impact from no-till decreases when crop rotation and residue retention practices are implemented.

What is one strategy to comprehensively adjust crop management practices?

Adjust crop management practices at a systems-level so that multiple aspects of the no-till system are optimized to improve productivity and environmental outcomes rather than simply switching from conventional tillage to no-till in isolation

Why is it advisable to address the effects of yield loss in promoting no-till?

Adopting no-till alone may not produce the expected cropping systems benefits, hence simultaneous crop management changes, such as fertilization and integrated pest management, are often required to address these risks and optimize no-till yields.