The efficiency of organic farming compared to conventional farming can vary widely depending on various factors such as the specific crop being grown, local climatic conditions, farming practices, and the definition of "efficiency" (e.g., yield, environmental impact, resource use).
The percentages you provided—75%, 50%, 25%, and 65%—don't have a universally correct answer without specific context.
Generally, organic farming may yield lower amounts per acre compared to conventional farming, often in the range of 10% to 30% lower, but it can be more efficient in terms of resource use, biodiversity, and environmental health.
If you have a particular metric in mind, such as yield efficiency, environmental impact, or economic profitability, please specify, and I could provide a more tailored answer!