Answer:

Research questions 1: What model should be use to soil changes in agroforestry systems:

Proposed title A: a model to estimate soil change under agroforestry.

Proposed title B: modeling experiments for evaluating the effects of trees increasing temperature and soil texture on carbon stock in agroforestry.

Proposed title C: agroforestry and the improvement of soil fertility.

Explanation:

Yan pa lang po saakin