How does 'no till farming' help in soil conservation?

Question

$\begin{array}{1 1} (a)\; \text{they help in suppressing }\\ (b)\; \text{by impeding surface flows which prevent soil erosion} \\ (c)\; \text{revive damaged soil, minimize erosion, encourage plant growth} \\ (d)\; \text{furrows are formed which maintains constant altitude reducing run off } \end{array}$