Which of the following statements are correct statements?

(a) Masonry check dams are used for controlling gully erosion and water harvesting.

(b) soil cloudiness, surface roughness, roughness, soil curst and soil moisture are the main factors affecting water erosion.

(c) In Agronomic measures water erosion is controlled by appropriate crops and cropping systems.

(d) Stubble mulching and minimum tillage be practiced to minimise wind erosion.