Concept:Clay soil requires a practice that opens its stiff structure and adds fertility.
Explanation:Clay soil is composed of very fine particles that pack tightly together.
It remains waterlogged and slow to warm, and such compact clay restricts root growth.
Organic material, such as compost or aged manure, solves these issues by binding clay particles into crumbs.
Larger pores form between the crumbs.
Consequently, drainage and aeration improve, and roots can penetrate easily.
In addition, organic matter decomposes to release nutrients into the soil.
Acid-forming fertilizers raise acidity and destroy beneficial organisms.
Bush burning removes the existing organic cover and makes the soil more compact.
Sodium chloride (
NaCl) introduces sodium ions, which disperse clay particles and ruin soil structure.
Answer:D. addition of organic material