USA HISTORY

Detailed explanation-1: -The earliest evidence of crops appears between 9000 and 8000 bp in Mexico and South America.

Detailed explanation-2: -Clay soil is soil that contains a high percentage of clay particles. It is slow to drain water and quick to harden leading to water logging. It blocks root absorption, which prevents plants from getting nutrients required for survival. Hence it is not suitable for plant growth.

Detailed explanation-3: -Indian planting techniques are called Three Sisters agriculture. About five maize seeds were sown in a low mound of soil. The mounds were spaced about five feet apart. When the maize plants were a few inches high, climbing beans and squash seeds were planted between the mounds.

Detailed explanation-4: -Due to intense, mismanaged farming, soil nutrients are declining. Nitrogen stores have decreased by 42 percent, phosphorus by 27 percent, and sulfur by 33 percent. (3) To grow optimally, plants require these nutrients for photosynthesis, enzymes, protein synthesis, and more.