If the period of a wave decreases, its frequency must

Increase

Explanation:

The time period depicts the amount of time taken for completing one cycle of vibration. While frequency is the measurement of a number of cycles in a unit time.  

Therefore, both the period of wave and frequency are inversely proportional to each other. The higher will be the time period, the lower will be the frequency and vice versa.  

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.