Managing Garden Soil Moisture

Introduction

Compost, aerobically decomposed remnants of organic materials, is commonly mixed into soil to improve soil fertility and water holding capacity. Grass clippings, leaves, sawdust, kitchen refuse, wood ashes, garden refuse, and shredded newspapers are just some of the common materials that are composted.

Mulch, in contrast, is placed on the soil surface. Mulch affects soil moisture by slowing evaporation, reducing weed transpiration, and reducing runoff. Grass clippings, leaves, sawdust, wood chips, straw, shredded newspapers, and compost are common materials used as mulch. Inorganic mulches, such as plastic sheeting, rocks, and gravel are also widely used.

In this experiment, you will investigate the ability of a soil sample to retain moisture with and without the addition of a surface layer of mulch.

Objectives

In this experiment, you will

• Learn to use a Soil Moisture Sensor.
• Determine the volumetric soil water content of a soil sample.
• Investigate moisture retention with and without mulch.
• Gain increased understanding of the role of soil moisture in ecosystems, watersheds, and the water cycle.