water infiltration – Greenacres Foundation

Change Over Time

Late summer we had the chance to re-monitor some of our pastures to see how soil properties have changed in 3 years. This was an opportunity for 3 of us (Megan, Chad G. and Jennifer) to learn the pasture monitoring methods. Front Nippert field was first monitored in 2016 and the same transect was set up in 2019. Vegetation, bulk density, soil carbon and water infiltration were all measured. In the upper layer of the soil (0-10 cm), bulk density decreased from 1.28 to 1.18 g/cm³. Both values are low enough for proper root growth. Figure 1 shows infiltration improved over three years. And Table 1 shows the carbon results. Carbon in the lowest layer of soil increased over the 3 years.

–Jennifer

Healthy Soil Holds Water

In addition to testing the soil itself, we collect other types of information. Water infiltration is a measure of how quickly 1 inch of water will enter the soil. Metal rings are driven into the ground, water poured into the ring and the timer begins. Without stable soil aggregates the pores collapse and water will not move into the soil. Stable soil aggregates (produced by biology) maintain the pore structure and water moves into the soil. Our newest property in Lewis Township (Brown County, OH) has historically been used for soybean crops. Many of the areas tested there had standing water in the ring after 30 minutes. In contrast, some of the pastures in Indian Hill had the inch of water move into the soil in less than 2 minutes.

Soil compaction is another measurement we make on our fields. High soil compaction negatively impacts root growth and water infiltration. A penetrometer is the tool we use to measure soil compaction. The tip of the penetrometer is pushed into the ground and the depth at which 300 psi is reached is recorded. At the Lewis Township site that depth averaged between 11.4 to 16.8 inches.