The Fourth National Climate Assessment (NCA4) prepared by 13 U.S. federal agencies and widely reported in the national media forecasts that rising temperatures, extreme heat, drought and heavy downpours will disrupt the daily operations and seasonal yield of our farmers and food producers.1
Symptoms of climate change include an increase in the frequency of extreme weather, including extended droughts and flooding driven by extreme rainfall events2. Take, for example, the 2018 record flooding in central Pennsylvania3; the 2008 flooding in the Midwest that submerged nine million acres of farmland4; and 2015 droughts in California that forced farmers to let 540,000 acres lay fallow for years5. Climate and environmental scientists predict that it will get even worse in the near future.
A farmer’s dependence on complex and remote support systems can increase their vulnerability during infrastructural or systemic disruptions. It’s time for us to look towards nature in our race against a chaotic and unpredictable climate. Using natural, ecological and organic methods that have been historically implemented for centuries can not only provide a significant hedge against climate change, but also can supplement our modern technological tools. In the last four decades, organic farming practices have proven to be a great alternative to conventional practices when it comes to producing comparable crop yield while ensuring the soil-crop ecosystems are healthy, dynamic and resilient6.
The Farming System Trial (FST) at Rodale Institute provides the perfect blueprint to investigate the effects of regenerative organic farming on flood resilience and drought resistance properties. In collaboration with Abdel Alfahham, a MS student at the Department of Earth and Environmental Sciences at University of Pennsylvania, researchers at Rodale Institute are analyzing soil samples from FST for soil water retention, saturated hydraulic conductivity, and organic carbon/nitrogen.
What We’re Studying
How are these measurements relevant to farmers?
Soil water retention is a property that helps quantify the ability of soil to hold on to and store water in conditions varying from wet, moist to extremely dry. That measurement directly quantifies the amount of water that is available for our crops to grow and photosynthesize.
Saturated hydraulic conductivity can give us an idea on how fast the soil will allow water to flow (or drain) through the soil during high rainfall events, which can predict flooding and pooling on the farm. Soil organic carbon and nitrogen measurements provide a robust method to quantify the amount of organic matter integrated into the soil biosphere which can help determine soil health.
The Farming Systems Trial has six different management systems: (1) conventional synthetic with tillage, (2) conventional synthetic no-till, (3) organic manure with tillage, (4) organic manure no-till, (5) organic legumes with tillage, and (6) organic legumes no-till. Each treatment is replicated four times across the field to ensure that data collected from FST can be statistically analyzed; that means there is a total of 24 experimental plots.
In 2018, two types of soil samples were collected. A total of 72 intact soil cores and 72 composite soil samples were collected from 0 – 10 cm, 10 – 20 cm and 20 – 30 cm depths from all 24 plots. Collecting samples from three different depths will help us develop a more comprehensive understanding of how farm management influences the properties of different soil zones.
The intact soil cores will be analyzed using the METER HYPROP and METER WP4C instrument to quantify soil water retention properties (how soil behaves from wet to dry conditions). The same intact soil cores will also be analyzed on the METER KSAT which characterizes the rate at which water can move through saturated soil. The three instruments being used integrate cutting edge modern sensor technology with quantitative computer models to efficiently produce robust and high quality data. Composite soil samples will be used to determine soil organic carbon and organic nitrogen using an elemental analyzer, a common method for determining amount of carbon and nitrogen in the soil.
Project Objectives and Preliminary Results
By measuring soil hydraulic conductivity, water retention, and organic carbon and nitrogen content in six different farm management systems, we can compare and contrast how farm practices might lead to drought resistance and improved water holding capacity.
Our goal is to determine to what extent organic farming provides a practical and economically viable climate adaptation method by quantifying the changes that developed in the soil that is farmed organically at FST for the last 40 years. By conducting such a comprehensive analysis on soil, the data will provide a predictive structure by which farmers can understand the optimal climate-resilience farm management practices applicable for their geographic area, the crop of choice and climatic conditions.
The preliminary results of this project will be shared for the first time on January 7, 2019, in the International Soils Meeting, San Diego, CA and reported here.
Abdel Alfahham is a Penn Program of Environmental Humanities Graduate Fellow at University of Pennsylvania. He joined Rodale Institute as a research intern for the 2018 season.