Notice: This project page is no longer being updated as of January 2023.
Warmer temperatures and longer growing seasons offer Pennsylvania dairy farmers the ability to plant more than one crop in a season.
But increasing frequency of extreme rainfall presents new challenges. Double cropping with winter annuals can increase forage production and help minimize off-farm feed purchases. It also provides protection from soil erosion and helps reduce nutrient losses. Other conservation practices such as no-till, keeping the soil covered with cover crops and perennials, and manure injection can also reduce soil and nutrient losses.
Researchers at the Penn State University are studying sustainable cropping systems for use on dairy farms. A practice such as double cropping with winter annuals or other cover crops keeps the soil covered, making it less susceptible to erosion. When coupled with other conservation practices, the need for fertilizers, pesticides, and fuel can be reduced. Other practices may include no-till, rotations with perennials, and injecting liquid manure. The goal of this research is to make dairy operations in the Northeast more resilient to climate change.
“We are in the seventh year of a project that is really designed to identify how to help dairy farms in Pennsylvania and the Northeast minimize off-farm inputs such as feed, fertilizers, pesticides, and fuel and have minimal impact on the environment and be more resilient to changes in weather and climate change.”
- Heather Karsten, Associate Professor, Penn State University Plant Sciences Department
Welcome to Penn State's Sustainable Dairy Cropping Systems project. Dr. Heather Karsten, Associate Professor of Crop Production, introduces us to the research. This interdisciplinary team is looking at ways that dairy farmers can minimize farm inputs while making the farm more resilient to climate change. The goal is to produce the forage, feed, and fuel needed to sustain an average size Pennsylvania dairy herd.
Here at the Dairy Cropping Systems site, researchers are exploring ways that dairy farmers can take advantage of a changing climate. As growing seasons lengthen, double cropping is emerging as a viable opportunity. Planting winter annual crops like rye, triticale, wheat, and canola between summer field crops helps maximize forage production. The team is also testing heat and drought tolerant forage crops, including sorghum-sudangrass, to see how they withstand increasing summer stress. Another goal is to improve soil health using no-till, cover crops and rotating with perennial crops. These practices can minimize soil and nutrient losses during wet periods and improve water retention during dry periods.
To learn more about how Penn State's Dairy Cropping System works, please contact Dr. Heather Karsten at hdk3@psu.edu.
The USDA Northeast Climate Hub has partnership agreements with each of the 16 land grant universities in the Northeast region. The Hub and partners work on various climate related projects. Our partners at Penn State led initial effort to create a Vulnerability Assessment for the Northeast and then a more detailed assessment of the impacts of climate change on livestock. A companion report looks at impacts of climate change on crops. These reports identify susceptibilities that may exist in each sector of agriculture and practices that producers are using to reduce impacts and take advantage of new opportunities.
Howards Skinner is the recently retired Deputy Director of the USDA Northeast Climate Hub. Here he describes the purpose of the regional Climate Hubs. When partners and producers collaborate, they can identify needs and practices that can help mitigate or adapt to climate change.
This Penn State University research farm is located within the Susquehanna River watershed. The watershed is the largest source of water entering the Chesapeake Bay, our nation’s largest estuary. The Bay is a critical habitat for many species of plants and animals and it supports many economically important industries. However, the Chesapeake Bay suffers from excess nutrients. Fertilizers and manures in farm runoff are getting into the rivers that flow into the Bay. Practices such as perennials, double crops, cover crops, conservation tillage, and manure injection can help to reduce the loss of nitrogen and phosphorus. To restore water quality to the Chesapeake Bay, each state within the watershed has developed a Watershed Implementation Plan. Pennsylvania’s plan sets goals for practices like those being studied here on this farm. Results from our research are expected to help inform decisions for managing the Chesapeake Bay.
Cory Dillon, Penn State Horticulture Farm Manager, is a member of the original team that developed the Interseeder. Here Cory explains what the Interseeder is, how it works, and when it is used.
The Interseeder shown in the above video is a 4-row model that plants cover crops between 4 rows of corn, making it a good size for research purposes. The unit can be adapted from 2 to 16 rows, making it useful on small farms or larger operations.
Heather Karsten, Associate Professor of Crop Production at Penn State, explains the benefits of planting winter annual double crops and cover crops. The plants minimize sediment and nutrient losses and can be harvested as forage to feed the dairy herd in the spring.
In addition, Penn State has modified two of their tractors to run off the canola they grow on site and press into a biofuel. The meal produced when the seed is processed is fed to the dairy herd. This is just one example of how Penn State is helping dairy operations find sustainable solutions.
Cover crops provide many benefits to both the environment and the farming operation. Cover crops help build soil organic matter and improve soil health, thereby sequestering carbon from the atmosphere. Since soil organic matter can help make farms more resilient to climate variability, planting cover crops can be both a climate mitigation and climate adaptation practice. Yet, establishing a cover crop in the fall can be difficult due to weather, a late harvest, or a short season. Complications can be minimized by using the Interseeder to plant the cover crop while the primary crop is still growing. This helps to improve cover crop establishment, while having minimal effects on the primary crop. Penn State researchers have found that interseeding cool season species such as red clover and annual rye, do not reduce corn yields in the fall.
Before liquid manure injection systems were developed, growers wishing to use a no-till system had to apply manure to the soil surface. Valuable nutrients can be lost from manure that is not incorporated into the soil. Nitrogen in the form of ammonia volatilizes and moves into the atmosphere. In addition, nitrogen and phosphorus move off-site through water runoff. This is a case of one conservation strategy (no-till) limiting the use of another (manure incorporation). By applying manure with the injector unit, producers get the best of both of worlds—the manure is injected below the surface with limited disruption to the soil.
Dr. Curt Dell, USDA Agricultural Research Service, is also a co-director of the Northeast Climate Hub. Here, Dr. Dell shows us Penn State's liquid manure injection unit. Nitrogen in broadcast manure is often lost to the atmosphere, while phosphorus can be lost through runoff. Heavy rains are becoming more frequent in Pennsylvania and the rest of the Northeast, and are expected to increase further. This can lead to an increase in the loss of nitrogen and phosphorus from applied manure as well. Losses, however, can be reduced by injecting manure into the soil rather than applying it on the surface. With the injection method, more nitrogen and phosphorus stay in the soil. The crop benefits from the added nutrients and less is released into the waterways and air. Manure injection is also an effective way to reduce odors.
Researchers at Penn State are looking at the net benefits of manure injection as a way to increase the nitrogen taken up by the crop and decrease the nitrogen lost to the environment. Nitrogen loss as the greenhouse gas nitrous oxide increases for a short period of time after injecting compared to broadcast applying manure. With broadcast spreading, though, even more nitrogen can be released into the atmosphere as ammonia gas (also an air pollutant). By injecting the manure, nitrogen is saved below the soil surface where crops can access it. This means the need to apply additional nitrogen later in the growing season is reduced, which saves money. The benefits of manure injection are even greater when cover crops are used because they help retain leftover nitrogen.
In this video, Curt Dell, USDA Agricultural Research Service scientist, explains how greenhouse gas emissions are measured in the field. Researchers are looking at how cover crops and manure management affect these emissions.
Because this part of the research farm is underlain by shallow bedrock, the water that naturally collects here resurfaces in a seep further down the hill. This geologic feature provides an opportunity to study how the water moves both above and below the ground. Lysimeters are set up to sample water and nutrient movement through the soil. Each of the 12 plots located here is surrounded by an earthen berm and underground tiles. The berm directs the overland flow to drains like the one shown below, and underground tiles located at the bedrock collect the water that filters through the soil. From here, the captured water moves to the collection houses.
Ground and surface water leaving the lysimeter plots moves into these collection houses. Tipping buckets located inside these structures separately measure the volume of water that moves above the ground and the volume that moves below the ground. The water samples are then taken to a laboratory where they are analyzed for different forms of nitrogen and phosphorus.
These 12 lysimeter plots were used in a 5-year study to compare nutrient losses under two manure management strategies. Manure was broadcast applied in six plots and injected in the other six plots. Researchers wanted to know if injecting manure increased the leaching of nutrients. They found that, even though manure injected below the surface is closer to the groundwater, this method does not increase nutrient leaching and can reduce phosphorus losses in years with heavy rainfall and run-off. The lysimeter plots were also used to study different winter annual double crop and cover crop management approaches.