Livestock production has increased considerably in the United States over the last 60 years, leading to a corresponding increase in demand for animal feed — of which the state of Nebraska plays a major part in fulfilling.
Crop yields and livestock production are closely intertwined in Nebraska. According to the Nebraska Corn Board, about 16% of Nebraska corn is fed to livestock within the state. Another 24% is used to feed livestock throughout the U.S. and around the world. When our crop systems are efficient and productive, our livestock production is as well — and this includes the effective use of water.
Water productivity of crops and livestock
Given the importance of livestock production to Nebraska’s economy and its impacts on water resources, there are surprisingly few studies related to its water productivity. However, in 2019, the Daugherty Water for Food Global Institute (DWFI) at the University of Nebraska produced the Nebraska Water Productivity Report (NWPR), which assesses the water productivity of crop and livestock production.
The water productivity of an animal is how much animal output is produced per unit of water over its lifetime. It includes the amount of water used to produce its feed, provide it with drinking water, any necessary cleaning, and to carry out other services to maintain its environment.
Water productivity includes both rainfall (green water) and water used through irrigation for feed crops (blue water). In Nebraska cattle production, most of the water used (more than 75%) is green water (precipitation) and more than 90% of the overall water use is used for growing feed crops.
Nebraska water productivity has improved
Researchers found that from 1960 to 2016, water productivity of animal products (meat, milk and eggs) improved considerably — beef improved by 1.8 times and milk improved by 5.1 times.
This improvement in livestock productivity resulted from a combination of factors. One is a decrease in feed consumed per unit of animal products produced resulting from improved genetics, faster growth rates (in part due to better feed) and improved management practices.
Another way water productivity of livestock is improved is by replacing or supplementing primary feed products (corn grain) with by-products (cornstalks or distiller’s grain). In this way, the water that was used to grow the primary crop is stretched farther with more feed.
Another factor is a reduction in the amount of water needed to produce grain crops. This includes adoption of center pivots, advances in crop genetics and crop management practices. Nebraska has been producing more food (for both cattle and people) with less water.
DWFI and its partners throughout the U.S. and the world will continue to explore new technology and enhance existing tools and partner with farm producers and water managers to address complex challenges to water use in agriculture. With a large portion of Nebraska crops being grown to feed cattle, any additional efficiencies gained in use of water resources directly improve the water productivity of cattle. Innovations can also help producers adapt to climate change and unpredictable weather; crop water use; and nutrient variability — all factors that can ultimately affect yields and profitability.
Applying the exact amount of water a plant needs
DWFI uses its Parallel 41 Flux Network — a series of advanced gas monitoring towers across the central plains of the United States — to determine movement of water vapor and other gasses (mainly carbon dioxide) in cropped fields and obtain crop evapotranspiration in real time. This accurate and timely data ultimately helps growers know how much water their crop has consumed in order to precisely apply the amount of irrigation water to replace it, with the goal of achieving the best possible yields and minimize energy costs.
The data collected from these towers is also being used to ground truth satellite-based estimates of evapotranspiration (generated by GloDET) that is freely shared online to help growers around the world with water decision-making. GloDET has a powerful potential impact on improving water accounting, water productivity, irrigation scheduling and drought monitoring.
Measuring greenhouse gas emissions for future carbon credits
Not only is this network of towers useful in measuring exactly how much water is needed for a plant, with added gas analyzers it can also help measure other greenhouse gas emissions like nitrous oxide and methane, as well as help quantify the fixing of carbon in the soil and by crops, paving the way for potential carbon credits to farmers in future carbon markets.
The combination of greenhouse gas-measuring technology and modeling will lead to an increase in overall profitability as farmers adopt more efficient production systems in fixing carbon and management approaches that reduce emissions. Widespread adoption of efficient production systems has the potential to improve water productivity significantly and sustainably while reducing the carbon footprint, improving food production and environmental quality in Nebraska and around the world.
A dashboard to inform grower decisions
DWFI also contributes to the Dashboard for Agricultural Water Use and Nutrient Management (DAWN) project, which aims to provide farmers with a powerful, predictive decision-making support tool to sustain food and energy crop production. DAWN is supported by the U.S. Department of Agriculture – National Institute of Food and Agriculture and is a collaborative effort among several universities and organizations.
Through DAWN, collaborators hope to provide an accurate set of seasonal climate forecasts from one to nine months in advance, as well as one to six-day weather forecasts during the growing season. Both long- and short-term reliable forecasts are critical to growers and can translate into concrete decision-support tools to help them optimize the application of nitrogen-based fertilizers and maintain or increase crop productivity while minimizing environmental impacts.
The DAWN project is being designed with a user-friendly interface, providing field specific irrigation scheduling decision support. It will also help farmers manage weather risk by providing planning scenarios that allow producers to explore how crops will fare under different conditions. Altogether, this system will provide crucial information to producers in understanding costs and benefits of different management strategies, help improve water and nutrient efficiencies and make significant advances in advancing food security.
Crop efficiencies improve livestock productivity
Using less water to produce the same crop yield is beneficial to both crop and livestock growers by reducing costs, while simultaneously reducing environmental impacts like water depletion and degradation.
Through its suite of tools, DWFI aims to create a win-win-win for the sustainability of our water resources, crop and cattle producers alike.