Keeping Fertilizers Friendly: Swine manure research helps protect the environment
ONTARIO - Swine manure is crammed with nutrients that are beneficial for crops and environmentally friendly - if administered properly. Too much swine manure can cause environmental problems, such as greenhouse gas emissions that contribute to climate change, and nutrient leaching to ground and surface water, leading to algae growth in streams and ponds and drinking water pollution.
On the other hand, too little nitrogen can weaken the crop. Nitrogen is a key element in plant growth.
Ontario farmers are looking to researchers at the University of Guelph for detailed information that will help them determine how much manure to use, and when. Prof. Claudia Wagner-Riddle and research associate Dr. Susantha Jayasundara, Department of Land Resource Science, are researching nitrogen losses from swine manure. As little as 20 per cent of the nitrogen applied in swine manure is actually used by crops. This study will measure nitrogen losses and provide information for Ontario's Nutrient Management Plan.
"Farmers would change their practices if they knew how much fertilizer is environmentally acceptable," says Wagner-Riddle. "Our challenge as scientists is to provide them with that information."
The results of Wagner-Riddle's study will be used in the Ontario N-Index, a complex procedure that takes into account excess nitrogen before and after plant growth. Responsible farmers can apply the amount of manure recommended through this process to make sure their fertilizer application stays environmentally friendly.
Scientists already understand how nitrogen transforms in the nitrogen cycle through organisms, soil and the atmosphere. What is left to discover is the amount of nitrogen that escapes, and which factors contribute to that amount.
Over the next three years, Wagner-Riddle's team will be tracking the in-soil movement of N-15, an isotope of nitrogen which has an extra proton, making it easy to find. After obtaining manure from a pig with N-15 in its diet, farm conditions will be simulated by mixing manure with water, then applying it to crops.
The project will take place over three applications: fall, spring pre-plant, and spring side-dress. Soil samples will be taken from different depths, and analyzed along with water samples and plant material.
Other researchers involved are Prof. Ming Fan, Animal and Poultry Science, and Prof. John Lauzon and Prof. Gary Parkin of the Department of Land Resource Science.
This project is funded by the Ontario Ministry of Agriculture, Food and Rural Affairs New Directions program and Ontario Pork.
For more information, contact Jean Howden, Ontario Pork research coordinator, at 1-877-668-7675 or [email protected].
Arthur Churchyard is a writer with SPARK, the University of Guelph's student writing program.
Source: By Arthur Churchyard, Ontario Pork - 3rd March 2006