Project looks at new methods of using traditional fertilizer
Gary Bishop, an agricultural systems engineer, holds up brome grass and alfalfa in one of six plots of forage crops for cattle at Agriculture and Agri-Food Canada’s Atlantic Cool Climate Crop Research Centre on Brookfield Road in St. John’s. — Photo by Joe Gibbons/The Telegram
In a huge field off Brookfield Road in St. John’s, tall blades of brome grass wave gently in the breeze, brushing against leafy, aromatic alfalfa and tufts of timothy hay.
There are no root vegetables in these six plots of land behind the Atlantic Cool Climate Crop Research Centre, only tall green vegetation, but all will soon be harvested to feed cattle.
While still in the growing stages, the forage crops are getting essential nutrients from the very animals they will soon feed. Manure collected from a nearby dairy farm is being used as a natural fertilizer.
Gary Bishop, an agricultural systems engineer with Agriculture and Agri-Food Canada, is overseeing a research project at the centre, part of a bigger project involving the Atlantic provinces.
When completed, it will give farmers more precise information on how to fertilize with manure, while protecting the quality of water in streams, rivers and underground water tables from bacterial contamination.
“Basically, the idea behind the project is to gain a better understanding of how farmers use dairy manure, particularly as a fertilizer and how we can minimize impacts with the environment,” Bishop said.
There are five researchers involved in the Atlantic region, with four managing the sites in each province and one person co-ordinating identification of bacteria detected in water from the fields.
“We have similar water quality monitoring sites in each province,” Bishop said, “so we can do similar projects with similar treatments and compare results across the Atlantic region, comparing climate, different soil types, different crops.”
The four groups decided last year the crops they wanted to grow, then began seeding the plots.
Bishop said this is the first year they’ve actually been able to get full-grown crops.
In the six plots of land, two different manure application methods were used.
A traditional broadcast method with a manure spreader was used on three plots and a new type of application with a surface banding applicator was used on the other three.
“It basically just applies the manure in narrow bands underneath the canopy of the crop,” Bishop said, “so it keeps it off of the crop foliage, right down on the ground out of the wind.”
That’s supposed to be helpful in retaining nutrients.
The plots have perforated drainage tubing to collect excess soil water.
“Soils in Newfoundland tend to be shallow before we come to an impermeable layer, so the incidence of rainfall we have normally would tend to keep the soil wet,” Bishop said. “We put a drain tube in there to give that water a way out of the field.”
The water is held in a small retention pond and then it’s released into the environment.
“The main benefit of this is if we can sort of dry the soil out, so there will be a greater storage capacity there to absorb rainfall when it does come, which helps reduce overland flow, which I think is the more serious issue here,” Bishop said.
At the end of the fields of green vegetation, a drainage facility contains pipes connected to the drainage tubing in each plot of land.
“Mainly we’re looking for the existence of the E. coli coming out of the drainage system, and how it persists or stays around,” Bishop said.
E. coli is a normal intestinal bacteria, but some strains can produce harmful toxins.
Bishop said about 10 per cent of samples from preliminary tests have been positive for some E. coli bacteria, but it will take longer to narrow that down to determine the particular strains.
Besides the drainage system, Bishop said the type of crops, different tillage methods and the length of time manure is stored before being spread on the fields will all be considered in the project to see if they have any influence on the persistence of E. coli bacteria.
Bishop said the findings will be published in scientific journals and displayed on posters and in presentations by the research scientists involved.
“We think it will benefit farmers,” he said.
“We’ll be able to tell them, for instance, what the risk of E. coli perseverance could be. We could tell them what type of crops would be best for limiting or reducing E. coli output. We’ll be able to tell them what application method would be better than another and, hopefully, we could tell them whether or not length of time and storage would have an impact as well,” he said.
The four-year project was funded through a strategic agriculture environmental strategies program. Bishop said there are two years remaining and, depending on the results, he’s hopeful it may be extended to analyze other aspects of farming.
“This is fairly new for us. We’ve looked at nutrients and things in the past, but this is the first time we’ve looked at bacteria,” Bishop said. “We’re just trying to broaden those aspects of what we’re looking at, trying to look at every possible thing that could have an impact on the environment and then find ways to manage it.”