source: Farm and Food Report
How do repeated swine manure applications affect crop production, soil and environmental quality over time in Saskatchewan?
A new study funded by Saskatchewan Agriculture and Food’s Agriculture Development Fund (ADF) provides some encouraging news.
Results show that manure that is applied at agronomic rates — meaning that the rate of application is in balance with crop nutrient requirements and removal over time — is a sustainable management practice.
Dr. Jeff Schoenau of the Department of Soil Science at the University of Saskatchewan is the lead scientist on the research project.
“Our intent was to develop guidelines and recommendations as to how the nutrients and organic matter in manures are best utilized in an agronomic and environmentally sustainable manner,” says Schoenau. “We have in place four long-term manure research trial sites across Saskatchewan where we are looking at different rates, sequences and methods of application of manure.”
The scientists measure soil properties like nutrient content, organic matter, soil structure, crop yield and quality. Teams worked mostly with hog manure, but also with cattle manure.
“We found that, when manure is applied at agronomic recommended rates – which may be accomplished by manure testing and soil testing to determine the appropriate rate and balance of manure and fertilizer nutrients to meet the crop demand – we see no evidence of nutrient loading or any negative effect on the quality of the soil.”
There is a caveat to this finding, however, according to Dr. Schoenau:
“We do see evidence of nutrient build up, increased losses by leeching or denitrification in situations where agronomic rates are exceeded. Respecting agronomic rates is also key to good yield responses to the nutrients contained in the manure over sustained periods. When manure is over-applied, we do see negative effects like lodging — where the crop falls over — and injury to germinating seeds and seedlings due to excessive salts and ammonium.”
In addition, Dr. Schoenau’s team confirmed that the method of manure application that is used is also important in achieving the best nutrient recovery by the crop.
“We found that, with injected liquid manure, we consistently achieved better crop recovery of nutrients and yields — which is the most desirable outcome — than with surface broadcast applications. This liquid injection of manure into the soil as bands was achieved during our trials with the help of a low disturbance coulter injector system. The system was incorporated by Prairie Agricultural Machinery Institute on their swine manure injector truck, used for manure application research and demonstration purposes. Similar approaches to manure injection are now being utilized by commercial applicators.”
The study shows that, overall, annual applications of manure made for five to eight years on these soils at agronomic rates, in balance with crop nutrient removal, greatly enhanced crop production while maintaining or improving soil and environmental quality.
To download a copy of the study, click here.
For more information, contact:
Dr. Jeff Schoenau
University of Saskatchewan
(306) 966-6844
How do repeated swine manure applications affect crop production, soil and environmental quality over time in Saskatchewan?
A new study funded by Saskatchewan Agriculture and Food’s Agriculture Development Fund (ADF) provides some encouraging news.
Results show that manure that is applied at agronomic rates — meaning that the rate of application is in balance with crop nutrient requirements and removal over time — is a sustainable management practice.
Dr. Jeff Schoenau of the Department of Soil Science at the University of Saskatchewan is the lead scientist on the research project.
“Our intent was to develop guidelines and recommendations as to how the nutrients and organic matter in manures are best utilized in an agronomic and environmentally sustainable manner,” says Schoenau. “We have in place four long-term manure research trial sites across Saskatchewan where we are looking at different rates, sequences and methods of application of manure.”
The scientists measure soil properties like nutrient content, organic matter, soil structure, crop yield and quality. Teams worked mostly with hog manure, but also with cattle manure.
“We found that, when manure is applied at agronomic recommended rates – which may be accomplished by manure testing and soil testing to determine the appropriate rate and balance of manure and fertilizer nutrients to meet the crop demand – we see no evidence of nutrient loading or any negative effect on the quality of the soil.”
There is a caveat to this finding, however, according to Dr. Schoenau:
“We do see evidence of nutrient build up, increased losses by leeching or denitrification in situations where agronomic rates are exceeded. Respecting agronomic rates is also key to good yield responses to the nutrients contained in the manure over sustained periods. When manure is over-applied, we do see negative effects like lodging — where the crop falls over — and injury to germinating seeds and seedlings due to excessive salts and ammonium.”
In addition, Dr. Schoenau’s team confirmed that the method of manure application that is used is also important in achieving the best nutrient recovery by the crop.
“We found that, with injected liquid manure, we consistently achieved better crop recovery of nutrients and yields — which is the most desirable outcome — than with surface broadcast applications. This liquid injection of manure into the soil as bands was achieved during our trials with the help of a low disturbance coulter injector system. The system was incorporated by Prairie Agricultural Machinery Institute on their swine manure injector truck, used for manure application research and demonstration purposes. Similar approaches to manure injection are now being utilized by commercial applicators.”
The study shows that, overall, annual applications of manure made for five to eight years on these soils at agronomic rates, in balance with crop nutrient removal, greatly enhanced crop production while maintaining or improving soil and environmental quality.
To download a copy of the study, click here.
For more information, contact:
Dr. Jeff Schoenau
University of Saskatchewan
(306) 966-6844
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