Project: MLMMI 07-01-03
The long term objective is to ensure that cropping systems and manure management techniques are available to swine producers within Manitoba such that that there is minimal leakage of phosphorus and nitrate to the environment from animal production.
The short term objectives are:
1.) To compare the amount of nitrate and phosphorus that is lost below the root zone from liquid and solid manure production systems.
2.) To determine the influence of cropping system, i.e. perennial versus annual, on the loss of water, phosphorus and nitrate below the root zone.
3.) To determine the influence of nutrient management system, i.e. Nitrogen based versus phosphorus based, on the loss of water, phosphorus and nitrate below the root zone.
4.) To compare the use of field core lysimeters with traditional soil profile sampling in measuring nutrient loss from the soil.
5.) To use a computer model to summarise and extrapolate field results to other soils through out the province of Manitoba.
KEYWORDS: manure management system, cropping system, nutrient management system, soil water, nutrient leaching, Lysimeter
Dr. Wole Akinremi
Dr. Dupe Ige
Dr. Don Flaten
University of Manitoba
Funding Partners: who have contributed to MLMMI in support of this project:
ARDI - $35,480;
SDIF - $25,000;
Manitoba Pork Council - $58,050
Amount Funded: $112,050.00
Performer Funded: $0.00
Total Cost: $112,050.00
Progress Report #1 due May 1, 2010.
Progress report #1 received June 2010.
Progress Report #2 due May 1, 2011.
Final Report due May 1, 2012.
The annual cropping system lost substantially more nitrogen through nitrate leaching than the perennial system. These differences could not be attributed to differences in crop removal as the annual crops sometimes took up more nitrogen than the perennial. The lack of nitrate leaching from the perennial system was due to a combination of several factors including better synchrony between available nutrients and crop removal and greater soil water use by the perennials.
Perennial cropping systems consisting of a mixture of grasses have the capacity to receive and utilize significant amounts of nutrients. The inclusion of grasses in a crop rotation and their use to mop up excess nutrients are sustainable practices that will benefit the environment. In the annual cropping system of this study, nitrate leaching occurred in the control plots where no nutrients were applied suggesting that nitrate leaching can be reduced by management but not eliminated.
There was no evidence of significant downward movement of phosphorus below the top 15 cm soil layer. However, repeated, annual applications of manure at an N-based rate resulted in increased STP by the 3rd year of the study. Because increasing STP results in increasing P concentration in runoff (Sawka 2009), STP buildup should be managed through field rotation when N-based manure application rates are applied. In contrast to annual applications of manure based on N, soil test P levels were no different than the control by the end of the 3rd year of this study when manure was applied at a multi-year, P-based manure application rate (i.e. where manure was applied at the N rate in 2009 and received urea 2010 and 2011).
Solid manures with lots of bedding may reduce the risk of nitrate leaching. Application of solid manure at the P-based manure application rate followed by urea in subsequent years, reduced the risk of nitrate leaching over the course of the rotation, likely due to immobilization of N with the addition of the straw in the manure.
Both soil samples and lysimeters provide valuable and complementary information regarding nitrate leaching. Soil samples throughout the profile show the pattern of nitrate distribution up to the sampling depth. Lysimeters capture all of the nitrate and water that has moved below the root zone.