Evaluating Tile Drainage/Water Management Effects on Wheat, Canola and Soybeans productivity in Heavy Clay soils
Dr Ramanathan Sri Ranjan, University of Manitoba
Canadian Agricultural Partnership Program
Dr. Nirmal Hari, PESAI
The main objective of this research is to assess the impact of tile drainage (15’, 30’ and 45’ wide) and water table management on yield and quality of canola, soybean, and wheat. The data collected from this research will be used to develop computer models that can simulate tile drainage operation under different rainfall patterns, thus extending the usefulness of this research beyond the three-year period.
Arborg site received only 55% of normal precipitation from May 1 to September 1. Excess moisture was not a limiting factor in crop production this season, meaning that it was difficult to assess the effect of tile drainage on crop production. Yield was not affected by any tile drainage spacing treatment on any crop type, although plant height was affected by tiles in wheat and canola.
Excessive soil moisture delays agronomic operations, such as field preparations or seeding, during the early cropping season. These delays can result in a shorter cropping season and sometimes decreased yield. Excess moisture is a big constraint in crop production in Manitoba.
The Manitoba Agricultural Services Corporation (MASC) reported that between 1996 and 2014,
approximately 40% of crop losses were the result of excess moisture (with some reports placing
that number at 55% from 2005-2014).
The presence of heavy clay soils in the Interlake contributes to high moisture content, particularly during the spring. The Province of Manitoba has identified the importance of surface drainage in peat areas of Interlake and built drains (Provincial waterways) for proper runoff after rainfall. In regions with heavy clay soils, removal of surface water alone might not be a solution to excess moisture if the soil below the surface remains saturated. Draining water from the root zone is important to gain access to a field and to avoid loss of moisture-sensitive crops. Subsurface drainage systems help to remove excess soil moisture from the root zone. The amount of water removed daily is dependent on the drainage rate of the system, which must be carefully considered during the design process. The drainage rate determines the capability of the system to prevent soil saturation during high intensity rainfall events. Other parameters affecting the drainage rate are soil type, topography, tile installation depth and spacing of tile drains.
Tile drainage is becoming popular as a way to control excess moisture in the field to increase crop productivity. Yet, the economic return on investment (ROI) on installing tile drainage is not
known for wheat, canola, and soybeans in Manitoba. This research will allow us to assess the
impact of water management through controlled drainage on yield and quality of wheat, canola,
and soybeans. Detailed soil moisture measurements along with water table depth at different times will help us model water flow within the rootzone and its impact on crop yield. Data collected in this study will be used to calibrate computer models (HYDRUS, DrainMOD) for this location so that weather data from different years could be modeled to assess the long-term impact of tile drainage. The Prairie East Sustainable Agricultural Initiative (PESAI) research site has drains placed at 15’, 30’, and 45’ allowing different degrees of drainage. Rotating the three crops through these different spacings will help assess the impact of different drainage intensities.