A field experiment was conducted on a homogeneous sandy soil and a layered soil of southern Quebec from 1988 to 1990. This was done in order to evaluate the yield response of indeterminate soybean to subsurface irrigation and to determine the performance of subsurface irrigation in a layered soil. It was found that indeterminate soybean varieties increase their yield by approximately 30% for two out of three years. Soybean are very sensitive to competition between themselves as well as with weeds. This sensitivity is increased during subsurface irrigation. Weeds were more prominent in the irrigated area. It was concluded that the soybean yields are functions of water table depth, percent weed and plant population density. The minimum allowable water table depth for soybean was found to be 45 cm. At a water table depth greater than 95 cm no yield response was observed. / Water table management is not only possible but very functional in the layered soils of southern Quebec. It was found that surplus water did not drain from the irrigated area until the water table anywhere in this area was 10 cm higher than the elevation of the overflow pipe in the control chamber. It was therefore concluded that a water table depth range of 10 cm should be included in the design of the water table control system to allow for the effects of rain.

No description available.

A field subirrigation experiment, using saline-sodic water, was carried out on a loamy sand soil in southwestern Quebec. The experimental field was divided into 16 plots with 4 treatments; saline-sodic water, "fresh" water, controlled drainage and non-irrigated. Each treatment had four replicates. Maize yield, hydraulic conductivity, salt concentration, and salt movement through the soil were recorded in all plots. / No significant difference in maize yield occurred between plots irrigated with saline-sodic or fresh water in any of the three years. Irrigated maize plots yielded approximately 30% more than non-irrigated plots. / Hydraulic conductivity reductions in the saline plots were noted in May 1986, after the first snowmelt. From statistical analysis carried out, it appears that the saline-sodic water had an effect on hydraulic conductivity, significant at the 0.05 level. / From the measurements taken from piezometer stations, located throughout the field, salt concentrations and salt movement through the saturated soil profile were determined. Using salt concentration data from both irrigation water and soil water, an average effective field porosity was calculated with a computer program. The results obtained were within 4% of those obtained in laboratory tests. Moreover, the program was then used to model the salt balance of the soil from May 85 to May 87. Results indicated that most salts were removed with the rainfall and snowmelt of the winter months of 85/86 and 86/87.

Suitable areas for subirrigation and sprinkler irrigation were identified in Richelieu and St-Hyacinthe counties. / Land suitable for subirrigation includes uniform sandy textured profiles deeper than 1 m, with hydraulic conductivities greater than 0.5 m/d and lying on a clay layer at approximately 2 m from the surface, and with slopes less than 0.5% and little or no microrelief. / Soils that failed to satisfy the subirrigation criteria and that would most benefit from sprinkler irrigation were identified. These soils had available water holding capacities of less than 7.5 cm per 100 cm of soil. Most of the soils suitable for sprinkler irrigation were shallow sand (50 cm) over clay. / Both the Richelieu and St-Lawrence Rivers could meet the flow demand for the total irrigated area. However, 57% of the subirrigable land is located at more than 20 km from the Richelieu and St-Lawrence and could be more economically supplied by the Yamaska River. The Yamaska River could supply all the subirrigated land in its vicinity (4 900 ha) and part of the land suited for sprinkler irrigation (1 000 ha) 4 out of 5 years. (Abstract shortened by UMI.)

No description available.

No description available.

The purpose of this thesis is to design a computer model which compares three sprinkler irrigation systems---portable pipe with volume gun, traveller with volume gun and towable/non-towable centre pivot---for potato production. The model user is required to enter a set of basic data: crop and field conditions, irrigation technical parameters and basic economic data, following which the model establishes the preliminary irrigation system and a comparative investment analysis. The model was applied and tested on a potato farm situated in Notre-Dame-de-la-Paix (southwestern Quebec). Based on a 14-year climatic analysis, supplemental irrigation for a normal rainfall growing period (368 mm) was estimated at 250 mm. The application of the model indicates that for a normal rainfall period with an assumed yield increase of 25% over non-irrigated production, all three systems provide net profits (increases of 11% to 50%). However, when determining the Internal Rate of Return (IRR) on a 10-year period, the maximum rate attained by the more profitable systems---portable pipe and non-towable centre pivot (both with an electric pump)---was 14%, a rate inferior to the IRR for non-irrigated production (17%). The Net Present Value (NPV) analysis for the two most profitable irrigation systems provided a slightly higher NPV value for irrigated than for non-irrigated production ($10,942---irrigated vs $10,522---non-irrigated production). The payback period for those two irrigation systems was 7 years. Greater gains of irrigated over non-irrigated yields would be expected for a dry period because of low and unpredictable yields in non-irrigated conditions. A farmer planning to invest in an irrigation system must carefully investigate all technical and socio-economic aspects. The model presented gives the farmer a useful tool with which to do this.

An important number of Canadian dairy farms manage their manure as solids and in doing so, must handle large volumes of manure seepages and milk house wastewater (dairy farm effluent-DFE). The present project adapted surface irrigation as a more economical and sustainable method of disposing of this large volume of DFE on cropped land near their storage facility. The experimental surface irrigation system consisted of a gated pipe installed perpendicular to the slope of the field allowing the discharged DFE to run down the slope. / The adaptation of the system and the measurement of its environmental impact were conducted on two dairy farms, A and B, in the region South West of Montreal where their DFE were characterized. In 2003 and 2004, DFE was applied on one of two 0.5 and 0.3ha plots, on each farm, to observe losses through the subsurface drainage system, by means of sampling wells, and effects on soil nutrient levels. / The DFE collected in 2002 and 2003 had a lower nutrient content than that collected in 2004 because of higher precipitations. The DFE generally contained between 150-500 mg/L of TKN, 15 to 40 mg/L of TP and 500 to 700 mg/L of TK. / DFE losses through the subsurface drainage system were observed on both farms during each irrigation test. Nevertheless, outlet losses were observed only when irrigating under wet soil conditions or when applying more than 50mm of DFE. Outlet losses represented at the most 1.2% of the total DFE volume applied and 0.32% of the nutrient and bacterial loads. / Although only 65 to 75% of the soil surface was covered by the applied DFE, the irrigation sessions did provide some additional soil moisture for crops, increasing yield by 31% in 2004. Once absorbed by the soil, the applied DFE did not increase the soil nutrient level and variability in the presence of crop. Thus, the DFE contributed to the irrigation and fertilization of the plots. / Surface irrigation to spread low nutrient DFE, as compared to the conventional tanker system reduced the application costs from $3.05/m3, to $0.95/m3.

No description available.

No description available.