Effect of application method on fate of phosphorus fertilizer

Non-Peer Reviewe

Effect of phosphorus application on wheat yield and phosphorus uptake in a Brown Chernozem in southern Saskatchewan

Non-Peer Reviewe

Determination of heavy metal contamination in the soil environment using ion-exchange membranes

Non-Peer ReviewedAn anion exchange resin membrane saturated with chelating agent (AEM-DTPA) was used to assess the bioavailability of four heavy metals, Cd, Cr Ni and Pb via direct in soil burial. Two soils with four contamination rates of each metal were tested using three crops: oats, radish and lettuce. The resin membrane was buried in saturated soil with de-ionized water for 60 min. and extractable metals from the soils were correlated with uptake by plants grown in the soils. The amounts of heavy metals extracted by AEM-DTPA were significantly correlated with plant uptake and with metal extracted by the conventional DTP A method. The critical levels of the four heavy metals varied from crop to crop, and soil to soil. It was demonstrated that AEM-DTPA direct in-soil burial is a suitable method in assessing relative heavy metal bioavailability in polluted soil environments. It is a simple and easy to use procedure which reduces soil handling

Evaluation of fate of added copper and zinc in prairie soils using chemical speciation and XANES spectroscopy

Non-Peer Reviewe

Soybean yield and release of nutrients from soybean residue in comparison to pea and lentil in Saskatchewan soils

Non-Peer Reviewe

Impact of grazing native prairie on soil and plant nutrients in southwestern Saskatchewan

Non-Peer ReviewedA reduction in the sage grouse population could be a result of the export of nutrients from the long term grazing management that has been in place in grassland ecosystems such as southwestern Saskatchewan for the past century. The objective of this study was to measure the supply rates of nitrogen and phosphorus in the soils and their content in the sage plants and determine what impact grazing has had on nutrient availability. Plant and soil samples were taken from five side-by-side normally grazed and ungrazed for ~20 years, native grassland sites in southwestern Saskatchewan and analyzed for nitrogen, phosphorus and selected micronutrients. PRS™-probes were buried in situ for 21 days to measure soil supply rates of nitrogen and phosphorus. Sage plants and grasses were collected and analyzed for nutrient content. At four (Butte Creek Upland and Low Sage; Frenchman Mid and Low slope) of the five sites, grazing had relatively minor, non-statistically significant effects on soil and plant nutrients. At the Consul site, a site that may be considered a drier site of poorer inherent fertility, grazing significantly reduced soil and plant P. Introduction of beef cattle into the pasture in the spring significantly increased supply rates of available N, likely due to fresh addition of N as fecal material and urine. Plant analysis revealed that calcium levels were significantly higher in the ungrazed Butte Creek low-sage and potassium levels were significantly higher in the ungrazed sage at Frenchman low slope and Consul sites. Overall, well managed grazed pastures located on good quality soils do not appear to be at risk of nutrient depletion. Cessation of grazing for ~20 years did not cause major differences in nutrient amounts and supplies compared to normally grazed pastures

Effect of uniformity of land application of solid cattle manure on crop yield and soil nitrate

Non-Peer ReviewedEquipment used in Western Canada to apply solid cattle manure (SCM) are known to exhibit uneven uniformity of distribution of material. For organic bio-solid manures to be a viable supplement or alternative to chemical fertilizers, it is essential that the uniformity of distribution of the product be measured by the effect that occurs on soil components and crop yields. A precise field scale solid manure applicator has been developed at the University of Saskatchewan and Prairie Agricultural Machinery Institute that is capable of precise surface and subsurface application of solid organic manure. The Low and Mid C.V. treatments at the low SCM application rate achieved similar grain yield results and were significantly higher than the High C.V. high SCM rate treatments. Addition of urea fertilizer to the treatments boosted grain yield production in most of the C.V. and rate treatments, however most of these increases were found to be not significantly different from urea only fertilized treatment plots. The addition of urea fertilizer in most of the treatments increased soil NO3-N compared to the non-urea fertilized treatments. There was however, no significant difference in soil NO3-N among the three C.V. treatments without the addition of urea fertilizer. The lack of large manure impacts is likely related to low release of available nutrient in the year in application

Assessment of Wild Mustard (Sinapis arvensis L.) Resistance to ALS-inhibiting Herbicides

There is an urgent need for rapid, accurate, and economical screening tests that can determine if weeds surviving a herbicide application are resistant. This chapter describes development and application of a simple root length bioassay technique for detection of wild mustard (Sinapis arvensis L.) resistance to ALS-inhibiting herbicides. This bioassay was performed in 2-oz WhirlPak® bags filled with 50 g of soil wetted to 100% moisture content at field capacity. Wild mustard seeds were pre-germinated in darkness in Petri dishes lined with moist filter paper for 2 days. Six seeds with well-developed radicles were planted in the non-treated soil and in soil with added herbicide, and plants were grown in a laboratory under fluorescent lights. After 4 days of growth, WhirlPak® bags were cut open, soil was washed away, intact plants were removed, and root length was measured with a ruler. The concentration of each herbicide in soil at which a significant root inhibition of susceptible biotype, but no root inhibition of a resistant biotype occurred was selected. Susceptibility/resistance of wild mustard populations was estimated by calculating the percentage of uninhibited roots of plants grown in the herbicide-treated soil as compared to the plants grown in the non-treated soil

Influence of urease and nitrification inhibitors on ammonium and nitrate supply and the soil microbial population in western Canadian soils

Non-Peer ReviewedImproving nitrogen use efficiency and limiting losses of N from the soil system is important both economically and environmentally. This study assessed the potential of using a urease inhibitor, Agrotain®, or a nitrification inhibitor, nitrapyrin, to create a slow release effect similar to that found in sulfur coated urea in western Canadian soils of the Brown and Black soil zones. The nitrapyrin significantly reduced the cumulative NO3- supply to the point of inhibition of nitrification for 21d in the Brown soil, but had little effect on the Black soil. Nitrapyrin had little effect on the supply of NH4+ in both soils. The Agrotain® had some effect on NO3- supply and significantly reduced the NH4+ supply for 14d in the Brown soil. Differences between the two soils were consistent with results in other studies and attributed to pH and organic matter content differences. The total heterotrophic and Nitrosomonas microbial populations were enumerated using spread plates and most probable number assays. It was concluded that Agrotain® had little effect on the microbial population, where as nitrapyrin reduced Nitrosomonas populations and increased total heterotrophic counts in both soils. Similarity between the results in this study and the literature suggest that the soils in Western Canada have similar responses to inhibitors as those characterized by the literature. Therefore, whether improved nitrogen use efficiency from the use of inhibitors in wheat in Western Canada would be large enough to justify the used of inhibitors will depend on whether local soil properties are conducive to promote volatilization, leaching and denitrification losses of N

Greenhouse gas emissions from land application of manure

Non-Peer ReviewedGreenhouse gas (GHG) emissions from agricultural activities such as land application of livestock manure cannot be ignored when assessing overall emissions from anthropogenic sources. The magnitude of these emissions will be influenced by management practices such as manure placement during land application. The objective of this work was to compare GHG fluxes resulting from the surface and subsurface application of liquid and solid manure. For this comparison, all measurements were made 24 hours after application. The results showed that subsurface application significantly increased carbon dioxide equivalent (CO2-e) fluxes for both solid and liquid manure. The overall CO2-e fluxes from the injected treatments were 3.2 times higher than CO2-e fluxes from the surface applied plots, mainly due to a pronounced increase in N2O fluxes which was likely caused by increased denitrification rates. The CO2-e fluxes from the liquid manure applications were also higher than the CO2-e fluxes from the solid manure applications, probably due to higher levels of ammonium available for nitrification and subsequent denitrification. For this particular study, the measured specific fluxes (total flux per kg N applied) remained relatively constant with application rate, indicating that GHG emissions from manure applications were approximately proportional to the amount of land applied manure