Objective of the research – the research was to determine the effect of different sulphur fertilisation rates on the mineral sulphur content in soil and the seed/grain yield and quality of spring rape and spring wheat crops grown on low in sulphur sandy light loam Epicalcari – Endohypogleyic Cambisols and very low in sulphur sandy loam on light loam Orthi-Haplic Luvisols. Tasks of the research: To determine the effect of different sulphur fertilisation rates applied to low in sulphur sandy light loam Epicalcari – Endohypogleyic Cambisols and very low in sulphur sandy loam on light loam Orthi-Haplic Luvisols on: • Spring rapeseed yield and crop structural elements; • Spring rapeseed quality; • Spring wheat yield and crop structural elements; • Spring wheat grain quality; • Changes in the mineral sulphur content in soil. / Tyrimų tikslas – nustatyti skirtingų sieros trąšų normų įtaką vasarinių rapsų ir vasarinių kviečių derliui, jo kokybei bei mineralinės sieros kiekiui mažai ir labai mažai sieringame smėlingame lengvo priemolio sekliai karbonatingajame giliau glėjiškajame rudžemyje (Epicalcari – Endohypogleyic Cambisol ) ir priesmėlio ant lengvo priemolio tipingajame paprastajame išplautžemyje (Orthi-Haplic Luvisol). Tyrimų uždaviniai: Nustatyti sieros trąšų normų įtaką mažai ir labai mažai sieringame smėlingame lengvo priemolio sekliai karbonatingajame giliau glėjiškajame rudžemyje (Epicalcari – Endohypogleyic Cambisol ) ir priesmėlio ant lengvo priemolio tipingajame paprastajame išplautžemyje (Orthi-Haplic Luvisol): • Vasarinių rapsų sėklų derliui ir struktūros elementams. • Vasarinių rapsų sėklų kokybei. • Vasarinių kviečių derliui ir struktūros elementams • Vasarinių kviečių grūdų kokybei. • Mineralinės sieros kiekio pokyčiams dirvožemyje.

The main objective of this study was to evaluate the organic N in silty clay loam soil as an indicator of soil fertility. The incubation method was used in this study. The N03 -N, the total N percent, and the organic matter were determined. The soil which was used in this study came from Evans Research Farm. The samples were taken from two different N experiments which were adjacent to each other. The soil samples were taken in October-November, 1973, after the crop had been harvested. These two experiments had different cropping histories. The results of the first experiment which had continuous corn for four years indicated that there was no correlation between the mineralizable-N and the crop performance, but there was a good correlation between the No3 -N and crop yield. The results of the second experiment which had alfalfa for three years prior to corn indicated that there was a good correlation between N03-N and the crop performance and also there was a correlation between mineralizable-N and crop performance. It was concluded that cropping history could be used as a guideline as to whether mineralizable-N should be tested as an indication of soil N availability. In situations where the cropping history is unknown, N03-N could be used exclusively since it was a good fertility predictor in both of these field experiments.

No description available.

No description available.

A laboratory study of the mobility of Malathion in the soil environment was conducted. / Master of Science

The objectives of the investigation were to relate yield and P uptake of orchard grass grown on Davidson clay loam to P fertilization and to determine the fate and availability of applied and native P in this soil. A further aim of the investigation was to elucidate mechanisms controlling the availability of P to plants in Davidson clay loam that was limed to several pH values. These objectives were accomplished by a study of orchard grass yield data obtained during a long term field investigation and by performance of greenhouse and laboratory experiments. Annual surface application of 21 lb P/A increased orchard grass yield during the initial phase of the field experiment, from 1948 to 1957. Thereafter, from 1958 to 1962, continued application of 21 lb P/A no longer increased yield. Lack of yield response to P application was attributed to plant uptake of residual P. The conclusion was supported by data from a greenhouse study. In the study, P application did not significantly affect yield or P uptake of alfalfa grown on Davidson clay loam that had received annual application of 21 lb P/A for 15 years. Total inorganic P analysis indicated that the major portion of surface applied P remained in the 0-2 inch soil layer. However, statistical analysis of the total inorganic P data showed a significant downward movement of P into the 4-6 inch soil layer. Fractionation analysis indicated the applied and native P was present in Davidson clay loam predominantly as Fe-P. Iron-P made up greater than 70% of the total inorganic P at the 0-2, 2-4, 4-6 and 6-12 inch soil depths. High accumulation of applied P as Fe-P in Davidson clay loam was explained on the basis of the high free Fe oxide content of the soil. Application of either lime or P increased yield and P uptake of alfalfa grown on Davidson clay loam which received annual application of 0 or 10.5 lb P/A for 15 years. From these results it was concluded that liming increased the availability of native and residual P in the soil. Fractionation analysis indicated that the Fe-P fraction decreased to a greater extent than Al-P or Ca-P during growth of alfalfa on the limed soil. These data indicated that liming increased the availability of the Fe-P. Iron P decreased to a greater extent than Al-P or Ca-P during growth of alfalfa on Davidson clay loam that received annual application of O, 10.5 and 21 lb P/A for 15 years. Coefficients of simple correlation for the data, showed a higher correlation between Fe-P than Al-P or Ca-P with P uptake by alfalfa plants. From these data it was concluded that Fe-P was more important than Al-P or Ca-P in supplying P to plants grown on Davidson clay loam. Higher uptake of P from Fe-P rather than from Al-P or Ca-P was explained on the basis of the greater amount of Fe-P in Davidson clay loam. It is suggested that a large percentage of the Fe-P fraction in the soil consists of relatively soluble amorphous compounds. The presence of relatively soluble amorphous Fe-P as well as the high percentage of this compound in the soil then may account for Fe-P being more available than was anticipated. / Ph. D.

Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction. In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.

Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction. In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.

No description available.

Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction. In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.