Winter cropping often does not realise its full potential in south-western Victoria, where waterlogging is a major problem on the poorly drained soils of conventional cultivation (CC) systems. Consequently, cropping has been undertaken on raised beds (RB) to reduce the risk of waterlogging. Initial reports on the yields of RB were encouraging. It was hypothesized that an improvement in soil properties of RB may account for their better performance compared to CC systems. / The aim of the thesis was to evaluate selected soil physical properties of RB and to make comparisons with other treatments (CC and pasture). The specific objectives were to: 1) evaluate plant growth and crop yield; 2) quantify soil water dynamics; 3) assess changes in the soil water retention characteristic (SWRC), soil strength and soil hydraulic properties; 4) describe pore pathways from solute transport; and 5) quantify soil macropore structure. / Measurements of volumetric water content (θv) were taken at 20, 40, 60 and 80 cm and at the soil surface. These data allowed the determination of the profile soil water deficit (SWD), which was found to be greater under the RB than the CC, although at times the pasture had the largest SWD. The RB mostly remained drier than the CC, but the response to rainfall in the surface θv was similar between treatments. Below average rainfall was received during the whole study period which resulted in drier than normal conditions. / There was no consistent difference in plant growth between crops on the RB and CC; e.g. in 2004 periods of waterlogging resulted in greater dry matter production on the RB; while drier conditions in 2003 saw better crop growth on the CC. Grain yield varied annually according to rainfall, and overall the treatment yields were similar. Analysis of regional yield data showed that there was no yield difference in years with average or below average rainfall, but years with higher rainfall favoured RB. / Little difference was found in the laboratory-derived SWRC, but in the field the RB were consistently drier at all depths and at 60 cm depth the CC had a saturated zone. The RB were found to have a lower soil strength characteristic within the surface 24 cm compared to the CC. The air-filled porosity (AFP) was higher in the RB while for long periods the CC were <10 per cent AFP. There was no significant difference between the treatments in unsaturated hydraulic conductivity (Kus) in the soil surface. Saturated hydraulic conductivity (Ks) in the subsoil was very small, although the RB had significantly greater Ks than the CC. / A solute transport experiment investigated the movement of a solute in large soil cores of the RB and CC treatments. Derived parameters from a transfer function model were used to assess the solute transport characteristics. This showed that under nearly saturated conditions the CC had significantly greater solute spreading than the RB. Furthermore, the transport volume (θst) to θv ratio was smaller in the RB which indicated a greater proportion of preferential flow. These and other data suggested that the RB had a better connected and more stable pore network. / Soil macropore structure was quantified using image analysis of resin-impregnated soil. Samples were taken twice; the first samples showed that the RB had improved pore connectivity, slightly greater porosity and a pore network with smaller sized pore components than the CC. In comparison, at the second sampling time the structural parameters of the two treatments were similar. / Uncertainty exists in the scenario of higher rainfall or of the longer-term changes of soil properties under RB cropping. Nevertheless after three years of measurements, this thesis concludes that most soil physical properties of RB are distinctly better for cropping than under CC systems.

Soil physical and chemical properties determine a soil's crop production potential and the sustainability of a production system. The objective of this study was to determine the effect of solid and liquid pig manure application on the physical and chemical properties of soil after 5 years of manure application. Solid pig manure increased saturated hydraulic conductivity (Ksat) by 110%, aggregate stability by 30%, available and total phosphorus by 471% and 52% respectively, available nitrogen by 38%, organic carbon by 29% and exchangeable K by 308%, and reduced soil bulk density by 14%. Liquid pig manure (LPM) also increased aggregate stability by 21%, exchangeable K by 45%, available P and total P by 258% and 27%, respectively and, reduced bulk density by 6%. An important finding was the 33% decrease in the concentration of exchangeable Ca in LPM-amended soils. Significant manure by cropping system interaction was also obtained for water retention parameters and available water, total nitrogen and electrical conductivity. There was no effect of pig manure on pH and exchangeable Mg concentrations. Soils under perennial vegetation had 31% greater Ksat, 26% increase in available N, 31% greater available P, 15% greater total P and 12% lower bulk density compared with those under annual crops. Our results show that SPM has a potential as a better organic amendment in improving physical and chemical properties of surface soils. / February 2016

Applications of fertilizers derived from non-renewable resources, along with improved land management practices have contributed greatly increased crop yields in the past 70 years. Biofertilizers and organic amendments, provide alternative sources of nutrients for increased plant yields and resistance against abiotic stress. The objective of this work was to evaluate the effectiveness of various biofertilizers and an organic amendment on improve plant health and/or crop yield. The first study focused on the organic amendment, glucoheptonate and found that applications of 800-1600 kg/ha can increase available water capacity in fine textured soils by up to 3%. The second study evaluated the effectiveness of dual-inoculating biofertilizers Mung beans (Vigna radiata (L.) Wilczek) with two, bradyrhizobium spp. and arbuscular mycorrhizal fungi. Dual inoculation significantly increased grain yield (+33%) compared to a synthetic N fertilizer application but did not significantly increase grain yield compared to the control (+22%). Dual inoculation may increase grain yields of mung beans compared to synthetic fertilizer regime but does not show evidence of improving N fixation. The final study was a greenhouse experiment focused on evaluating some mung bean cultivars to determine their susceptibility to salt stress while also evaluating the effect of inoculation in combating saline soils. Germination was significantly decreased at 6 dS/m in all cultivars by about 36% when compared to the control treatment (0 dS/m). Seed yields, pods per plant and seeds per plant, increased as salt concentration increased. No factors recorded where affected by inoculation. Overall, our research suggests that the use of biofertilizers and organic amendments can improve crop health, but other management and environmental considerations need to be accounted for when reporting effectiveness of such alternative soil amendments / Doctor of Philosophy / Applications of fertilizers derived from non-renewable resources, along with improved land management practices have contributed greatly to increased crop yields in the past 70 years. Biofertilizers and organic amendments, provide alternative sources of nutrients for increased plant yields and resistance against abiotic stress. The objective of this work was to evaluate the effectiveness of an organic amendment and various biofertilizers to improve plant health and/or crop yield. The first study focused on the organic amendment, glucoheptonate and found that applications of 800-1600 kg/ha can increase available water capacity in fine textured soils by up to 3%. The second study evaluated the effectiveness of dual-inoculating Mung beans (Vigna radiata (L.)Wilczek) with two biofertilizers, bradyrhizobium spp. and arbuscular mycorrhizal fungi. Dual inoculation significantly increased grain yield (+33%) compared to a synthetic N fertilizer application but did not significantly increase grain yield compared to the control (+22%). Dual inoculation may increase grain yields of mung bean compared to synthetic fertilizer regime but does not show evidence of improving N fixation. The final study was a greenhouse experiment focused on evaluating mung bean cultivars (4) to determine their susceptibility to salt stress while also evaluating the effect of inoculation in combating the effect of saline soils. Germination was significantly decreased by about 36% at a salinity of 6 dS/m across all cultivars compared to the control at 0 dS/m. Seed yields, pods per plant and seeds per plant, increased as salt concentration increased for some cultivars. No factors recorded were observed to be affected by inoculation. Overall, our research suggests that the use of biofertilizers and organic amendments can improve crop health, but other management and environmental considerations need to be accounted for when reporting effectiveness of such alternative soil amendments.

<p>The removal of vegetation and overburden changes the naturalwater purifying processes and thus decreases the groundwaterprotection in gravel pit areas. The sand and gravel depositsusedfor aggregate extraction in Sweden are also often valuablefor extraction of groundwater as a drinking water resource. TheSwedish legislation requires that gravel pits be restored afterthe cessation of extraction, the aim being to reestablishvegetation and to reinstate groundwater purifyingprocesses.</p><p>The objective of this study was to improve our understandingof the processes governing groundwater protection andvegetation establishment so that these could be applied toimproving restoration methods for reestablishing naturalgroundwater protection. The focus was on the importance of soilphysical properties of the topsoil for vegetation establishmentand groundwater recharge.</p><p>Actual field methods for restoration were reviewed.Conflicts between aggregate extraction and groundwaterinterests were common. In many cases the actual restorationcarried out differed from pre-planned specifications in permitdocumentation.</p><p>Commonly available substrates that might be used forrestoration of gravel pits were investigated. The soils weredescribed as regards texture, organic content, porosity, waterretention and hydraulic conductivity. The way in which acombination of the water retention characteristic and theunsaturated conductivity influenced the behaviour of thesoil-plant-atmosphere system was demonstrated using aprocess-orientated simulation model. Plants with well-developedaboveground characteristics and shallow roots in particularexerted the highest requirements on the soil physicalproperties.</p><p><b>Key words:</b>groundwater protection, soil physicalproperties, CoupModel, unsaturated conductivity, waterretention, transpiration, soil evaporation</p>

Development of the swine and cattle industries has led to an increase of manure application to agricultural lands in Saskatchewan. Studies have been conducted to determine the nutrient benefits of swine manure application. However, a need was also identified for information on the effects of manure application on soil physical and chemical properties. The objective of this study was to examine the effect of repeated applications of manure on soil physical and chemical properties and to relate those effects to early plant growth and development.<p>Four experimental sites were used, representing the Dark Brown (Plenty), Brown (Riverhurst irrigated), Black (Dixon) and Gray (Melfort) Soil Zones of Saskatchewan, where liquid swine manure had been applied for four to seven years. At each site, treatments were 1) a control treatment, 2) a nitrogen based agronomic rate of manure application, 3) a high rate of manure application (2-4x the agronomic rate) and 4) a urea fertilizer treatment. At the Dixon site, the same two manure treatments with cattle manure were also examined.<p>Soil strength, as determined by penetration resistance measurements and barley (<i>Hordeum vulgare</i>) emergence were measured at two experimental sites (swine and cattle manure trials at Dixon, SK) in a field study. Penetration resistance was measured at 5, 10, 15 and 20 cm depths, 20, 39 and 123 days after seeding using a recording cone penetrograph. Twenty days after seeding, there were no significant differences among treatments at the 10, 15 and 20 cm depths. But, at the 5 cm depth, the control treatment had soil strength 0.11 MPa lower than the two manure rates. The manure treatments were not significantly different from the urea treatment. Thirty-nine days after seeding, the soil strength of the low rate manure treatment was 1.1 MPa greater than the control at the 10 cm depth, but not significantly different from the urea treatment. One hundred and twenty three days after seeding, the control treatment had greater soil strength than the high rate of manure at 5 and 10 cm depths by 0.28 and 0.71 MPa respectively. At the 20 cm depth, the high rate of manure had the greatest soil strength. Barley emergence on the two manured treatments did not differ significantly from the control. Aggregate size was measured in field samples collected from all sites. Aggregate size for the manured treatments did not differ from the control at any site.<p>Soil crust strength, flax emergence, infiltration rate, salinity, sodicity, coefficient of linear extensibility (COLE) and modulus of rupture were measured under controlled conditions in intact cores of soil removed from all five experimental sites. All soils were treated with a simulated rainfall from a Guelph Rainfall Simulator II. Following the simulated rainfall, crust strength was measured with a hand-held penetrometer. Soil crust strength was measured daily for 10 days as the cores dried. Repeated applications of liquid swine manure at either low or high rates decreased soil strength in the Plenty, Riverhurst and Melfort soils, and increased soil strength in the Dixon soil. Repeated applications of liquid swine manure at low rates caused flax emergence to decrease for the Riverhurst soil compared to its control and had no significant effect at the other sites. There were no notable differences in infiltration rates among treatments. Repeated applications of liquid swine manure caused salinity (EC) to increase slightly for the Plenty and Riverhurst soils, and sodicity (ESP) to increase slightly for the Melfort and Dixon soils relative to their control. The COLE and modulus of rupture measurements indicated no significant effects and were inconclusive due to difficulties in measurement. <p>None of the properties measured in any of the treatments exceeded threshold values for soil productivity, or where plant injury might be considered an issue. It is concluded that repeated (four to seven) annual applications of liquid swine or cattle manure would not cause any large alterations in soil strength, aggregation, infiltration, salinity, or sodicity that would affect early plant growth and development. This was supported by field and lab measurements of emergence that showed limited effect.

Development of the swine and cattle industries has led to an increase of manure application to agricultural lands in Saskatchewan. Studies have been conducted to determine the nutrient benefits of swine manure application. However, a need was also identified for information on the effects of manure application on soil physical and chemical properties. The objective of this study was to examine the effect of repeated applications of manure on soil physical and chemical properties and to relate those effects to early plant growth and development.<p>Four experimental sites were used, representing the Dark Brown (Plenty), Brown (Riverhurst irrigated), Black (Dixon) and Gray (Melfort) Soil Zones of Saskatchewan, where liquid swine manure had been applied for four to seven years. At each site, treatments were 1) a control treatment, 2) a nitrogen based agronomic rate of manure application, 3) a high rate of manure application (2-4x the agronomic rate) and 4) a urea fertilizer treatment. At the Dixon site, the same two manure treatments with cattle manure were also examined.<p>Soil strength, as determined by penetration resistance measurements and barley (<i>Hordeum vulgare</i>) emergence were measured at two experimental sites (swine and cattle manure trials at Dixon, SK) in a field study. Penetration resistance was measured at 5, 10, 15 and 20 cm depths, 20, 39 and 123 days after seeding using a recording cone penetrograph. Twenty days after seeding, there were no significant differences among treatments at the 10, 15 and 20 cm depths. But, at the 5 cm depth, the control treatment had soil strength 0.11 MPa lower than the two manure rates. The manure treatments were not significantly different from the urea treatment. Thirty-nine days after seeding, the soil strength of the low rate manure treatment was 1.1 MPa greater than the control at the 10 cm depth, but not significantly different from the urea treatment. One hundred and twenty three days after seeding, the control treatment had greater soil strength than the high rate of manure at 5 and 10 cm depths by 0.28 and 0.71 MPa respectively. At the 20 cm depth, the high rate of manure had the greatest soil strength. Barley emergence on the two manured treatments did not differ significantly from the control. Aggregate size was measured in field samples collected from all sites. Aggregate size for the manured treatments did not differ from the control at any site.<p>Soil crust strength, flax emergence, infiltration rate, salinity, sodicity, coefficient of linear extensibility (COLE) and modulus of rupture were measured under controlled conditions in intact cores of soil removed from all five experimental sites. All soils were treated with a simulated rainfall from a Guelph Rainfall Simulator II. Following the simulated rainfall, crust strength was measured with a hand-held penetrometer. Soil crust strength was measured daily for 10 days as the cores dried. Repeated applications of liquid swine manure at either low or high rates decreased soil strength in the Plenty, Riverhurst and Melfort soils, and increased soil strength in the Dixon soil. Repeated applications of liquid swine manure at low rates caused flax emergence to decrease for the Riverhurst soil compared to its control and had no significant effect at the other sites. There were no notable differences in infiltration rates among treatments. Repeated applications of liquid swine manure caused salinity (EC) to increase slightly for the Plenty and Riverhurst soils, and sodicity (ESP) to increase slightly for the Melfort and Dixon soils relative to their control. The COLE and modulus of rupture measurements indicated no significant effects and were inconclusive due to difficulties in measurement. <p>None of the properties measured in any of the treatments exceeded threshold values for soil productivity, or where plant injury might be considered an issue. It is concluded that repeated (four to seven) annual applications of liquid swine or cattle manure would not cause any large alterations in soil strength, aggregation, infiltration, salinity, or sodicity that would affect early plant growth and development. This was supported by field and lab measurements of emergence that showed limited effect.

The removal of vegetation and overburden changes the naturalwater purifying processes and thus decreases the groundwaterprotection in gravel pit areas. The sand and gravel depositsusedfor aggregate extraction in Sweden are also often valuablefor extraction of groundwater as a drinking water resource. TheSwedish legislation requires that gravel pits be restored afterthe cessation of extraction, the aim being to reestablishvegetation and to reinstate groundwater purifyingprocesses. The objective of this study was to improve our understandingof the processes governing groundwater protection andvegetation establishment so that these could be applied toimproving restoration methods for reestablishing naturalgroundwater protection. The focus was on the importance of soilphysical properties of the topsoil for vegetation establishmentand groundwater recharge. Actual field methods for restoration were reviewed.Conflicts between aggregate extraction and groundwaterinterests were common. In many cases the actual restorationcarried out differed from pre-planned specifications in permitdocumentation. Commonly available substrates that might be used forrestoration of gravel pits were investigated. The soils weredescribed as regards texture, organic content, porosity, waterretention and hydraulic conductivity. The way in which acombination of the water retention characteristic and theunsaturated conductivity influenced the behaviour of thesoil-plant-atmosphere system was demonstrated using aprocess-orientated simulation model. Plants with well-developedaboveground characteristics and shallow roots in particularexerted the highest requirements on the soil physicalproperties. Key words:groundwater protection, soil physicalproperties, CoupModel, unsaturated conductivity, waterretention, transpiration, soil evaporation

No description available.

Traditional aerification programs can cause substantial damage to the playing surface resulting in prolonged recovery. A growing trend in the industry involves using aerification techniques that cause minimum surface disruption; however, despite growing interest in new and alternative aerification technology, there is a lack of information in the literature comparing new or alternative technology with traditional methods on warm season grasses. Therefore, the objective of this research was to determine the best combination of new dry-injection (DI) cultivation technology with modified traditional aerification programs to achieve minimal surface disruption without a compromise in soil physical properties. Research was conducted at the Mississippi State University golf course practice putting green and at the Mississippi State University practice football field during. Treatments compared different combinations of hollow tine (HT) aerification and DI from Jun to Aug in 2014 and 2015.

No description available.