Quantifying nitrogen fixation of agroforestry shrub species by the 15N natural abundance and dilution techniques under the greenhouse condition

Non-Peer ReviewedThe land use systems of the province of Saskatchewan has agroforestry trees such as sea buckthorn (Hippophae rhamnoides L.), caragana (Caragana arborescens Lam.) and buffaloberry (Shepherdia argentea Nutt.) as important components. They have been employed within the systems to perform functions such as ameliorating soil moisture, light and temperature through wind speed reduction and trapping snow. However, their N2-fixation capability has not been determined. Therefore in a greenhouse experiment conducted at the Agriculture greenhouse at the University of Saskatchewan, Saskatoon, SK, Canada from January 2012 ̶ April 2012, the N2-fixation rates in the test species were evaluated to know their contributions to on-farm nitrogen management. After 120 days after planting, the shoot N derived from the atmosphere (%Ndfa) in the species ranged from 20-59%, 21-70% and 3-15% for caragana, sea buckthorn and buffaloberry, respectively. Also the whole plant %Ndfa in the species ranged from 18-47%, 49-54% and 38-41% for caragana, sea buckthorn and buffaloberry, respectively by both estimation methods. The contributions of the species to soil N were 73-91, 25-261 and 15-110 kg N ha-1 for caragana, sea buckthorn and buffaloberry, respectively by both methods. The amount was sufficient to meet the N requirements of most of the forage and grass species in the province which would progressively reduce the overreliance on synthetic fertilizers and minimize the risk of agrarian-derived soil and water pollution from inorganic nutrient sources

Effects of biophysical interactions of the alley cropping system on yield and nutrition of forage crops in Saskatchewan

PresentationCompetition between trees and crops in alley cropping systems for soil moisture, light and nutrients, especially N can lead to decreased crop yield. However, there is tree-crop interactions in alley cropping the Canadian prairies are poorly understood. This study examined the effects of light and soil moisture conditions in the alleyways on yield and nutrition of forage crops. The experiment was conducted using a 9-yeald old Manitoba maple alley cropping site with oats inter-planted in the alleys at the experimental site of the Agroforestry Development Centre, Indian Head, SK. Apart from crude protein (CP) and total nitrogen (TN) in the oats plant, dry matter content (DM), and acid detergent fiber (ADF) were not affected by distance from the tree row, orientation of oats plots and their interactions. Apparently, soil moisture (SMC) influenced yield and nutrition of oats in the northern orientation since DM, TN and CP were also higher in north facing plots. Producers may integrate trees on farm to diversify production cycles without comprising forage crop production and nutrition because no significant adverse effects were noted within 6m from the tree row

Successful electroconvulsive therapy for depression in a man with cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is a condition characterised by accumulation of amyloid beta protein (A beta) in the wall of cerebral blood vessels which increases the risk of intracranial haemorrhage and contributes to cognitive impairment. We describe the case of a man around the age of 70 with 'probable' CAA according to the modified Boston criteria and severe depression whose depression was treated successfully with electroconvulsive therapy (ECT). To the best of our knowledge, there are no earlier published reports of ECT in a patient with CAA. We briefly discuss possible safety measures for these patients, the impact of ECT on cognition in CAA and a possible influence of ECT on A beta clearance

Diabetes mellitus type 2 and subsite-specific colorectal cancer risk in men and women: results from the Netherlands Cohort Study on diet and cancer

Background: Type 2 diabetes mellitus (T2DM) is associated with an increased risk of colorectal cancer (CRC); however, studies differentiating between subsites of CRC are limited. We investigated how diabetes mellitus (DM) was associated with subsite-specific CRC risk in men and women. Methods: The Netherlands Cohort Study on diet and cancer is a prospective study among 120 852 men and women aged 55-69 years old at baseline in 1986. Information on DM, anthropometric, dietary and lifestyle factors was self-reported at baseline. T2DM was defined as the diagnosis of DM after 30 years of age. Incident CRC cases were identified by record linkage with the Netherlands cancer registry and the Dutch pathology registry. After 17.3 years of follow-up, 1735 incident male CRC cases and 1321 female CRC cases were available for analyses. Subsite-specific hazard ratios (HRs) for CRC were estimated in case-cohort analyses using Cox regression. Results: At baseline, 3.1% of subcohort members reported T2DM, of whom 80% were diagnosed after 50 years of age. Multivariable-adjusted models showed that the risk of proximal colon cancer was significantly increased in women with T2DM versus women without T2DM (HR=1.80, 95% confidence interval: 1.10-2.94). There was no association between T2DM and the risk of overall CRC, distal colon cancer and rectal cancer in women. In men, T2DM was not associated with overall CRC (HR=0.98, 95% confidence interval: 0.64-1.50), or with risk at any subsite. Conclusions: This prospective study showed an increased risk of proximal colon cancer in women with T2DM compared with non-T2DM women