The effect of pulse crop rotation and controlled-release urea on the N accumulation and end-use quality of CWRS wheat

Non-Peer ReviewedSpring wheat was grown at Carman in 2000 and 2001, and at Brandon, MB, in 2001, on field pea and flax stubble at three rates of N (0, 30, and 90 kg N ha-1) supplied as ammonium nitrate (AN) or controlled release urea (CRU), a polyurethane-coated urea. Wheat was grown in 2000 and 2001 at Swift Current, SK, on field pea and durum stubble at three rates of urea N (34, 50, and 78 kg N ha-1) based on soil test recommendations. Wheat grown on field pea stubble (P-W) had higher protein content (PC) than wheat grown on flax/durum stubble (F-W) at four of the five sites evaluated. Contrary to expectations, post-anthesis apparent net mineralized N and proportion of total N uptake were higher for F-W compared to P-W at the Carman 2000 and Brandon 2001 sites. Differences between fertilizer N sources were minor. Breadmaking quality of the wheat end-use quality was also assessed. At the same flour protein content (FPC), P-W had a shorter Mixograph dough development time, work input-to-peak, dough strength index, and breakdown resistance, and also tended to be more extensible than F-W

Evolution of Integrated Crop-Livestock Production Systems

Key points 1. Many factors contribute to changes in the crop-livestock systems, but no logical end-point in the evolution process exists. 2. While benefits of integrated crop-livestock systems over specialised crop and livestock systems are well documented, there has been a move to specialised crop and livestock production. 3. Sustainability issues (manure nutrient concentration, soil quality maintenance, salinity, herbicide resistance, economic instability) have created a renewed interest in integrated crop-livestock systems. 4. Farmer adaptability is as an important link in the evolution between ‘states of integration’

Evolution of Integrated Crop-Livestock Production Systems

Many factors contribute to changes in the crop-livestock systems, but no logical end-point in the evolution process exists. While benefits of integrated crop-livestock systems over specialised crop and livestock systems are well documented, there has been a move to specialised crop and livestock production. Sustainability issues (manure nutrient concentration, soil quality maintenance, salinity, herbicide resistance, economic instability) have created a renewed interest in integrated crop-livestock systems. Farmer adaptability is as an important link in the evolution between ‘states of integration’

Assessment of selected soil parameters in a long-term Western Canadian organic field experiment

Abstrac

Comparison of potential growth rates of Ceratium hirundinella with observed population density changes

Ceratium hirundinella cells in Lake Constance divided during the second half of the night. Growth rates are calculated from the fraction of cells undergoing cell division. Potential growth rates are compared with observed changes in population density. The discrepancy between both is discussed as a possible function of fungal parasitism

Diagnostic criteria for constitutional mismatch repair deficiency syndrome: suggestions of the European consortium 'care for CMMRD' (C4CMMRD)

Constitutional mismatch repair deficiency (CMMRD) syndrome is a distinct childhood cancer predisposition syndrome that results from biallelic germline mutations in one of the four MMR genes, MLH1, MSH2, MSH6 or PMS2. The tumour spectrum is very broad, including mainly haematological, brain and intestinal tract tumours. Patients show a variety of non-malignant features that are indicative of CMMRD. However, currently no criteria that should entail diagnostic evaluation of CMMRD exist. We present a three-point scoring system for the suspected diagnosis CMMRD in a paediatric/young adult cancer patient. Tumours highly specific for CMMRD syndrome are assigned three points, malignancies overrepresented in CMMRD two points and all other malignancies one point. According to their specificity for CMMRD and their frequency in the general population, additional features are weighted with 1-2 points. They include multiple hyperpigmented and hypopigmented skin areas, brain malformations, pilomatricomas, a second childhood malignancy, a Lynch syndrome (LS)-associated tumour in a relative and parental consanguinity. According to the scoring system, CMMRD should be suspected in any cancer patient who reaches a minimum of three points by adding the points of the malignancy and the additional features. The diagnostic steps to confirm or refute the suspected diagnosis are outlined. We expect that application of the suggested strategy for CMMRD diagnosis will increase the number of patients being identified at the time when they develop their first tumour. This will allow adjustment of the treatment modalities, offering surveillance strategies for second malignancies and appropriate counselling of the entire family

Green and animal manure use in organic field crop systems

Dual-use cover/green manure (CGM) crops and animal manure are used to supply nitrogen (N) and phosphorus (P) to organically grown field crops. A comprehensive review of previous research was conducted to identify how CGM crops and animal manure have been used to meet N and P needs of organic field crops, and to identify knowledge gaps to direct future research efforts. Results indicate that: (a) CGM crops are used to provide N to subsequent cash crops in rotations; (b) CGM-supplied N generally can meet field crop needs in warm, humid regions but is insufficient for organic grain crops grown in cool and sub-humid regions; (c) adoption of conservation tillage practices can create or exacerbate N deficiencies; (d) excess N and P can result where animal manures are accessible if application rates are not carefully managed; and (e) integrating animal grazing into organic field crop systems has potential benefits but is generally not practiced. Work is needed to better understand the mechanisms governing the release of N by CGM crops to subsequent cash crops, and the legacy effects of animal manure applications in cool and sub-humid regions. The benefits and synergies that can occur by combining targeted animal grazing and CGMs on soil N, P, and other nutrients should be investigated. Improved communication and networking among researchers can aid efforts to solve soil fertility challenges faced by organic farmers when growing field crops in North America and elsewhere

Optimizing the Productivity and Resiliency of Cropping Systems in the Major Ecozones on the Canadian Prairies

Non-Peer ReviewedAgriculture faces grand challenges of meeting growing food demands and increasing profitability while reducing environmental impacts. A systems approach is required to design and manage cropping systems to meet the goal of agricultural sustainability under climate change. A 4-year rotation study was established in 2018 at seven sites across the Canadian Prairies, including Beaverlodge, Lacombe, and Lethbridge, AB; Melfort, Scott, and Swift Current, SK; and Carman MB. The objective of this project is to develop resilient cropping systems for different ecozones on the Canadian Prairies. This study tested six cropping systems consisting of 1) conventional cropping system (Control), 2) pulse- or oilseed-intensified cropping system (POS), 3) diversified cropping system (DS), 4) market-driven cropping system (MS), 5) high risk and high reward cropping system (HRHRS), and 6) green-manure incorporated soil-health focused cropping system (GMS). Each cropping system varies slightly among experimental sites (ecozones) to mimic local farming practices. Cropping system indicators such as yield, resource use efficiency, soil health, profitability, environmental impact, resiliency, and sustainability will be fully assessed at the end of rotations. The preliminary results from the first 2 years indicated that there was no single cropping system suitable for all study ecozones although POS had an above-average yield and stability among the six cropping systems. We suggest that the optimal cropping system will maximize yield in the high-yielding ecozones and stabilize yields in the low-yielding ecozones. Link to Video Presentation: https://youtu.be/VsK4RNIzaZ

Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy

Background Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.Methods ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.Findings Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow- up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2. 5% in each group for fatal or disabling stroke, and 5.3% with CAS versus 4.5% with CEA for any stroke (rate ratio [RR] 1.16, 95% CI 0.86-1.57; p=0 .33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1.11, 95% CI 0.91-1.32; p=0.21).Interpretation Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable