Optimum strategies for mapping management zones using temporal remote sensing information

Non-Peer ReviewedTechnological advances in variable rate application and global positioning systems (GPS) make site-specific management technically feasible. No longer do fertilizer and pesticides need to be applied uniformly across a field, they may be varied to match the soil productivity across the field. However, successful site-specific management depends on identifying management zones and the determining optimum input application rate for those zones Unfortunately, identifying management zones that are reasonably consistent from year to year has been the greatest problem to successful site-specific management. In this study we found that crop vigor measured with normalized difference vegetation index (NDVI) based on satellite (LANDSAT) remote sensing for two different years was successful for identifying management zones. Based on the NDVI, we divided a field near Shaunavon in southwestern Saskatchewan into two zones: zone 1 with low crop and vigor zone 2 with high crop vigor. The zones corresponded to differences in soils, particularly, soil moisture, but it would be too costly and impractical to try to delineate these zones from detailed soil sampling. Wheat yield and protein were more responsive to N in zone 1 than in zone 2. The optimal N fertilizer rate was 95 kg/ha for zone 1 and 75 kg/ha for zone 2. Satellite remote sensing is a cost-effective method to delineate management zones for site-specific management

Analysis of spatio-temporal field productivity of a wheat field in southern prairie region

Non-Peer ReviewedThe site-specific management of agriculture inputs have spawned a revolution in how farmers are managing their fields with the improvement in technology involving variable rate chemical applications and geographic positioning system. No longer do fertilizer and pesticides need to be applied uniformly across a field, but now may be varied to match the soil potential as the soil type varies across the field. Success of this method of precision farming depends on being able to set application rates matching field productivity. Unfortunately, little information is available on how variable yields are across fields, what patterns of yield can be expected, and how consistent these patterns are from year to year. In this study we found that wheat yield varies across a field, but that the yield pattern is not the same each year. Overall spring soil moisture level does affect the strength of the spatial pattern.This information is important to those trying to use yield patterns for making chemical applications for precision farming. Our study indicates that several years are needed before a clear pattern of yield potential can be determined

Agriculture field characterization using GIS software and scanned color infrared aerial photographs

Non-Peer ReviewedThis paper addresses the potential of a color infrared aerial photograph to provide spatially distributed information for site specific management. In this process digitized color infrared aerial photographs were used to extract vegetation index information. In addition, important crop and soil information were also collected using a grid sampling technique. Crop and soil information contributing most to explain variability were determined and used in further analysis. Grain yield data obtained using combine sampling were noted along with the coordinate information of the sample points. Locational information were collected using GPS. Kriged surface were generated using soil and crop point sample information. Point information were extracted from each kriged surface using centroid of uniformly spaced grid (15 m cell). Fuzzy k-means with extragrades algorithms were used to delineate potential within-field management units based on soil and crop information and vegetation index separately. Then “goodness” of potential management zones generated using within zone variability of grain yield. Ideal number of zones were determined using the decrease in total within-zone variance. Finally, management zones determined using crop and soil information and vegetation index information were compared for similarity. The methodology is fast, can be easily automated in commercially available GIS software and has considerable advantages when comparing to other methods for delineating within-field management zones

Analyzing color infrared aerial photographs for the delineation of management units in site-specific agricultural management

Non-Peer ReviewedThis poster addresses the potential of a color infrared aerial photograph to provide spatially distributed information for site specific management. In this process digitized color infrared aerial photographs were used to extract vegetation index information. Crop and soil information were obtained through field sampling. Most important factors for affecting crop productivity were determined using principal component analysis. Point information were interpolated using kriging to create grid surface of the study area. Centroid of each grid cell was used to collect crop and soil information, and vegetation index at a regular interval throughout the study area. Fuzzy k-means with extra-grades algorithms were used to delineate potential within-field management units based on soil and crop information and vegetation index separately. Within-zone grain yield variation were calculated and used to evaluate management zones. The methodology is fast, can be easily automated in commercially available GIS software and has considerable advantages when comparing to other methods for delineating within-field management zones

Grain Boundary Sliding Mechanisms in ZrN-Ag, ZrN-Au, and ZrN-Pd Nanocomposite Films

Nanocomposite films of ZrN-Me (Me = Ag, Au, or Pd) were produced by reactive unbalanced magnetron sputtering and were found to form a dense and homogeneous microstructure whereby nanocrystals of Me are distributed evenly throughout the ZrN matrix. Interestingly, the Young’s modulus was found to decrease much more dramatically with the increase in metal content for the ZrN-Ag system. A systematic ab initio study was undertaken to understand the mechanism of grain boundary sliding in these nanostructures. The maximum energy variation during the sliding was found to be the largest and the smallest for ZrN-Pd and ZrN-Ag, respectively

Water use efficiency and precipitation use efficiency of crops in the semiarid prairie

Non-Peer ReviewedThe importance of water use efficiency (WUE) in crop production, in the semiarid prairie, is based on the fact that the available water is the most limiting factor influencing crop production. This poster compares water use efficiency of four crop rotations from the Swift Current, SK, long-term rotation experiment: fallow-wheat-wheat (F-W-W), F-flax-W (F-Flx-W), continuous wheat (Cont W) and wheat-lentil (W-Lent). We found that, the WUE of flax and lentil averaged 50% and 64%, respectively, of wheat following wheat. The precipitation required per unit of produce from the complete cropping system (PUE) increased with cropping intensity on a yield basis (kg ha-1 mm-1): Cont W (4.8) > W-Lent (4.2) > F-W-W (4.1) > F-Flx-W (2.9) (opposite response to WUE) and when PUE was calculated on a dollars produced per rotation basis ($ ha-1 mm-1): W-Lent (1.0) was higher than the other two rotations (0.6 to 0.7)

Effect of fallow frequency, fertilizer, and available water on net N mineralization under wheat grown in the semi-arid Brown Soil Zone

Non-Peer Reviewe

Effect of fallow frequency on soil water conservation in the semi-arid region of Saskatchewan

Non-Peer ReviewedThe effects of fallow frequency on soil water conservation were quantified for a 40 yr (1967-2006) field experiment conducted on a medium textured Orthic Brown Chernozem (Aridic Haploboroll) in semiarid southwestern Saskatchewan, in which soil water contents were measured each year in early spring, shortly after harvest, and again just prior to freeze-up in the fall. The three treatments examined were continuous wheat (Triticum aestivum L.) (Cont W) and fallow-wheat (F-W), each receiving N and P fertilizer and Cont W receiving only P. On average, 36 % of the precipitation received during the fall and winter months for Cont W (N+P) was conserved in the soil. In the summer fallow system (F-W (N+P)) a greater proportion (42 %) of the precipitation was conserved during the first fall and winter. During the second overwinter period, only 6 % of the precipitation received was conserved in the F-W system compared to 44 % in the first overwinter period. Compared to the 36% of fall and wither precipitation conserved in Cont W (N+P), inadequate N fertility (Cont W (+P)) resulted in only 27 % of the precipitation being conserved during this period. We developed equations that will allow estimation of water conserved as a function of precipitation received between harvest and seeding for F-W and Cont W (N+P. Trends in grain yield were fairly closely correlated with growing season precipitation and potential evapotranspiration

Strengthening Altitude Knowledge: A Delphi Study to Define Minimum Knowledge of Altitude Illness for Laypersons Traveling to High Altitude.

Berendsen, Remco R., Peter Bärtsch, Buddha Basnyat, Marc Moritz Berger, Peter Hackett, Andrew M. Luks, Jean-Paul Richalet, Ken Zafren, Bengt Kayser, and the STAK Plenary Group. Strengthening altitude knowledge: a Delphi study to define minimum knowledge of altitude illness for laypersons traveling to high altitude. High Alt Med Biol. 00:000-000, 2022. Introduction: A lack of knowledge among laypersons about the hazards of high-altitude exposure contributes to morbidity and mortality from acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE) among high-altitude travelers. There are guidelines regarding the recognition, prevention, and treatment of acute-altitude illness for experts, but essential knowledge for laypersons traveling to high altitudes has not been defined. We sought expert consensus on the essential knowledge required for people planning to travel to high altitudes. Methods: The Delphi method was used. The panel consisted of two moderators, a core expert group and a plenary expert group. The moderators made a preliminary list of statements defining the desired minimum knowledge for laypersons traveling to high altitudes, based on the relevant literature. These preliminary statements were then reviewed, supplemented, and modified by a core expert group. A list of 33 statements was then presented to a plenary group of experts in successive rounds. Results: It took three rounds to reach a consensus. Of the 10 core experts invited, 7 completed all the rounds. Of the 76 plenary experts, 41 (54%) participated in Round 1, and of these 41 a total of 32 (78%) experts completed all three rounds. The final list contained 28 statements in 5 categories (altitude physiology, sleeping at altitude, AMS, HACE, and HAPE). This list represents an expert consensus on the desired minimum knowledge for laypersons planning high-altitude travel. Conclusion: Using the Delphi method, the STrengthening Altitude Knowledge initiative yielded a set of 28 statements representing essential learning objectives for laypersons who plan to travel to high altitudes. This list could be used to develop educational interventions

Adaptation with the to high altitude in sherpas: Association insertion/deletion polymorphism in the angiotensin-converting enzyme gene

ArticleWILDERNESS & ENVIRONMENTAL MEDICINE. 19(1): 22-29 (2008)journal articl