Browsing by Author "van Kessel, C."
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Item Availability of N to plants from legume and fertilizer sources: which is greater?(1990-02-22) Bremer, E.; van Kessel, C.One benefit often cited for legumes crops is that they contribute N to subsequent crops, but the magnitude of this effect has been difficult to quantify. A study was conducted to compare how much and when N from fertilizer and residue sources was taken up by wheat Wheat straw (W), lentil straw (L), and lentil green manure (G), unenriched or enriched in 15N, were both surface placed and incorporated into microplots (10 x 40 cm) in the field in the fall of 1988. In the spring of 1989 wheat was planted in all microplots, and unenriched and enriched fertilizer N was added to microplots containing enriched and unenriched plant residues, respectively. Microplots were destructively sampled at planting and at 6, 10 and 13 weeks after planting. Approximately 29 % of added fertilizer was recovered in wheat tops by 6 weeks after planting in all treatments except incorporated W, where immobilization reduced this value to 19 %. Maximum recoveries of fertilizer 15N were 34 % by the final sampling date. The proportion of residue 15N recovered in wheat tops at the final sampling dates was 19 and 11 % from incorporated and surface-placed G, respectively, and 5.4 and 5.3 % from L and W, respectively. Surface placement of residues reduced immobilization of fertilizer N but increased losses of residue N. Comparisons of N availability based on recovery of 15N may be misleading because 15N recovery does not account for changes in mineralization of native N, which is likely to be affected unequally by the addition of different N sources.Item Bi-directional nitrogen transfer between legume and non-legume plants(1992-02-20) Tomm, G.O.; van Kessel, C.; Slinkard, A.E.; Embrapa, P.F.Non-N2-fixing crops inter-cropped with legumes may benefit through transfer of symbiotically fixed N from the legume crop. The pattern of N transfer by mechanisms non dependent on decomposition of plant tissues was studied in a greenhouse. In addition, a study accessed the effect of inter-cropped alfalfa (Medicago sativa L.) on meadow bromegrass (Bromus riparius Rhem.) forage and N yield by a combination of N transfer mechanisms occurring under field . conditions. In the first study, shoot portions of one alfalfa or one bromegrass plant (donor) were foliarly fed with N labelled ammonium sulphate. No 15N from bromegrass was transferred to alfalfa, whereas 15N from alfalfa plants was transferred mainly to bromegrass plants. Transfer of 15N between plants of the same species was not significant in alfalfa and only detected in the nearest plant of bromegrass. The 15N content of the receptor plants showed that underground movement of N between plants occurred within 3 days. In the field study, swards of single bromegrass and alfalfa inter-cropped with bromegrass were seeded in rows 17. 8 cm apart. In the fell owing year individual rows of plants, adjacent to each other, on both sides of the edge between the different swards were harvested separately for dry matter (DM) and N yield. Results of bromegrass were related to distance from the nearest row of alfalfa. Forage yield gradually increased from 427 to 1230 kg ha-1 and N yield increased from 53 to 184 kg ha-1 as the distance between the bromegrass row and the alfalfa row decreased from 71.1 to 17. 8 cm. Yield of bromegrass located up to 35.6 cm from alfalfa was significantly increased, indicating transfer of N from alfalfa to bromegrass in agronomically relevant amounts.Item Calibration of bicarbonate-extractable phosphorus on wheat(1991-02-21) Liang, J.; Karamanos, R.E.; van Kessel, C.Nine locations were selected throughout Saskatchewan so that a summerfallow an oilseed stubble and a wheat stubble experimental site were adjacent to each other. Each site was characterized by analyses carried out on a composite soil sample obtained from the whole site. A randomized complete block (RCB) design with three treatments (control, 10 lb P2O5/ac , and 20 lb P2O5/ac) and four replicates was established at all sites. Subsequently, composite soil samples from each plot were taken. Comparison between the two sampling schemes suggested that characterizing a site on the basis of one composite sample may not result in a true representation of the P fertility status of individual plots within the site. Analysis of variance for a RCB design resulted in non-significant response of spring wheat to P fertilizer application independent of previous crop history. However, examination of soil P levels in each plot of every experiment revealed that sites were extremely variable. Hence, comparison of mean grain yields in many cases was based on averaging "non-responsive" parts of the field with "responsive" ones. When the probability of grain yield response was plotted on a per plot basis, a 65, 72 and 78% probability of positive response to P fertilization was obtained on the fallow, wheat stubble and canola stubble, respectively. Boundary-line analysis indicated that spring wheat had very small possibility of positive yield response to P fertilization when soil bicarbonate-P was over 25 lb/ac. Spatial variability of a site must be determined prior to carrying out an experiment and number of replications must reflect the differences sought.Item Comparison of available soil moisture and nitrogen following wheat and lentil(1989-02-16) Bremer, E.; van Kessel, C.Lentil is generally grown in rotation with cereals, and may benefit the succeeding crop by using less moisture or by increasing the amount of available N. Soil moisture and N depletion was measured for lentil and wheat at five sites in 1985, three sites in 1987 and one in 1988. Lentil depleted soil moisture and mineral N to a similar extent as wheat at most sites. Exceptions occurred due to differences between lentil and wheat in their response to rainfall distribution or in their effectiveness at exploiting moisture and nitrate at deeper soil layers. Lentil residues contained more N than wheat residues, but this did not represent a net gain in N because as much N was removed with the seed as was fixed. Lentil residues had a higher and more variable N concentration than wheat Thus, net N mineralization will on average be higher following lentil than following wheat, but the magnitude of these differences will be variable.Item Contribution of hay harvest losses and "leaf fall" to N cycling and the N nutrition of intercropped alfalfa and bromegrass(1993-02-25) Tomm, G.O.; van Kessel, C.; Slinkard, A.E.; Embrapa, P.F.A significant amount of forage plant biomass is deposited on the ground as senescent leaves, petioles and flowers (leaf fall). In addition, a varying amount of plant biomass is lost during harvest of hay crops (hay loss). These two sources of plant biomass and nitrogen (N) were quantified over a 3-year period in replicated plots of single or inter-cropped alfalfa (Medicago sativa cv. Beaver) and meadow bromegrass (Bromus riparius Rhem. cv. Fleet) swards grown under irrigation near Outlook. Another experiment in the same field provided an estimate of the quantity of N in the hay losses or leaf fall that was recycled between or within the two species. Alfalfa plants grown on 15N-enriched soil supplied 15N-labelled leaf fall and hay loss biomass which was applied to inter-cropped swards. The proportion15of N taken up by bromegrass or alfalfa was estimated. Similarly, N labelled bromegrass biomass was applied to inter-cropped swards and the uptake by each of the species was estimated. Leaf fall from alfalfa, bromegrass or alfafa+bromegrass swards contained an average of 22, 6, and 16 kg N ha-1 yea-1, respectively, whereas hay losses returned an average of 26, 9, and 22 kg N ha-1 year-1, respectively. The accumulation of 15N from those two N sources was detected in neighbouring plants as early as 13 days following application of the simulated leaf fall or hay losses.Item The development of management units for site-specific farming(1996-02-22) McCann, B.L.; Pennock, D.J.; van Kessel, C.Image analysis is a valuable tool that can be used to delineate management units for Site-Specific farming applications. Soil landscapes are often highly variable in terms of their productive potential. Because of the complex nature of these landscapes, only large-scale maps can provide the level of detail necessary for Site-Specific farming. Image analysis of black and white aerial photographs can be used as a cost effective method to delineate soil management units. In this study, extensive field sampling and laboratory analysis were used to characterize a soil landscape belonging to the Oxbow Association. The site was stratified into four management units by grouping the digital numbers on the scanned black and white aerial photograph into categories that reflect the changes in different soil properties across the landscape. The close relationship between the management units and the soil properties suggests that this technique is an effective method for stratifying landscapes into management units.Item Do different tillage systems and crop rotations affect nitrogen fixation in lentil and pea?(1996-02-22) Matus, A.; Derksen, D.A.; van Kessel, C.Item Does crop residue N influence soil N availability?(1998-02-19) Fu, G.; Walley, F.L.; van Kessel, C.A landscape study was conducted near Biggar, Saskatchewan, to study the influence of crop residues on the availability of soil N in the second phase of crop rotations. In order to compare leguminous and cereal residues, chickpea (Cicer arierinum) and wheat (Triricum aestivm) residue were used. The results showed that plant N derived from soil (Ndfs), added nitrogen interaction (ANI) and N recovery from chickpea residue were higher than from wheat residue in footslopes, but not in the shoulders. Chickpea residue increased soil N availability and crop production, whereas wheat residue decreased crop production in the footslopes, but there was no difference between these two residues in the shoulders, indicating that the impact of crop residues was variable and dependent on landscape position.Item Dual inoculation of Pisum sativum with Rhizobium leguminosarum and Penicillium bilaji(1990-02-22) Downey, J.; van Kessel, C.To investigate the effect of single versus dual inoculation of Trapper-pea with Rhizobium leguminosarum and Penicillium bilaji, a P-solubilizing fungi, an experiment under controlled conditions was carried out using a sandy soil containing low levels of available N and P. The following treatments were installed: control, P application at a rate of 100 kg P/ha, pea inoculated with P. bilaji (PB50) applied at recommended rate as PB50™ supplied by Philom Bios, pea inoculated with R. leguminosarum (R) and all possible combinations of the four treatments. To determine N2 fixation by 15N-natural abundance, flax was included as the reference crop. Treatments were replicated four times and placed in a randomized complete block design. Throughout the experiment, soil was kept at 75 % of field capacity and additional light was provided. After 8 weeks of growth, two plants/pot were harvested and total shoot weight, total N, total P, percent N derived from N2 and the amount of N2 fixed was determined. P fertilization increased yield significantly from 3.0 to 4.2 g/pot. PB50 alone increased shoot yield to 3.6 g/pot. Whereas pea inoculated with R showed only a small yield increase, the additional application of P increased yield to 4.1 g/pot. Application of P and both the inoculants reduced yield to 3.7 g/pot. Total N accumulation was highly dependent on the presence of R. Whereas the control, which was sparsely nodulated, showed a total N yield of 62.3 mg N/pot, inoculation with R and P fertilization increased total N to 100 mg N/pot. Double inoculation with Rand PB50 along with P fertilization reduced the total N yield to 95 mg N/pot. Pea inoculated with PB50 and R showed a total N yield of 78.5 mg N/pot. The highest N2-fixing activity (39 % Ndfa or 39.6 mg of N) was observed in pea inoculated with R and which had received inorganic P. Total P uptake was solely dependent on P fertilization. Results indicate that PB50 had no beneficial influence on P uptake and N2-fixing activity.Item Effects of different nitrogen fertilizer sources, placements, and rates on agronomic traits of barley grown at the landscape-scale(1996-02-22) Matus, A.; Hnatowich, G.L.; van Kessel, C.Item Evaluation of carbon isotope discrimination as selection criteria for yield and water use efficiency in lentil(1993-02-25) Matus, A.; van Kessel, C.; Slinkard, A.E.Item Evaluation of Penicillium bilaji inoculation and copper and zinc fertilization in relation to crop yield and nutrient uptake(1991-02-21) Doyle, P.J.; van Kessel, C.; McKercher, R.B.; Karamanos, R.E.Growth chamber and field experiments were conducted on three low micronutrient alkaline soils from Northeastern Saskatchewan to test the efficacy of PB-50 inoculation and phosphorus (P), copper (Cu) and zinc (Zn) fertilization in relation to plant yield and nutrient uptake responses. Field experiments involving wheat (Triticum aestivum; 'Katepwa') and peas (Pisum sativum; 'Titan') showed no yield or P uptake as a result of PB-50 seed inoculation or P2O5 fertilization for three locations. Fertilization of wheat with CuSO4 and peas with ZnSO4 produced increases in seed and total plant uptake of Cu and Zn. A yield increase from 2722 kg/ha to 3682 kg/ha (40 to 54 bu/ac) as a result of Cu fertilization was observed for Katepwa wheat on Nipawin Soil (DTPA Cu = 0.1 ug/g). No other yield increases were observed for Cu or Zn fertilization on the other soils. Growth chamber experiments involving wheat (Triticum aestivum; 'Park') and navy beans (Phaselous vulgaris L.) produced results similar to field experimentation. Increased Cu uptake in wheat for CuSO4 fertilized treatments was observed for all three soils. Copper fertilization in the Nipawin soil showed a yield increase in wheat relative to control. Wheat seed inoculation with PB-50 produced no yield increases and minor nutrient uptake differences. Increased yields and Zn uptake in beans for ZnSO4 fertilized treatments was observed in all three soils. Seed inoculation of navy bean with PB-50 produced variable yield increases and nutrient uptake differences in two of three soils.Item Evaluation of the effectiveness of Rhizobium leguminosarum strains for pea under field conditions(1989-02-16) Nelson, L.; van Kessel, C.One hundred and eight isolates of Rhizobium leguminosarum were screened for effectiveness for pea under controlled environments. Eight superior strains plus the commercially available pea inoculants, Nitragin 'C', Grip-Inotec, and Rhizogen were tested at Waldheim and Brooksby for effectiveness with Tipu and Trapper pea as host plants. The experiment was a RCBD, laid out as a split plot with the two pea varieties as main plot treatments and rhizobia! strain as the subplot treatments, replicated four times. At Waldheim total dry matter ranged from 2429 kg/ha for uninoculated Trapper to 4024 kg/ha for Tipu inoculated with strain 128C79. Grain yield ranged from 1046 kg/ha for Trapper inoculated with strain 175G3 to 1665 kg/ha for Tipu inoculated with strain 175G3. Total grain-N ranged from 33.7 kg/ha for uninoculated Tipu to 55.5 kg/ha for. Trapper inoculated with strain 128C56G. At this site, strain 175G3 appears to be a superior strain for Tipu but is the least effective strain tested for Trapper. At Brooks by, no significant differences due to strain or cultivar were observed. Values for total dry matter, grain yield, and total N were around 75 % of those values found at Waldheim. A survey to assess nodulation was carried out and all uninoculated pea were nodulated. This would indicate the presence of indigenous R. leguminosarum nodulating pea or possible cross contamination from adjacent plots. The below average yield and the absence of a yield response due to inoculation can largely be attributed to the extreme dry weather occurring at both sites. Nodulation of the uninoculated control has also reduced the effect of inoculation on yield.Item Factors affecting spatial variation in two crop rotations(1999-02-25) Stevenson, F.C.; Knight, J.D.; van Kessel, C.An experiment was initiated at two 4-ha sites with hummocky to undulating terrain, to examine the spatial variation rotation benefits of wheat grown after pea compared to wheat grown after wheat. In the second year of the rotations, N and non-N effects related to rotational differences - soil water content, root and leaf disease, weed density, growing season N availability - were used to assess spatial variation of wheat seed yield in the two crop rotations. ANOVA and state-space modeling and landform complex approaches were used to quantify spatial variation. Yield was 10% greater in the footslopes of both rotations at St. Louis, and 10% lower in the footslopes of only the wheat-wheat rotation at Birch Hills, when compared with yield in the shoulders. The lower yield in the footslopes of the wheatwheat rotation at Birch Hills partly was associated with higher weed density. The landform effect at St. Louis could not be explained with ANOVA. State-space analysis showed that the factors responsible for the spatial variation of seed yield differed between sites. Furthermore, local variation for soil water and N availability in the pea-wheat rotation, and lower leaf disease severity, mainly explained wheat yield at given locations in space at St. Louis. At Birch Hills, local variation for common root rot incidence in both rotations explained wheat yield at given locations in space. Preliminary results from this study reflect the spatial variation can be rotation specific, depending on the site.Item The feasibility of inter-cropping pea with canola, mustard, and barley(1989-02-16) Cowell, L.E.; van Kessel, C.; Livingston, N.J.An inter-cropping trial was conducted in the summer of 1988 to compare pea inter-crops with Tobin and Westar canola, yellow mustard, and barley. At two sites, a number of different pea varieties were inter-cropped with canola, mustard, and barley, and compared to mono-crops of each. At four sites, a seeding rate trial was conducted with Westar canola and barley inter-crops with Trapper pea. Measurements to assess the success of the inter-crop included grain yield, land equivalent ratio (LER), grain nitrogen yield, and economic return. In the variety trial, inter-cropping reduced the yields of both component crops, and the LER was not significantly higher than 1 in any case. There were significant differences in economic return for the crop. Inter-cropping did not increase the $/ha return, while pea mono-crops provided the greatest income. Significant differences in grain N yield were also observed, with pea varieties being highest. Little or no increase occurred in grain N yield when pea was inter-cropped with barley. In the seeding rate trial, inter-cropping again did not benefit yield nor economic return. Some benefit resulted from inter-cropping barley with pea, as this increased the grain N yield as compared to mono-cropped barley. Although neither yield nor economic return was consistently increased by inter-cropping, other benefits to the pea were noted. Lodging of pea was reduced, especially when inter-cropped with mustard or Westar canola. This could facilitate harvest, and reduce associated grain loss. In addition, the pea crop would be less subject to pre-harvest weather damage, thus producing a higher quality crop.Item A field-scale assessment of the rotation benefits of pea and canola(1998-02-19) Stevenson, F.C.; van Kessel, C.Producers and researchers have observed that higher cereal yields occur when oilseed and pulse crops are included in a cereal-intensive cropping system. A study was established in the spring of 1996 to compare the rotation benefit of a pulse crop (pea) with a second nonlegume broadleaf crop (canola) to succeeding cereal crops. It is anticipated that the benefit of pea in a crop rotation is due largely to non-N related factors, and that other broadleaf crops could provide the same benefits. Pea-wheat-barley, canola-wheat-barley, and wheat-wheat-barley rotations, were established in two field-scale (10 acre; each plot 30-m by 80-m) sites. The expression of rotation benefits from pea and canola to wheat were compared in different management units (shoulder, footslope, and level landform complexes). The seed yield of wheat sown after pea or canola was 14% higher than wheat sown after wheat at the St. Louis and Birch Hills sites. Furthermore, the N content of wheat seed was improved in the peawheat and canola-wheat rotations compared with the wheat-wheat rotation. Wheat leaf disease severity in the pea-wheat and canola-wheat rotations compared with the wheat-wheat rotation was reduced by 17% at St. Louis and 30% at Birch Hills, whereas, common root rot incidence did not differ among rotations. The reduction in leaf disease severity accounted for a portion of the yield advantage associated with wheat grown in the pea and canola rotations compared with the wheat-wheat rotation. The relationship between leaf disease severity and the yield advantage associated with crop rotation was strongest at Birch Hills. The unexplained portion of the rotation benefit at St. Louis was not associated with differences in weed infestations among the different crop rotations. Common root rot and weed infestations were similar among rotations, and there was no evidence to suggest that there were significant differences in soil N availability among rotations. It appears that pea and canola provide similar benefits to a succeeding wheat crop. Unaccountable reasons for the rotation effect on the seed yield of wheat among rotation and the spatial variation affecting growing conditions in the different rotations the complexity of field-scale processes associated with rotation benefit of broadleaf crops to succeeding cereal crops.Item Growth and water use of irrigated and dryland lentils and wheat(1988-02-19) Livingston, N.J.; van Kessel, C.; de Jong, E.Lentils are becoming an increasingly more important crop in Saskatchewan with over 230,000 ha planted in 1987. A large part of this acreage was in the Brown Soil Zone. To date lentil water relations and adaptation to water deficits are largely undescribed. This study was initiated to determine the drought tolerance characteristics of lentils and to compare them to those of wheat growing under the same weather conditions. Dryland lentils exhibited considerable drought tolerance with large changes in osmotic potential in response to increasing soil water deficits. Despite maintaining high levels of turgor, values of stomatal conductance were very low. This behaviour enabled leaves to maintain high relative water contents and survive an extensive dry period. In contrast wheat displayed little drought tolerance. Consequently throughout the growing season the rates of dry land to irrigated above-ground dry matter was consistently higher for lentils than for wheat and at final harvest was 0. 71 and 0.41 for the two crops, respectively. Wheat and lentils had similar water use efficiencies, but lentils used more water because of their greater dry matter production. Very high dry matter production in irrigated lentils did not translocate into high grain yields.Item Herbage and protein productivity of single or inter-cropped alfalfa and bromegrass under zero nitrogen fertilization(1993-02-25) Tomm, G.O.; van Kessel, C.; Slinkard, A.E.; Embrapa, P.F.Nitrogen (N) fertilizer enhances the growth of grass in grass-legume associations and frequently inhibits N2 fixation by the legume-Rhizobium symbiosis. The cost of N fertilizer and environmental concerns related to contamination of groundwater make the use of N fertilizers a less attractive alternative. The herbage and crude protein production of single or inter-cropped alfalfa (Medicago sativa cv. Beaver) and meadow bromegrass (Bromus riparius Rhem. cv. Fleet) grown under irrigation, without N fertilization, were evaluated near Outlook, Saskatchewan, from 1990 to 1992. Hay yield alfalfa increased from 4.5 t ha-1 in the first year to 10.6 t ha-1 in the third year following seeding. The hay yield of bromegrass decreased from 5.3 t ha- in the second year to 1.2 t ha-1 in the following year due to limited availability of N for plant growth. Alfalfa+bromegrass hay yield increased from 4.1 t ha-1 in the first year to 10.5 t ha-1 in the third year. Crude protein yields of single alfalfa or alfalfa+bromegrass were above 750 kg ha-1 year-1 in the first year and increased to 1700 kg ha-1 year-1 in the third year whereas the crude protein yield of bromegrass declined from 300 kg ha-1 in the first year to 80 kg ha-1 in the third year. Crude protein yield bromegrass seeded in alternate rows with alfalfa was up to 25 % higher than that of single bromegrass (not sharing resources). The amount of nitrogen fixation (kg ha-1) on inter-cropped alfalfa in the third year was as high as that of alfalfa not sharing space with bromegrass.Item Impact of agriculture and forestry on landscapescale soil organic carbon storage in Saskatchewan(1995-02-23) Pennock, D.J.; van Kessel, C.; Corre, M.D.The development of sound management approaches to reduce soil organic carbon (SOC) losses from soils presuppose that we thoroughly understand the sources of these losses. We use a landscape-scale research design to estimate the magnitude of carbon losses due to human activity by comparing SOC storage in undisturbed landscapes with comparable landscapes disturbed by clear-cutting of forests in the Mixedwood/Gray Luvisolic zone of central Saskatchewan and by agricultural activity in the Black soil zone. A slight drop in median levels of soil organic carbon storage in the upper 45 cm of the soil (from 56.8 Mg ha-1 in mature mixedwood sites to 52.7 Mg ha-1 in clear-cut landscapes) occurs due to clear-cutting of the Mixedwood forest. The dominant soil type in these landscapes, Gray Luvisolic soils, experience no significant change in SOC storage; however significant losses occur from Brunisolic (29% loss) and Gleysolic (32% loss) inclusions in these landscapes. Changes in SOC from Black soil zone landscapes are strongly related to texture: sandy glacio-fluvial landscapes experience slight gains of SOC (from 54.1 to 60.1 Mg ha-l); silt and clay glacio-lacustrine landscapes experience a 15.3% decrease in SOC (from 145.2 to 122.9 Mg ha-l); and loamy glacial till landscapes undergo a major decrease in SOC storage (from 119.6 to 75.2 Mg ha-l). Our results indicate that attempts to mitigate SOC losses from soils in Saskatchewan should concentrate on agricultural activities, especially in glacial till landscapes.Item Impact of nitrogen source, anhydrous ammonia rate, opener type, and landscape position on grain yield and grain protein of spring wheat(1998-02-19) Matus, A.; Hnatowich, G.; Walley, F.L.; Farrell, R.E.; van Kessel, C.; Knight, J.D.
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