bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yield Response of Canola to Nitrogen, Phosphorus, Precipitation, and Temperature
Authors: Nuttall W.F. , Moulin A.P. , Townley‐Smith L.J. 
Published: July 2010

AbstractCanola (Brassica nupus L.) is a major crop in western Canada, and been used extensively as an alternative crop to wheat (Triticum aestivum L.). Yet, little information is available on the response of this crop to N and P fertilizers in relation to soil tests for these elements under varying environmental conditions. Accordingly, this study was conducted for a 16‐yr period to determine the yield response of canola to N and P fertilizers in relation to soil tests for these elements in northeastern Saskatchewan on black Melfort silty clay (Typic Cryoboroll) previously cropped to spring wheat. Nitrogen fertilizer was applied at 45 and 134 kg N ha−1 in factorial combination with 0, 10, 20, 30, and 40 kg P ha−1. Extra treatments consisted of 10N–20P kg ha−1 and a control with no fertilizer applied. Canola grain and straw response to N and P fertilizer was significant, but the N by P interaction was not significant. The interaction effects of Year by P and Year by N were significant, indicating a wide range of response to applied elements among years because of temperature, precipitation and soil nutrient effects. Grain yield was positively correlated to total precipitation and negatively correlated to mean maximum daily temperature for the months of July and August (R2 = 0.32). The highest grain yield (2.46 t ha−1) was obtained in 1987 with P fertilizer applied at 40 kg P ha−1 (averaged across N rates), 162 mm of rainfall and an average maximum temperature of 21.2 °C. The lowest yield (0.37 t ha−1) was obtained in 1989 with P fertilizer applied at 20 kg P ha−1, 95 mm of rainfall and an average maximum temperature of 25.1 °C. In conclusion, soil tests for N and P accounted for much of the variation in yield response to these elements (r2 = 0.58 and R2 = 0.46, respectively) despite large yield differences among years because of temperature and precipitation.
Conserving Residual Corn Fertilizer Nitrogen with Winter Cover Crops
Authors: Shipley P. R. , Messinger J. J. , Decker A. M. 
Published: July 2010

AbstractAutumn residual fertilizer nitrogen (FN) can be easily leached into groundwater in humid climates. Winter cover crops were evaluated for their ability to assimilate residual corn FN and thereby reduce N losses. Labelled FN (15N depleted) was applied to corn in Maryland in 1986 and 1987 at rates of 0, 168, and 336 kg FN ha− on a Mattapex silt loam (fine‐loamy, mixed, typic Hapludult). Cover crop treatments following corn harvest were hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), cereal rye (Secale cereale L.), or annual ryegrass (Lolium multiflorum Lam.), and a weed/fallow control of chickweed (Stellaria media L.). The covers were harvested three times the following spring and dry matter yields (DM), %N, and atom % 15N were determined to assess FN uptake. Fall labelled N in the soil (to 80 cm) averaged 17 and 114 kg FN ha−1 over both years for the 168 and 336 kg FN ha−1 rates, respectively. However, the quantity of total residual mineral N (soil N plus FN) after the 168 kg ha−1 rate was 87 kg N ha−1, which was comparable to the quantity of labelled N at the high fertilizer rate. The average cover crop FN uptake (kg FN ha−1) in mid‐April after the 336 kg N ha−1 treatment was 48 for cereal rye, 29 for annual ryegrass, 9 for hairy vetch, 8 for crimson clover, and 6 kg FN ha−1 for the native weed cover (LSD P = 0.05 of 7 kg FN ha−1). Corresponding percent recoveries of the fall N in the aboveground DM were 45% for cereal rye, 27% for annual ryegrass, 9 for hairy vetch, 8% for crimson clover, and 8% for native weed cover. These results show that grass cover crops conserved the most FN. Cereal rye recovered more FN through mid‐April because of its growth in cool weather, although annual ryegrass was equally effective if grown to mid‐May. Renewed efforts should be made to utilize grass cover crops to conserve N in humid climates.
Corn Grain Yield and Nitrogen Utilization in Relation to Subsoiling and Nitrogen Rate on Paleudults
Authors: Wagger M. G. , Vepraskas M. J. , Vepraskas M. J. , Denton H. P. 
Published: July 2010

AbstractSubsoiling is used to loosen root‐restricting layers and increase rooting depth and water availability; however, little information is available regarding how to adjust the recommended fertilizer N rate. This study evaluated corn (Zea mays L.) grain yield response to subsoiling and N rate in 12 Typic and Arenic Paleudults from 1985 through 1987. Corn earleaf and grain N concentrations were also measured. Chisel plowing and subsoiling were factorially combined with either 0, 80, 120, 160, and 200 kg N ha−1 or 80, 120, and 160 kg N ha−1. The relative yield increase (RYI) due to subsoiling ranged from –2 to 145% during the 3‐yr period due to variations in soil physical properties and rainfall distribution during the growing seasons. Regression equations for corn yield response to fertilizer N, based on pooled data sets with a RYI < or > 15% each year, were characterized as having the same slope but only different intercepts for each site and/or tillage system. Earleaf and grain N concentrations tended to be lower with subsoiling while grain N uptake was higher at five sites with relatively high RYIs. Apparent recovery of fertilizer N was similar between tillage systems, averaging 36% for subsoiled and 33% for nonsubsoiled treatments. Results from this study indicated that to obtain optimum corn yields the recommended N rate should be the same for chisel plowed and subsoiled tillage systems for soils with root‐restrictive E horizons.
Annual Phytomass Production of a Rye‐Corn Double‐Cropping System in Ontario
Authors: Tollenaar M. , Mihajlovic M. , Vyn T. J. 
Published: July 2010

AbstractA rye (Secale cereale L.)‐corn (Zea mays L.) double‐cropping system has the potential to maximize annual phytomass production in Ontario. Field experiments were conducted at Elora and Woodstock, ON, from 1981 to 1984 to evaluate the impact of rye harvest and corn planting date combinations during the spring as well as tillage methods on annual above‐ground phytomass production. Winter rye was planted in late September or early October after corn harvest and either chemically killed in early May or harvested as silage before corn planting. The rye/tillage treatments consisted of no‐rye/rototill, rye/rototill, and rye/no‐till. Corn phenology was monitored during the growing season and corn above‐ground dry matter was harvested in late September. Rye phytomass was 2.7 and 4.5 Mg ha−1 at the middle of May in Elora and Woodstock, respectively, and 5.4 Mg ha−1 at the end of May in Elora. Rate of leaf appearance and plant height during early development was reduced, silking date was delayed, and plant moisture at corn harvest was higher for corn following rye in comparison to single‐crop corn. The impact was largest in the no‐till treatments. The combination of rye harvest date/corn planting date and tillage treatment that resulted in the highest phytomass production in the rye‐corn double‐cropping sequence was 6 to 10% higher than that of early planted corn. The reduction in corn dry matter accumulation due to the preceding rye crop and the delay in date of corn planting negated to a large extent the contribution of rye phytomass to the total phytomass production of the rye‐corn double‐cropping sequence.
Growth of Relay Intercropped Soybean
Authors: Wallace S. U. , Whitwell T. , Palmer J. H. , Hood C. E. , Hull S. A. 
Published: July 2010

AbstractRelay intercropping of wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] allows for earlier soybean planting than in conventional doublecropping systems, but shading and other influences of the wheat crop may be detrimental to intercropped soybean development. The purpose of this study was to determine the effect of relay intercropping on soybean growth and yield. Intercropped soybean, planted 19 (1989) or 14 (1990) days before wheat harvest, was compared with a control treatment (same no‐till planting pattern and date, but no wheat) on a Cecil sandy loam (clayey, kaolinic, thermic Typic Hapludults) soil. Intercropping had a greater influence on soybean growth in 1989, when there was more shading by the wheat canopy and also when the period between soybean planting and wheat harvest was longer, than in 1990. In both years, the greatest effects of intercropping on growth occurred early in the season, when intercropped plants were taller but had smaller stem diameters, less leaf area, and less aboveground dry weight, as compared with control plants. Photosynthetic rates of upper canopy leaves were reduced by intercropping for 2 wk after wheat harvest in 1990. This was associated with an increase in specific leaf area in intercropped plants. Lateseason growth, including that of reproductive parts, was similar for intercropped and control treatments, and there were no detectable effects of intercropping on final yield components or yield in either year. In environments where the period of overlap between the wheat and soybean crops is relatively short, negative effects of relay intercropping on early soybean growth may not result in yield reductions.
Prediction of Sweet Corn Phenology in Subtropical Environments
Authors: Olsen J. K. , McMahon C. R. , Hammer G. L. 
Published: July 2010

AbstractLimited information on phenology of sweet corn (Zea mays L.) grown in subtropical regions is available to processors wishing to manage harvest scheduling. This study was conducted to investigate developmental characteristics of both standard sugary (su) and mutant endosperm sugary enhancer (se), and shrunken‐2 (sh2) sweet corn in subtropical Australia. Field experiments were conducted at three locations with numerous times of planting so that a broad range of environments were encountered. Models of daily rate of development for the period sowing to kernel maturity (720 g kg−1 moisture) were derived by an iterative optimization procedure. Development rate was related to mean daily temperature and photoperoid. Temperature was the most important factor affecting rate of development. The temperature response was best described by a broken linear function. Various photoperiod functions fitted as multipliers to the temperature response did not improve goodness‐of‐fit. Cultivars were classified into three maturity groups based on analysis of covariance. Developmental characteristics appeared independent of genetic background as the response of the three sh2 cultivars was not significantly different from a tropical su type, and the se cultivar ‘Sweet Champion’ did not differ significantly from the majority of su types. Only su cultivar ‘Terrific’ differed significantly from both of these groups. Base temperatures (range from 5.4–6.4°C) were lower than the value traditionally quoted for sweet corn (10°C). Optimum rates of development occurred at temperatures ranging from 30.8 to 33.8° C. The models accurately predict the duration of sowing to maturity and were shown to be a practical tool for harvest date prediction of both standard and mutant endosperm sweet corn in subtropical environments.
Subsurface Compaction Effects on Tillering and Nitrogen Accumulation in Wheat
Authors: Oussible M. , Allmaras R. R. , Wynch R. D. , Crookston R. K. 
Published: July 2010

AbstractCompaction in the 0.05‐ to 0.30‐m depth may limit tillering and N accumulation in wheat (Triticum aestivum L.); these effects may be yield reducing. Before imposing compaction treatments in a field study in Minnesota, perforated small‐diameter tubing was buried in a Waukegan silt loam (sandy skeletal, mixed, mesic Typic Hapludoll) at a depth of 0.2 m in all plots. Compacted plots each received four passes with a heavy vibrating roller, while control plots were disk plowed and then disk harrowed. All plots were then surface roto‐tilled and seeded to wheat. At early tillering a K15NO3 solution was applied to the subsurface via the tubing. Plants sampled for 15N/N recovery 24 h after 15N application, at anthesis, and at maturity showed no significantly different 15N or N concentration or accumulation per culm/ individual organ in response to compaction. Because subsurface compaction reduced tillering, N uptake in the grain and straw was reduced by 21 and 30%, respectively. After the 0.10‐m surface layer was removed from all plots in a field study on a clay loam soil (Typic Calcixerolls) in Morocco, the subsurface was compacted by four passes with a 7.5‐ton tractor. Soil was then replaced, leveled, and only the control plots were disk plowed and disk harrowed twice. Both compacted and control plots were roto‐tilled and seeded. Nitrogen concentration and accumulation per culm/individual organ immediately after tillering was reduced less than 5% by the compacted treatment in both 1982 and 1983. Reduced tillering in the compacted treatment reduced average N uptake 11 and 28% in the grain and straw, respectively. In all three tests N concentration in the shoot at the end of tillering was high; yet it was higher in the compacted treatment. Then N concentration and uptake was reduced by compaction on a per culm basis at maturity, and earlier in one of the field studies. Root length density was reduced in the compacted zone in response to greater penetrometer load and higher bulk density. Tiller bud development was suppressed by the compaction treatment as much as 20% even though concentrations of N were high in the shoot. Tiller losses and declines of N concentration in the shoot in the post tillering stages were nearly the same in both treatments. Additional N before tillering therefore cannot overcome the adverse influence of subsoil compaction.
Pearl Millet‐Soybean Rotation and Nitrogen Fertilizer Effects on Millet Productivity
Authors: Mohammed M. S. , Clegg M. D. 
Published: July 2010

AbstractPearl Millet [Pennisetum glaucum (L.) R. Br.] plays an important role as a staple food grain in many developing countries, but is relatively new to the Great Plains of the USA. This study was conducted for 2 yr to evaluate the effects of a preceding soybean [Glycine max(L.) Merr.] crop and/or applied N fertilizer on pearl millet yield and N uptake, and to quantify the amount of residual soil NO3‐N resulting from the cropping system. The experiment was conducted on a fine montmorillonitic, mesic, Typic Argiudoll soil at the University of Nebraska Research Center near Mead, NE. The experiment included three treatments consisting of 0, 45, and 90 kg N ha−1 applied to continuous pearl millet, and two treatments consisting of 0 and 45 kg N h−1 applied to pearl millet following soybean. Pearl millet grain yield was 5.69 (1986) and 4.22 (1987) Mg−1 with no applied N, 6.42 (1986) and 5.82 (1987) Mg−1 with 45 kg ha−1 applied N, and 7.13 (1986) and 6.85 (1987) Mg−1 with 90 kg ha−1 applied N. Grain yields increased 0.73 (1986) and 1.48 (1987) Mg −1 when grown after soybean, increase equivalent to that with 45 kg ha−1 of applied N. Percent N in various plant parts and N uptake increased with applied N or when pearl millet followed soybean. Differences in pearl millet plant weight, leaf weight, and LAI did not occur until 62 d after sowing in plots with applied N, but an increase in these parameters due to rotation occurred at 37 d. Residual NO3 in the soil profile was higher in the rotation treatment, than the applied N treatments, but there was a tendency for more residual NO3‐N to occur with increased applied N in the continuous pearl millet. Pearl millet can be successfully used in cropping systems with soybean with no additional N, but addition of N may be necessary with continuous cropping.
Cultivar and Climatic Effects on the Protein Content of Soft White Winter Wheat
Authors: Rao A. C. S. , Smith J. L. , Jandhyala V. K. , Papendick R. I. , Parr J. F. 
Published: July 2010

AbstractHigh‐protein wheats (Triticum aestivum L.) are not preferred for Oriental diets. Because the protein content of soft white winter wheat grown extensively in the U.S. Pacific Northwest is often higher than the optimum (100 g kg−1) for export, there has been a decline of wheat exports to Japan and other Pacific Rim countries. The present study was undertaken to examine the trends in protein levels during 1979 to 1988 and to evaluate the influence of wheat cultivars and climatic parameters on protein content of SWW wheat in the Pacific Northwest. The maximum and minimum temperatures, precipitation, and evaporation during each of 9 wk prior to crop harvest were tested for their effect on protein content. Data on protein content used in the analysis were obtained from the annual reports of USDA Western Wheat Quality Laboratory for wheat grown at 10 different locations in Washington, Idaho, and Oregon. Five‐year moving averages indicated a rising trend in the protein content at Lind, WA, and Moro, OR, the two driest locations. Commercially grown cultivars had no significant influence on protein content in the presence of climatic parameters. Climatic parameters were found to have a significant influence on wheat protein content with coefficients of multiple determination ranging from 0.36 to 0.82 for the 10 locations. Maximum temperature during the grain‐filling stage influenced the protein content at 9 out of 10 locations, and, generally, a rise in temperature resulted in higher protein contents. With climatic factors significantly influencing protein levels in SWW wheat, suitable agronomic and fertility management practices are needed to ameliorate the climatic effects.
Leaf and Stem Traits and Herbage Quality of Multifoliolate Alfalfa
Authors: Juan Nestor A. , Sheaffer Craig C. , Barnes Donald K. , Swanson Douglas R. , Halgerson James H. 
Published: July 2010

AbstractMultifoliolate (MF) alfalfa (Medicago sativa L.) cultivars, with four or more leaflets per leaf instead of three, have been marketed for greater nutritive value and intake potential than standard trifoliolate (TF) alfalfa cultivars. A field study to determine the effect of harvest regimes on MF expression of alfalfa cultivars and germplasm, and to determine the association of MF expression with herbage yield, herbage quality, and leaf and stem traits, was conducted on a Tallula silt loam (coarse‐silty, mixed, mesic Typic Hapludoll). Four MF and two TF alfalfa genotypes were subjected to bud and first‐flower cutting regimes. Multifoliate expression on a leaf number basis (MF leaf number/total leaf number) ranged from 5 to 70%. Relative MF entry ranking was consistent across years and harvest regimes. Expression of the MF trait was not correlated with herbage yield. For all seasonal harvests and harvest regimes, MF expression was correlated with leaf concentration (r = 0.48) and number of leaflets per leaf (r = 0.84), but was not consistently associated with node number or plant height. Expression was not correlated with total herbage crude protein concentration, and at best explained 25% of the variation in acid detergent and neutral detergent fiber concentration. A TF genotype developed for superior herbage quality had leaf concentration, forage quality, and intake potential similar to MF genotypes with high MF expression levels. Multifoliolate alfalfa genotypes have the potential to produce higher quality herbage than some TF types; however, this can be achieved only with high MF expression levels.
Calibration of Granular Matrix Sensors for Irrigation Management
Authors: Eldredge Eric P. , Shock Clinton C. , Stieber Timothy D. 
Published: July 2010

AbstractGranular matrix sensors (GMS) represent an alternative technology for measuring soil water to schedule irrigation. When GMS were tested by drying them to measure changes in electrical resistance with decreasing water content, their resistance response to drying in air in an oven was similar (t = −0.87, 134 df) to that for drying in a field soil, with a response curve that suggested GMS could be used to measure soil water potential (Ψ). Granular matrix sensor meter readings were compared with tensiometer, neutron probe, and gravimetric measurements of soil water in the root zone of potato (Solanum tuberosum L. cv. Russet Burbank) grown in silt loam. Measurements with GMS were closely related to soil water potential measurements and to soil water measured gravimetrically or by neutron probe. Meter model 30KTC, as supplied by the manufacturer, when calibrated against tensiometers, had a linear response represented by the equation y = −6.44 − 0.738 x, where y = Ψ J kg−1), and x = 30KTC meter reading (dimensionless units) of GMS, with r2 = 0.89. Granular matrix sensors were used to monitor transitory soil water stress treatments in an experiment to determine potato response to water stress.
Legume Cover Crop Contributions to No‐Tillage Corn Production
Authors: Decker A. Morris , Clark Andrew J. , Meisinger John J. , Mulford F. Ronald , McIntosh Marla S. 
Published: July 2010

AbstractWinter cover crops can supply N to the next crop, reduce erosion and N leaching, and conserve or deplete soil moisture. To identify optimum corn fertilizer nitrogen (FN) rates following cover crops, we evaluated hairy vetch (VT: Vicia villosa Roth), Austrian winter pea [PE: Pisum sativum L. subsp. sativum var. arvense (L.) Poir.], crimson clover (CR: Trifolium incarnatum L.), and wheat (WH: Triticum aestivum L.) winter cover crops in the U.S. Coastal Plain and Piedmont for no‐tillage corn (Zea mays L.) at four FN rates (topdressed NH4NO3) over 4 yr. Parameters evaluated included cover crop yield and N content, corn N uptake, and corn grain yield. On the Coastal Plain, VT, PE, CR, and WH topgrowth averaged 205, 180, 170, and 40 kg N ha−1, respectively, and ≈40% less for the Piedmont. With no FN, grain yields were generally greater after legumes than after no cover crop, and lowest after WH, with the best yields after legumes with 90 to 135 kg FN ha−1. Synergistic responses occurred when FN was applied after legumes. Non‐N‐limited grain yield increases averaged 2 Mg ha−1 (Coastal Plain) and 0.5 Mg ha−1 (Piedmont), and were not directly related to cover crop N. With no cover crop, FN needed for maximum yield averaged 80 kg ha−1 (Piedmont) and 135 kg ha−1 (Coastal Plain). After WH, FN needs increased 15 to 30 kg ha−1, but decreased 10 to 75 kg ha−1 after legumes. Hairy vetch provided the most consistent increases, with average grain yield of 10.6 Mg ha−1 (Coastal Plain) and 8.2 Mg ha−1 (Piedmont), and an economic optimum FN rate of 127 (Coastal Plain) and 66 kg ha−1 (Piedmont).
Radiation Balance of a Soil‐Straw Surface Modified by Straw Color
Authors: Sharratt Brenton S. , Campbell Gaylon S. 
Published: July 2010

AbstractStraw color may alter the net radiative flux at the soil‐straw surface and, consequently, the availability of energy for soil, biological, and atmospheric processes. This study ascertained the radiation balance of a soil‐straw surface as modified by the color of the straw on the surface. Barley (Hordeum vulgare L.) stubble and loose straw on 36‐m2 plots near Fairbanks, AK, was painted black, white, or remained unpainted (natural) in a randomized block experimental design. Reflected global radiation was measured in the spring of 1988–1990 and net radiation was monitored in the spring of 1990. Midday reflected global radiation and soil‐straw surface temperatures were measured on clear days in 1989. The albedo of the black straw treatment was 0.05, of the natural straw treatment was 0.2, and of the white straw treatment was 0.3. The black straw treatment resulted in higher midday surface temperatures and consequently higher emission of longwave radiation compared with other straw color treatments. A soilstraw‐atmosphere system model provided good estimates of the measured net radiative flux in 1990 (R2 = 0.91). The model predicted that a soil‐black straw surface would absorb 10% more radiation than a soil‐natural straw surface and 15% more radiation than a soil‐white straw surface averaged over the three years. The results suggest that straw color management can be an option for altering the surface radiation balance in regions with extreme climates.