scholarly journals 1029 PREDICTING IN-SEASON NITROGEN REQUIREMENTS FOR IRRIGATED POTATOES USING NITRATE SAPTESTS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 575g-576
Author(s):  
Carl J. Rosen ◽  
Mohamed Errebhi
Keyword(s):  
Nitrogen Fertilizer ◽  
Management Practice ◽  
Rapid Test ◽  
Sandy Soils ◽  
Growing Season ◽  
Growth Stages ◽  
Nitrate Losses ◽  
Important Concern ◽  
Final Yield ◽  
Nitrogen Rates

Applying appropriate rates of nitrogen fertilizer during the growing season for potatoes on irrigated sandy soils is an important concern from both a production and environmental standpoint. Although potatoes on sandy soils are responsive to nitrogen fertilizer, high rates of nitrogen applied early in the growing season have been associated with nitrate leaching due to unpredictable rainfall. Use of lower nitrogen rates applied more frequently through the season is one strategy to minimize nitrate losses and improve nitrogen use efficiency. Portable nitrate electrodes were used to measure nitrate concentrations in petiole sap. Diagnostic criteria based on final yield and nitrate sap concentrations at various growth stages were developed over a three year period. This rapid test can now be used to make an immediate assessment of nitrogen status of the plant and a prediction for whether supplemental nitrogen will be needed. On-farm trials are currently being carried out to demonstrate the use of the saptest as a best management practice.

Impact of Nitrogen and Weeds on Glyphosate-Resistant Sugarbeet Yield and Quality

2014 ◽  
Vol 28 (1) ◽  
pp. 189-199 ◽  
Author(s):  
Alicia J. Spangler ◽  
Christy L. Sprague ◽  
Kurt Steinke
Keyword(s):  
Field Experiments ◽  
Growing Season ◽  
Growth Stages ◽  
Root Yield ◽  
Yield And Quality ◽  
N Removal ◽  
Yield Quality ◽  
N Rates ◽  
Nitrogen Rates ◽  
Weed Removal

Field experiments were conducted in 2010 and 2011 at two locations in Michigan to determine the effects of nitrogen and weed removal on glyphosate-resistant sugarbeet yield and quality. Nitrogen rates were 0, 67, 100, 134, and 67 : 67 kg N ha−1, and weeds were removed when they were < 2, 8, 15, and 30 cm tall. At the beginning of the growing season, weeds responded to N sooner than sugarbeet. Nitrogen assimilation by weeds was three times greater than sugarbeet at 0, 67, 100, and 134 kg N ha−1 and four times greater than sugarbeet with the split application of N (67 : 67 kg N ha−1) averaged over the weed removal timings. Higher N rates increased N sufficiency index values and sugarbeet canopy closure; weeds 30 cm tall had lower N sufficiency index values and a smaller sugarbeet canopy. The effect of N on root yields varied, but the highest N rates (134 kg N ha−1 or 67 : 67 kg N ha−1) were among the highest sugarbeet yields at all locations. Highest yields were achieved when weeds were controlled before reaching 2 cm tall at three of the four site-years. Delaying weed control until weeds were 8 or 15 cm tall reduced yield by 15%, whereas 30-cm-tall weeds reduced yield up to 21%. Recoverable white sucrose ha−1 (RWSH) also was reduced by 8 to 16% if weeds were 8 cm tall. These results indicate that weeds are highly competitive with sugarbeet and can assimilate large quantities of N early in the growing season, especially at larger growth stages. However, it appears that sugarbeets were able to scavenge sufficient N at the N rates used in this study to overcome N removal effects from larger weeds, resulting in no interaction between N rate and weed removal timing for sugarbeet root yield, quality, or RWSH.

Sulfonylurea herbicides applied to acidic sandy soils: movement, persistence and activity within the growing season

1992 ◽  
Vol 43 (5) ◽  
pp. 1157 ◽  
Author(s):  
WM Blacklow ◽  
PC Pheloung
Keyword(s):  
Sandy Loam ◽  
Sandy Soils ◽  
Growing Season ◽  
Shoot Biomass ◽  
Soil Profiles ◽  
Sulfonylurea Herbicides ◽  
Laboratory Bioassay ◽  
Wheat Seedlings ◽  
Late Application ◽  
Lime Addition

Chlorsulfuron and triasulfuron were applied to the surface of acidic, sandy loam at a low rainfall site in 1989 (129 mm June-October) and a high rainfall site in 1990 (217 mm July-August). Four environments were obtained by early and late application times and lime addition in 1989 and by a wetter site in 1990. The pH of the surface 10 cm was 4.9 in 1989, 5.8 in 1990 and 6.5 after the addition of limestone in 1989. The plots were left fallow or sown, prior to herbicide applications, to wheat (cv. Kulin). Hourly averages of rainfall, soil and air temperature were recorded. The temperature range was 2.7�C to 23.2�C. The soil profiles were sampled on 5 to 7 occasions and herbicide residues were determined by a laboratory bioassay (sensitivity >0.4 8g kg-1 soil). Chlorsulfuron and triasulfuron were detected to 300 mm in the wetter environment but neither herbicide was as mobile in the profile as water. More herbicide moved to the lower layers of the profile in the higher pH environment. The half-lives for residues ranged from 12 to 28 days. Shoot biomass of wheat seedlings was suppressed by both herbicides but grain yields were unaffected. The residues failed to prevent reinvasion of the wheat plots by weeds, notably Arctotheca calendula.

SOIL CONDITIONERS—THEIR EFFECT ON COARSE-TEXTURED SOILS, CROP YIELDS AND COMPOSITION

1957 ◽  
Vol 37 (2) ◽  
pp. 102-112
Author(s):  
R. M. Holmes ◽  
S. J. Toth
Keyword(s):  
Structural Changes ◽  
Crop Yields ◽  
Cultural Practices ◽  
Sandy Soils ◽  
Growing Season ◽  
Soil Aggregate ◽  
Crop Response ◽  
The Third ◽  
Soil Conditioners ◽  
The Stability

Crop response to soil structural changes caused by soil conditioner amendments was studied in several different sandy soils of New Jersey. The response varied with the crop and treatment. Those chemicals that were slightly hydrophobic were most effective and generally crop response was greatest on these treatments. Cations such as Na may be added in large amounts as part of some conditioners, and this may result in reduced uptake of other nutrients such as Mg. and K. Except for this effect, conditioners did not reduce nutrient uptake by plants. When elements such as Na and N are added in large amounts as part of some conditioners, there may be an increased uptake of these nutrients.Catalin and VAMA conditioners produced a dry surface mulch which appeared to reduce evaporation. Moisture reserves were, therefore, preserved through a drought and this resulted in increased growth of crops over those grown on other treatments. Cultural practices destroyed the stability of the conditioned aggregates, since in most cases the effect had largely disappeared by the third growing season. Chemicals which were effective in soil aggregate stabilization were also effective as anti-crustants when crusting was a problem.

Influence of fertilizers and of the autumn tillage method on potato yield and phytopathologiс characteristics of tubers

2021 ◽  
Vol 22 (3) ◽  
pp. 393-400
Author(s):  
V. I. Titova ◽  
E. T. Akopdzhanyan
Keyword(s):  
Field Experiment ◽  
Ammonium Nitrate ◽  
Nitrogen Fertilizer ◽  
Growing Season ◽  
Potato Yield ◽  
Loamy Soil ◽  
Pest Damage ◽  
Tillage Method ◽  
Nizhny Novgorod Region ◽  
Production Conditions

The field experiment on identifying differences in the effect of the herbicide and foliar feeding of plants with liquid nitrogen fertilizer (UAN-32) against the background of autumn tillage with a cultivator or plow on potato yield and phytopathologic characteristics of tubers during storage was carried out in 2019-2020 in the Nizhny Novgorod region. The experiment was laid on sod-podzolic sandy loamy soil in production conditions on two varieties of potato ‒ the super-early Сolomba variety and the medium-early Innovator variety grown for seeds. The variants under study were surface application of the soil herbicide Gezagard in a tank mixture with UAN-32 and foliar feeding of plants with UAN-32 (N42) during the growing season against the background of N42P42K169 (calcium chloride in autumn + ammonium nitrate phosphate in spring). The results indicate that the background fertilization provides the yield of Colombа variety potato of 20.7-29.0 t/ha, the Innovator variety – 17.4-23.1 t/ha. The use of the herbicide is more effective during autumn tillage with a cultivator, providing an increase in yield of 28-37 % on both potato varieties, feeding of plants with UAN-32 contributes to an increase in yield (8-10 %) only on the Сolomba variety. Plowing the soil for potatoes helps to avoid the pest damage of tubers and to reduce their susceptibility to rhizoctonia by 6-27 %, to wet rot ‒ up to 55 %. In general, it has been established that due to autumn plowing with fertilization at a dose of N42P42K169, it is possible to obtain an increase in potato yield exceeding the increase provided both by herbicides and the use of foliar feeding of potatoes.

The composition of the rhizosphere of chicory (Cichorium intybus L. var. foliosum Hegi)

1988 ◽  
Vol 34 (11) ◽  
pp. 1203-1208 ◽  
Author(s):  
M. F. Van Outryve ◽  
F. Gosselé ◽  
K. Kersters ◽  
J. Swings
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Growing Season ◽  
Cichorium Intybus ◽  
Growth Stages ◽  
Fluorescent Pseudomonad ◽  
Fluorescent Pseudomonas ◽  
Streptomyces Spp ◽  
Bacillus Spp ◽  
Pseudomonas Paucimobilis

The bacterial composition of the chicory rhizosphere (Cichorium intybus L. var. foliosum Hegi) was examined at four different growth stages in the field and also after 1 month storage of the roots. Based on protein fingerprints (SDS – polyacrylamide gel electrophoresis of total cell proteins) 233 isolates were grouped into 117 different groups. Forty percent of the isolates belonged to one of three groups: CH001, CH002, or CH213. Fingerprint type CH001 and CH002 were comprised of fluorescent pseudomonads. Fingerprint type CH213 was identified as Alcaligenes paradoxus. Fingerprint type CH213 strains, normally isolated early in the growing season, were inhibited in vitro by fingerprint type CH001 strains which appeared later in the growing season. Gram-negative isolates were predominant among the remaining fingerprint types: Pseudomonas paucimobilis, Xanthomonas maltophilia, Agrobacterium radiobacter, and Flavobacterium spp. A few Gram-positive isolates were found at the beginning of the growing season, i.e., Bacillus spp. and Streptomyces spp. The production of antifungal compounds was restricted to the 11 isolates among which were fluorescent Pseudomonas and Bacillus spp. Twenty-four fluorescent pseudomonad isolates from the rhizosphere were pathogenic on chicory leaves.

Compositional changes over four years for binary mixtures of grass species grown with white clover

2005 ◽  
Vol 85 (2) ◽  
pp. 351-360 ◽  
Author(s):  
D. B. McKenzie ◽  
Y. A. Papadopoulos ◽  
K. B. McRae ◽  
E. Butt
Keyword(s):  
White Clover ◽  
Tall Fescue ◽  
Principal Component ◽  
Growing Season ◽  
Kentucky Bluegrass ◽  
Repeated Measurements ◽  
Grass Species ◽  
Growth Stages ◽  
Meadow Fescue ◽  
Reed Canarygrass

Kentucky bluegrass, meadow fescue, orchardgrass, tall fescue, timothy, and reed canarygrass were seeded in all possible two-grass combinations with white clover in conventional and underseeded barley treatments using a split-plot design at the Western Agriculture Centre near Pynn’s Brook, NL. The objectives were: (1) to assess dry matter yield (DMY) of two binary grass species when sown with white clover in mixtures under a system with cuttings at similar crop growth stages as rotational grazing and to assess the effect of underseeding to barley on this system; (2) to identify mixtures that enhance herbage distribution throughout the grazing season; and (3) to assess the sward dynamics over successive cropping seasons. The composition of the binary grass mixtures with white clover affected seasonal DMY, seasonal herbage distribution, and sward dynamics over the production years. Orchardgrass in mixtures decreased DMY, shifted the herbage distribution toward early season, and competed with other species. Timothy composition of the stand showed the largest decline over the 3 production years, whereas white clover declined in mixtures with bluegrass, orchardgrass, or tall fescue. Meadow fescue and reed canarygrass with white clover was the most productive mixture with excellent persistence and good yield distribution over the growing season. Orchardgrass was the least compatible species in the mixtures; it dominated first growth and contributed the least to biomass production in later years. Both bluegrass and reed canarygrass performed well in mixtures over the 3 production years; bluegrass appeared to enhance the performance of the other species during summer regrowth whereas reed canarygrass was superior in the later part of the growing season. Underseeding with barley did not affect white clover yield in any production year but detrimentally affected the yield of orchardgrass and meadow fescue in mixtures, and their seasonal distribution. Key words: Bluegrass, orchardgrass, meadow fescue, tall fescue, timothy, reed canarygrass, repeated measurements, principal component analysis, herbage DM distribution, species competition

scholarly journals Impact of Deficit Irrigation on Shallow Saline Groundwater Contribution and Sunflower Productivity in the Imperial Valley, California

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 571
Author(s):  
Mohamed Galal Eltarabily ◽  
John M. Burke ◽  
Khaled M. Bali
Keyword(s):  
Irrigation Water ◽  
Deficit Irrigation ◽  
Growing Season ◽  
Yield Reduction ◽  
Growth Stages ◽  
Crop Evapotranspiration ◽  
Imperial Valley ◽  
Saline Groundwater ◽  
Irrigation Treatments ◽  
Groundwater Contribution

Yield and production functions of sunflower (Helianthus annuus) were evaluated under full and deficit irrigation practices with the presence of shallow saline groundwater in a semi-arid region in the Imperial Valley of southern California, USA. A growing degree day (GDD) model was utilized to estimate the various growth stages and schedule irrigation events throughout the growing season. The crop was germinated and established using overhead irrigation prior to the use of a subsurface drip irrigation (SDI) system for the remainder of the growing season. Four irrigation treatments were implemented: full irrigation (100% full sunflower crop evapotranspiration, ETC), two reduced irrigation scenarios (95% ETC and 80% ETC), and a deficit irrigation scenario (65% ETC). The salinity of the irrigation water (EC) (Colorado River water) was nearly constant at 1.13 dS·m−1 during the growing season. The depth to groundwater and groundwater salinity (ECGW) were continuously monitored in five 3 m deep observation wells. Depth to groundwater fluctuated slightly under the full and reduced irrigation treatments, but drastically increased under deficit irrigation, particularly toward the end of the growing season. Estimates of ECGW ranged from 7.34 to 12.62 dS·m−1. The distribution of soil electrical conductivity (ECS) and soil matric potential were monitored within the active root zone (120 cm) at selected locations in each of the four treatments. By the end of the experiment, soil salinity (ECS) across soil depths ranged from 1.80 to 6.18 dS·m−1. The estimated groundwater contribution to crop evapotranspiration was 9.03 cm or approximately 16.3% of the ETC of the fully irrigated crop. The relative yields were 91.8%, 82.4%, and 83.5% for the reduced (95% and 80% ETC) and deficit (65% ETC) treatments, respectively, while the production function using applied irrigation water (IW) was: yield = 0.0188 × (IW)2 − 15.504 × IW + 4856.8. Yield reduction in response to water stress was attributed to a significant reduction in both seed weight and the number of seed produced resulting in overall average yields of 2048.9, 1879.9, 1688.1, and 1710.3 kg·ha−1 for the full, both reduced, and deficit treatments, respectively. The yield response factor, ky, was 0.63 with R2 = 0.745 and the irrigation water use efficiencies (IWUE) were 3.70, 3.57, 3.81, and 4.75 kg·ha−1·mm−1 for the full, reduced, and deficit treatments, respectively. Our results indicate that sunflowers can sustain the implemented 35% deficit irrigation with root water uptake from shallow groundwater in arid regions with a less than 20% reduction in yield.

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