Assessment of the Effects of Environmental Factors on the Response of Wheat to Fertilizer in On-farm Trials in a Mediterranean Type Environment

1996 ◽  
Vol 32 (3) ◽  
pp. 339-349 ◽  
Author(s):  
M. Pala ◽  
A. Matar ◽  
A. Mazid
Keyword(s):  
Seasonal Rainfall ◽  
Fertilizer Treatment ◽  
Regression Equations ◽  
Strongly Correlated ◽  
Soil Mineral ◽  
Wheat Grain ◽  
Soil Mineral Nitrogen ◽  
Fertilizer Rate ◽  
On Farm ◽  
Fertilizer Rates

SUMMARYA series of researcher-managed wheat fertilizer trials was conducted on representative farmers' fields across northwest Syria between 1986 and 1990. Wheat grain and straw yields were strongly correlated with seasonal (October-May) rainfall, almost irrespective of soil fertility, crop sequence or fertilizer rate, with a highly significant response to nitrogen fertilizer which increased with increasing rainfall and decreasing initial soil mineral-nitrogen values. These results were summarized in regression equations which express yield in terms of fertilizer rates, seasonal rainfall and their interactions. The equations with applied nitrogen and seasonal rainfall were the most appropriate for determining fertilizer needs. Economic analysis indicated that all fertilizer treatment rates were profitable under existing price conditions and that fertilizer use would still be beneficial for a nitrogen price up to three times higher than that of the price of grain (weight for weight) with a seasonal rainfall of 250 mm, and up to six times higher with a seasonal rainfall of 450 mm.

scholarly journals The effect of non-targeted application of propiconazole on the yield and quality of malt barley

2012 ◽  
Vol 92 (2) ◽  
pp. 341-349 ◽  
Author(s):  
R. E. Karamanos ◽  
N. A. Flore ◽  
J. T. Harapiak ◽  
F. C. Stevenson
Keyword(s):  
N Fertilizer ◽  
Yield Potential ◽  
Fertilizer Treatment ◽  
Fertilizer Rate ◽  
Net Returns ◽  
Yield And Quality ◽  
K Fertilizer ◽  
Malt Barley ◽  
Fertilizer Rates

Karamanos, R. E., Flore, N. A., Harapiak, J. T. and Stevenson, F. C. 2012. The effect of non-targeted application of propiconazole on the yield and quality of malt barley. Can. J. Plant Sci. 92: 341–349. There is a desire to use non-targeted applications of foliar fungicide to improve malting barley production under higher fertility situations. An experiment was conducted at 80 sites (location by year combinations) with a 12 combinations of N/P/K rate-placement to determine if applications of propiconazole improve malt barley yield and quality under high fertility conditions. Treatment differences for days to maturity were no greater than about 1 d. Fungicide by fertility treatment interactions were not significant (P>0.05). Applications of propiconazole improved yield by 305 kg ha−1 (6%) and plump kernels by 3 g kg−1 (3%) across all fertility treatments, which included N fertilizer rates ranging from 0 to 90 kg N ha−1. The effect of fungicide on yield was greatest at sites with highest yield potentials (ca. 8000 kg ha−1) and was not statistically significant at lower-yielding sites (ca. 3000 kg ha−1). Application of propiconazole also improved net returns [barley revenue – (N cost+propiconazole cost+other operating costs)] by $22 ha−1 with higher barley priced ($190 T−1) and high yield potentials. At sites with low yield potential, the application of propiconazole resulted in net losses of about $7 ha−1 compared with not applying propiconazole. Nitrogen fertilizer rates from 0 to 90 kg N ha−1 (15/30-0 P-K fertilizer treatment combinations) increased yield and protein concentration, and reduced plump kernels in a curvilinear fashion when averaged across fungicide treatments. Net returns were maximized at N fertilizer rates slightly less than 90 kg N ha−1, depending on the price/cost regime. Consequently, malt barley producers will have to consider tradeoffs regarding N fertilizer rate that optimizes yield/returns and kernel quality. Also, decisions regarding fungicide applications and N/P/K fertilizer rate-placement applications can be made independent of each other for malt barley production.

Direct drilling experiments with wheat

1974 ◽  
Vol 14 (67) ◽  
pp. 237 ◽  
Author(s):  
TG Reeves ◽  
A Ellington
Keyword(s):  
Dry Matter ◽  
Nitrogen Nutrition ◽  
Fertilizer Application ◽  
Soil Mineral ◽  
Wheat Grain ◽  
Soil Mineral Nitrogen ◽  
Wheat Growth ◽  
Grain Yields ◽  
Nitrogen Levels ◽  
Direct Drilling

Results are presented from three experiments, on land being cropped for the third time after a ley period, in which the growth and nitrogen nutrition of direct drilled and conventionally cultivated and sown wheat was investigated. In 1968 and 1969 wheat growth from emergence to heading was superior on the cultivated plots but grain yields did not differ. In 1970 direct drilling increased wheat grain yield by 0.97 tonne ha-1. Nitrogen fertilizer application at seeding increased herbage dry matter and nitrogen content, fertile tiller production and grain yields on both direct-drilled and cultivated treatments. Soil mineral nitrogen levels at seeding were lower on cultivated plots than on direct-drilled plots, but incubation nitrogen was not different in any year. Direct drilling did not adversely affect mineralization of soil nitrogen, but it retarded early wheat growth.

Site-factor Influence on Barley Response to Fertilizer in On-farm Trials in Northern Syria: Descriptive and Predictive Models

1992 ◽  
Vol 28 (1) ◽  
pp. 63-87 ◽  
Author(s):  
M. J. Jones ◽  
A. Wahbi
Keyword(s):  
Rainfall Variability ◽  
Growth Period ◽  
Yield Response ◽  
Regression Equations ◽  
Nitrogen And Phosphorus ◽  
Fertilizer Rate ◽  
Data Set ◽  
Site Factor ◽  
Yield Responses ◽  
Fertilizer Rates

SummaryThe effects of site and rate of application of fertilizer on the grain and straw production of barley were investigated in 75 trials on representative farmers' fields. Grain and straw production were strongly but curvilinearly correlated with growth-period rainfall over the range 136–568 mm, almost irrespective of soil type, previous crop or fertilizer rate, and responded positively to applied nitrogen and/or phosphorus in 74 of the trials. Responses to nitrogen increased and those to phosphorus decreased with increasing rainfall. Yields tended to be lower but responses to nitrogen were higher where barley followed barley and were influenced by the availability of phosphate and mineral nitrogen in the soil at planting time.These results are summarized in regression equations, which express yield quadratically in terms of fertilizer rates, seasonal rainfall and their interactions over the full 75-trial data set and within representative sub-sets. The wide differences in crop response to fertilizer highlight the problem of recommending fertilizer rates for a low and variable rainfall environment. Simple second-order multiple regressions for different geographical areas, rainfall zones, crop rotations etc., based on mean rainfall values, account for around 40% of the variance in yield response to nitrogen and phosphorus fertilizer; only a small proportion of the remaining variance appears attributable to rainfall variability. Alternatively, yield may be expressed as a function of fertilizer rate and rainfall using rainfall probability values derived from long-term records. This can be used to estimate the probabilities of predetermined yield responses for specified sites and fertilizer rates and to produce maps of those probabilities.

Link between paddy soil mineral nitrogen release and iron and manganese reduction examined in a rice pot growth experiment

Geoderma ◽  
2018 ◽  
Vol 326 ◽  
pp. 9-21 ◽  
Author(s):  
Masuda Akter ◽  
Heleen Deroo ◽  
Eddy De Grave ◽  
Toon Van Alboom ◽  
Mohammed Abdul Kader ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Mineral Nitrogen ◽  
Nitrogen Release ◽  
Growth Experiment ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Manganese Reduction ◽  
Iron And Manganese

Soil mineral nitrogen and nitrate leaching losses in soil tillage systems combined with a catch crop

1999 ◽  
Vol 50 (2) ◽  
pp. 115-125 ◽  
Author(s):  
Maria Stenberg ◽  
Helena Aronsson ◽  
Börje Lindén ◽  
Tomas Rydberg ◽  
Arne Gustafson
Keyword(s):  
Nitrate Leaching ◽  
Mineral Nitrogen ◽  
Soil Tillage ◽  
Catch Crop ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Tillage Systems ◽  
Leaching Losses

scholarly journals Effects of Three Fertilization Methods on Weed Growth and Herbicide Performance in Soilless Nursery Substrates1

2018 ◽  
Vol 36 (4) ◽  
pp. 133-139
Author(s):  
Cody J. Stewart ◽  
S. Christopher Marble ◽  
Brian E. Jackson ◽  
Brian J. Pearson ◽  
P. Christopher Wilson
Keyword(s):  
Fertilizer Treatment ◽  
Fertility Rates ◽  
Weed Species ◽  
Fertilizer Placement ◽  
Digitaria Sanguinalis ◽  
Fertilizer Rate ◽  
Weed Growth ◽  
Eclipta Prostrata ◽  
Preemergence Herbicides ◽  
Large Crabgrass

Abstract Research objectives were to determine the effect of fertilization method (incorporation, subdress, and topdress) on weed growth and the performance of preemergence herbicides applied to soilless substrates. Nursery containers were filled with a pine bark:peat substrate and fertilized at two different rates [4.4 and 9.5 kg.m−3 (8.9 and 19.2 lb.yd−3)] via topdressing, subdressing, or incorporating. Containers were treated with either dimethenamid-P for spotted spurge (Euphorbia maculata L.), flumioxazin for eclipta (Eclipta prostrata L.) or prodiamine for large crabgrass (Digitaria sanguinalis L.). A control was established for each fertilizer rate/placement and weed species that was not treated. Incorporating or subdressing fertilizer resulted in reduced large crabgrass and spotted spurge growth in non-treated containers. Weeds grew larger at the higher fertility rates in both topdress and incorporated treatments but fertilizer rate did not affect growth of spotted spurge or large crabgrass when fertilizers were subdressed. Herbicides generally provided commercially acceptable weed control regardless of fertilizer treatment, but results varied with species. Results suggest that in the absence of herbicides, topdressing may result in greater weed growth compared with subdressing or incorporating fertilizers; however, fertilizer placement will have less impact on herbicide performance if proper herbicides are chosen and applied correctly. Index words: topdress, subdress, incorporate, large crabgrass, eclipta, spotted spurge, preemergence Chemicals used in this study: Flumioxazin (SureGuard®); 2-[7-fluoro-3,4-dihydro-3-oxo-4-(2-propynyl)-2H-1,4-benzoxazin-6-yl]-4,5,6,7-tetrahydro-1H-isoindole1,3(2H)-dione; Dimethenamid-P (Tower) 2-chloro-N-[(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide; Prodiamine (Barricade) 2,4-dinitro-N3, N3-dipropyl-6-(trifluoromethyl)-1,3-benzenediamine (Barricade®) Species used in this study: Large crabgrass (Digitaria sanguinalis L.); Eclipta (Eclipta prostrata L.); Spotted spurge (Euphorbia maculata L.)

scholarly journals Stock Plant Nutrition Influences the Adventitious Rooting of ‘Rotundifolia’ Holly Stem Cuttings

1991 ◽  
Vol 9 (2) ◽  
pp. 83-85
Author(s):  
William H. Rein ◽  
Robert D. Wright ◽  
Dale D. Wolf
Keyword(s):  
Adventitious Rooting ◽  
Stem Cuttings ◽  
Stock Plant ◽  
Fertilizer Rate ◽  
Percent Moisture ◽  
Growth Activity ◽  
Phosphorus And Potassium ◽  
Highly Correlated ◽  
Fertilizer Rates ◽  
Treatment Design

Abstract Containerized stock plants of Ilex crenata Thunb. ‘Rotundifolia’ were liquid-fertilized at least three times per week with nitrogen (N) at five rates (25, 50, 100,200, and 300 mg N/l) and in two forms (100% NH4NO3 or 50% NH4NO3 + 50% urea) in a factorial treatment design. Phosphorus and potassium were included in a constant ratio with N (100 N:15 P:50 K). Leaf and stem percent N levels were suboptimal at the lowest fertilizer rate and excessive at the highest fertilizer rate. Percent rooting of stem cuttings decreased linearly with fertilizer rate. With increasing fertilizer rates, total nonstructural carbohydrate (TNC) levels increased in leaves and remained constant in stems. Stem cutting percent moisture increased and was highly correlated with fertilizer rate. The form of N applied made no statistical difference in these trends. The decrease in percent rooting with increasing fertilizer rates was attributed to increases in shoot growth activity and decreased tissue maturation.

scholarly journals Application of the Bayesian calibration methodology for the parameter estimation in CoupModel

2009 ◽  
Vol 21 ◽  
pp. 13-24 ◽  
Author(s):  
Y. Conrad ◽  
N. Fohrer
Keyword(s):  
Soil Water ◽  
Parameter Space ◽  
Mineral Nitrogen ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Bayesian Calibration ◽  
Soil Temperatures ◽  
Simulation Results ◽  
Water Contents ◽  
Soil Water Contents

Abstract. This study provides results for the optimization strategy of highly parameterized models, especially with a high number of unknown input parameters and joint problems in terms of sufficient parameter space. Consequently, the uncertainty in model parameterization and measurements must be considered when highly variable nitrogen losses, e.g. N leaching, are to be predicted. The Bayesian calibration methodology was used to investigate the parameter uncertainty of the process-based CoupModel. Bayesian methods link prior probability distributions of input parameters to likelihood estimates of the simulation results by comparison with measured values. The uncertainty in the updated posterior parameters can be used to conduct an uncertainty analysis of the model output. A number of 24 model variables were optimized during 20 000 simulations to find the "optimum" value for each parameter. The likelihood was computed by comparing simulation results with observed values of 23 output variables including soil water contents, soil temperatures, groundwater level, soil mineral nitrogen, nitrate concentrations below the root zone, denitrification and harvested carbon from grassland plots in Northern Germany for the period 1997–2002. The posterior parameter space was sampled with the Markov Chain Monte Carlo approach to obtain plot-specific posterior parameter distributions for each system. Posterior distributions of the parameters narrowed down in the accepted runs, thus uncertainty decreased. Results from the single-plot optimization showed a plausible reproduction of soil temperatures, soil water contents and water tensions in different soil depths for both systems. The model performed better for these abiotic system properties compared to the results for harvested carbon and soil mineral nitrogen dynamics. The high variability in modeled nitrogen leaching showed that the soil nitrogen conditions are highly uncertain associated with low modeling efficiencies. Simulated nitrate leaching was compared to more general, site-specific estimations, indicating a higher leaching during the seepage periods for both simulated grassland systems.

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