scholarly journals The changes of soil mineral nitrogen observed on farms between autumn and spring and modelled with a simple leaching equation

2009 ◽  
Vol 4 (No. 4) ◽  
pp. 159-167 ◽  
Author(s):  
J. Haberle ◽  
H. Kusá ◽  
P. Svoboda ◽  
J. Klír
Keyword(s):  
Regression Line ◽  
Soil Layer ◽  
Mineral Nitrogen ◽  
N Leaching ◽  
Soil Mineral Nitrogen ◽  
Average Value ◽  
Pooled Data ◽  
Soil Zone ◽  
Study Support ◽  
On Farm

The content of nitrate or mineral nitrogen (N<sub>min</sub> = N-NO<sup>-</sup><sub>3</sub> + N-NH <sup>+</sup><sub>4</sub>) in soil in autumn is recognized as the indicator of potential risk of N leaching during winter. In this contribution, the apparent changes of N<sub>min</sub> in the 0&ndash;60 cm soil layer, during winter, on farm fields in the Czech Republic were calculated. A significant positive relationship between N<sub>min</sub> in autumn and the change during winter was observed in eight out of the nine farms. Nitrate N data produced similar relationships as N<sub>min</sub>. The regression analysis suggested that 40&ndash;90% of N<sub>min</sub> above a specific amount, 14&ndash;35 kg N/ha (interception of regression line, I1), on farms was apparently lost from the soil zone. Corresponding results for pooled data (n = 187) were 74% and 25 kg N/ha (r = 0.90, P &lt; 0.001). The proportion of N leached from the 0&ndash;60 cm layer, calculated with a simple leaching equation was significantly correlated (n = 187, r = 0.92, P &lt; 0.001) with observed N<sub>min</sub>change during winter, with the intercept (I2) significantly different from zero (&ndash;30.9 kg/ha). When the average value of regression intercept I1 of farms, or of pooled data, were introduced to the leaching equation as a constant correction parameter, the fit was satisfactory (r = 0.93 and 0.92, resp.) and the intercepts (&ndash;3.1 kg and &ndash;5.4 kg N/ha, resp.) were not significantly different from zero (at P &lt; 0.01). The results of the study support the use of autumn N<sub>min</sub> within the leaching equation as a robust indicator of the risk of N leaching.

scholarly journals Field experiments with slurry and dicyandiamide: response of potatoes and effects on soil mineral nitrogen

1993 ◽  
Vol 41 (2) ◽  
pp. 95-109
Author(s):  
W.P. Wadman ◽  
J.J. Neeteson ◽  
G.J. Wijnen
Keyword(s):  
Nitrogen Fertilizer ◽  
Field Experiments ◽  
Inorganic Nitrogen ◽  
Maximum Yield ◽  
Soil Layer ◽  
Nitrification Inhibitor ◽  
Mineral Nitrogen ◽  
Residual Soil ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen

In the period of 1983-1985, 18 field experiments with potatoes grown for industrial starch production were set up in the Netherlands to investigate the effects of poultry-slurry application on tuber yield and on soil mineral nitrogen. Slurry was applied in autumn with and without the nitrification inhibitor dicyandiamide (DCD) and in spring without DCD. Control treatments without slurry or DCD were included. Various nitrogen fertilizer rates were applied to all slurry treatments. In autumn, following slurry application without DCD, slurry-derived nitrate moved to the 0.3-0.6 and 0.6-1 m soil layers. Following DCD-application, most of the slurry-derived nitrate remained in the 0-0.3 m soil layer. Maximum yields as estimated from a nitrogen fertilizer response function were slightly increased by the slurry application. Nitrogen supplied from the slurry decreased the amount of fertilizer nitrogen needed for maximum yield. Increasing the amounts of soil mineral nitrogen in June from slurry or applied inorganic nitrogen fertilizer increased residual soil mineral nitrogen at harvest.

scholarly journals Distribution of Mineral Nitrogen in Soil in Relation to Risk of Nitrate Leaching in Farms with Irrigated Vegetables and Early Potatoes

2018 ◽  
Vol 26 (2) ◽  
pp. 47-54
Author(s):  
Jan Haberle ◽  
Pavel Svoboda ◽  
Tomáš Šimon ◽  
Gabriela Kurešová ◽  
Barbora Henzlová ◽  
...  
Keyword(s):  
Nitrate Leaching ◽  
Soil Layer ◽  
Mineral Nitrogen ◽  
Nitrate Content ◽  
Winter Period ◽  
Vegetable Production ◽  
Soil Mineral Nitrogen ◽  
The Czech Republic ◽  
Water Percolation ◽  
Residual Nitrate

Abstract Vegetable production may be the source of excessive residual nitrate that is prone to leaching to waters. To ascertain the risk of nitrate leaching in water collection area, the content of soil mineral nitrogen (Nmin = N-NO3− + N-NH4+) down to 120 cm depth was monitored in the years 2013–2016 on vegetable farms along lower Jizera river (in the Czech Republic). The risk of nitrate leaching below 30, 60, 90 and 120 cm during winter period was simulated with a simple model. The depths represent the limits of effective root depth and N depletion of groups of vegetables and field crops. The average autumn mineral nitrogen content in the fields, during experimental years, ranged from 101 kg to 134 kg N·ha−1 in the 0–120 cm soil layer, 85 to 92% of which was in the form of nitrate. The calculated leaching of nitrate from the topsoil (0–30 cm) and shallow subsoil (0–60 cm) ranged from 27 to 41%, and from 7 to 14% of autumn content, respectively. The risk of leaching below 60 cm and 90 cm was near to none during the experimental years due to the exceptionally low precipitation. High nitrate content in subsoil layers below 60 cm constitutes risk of leaching and water pollution due to shallow root systems of many vegetables and potatoes in seasons with normal weather and higher water percolation.

scholarly journals Environmentally Friendly Nitrogen Fertilizers Appplication for Winter Cereals Considering the Mineral Nitrogen Content in Soil

2006 ◽  
Vol 1 ◽  
pp. 284
Author(s):  
R. Timbare ◽  
M. Bušmanis
Keyword(s):  
Perennial Grass ◽  
Soil Layer ◽  
Soil Samples ◽  
Mineral Nitrogen ◽  
Loamy Sand ◽  
Organic Fertilizers ◽  
Nitrogen Fertilizers ◽  
Soil Mineral Nitrogen ◽  
Winter Cereals

In order to improve nitrogen fertilizers application recommendations for cereals, the soil mineral nitrogen (Nmin) investigations (1995 – 2000) were carried out on sod – podzolic and brown – lesssive loamy sand and loamy soils in co-operation with other research institutions. The soil samples for determination of NO3 – N and NH4 – N were taken in depth 0 - 20, 21 – 40 and 41 – 60 cm in spring before the start of growth on winter cereals fields, but in 2001,2002- also in autumn before the sowing of winter cereals. Data on soil properties, the amount of precipitation in autumn (August 1 until the first decade with the average temperature below 5 oC), preceding crops and the use of organic fertilizers at sites of investigations were considered. The determination of NO3 – N and NH4 – N content was carried out in wet soil samples using for extraction 1 M KCl. Statistical analysis of data obtained in spring has been carried out using MS EXCEL function CORREL, CORRELATION, REGRESSION and SPSS 8.0 for Windows (GLM procedure). According to this analysis the following model (R2 = 0,527) was elaborated: y = 103.513 – 13.515|X1=1 – 0.247·X3 – 27.069|X2=0 – 42.945|X2=1 – 39.044|X2=2 – 16.022|X2=3 – 44.212|X2=4 + 0.104·X3|X2=0 + 0.181·X3|X2=1+ 0.187·X3|X2=2 +0.117·X3|X2=3+0.175·X3|X2=4, where y- predicted Nmin content in spring in 0- 40 cm soil layer, kg ha-1; 103.513 – intercept; X3 – amount of precipitation in autumn, mm; X1 – soil texture; X1=1 – loamy sand soils, X2 – predecessor; X2=0 – cereals; X2=1 – perennial grass; X2=2 – tilled crops; X2=3 – legumes; X2=4 – green manure crops; X2=5- fallow. On the basis of this model and data on meteorological conditions at different sites of Latvia the recommendations on correction N top - dressing application rates for winter cereals in spring were prepared.

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

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 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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