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Quantification of nitrates leaching from grassland soils in winter using the Burns model

Pietrzak Stefan, Urbaniak Marek

Journal of Water and Land Development

2024

no. 60

39--49

This paper presents the results of a study on the level of nitrate leaching from the 0-30 cm layer of grassland (GL) soil in the Lublin Voivodship during the winters of 2018/2019, 2019/2020 and 2020/2021. The amounts of leached nitrates were determined using the Burns model. For the calculations based on this model - directly and indirectly, the results determination of residual nitrate nitrogen, texture and organic matter in GL soils, obtained within the framework of agricultural monitoring of soils by the National Chemical and Agricultural Station (KSChR), and results of system meteorological measurements conducted by the Institute of Meteorology and Water Management - National Research Institute (IMGW-PIB) were used. The analysed soil samples were taken from 39 permanent control and measurement grassland sites. The research discovered in particular that: - the average leaching of nitrate nitrogen from GL mineral soil in the three analysed periods was 16.2 and 5.1 kg N∙ha-1 from organic soil; - on average, in autumn during the entire study period, 55.3% of NO3-N leached from the 0-30 cm layer of GL mineral soil, and 27.3% from organic soil; - among different agronomic categories of mineral soil, the highest leaching of NO3-N was recorded from medium soil (17.4 kg N∙ha-1 ) and the lowest from heavy soil (11.5 kg N∙ha-1); - individually determined values of NO3-N leaching from soil varied significantly from 0 to 68.5 kg N∙ha-1 for mineral soil and from 0.1 to 23.65 kg N∙ha-1 for organic soil.

Groundwater flow and nitrate migration in a Dutch-Belgian chalk catchment; observed and future concentrations

Kłonowski M., Lanen H. van, Dijksma R.

Geological Quarterly

2001

Vol. 45, No 1

53-66

In the catchment of the Noor brook, by the Dutch/Belgian border, excess precipitation with high nitrate concentrations (80-120 mgˇl-1) recharges the Cretaceous multi-aquifer system under the plateau and foothill (agricultural area). The nitrates are transported through the aquifer (median NO3-> 50 mgˇl-1 under the plateau) towards springs and wetlands of the Noorbeemden nature reserve. The major spring has a concentration of 70-80 mgˇl-1. The concentration in the Noor brook is somewhat lower (median 46 mgˇl-1) because of denitrification in the wetlands. The groundwater flow and transport model FLONET/TRANS was used to simulate the development of the nitrate distribution in the last 50 years. The general NO3-distribution in the northern part of the catchment could be reasonably well predicted, whereas the concentrations in the southern part were underestimated by about 20 mgˇl-1. The simulated future trend in the northern part of the catchment in the next 100 years shows that a reduction of nitrate leaching by 50% is required to level off the currently still increasing concentrations. A dramatic decrease of leaching by 75% is needed to achieve pre-1950's concentrations. This implies that the management plan of the Noorbeemden Nature Reserve, which is complied by the Nature Conservation Organisation, should not aim at botanical restoration in the first decades, even if severe restrictions in nitrogen application are imposed on the farmers now.