The effect of fertilizer and N application rate on nitrogen and potassium leaching in cut grassland

Abstract

Although fertilization has a positive effect on agricultural productivity, its negative side effect can be the leaching of plant nutrients. Our objectives were to study the impact of fertilizer type and nitrogen application rate on the nitrogen and potassium leaching from grassland during and after the vegetative period. Within three years (2008-2011) mini-lysimeters experiment was conducted on grassland swards receiving mineral NPK, mineral PK, cattle slurry and sewage sludge based on nitrogen rate 0, 60, 120 and 180 kg ha -1 year -1 . Nitrogen and potassium leaching was measured monthly throughout the experimental period. From our results it can be concluded that nitrogen leaching is lower with the use of mineral NPK, because it increases the sward yield most efficiently. Potassium leaching in grassland can be reduced when using nitrogen containing fertilizers, as the fertilizer N:K ratio has a great effect on its leaching potential. Fertilizers are not the only N and K leaching source. It can be high also from unfertilized soil at the expense of soil reserves. Injection of slurry at rational amounts can be an effective method for the reduction of nitrogen leaching in grassland.

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

“…Source: own study. of 3-26.3 kg N•ha -1 was observed in the growing season and 2.8-1.8 N•ha -1 in non-growing season (Tampere et al, 2015); in both these periods, the leaching of nitrates was affected by the type of fertilisers used; -experimental work carried out using suction cups to determine nitrates in soil solution showed that from 17 to 60 kg NO 3 -N•ha -1 can leach from the pasture soil in a year depending on the age of the sward (at constant sward composition and nitrogen fertilisation of 300 kg N•ha -1 ) (Eriksen and Vinther, 2002); -based on the results of another experiment, in which the method of ceramic cups was used, it was determined that the losses of nitrates from soils of permanent grasslands used for mowing amount to only 2.1 ±0.3 kg•kg NO 3 -N•ha -1 (Smit et al, 2021); -in studies, carried out using continuous (flow proportional) soil leachate sampling, annual NO 3 -N leaching rates from pasture soil were 3.7-14.6 kg NO 3 -N•ha -1 when the soil was not fertilised with nitrogen, and 6.2-22.0 and 4.3-37.6 when different types of nitrogen fertiliser, namely urea and ammonium nitrate, were applied to it at the same rates (200 kg N•ha -1 ) (Eckard et al, 2004).…”

Precipitation, runoff and nutrient losses from cultivated Histosols in western Iceland

“…Although soil depth in the study catchment area is largely >2 m, most nutrient cycling takes place in the biologically most active top 10 cm of the soil, especially in grass swards and forages (Griffin et al 2002, Tampere et al 2015 which were dominant in the study area.…”

The Effects of Manure Application and Herbivore Excreta on Plant and Soil Properties of Temperate Grasslands—A Review

“…The proportion of herbs can be reduced by more than a third within two years. While P and K mainly influence the proportion of herbs, legumes are more affected by applied N. Tampere et al [97] found that high application rates above 120 kg N ha −1 led to the disappearance of white clover. These high N application rates compensated for this loss through higher grass yield but had no significant effect on total yield.…”

“…The different types of organic fertilizers had only a small effect on K leaching. According to studies by Kayser and Isselstein [91] and Tampere et al [97], the application of cattle slurry alone increased K leaching losses from grassland over the years. The type of application and application during or after the growing season had no effect on K leaching.…”

“…The highest leaching losses occurred without N fertilization, depending on the plant composition. An imbalance between N and K can have a negative effect on the ensiling quality of grass [97,146].…”