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Effects of the nitrification inhibitor dicyandiamide on potassium, magnesium and calcium leaching in grazed grassland
Author(s) -
Di H.J.,
Cameron K.C.
Publication year - 2004
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.2004.tb00330.x
Subject(s) - leaching (pedology) , lolium perenne , trifolium repens , chemistry , loam , agronomy , nitrification , potassium , lessivage , soil water , nitrogen , perennial plant , environmental science , soil science , biology , organic chemistry
. Leaching of calcium (Ca), potassium (K) and magnesium (Mg) from urine patches in grazed grassland represents a significant loss of valuable nutrients. We studied the effect on cation loss of treating the soil with a nitrification inhibitor, dicyandiamide (DCD), which was used to reduce nitrate loss by leaching. The soil was a free‐draining Lismore stony silt loam (Udic Haplustept loamy skeletal) and the pasture was a mixture of perennial ryegrass ( Lolium perenne ) and white clover ( Trifolium repens ). The treatment of the soil with DCD reduced Ca 2+ leaching by the equivalent of 50%, from 213 to 107 kg Ca ha −1 yr −1 on a field scale. Potassium leaching was reduced by 65%, from 48 to 17 kg K ha −1 yr −1 . Magnesium leaching was reduced by 52%, from 17 to 8 kg Mg ha −1 yr −1 . We postulate that the reduced leaching loss of these cations was due to the decreased leaching loss of nitrate under the urine patches, and follows from their reduced requirement as counter ions in the drainage water. The treatment of grazed grassland with DCD thus not only decreases nitrate leaching and nitrous oxide emissions as reported previously, but also decreases the leaching loss of cation nutrients such as Ca 2+ , K + and Mg 2+ .