Factors affecting potassium leaching in different soils
2004; Wiley; Volume: 20; Issue: 2 Linguagem: Inglês
10.1111/j.1475-2743.2004.tb00355.x
ISSN1475-2743
AutoresMarta Alfaro, S. C. Jarvis, Peter Gregory,
Tópico(s)Groundwater and Isotope Geochemistry
ResumoAbstract. A set of lysimeter based experiments was carried out during 2000/01 to evaluate the impact of soil type and grassland management on potassium (K) leaching. The effects of (1) four soil textures (sand, loam, loam over chalk and clay), (2) grazing and cutting (with farmyard manure application), and (3) K applied as inorganic fertilizer, dairy slurry or a mixture of both sources were tested. Total K losses in the clay soil were more than twice those in the sand soil (13 and 6 kg K ha −1 , respectively) because of the development of preferential flow in the clay soil. They were also greater in the cut treatment than in the grazed treatment (82 and 51 kg K ha −1 , respectively; P 0.01), associated with a 63% increase of K concentration in the leachates from the former (6.7 ± 0.28 and 4.1 ± 0.22 mg K L −1 for cut and grazed, respectively; P 0.01) because of the K input from the farmyard manure. The source of fertilizer did not affect total K losses or the average K concentration in the leachates ( P > 0.05), but it changed the pattern of these over time.
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