The Efficiency of Various Particle‐Size Fractions of Limestone

Abstract

The relative efficiency of various fractions of a calcitic limestone was studied under greenhouse conditions. Pure calcium carbonate, a commercial sample of agricultural limestone, and 6 particle‐size fractions separated from this commercial sample were applied at different rates to 3 acid soils. The soils were sampled at various times and the pH determined. The changes in pH with time followed an expression of the form, pHf = pHo + b Log (1 + t). The factor b varied with rate of application, particle size, and soil. The limestone particles in the 10‐ to 28‐mesh size fraction were, in general, 14% as effective as those in the < 100‐mesh fraction, and particles > 10 mesh were essentially of no value. The efficiency of the commercial sample of agricultural limestone was approximately equal to that exhibited by the 40‐ to 60‐mesh fraction of the sample. The results indicate that, for practical purposes, a large portion of commercial limestone should be ground fine enough to pass a 40‐mesh sieve.

Peanut growth as affected by liming, Ca-Mn interactions, and Cu plus Zn applications to oxidic samoan soils

“…Similarly, Morrison et al (1989) found that coralline lime was a good amendment for Fijian soils, provided that the lime was sufficiently fine. Such a finding is readily understood, given the fact that CaCO2 particles > 2 mm dissolve much slower than particles < 0.25 mm (Motto and Melsted, 1960).…”

Estudo dos materiais calcários usados como corretivo do solo no Estado de São Paulo: I - Composição granulométrica

“…Admitindo-se correta a conclusão de conhecidos trabalhos sobre efeitos de calcário em solos ácidos (2,6,7,8) ; de que partículas com diâmetros superiores a 0,8 mm têm pouco ou nenhum efeito corretivo do solo, poder-se-ia chegar à indicação de que grande parte dos pós calcários comercializados em São Paulo apresentam 20% a 30% de material ineficiente como corretivo do solo.…”

“…Numerosas investigações, realizadas com a finalidade de verificar o valor agrícola dos calcários, em função de diferentes graus de finura, e levadas a efeito tanto por meio de ensaios em terras ácidas (2,3,6,7,8) como por meio de processos químicos em laboratório (4,5,9,10,12), mostraram que quanto mais fino fôr o material empregado, maior e mais rápida será a sua ação corretiva de acidez dos solos. Subsistem dúvidas quanto à eficiência das partículas mais grosseiras.…”

“…Considera-se que as de diâmetro superior a 0,25 mm seriam desejáveis, em determinadas proporções, para proporcionarem efeitos a prazos mais longos (6). A partir de determinada dimensão, porém, as partículas de calcário teriam efeito nulo ou insignificante, ineficiência essa demonstrada por alguns autores (2,6,7,8) para partículas com diâmetro superior a 0,8 mm (peneira n.° 20).…”

Limestone Quality and Effectiveness for Neutralizing Soil Acidity

“…That same piece of limestone ground so that each particle is the exact size to just pass a 0.15 mm screen (100-mesh), and assuming that these particles remain perfect cubes, would have an increased flat surface area approximating 983 cm 2 . Motto and Melsted [6] showed that particles in the 2.0-to 0.85-mm (20 mesh) fraction were 14% as effective as those in the 0.15-mm (100 mesh) fraction, and particles larger than 2 mm were essentially of no value. [1] On soils very low in CEC, some slow release (relatively large particles) may extend the time the pH change will last before reapplication of limestone is necessary.…”