Performance assessment of nanoparticulate lime to accelerate the downward movement of calcium in acid soil

Calcium in conventional lime (CL) moves downward extremely slowly into the soil in the short term. To monitor the effects of using nanoparticulate lime (NL) in low affordable doses and in large doses on accelerating the downward movement of Ca in a simulated plough layer profile (0-25 cm), we ran a column leaching experiment with an acid soil with NL applied into the top 5 cm. The experiment evaluated a reference treatment (0 NL), three low doses of NL (8, 40 and 80 kg ha(-1) = 0.02x, 0.1x, and 0.2x the NL needed to raise soil pH to 6.0 in the top 5 cm: NLRpH-6), and two large doses (400 and 800 kg ha(-1) = 1x and 2x NLRpH-6). Over the short term (70 days), NL accelerated the downward movement of Ca, likely by mass flow of nanoparticles down soil micro-and macropores. Applying NL to the top 5 cm at 40 and 80 kg ha(-1) was effective at increasing the downward movement of Ca and the neutralization of soil acidity (in terms of pH) to 20 cm depth, as well as rectifying Al toxicity (in terms of exchangeable Al) to <= the critical limit to 10 cm. NL at 80 kg ha(-1) was most economically justified in terms of rectifying Al toxicity throughout the profile. Therefore, NL may introduce new and alternative application strategy that allowing lower rates of lime to be used and thereby offset economic constraints posed by high application rates.