The experiment was installed in a typic Aluminic
Humic Cambisol (EMBRAPA, 2013), with the following physical and chemical attributes, in the 0-0.20 m layer: clay and organic matter of 455 and 46 g kg-1, respectively; pH-[H.sub.2]O of 5.4, pH-SMP of 5.9; [Al.sup.3+], [Ca.sup.2+], [Mg.sup.2+] and CEC of 1.5; 5.6; 1.9 and 12.7 cmolc [dm.sup.-3], respectively; available P and K of 3.1 and 92 mg [dm.sup.-3], respectively, and base saturation of 61%, analyzed according to Tedesco et al.
In this study, the peloids were prepared using as solid phase two bentonites, aluminic and magnesium respectively, and as liquid phase, distilled water.
There are small differences in the degree of aggregation between the fabric of the aluminic phase and the magnesium.
It was first reported by Brown (1884) as "hydrous manganous aluminic sulphate."
(1884) A new hydrous manganous aluminic sulphate from Sevier County, Tennessee.
laterite consists of gibbsite (Al(OH)3) and boehmite (AlOOH) and is the main ore of aluminium.
Experiment II: Upland rice cultivation in aluminic soil
However, they were cultivated in pots containing aluminic soil (m% > 50%) and evaluated for the number of panicles per plant, grain production, shoot dry matter and harvest index of the cultivars under stress by [Al.sup.3+].
The soil used in the experiment was of low natural fertility and aluminic, classified as Dark Red Latosol, with medium sandy texture, which showed the following chemical characteristics: 7 mg [dm.sup.-3] of P-resin; 15 g [dm.sup.-3] of organic matter; 4.1 of pH in Ca[Cl.sub.2]; 0.7, 5, 3, 69, 11 and 78 mmolc [dm.sup.-3] of K, Ca, Mg, H + Al, [Al.sup.3+] and CEC, respectively; and 55.8% of saturation by [Al.sup.3+].
The region's soil has a basaltic rock origin, classified as brown latosol aluminic
cambic (Oxisol-class A) with clay texture (EMBRAPA, 1999).
The soil of the experimental area was a cambic aluminic
Brown Latosol, with prominent A horizon, gently undulating relief and basalt substrate (EMBRAPA, 1999), with textural class varying from clayey to very clayey.