NI 43-101 Preliminary Economic Assessment - Verde Potash

Verde Potash Plc 11-4
Cerrado Verde Project
NI 43-101 Preliminary Economic Assessment
11.1.4 Results of Agronomic Testwork
The available K in the soil shown in Table 11.1.4.1 and 11.1.4.2 indicated that there is no
difference between the water soluble K source (KCl) and Thermo-K, 60 days after application in
sandy and clay soil, using dosage applications of 200 and 400kg/ha K 2 O.
This result shows that the thermal treatment applied to the Verdete (raw material used in the
manufacture of Thermo-K) was very efficient from an agronomic point of view. This can be
seen when comparing the results against those of the pure Verdete, without heat treatment. In
this case, the K in the soil did not differ from the control standard which means that virtually no
potassium from the Verdete was released to the soil, indicating a low efficiency of this material
as a source of potassium for plants.
Table 11.1.4.1: K content in soil (Mehlich 1) After 60 Days of Incubation with Different
Sources of Potassium in a Clay Soil.
Dose K 2 O
K – Source
kg ha -1 KCl Thermo-K Verdete
Average
0 -- -- -- 0,07
200 0,24 * a B 0,23 * a B 0,07 ns b A 0,18
400 0,36 * a A 0,32 * b A 0,07 ns c A 0,25
Average 0,30 0,27 0,07
CV% = 9,40
DMS dose = 0,03; DMS source = 0,03; DMS Dunnet = 0,04
Averages followed by distinct letters, lowercase on the line and uppercase in the column, differ by Tukey test at 0.05 significance; ns not
significant by the Dunnett test at 0.05 significance, * significant by the Dunnett test at 0 05 significance;
Table 11.1.4.2: K Content in Soil (Mehlich 1) After 60 Days of Incubation with Different
Sources of Potassium in a Sandy Soil.
Dose K 2 O
Source
kg ha -1 KCl Thermo-K Verdete
Average
0 0,04
200 0,25 * a B 0,24 * a B 0,04 ns b A 0,18
400 0,41 * a A 0,38 * a A 0,04 ns b A 0,28
Average 0,33 0,31 0,43
CV% = 12,89
DMS dose = 0,04; DMS source = 0,05; DMS Dunnet = 0,05
Averages followed by distinct letters, lowercase on the line and uppercase in the column, differ by Tukey test at 0.05 significance; ns not
significant by the Dunnett test at 0.05 significance, * significant by the Dunnett test at 0 05 significance;
In addition to potassium addition the application of Thermo-K also appears to increase available
Ca and Mg in the soil after 60 days of incubation. Presumably, magnesium is also released from
clays in the Verdete and Ca is present as lime from calcining of limestone in the kiln (Tables
11.1.4.3 through 11.1.4.6). Further with a higher application mass of Thermo-K (400kg/ha)
greater availability of Ca and Mg was also observed. Potassium chloride did not affect the Ca
and Mg in the soil because it simply does not have these elements in their composition.
The Verdete, however, despite containing Ca and Mg in its composition, did not increase the
levels of these elements in the soil, strengthening the conclusion that the Verdete has low
reactivity and is not able to release nutrients to the soil in the short term.
SRK Consulting (U.S.), Inc. September 16, 2011
Cerrado Verde_NI 43-101 PEA_343500.020_007_KG