Hi all,
Was wondering if any of you may take the time and make comments towards my
interpretation of soil tests. (Testing myself for the exam)
Wanting to see if I'm getting the hang and where I'm not making links.
There is no physical assessment of the soil, just the data to work from.
(I've already given them an ear full of not treating the test but the soil,
the cause not the symptom, but this hoop I must jump through)
Incitec Soil Test Analysis
0 - 15 cm Ca - 76.8% Mg - 8.69% K - 13.04% Na - .72% Al - .72%
OC - 1.2 CEC 6.9 pH (CaCl2) 6.9 EC - .6 Ca/Mg - 8.2 P - 18
OM - .72 Cl - 13 Cu - 1 Zn - .8 Mn - 12 Fe - 43 B - .5
20 + cm Ca - 70.1% Mg - 23.1% K - 6.1% Na - .34% Al - .34%
P - <5 CEC 14.7 pH(CaCl2) 14.7 EC - .5 Ca/Mg - 3
Organic matter levels need to be increased. The pH increases from mod. acid
to a weakly alkaline. The nitrate N is 12 mg/kg in the top and 0 in the
20+cm zone. S at 9 mg/kg in the top and again 0 in the lower zone. P is at
18 mg/kg followed by 4 at 20 +cm. K is at .9 in both soils. Mg, pH and CEC
Increase with depth. figure the increase in CEC may be due to more clay
content, seeing no OC
the first 15 cm appear to be a sandy clay loam the lower being a light clay.
the CEC indicates a poor shrink swell potential, whilst the Ec indicates a
likelihood of dispersion. Negligible salinity with ECe at .77 & .68.
the levels of Mg in the subsoil indicate leaching and may be causing K
deficiency, the K in the topsoil could result in Mg deficiency. The drop in
Ca/Mg ratio has me stumped. Would liming be required, but that would then
impact on the Ca/Mg ratio especially on the top 15cm. The cations are below
to take up the Ca when it gets down there. Tend to think that there shoud
be more P available below for the rhizosphere, but also see this as moving
slowly through the profile. Availablility of P being affected by pH, which
if increased in top 15 cm from lime application would make more P available
up top, but not necessarily in bottom sample.
Zinc could be lacking due to climatic conditions cold winters / wet springs
(not this year) more required especially for high productive crops such as
fruit and Veg.
Nitrogen fertility is rated at moderate fertility in the top 15 cm, thinking
the drop in Ca/Mg ratio has decreased the N in the lower sample.
Any indications of where I'm not linking or looking would be helpful.
Thanks
L&L
Liz
