modern him As aeawaiee eyaporaios, (irst ialeiie and
dolomite, men gypsum and anhydi-iie sepaiaie out, all
are med ior soil Eondlllomllg. pH adiiisimeni, or to
restoie soil erumb siriieiiire.

Neil, rock sales crystallize om, biii only wei irupieal
uplands may aduilly laek this common nutrient,
allhnugh even iheie speeiiie planis (allen aquatiei
eonteniraie sali whieh (an be gatlwlrd or leaehed hdin
iheirashes

lasfly, pmdsh, mlgneslum salts, and a host 9! minor
elemenis remain, the evapmiils ittiose already
deposited; being the mosi soluble nnd iheietoie earliesi
deposited, TM liquid ihai remains alter the eornrnori
sali eoneeni deposition is a ”(h sonree ol minor
minerals end irate elemeiiis. it is, in iaet, sold ii
~biiierni~ ibiiier oily niiidsi tor diluiiiin and
immunon in mop soi , or in low eoneeniratioiii
(diluied lwsmil) used direeily as iiiliar sprays in
atiengths Virymg lrom l-zo l/ha Very eoriosiiie,
liltiei-iia iwhieh indude bromine and many oi the early
elements oi the periodie table, plus some rare
minerals), are saiely held and disinbiited only via
non<oriwive vessels and pipes (today, poiyeihylene
papa and drums).

mm are dlup, and easily mmporbed hi leaehed
aieas, biit their euoeis musi be established by loeal
timls oii speeiiie erop. As timeeyaponies aie so easily
dissalved they are also those most likely to be earried
iii sea in iris

mm

craniiis column ielspais yielding potash or sodium
salts Limestone and dolomite yield ealeium and
magnesium, and mineral deposits or iheir ores give
traees oi the bane minor elements 01 these, ealeiiim (in
all bul highly taleareoiis areasi is mosi needed,
dolomite ieiieept wheie magnesium is aheady in high
mum is next, phosphaies and telapars lollow, along
with true elements in small qulnlme: ias low as 5.7
igloo ha int zinc. topper, mbah, and molybdenum,

Field ei-ials have esin ished ihai eheap eiies, tinely
giound, are as euairiye as more relined sulphales or
oaidea lLeeper mzl. Someilmes sueh minerals are
given to aniinah as salt mks, in molasses, in water, or
as inieeiions or “bullds” oi slowerelease elements
icobaltl in a pellet which lodges in IN ruinen, Some
mineral elemenls also ream ptnnm VII LU'IM, but ioliar
sprays are more rapidi g and eitsoive.

nne mtk dusts ova Spedllt nxk suited ioloeal meds
are ohen eheaply available troni quarries or grayel pits.
basali dusts are helpiul, tor :xample, on leaehed
iropieal soils Rock phosphate eoniains s-ls-Ji
phosphouos, but is very slow to release nutrieni, and
may in ten beabsorbad tornpleiely on ioleaehed clays
ind (lay-Imms. super-arid phosphate added to
composi, or to plants used in eumpost, may be
neeessary iinder sueh eiiiiditions, Rock dust as an
niiseleeeiiie ukgmy oon du as mum harm as good on
soils, adding eitesaiye or poisonous nutrients in lame
eases, or enoessiwe mieronuments,

 

8 7
THE DISTRIBUTION OF ELEMENTS

IN THE SOIL PROFILE

There ieeiii to be Iwo important deierminanis oi the
concentration olelenienis or nutrients Ihmugh the soil
proiile ithdi vzniul eolumn eil soil horn the sin-hm iii
2 m or ao deep: The dial is the peiieiraiion oi warm,
Water is a uniyemal solvent, enabling eoinpiiunda to
dissoeiaie iulo ions, and Innspo‘mng ihem, firstly, to
val-mus deposit. at inisrosiies in the Jail This eiceee
works in three dimensions

. Water iraiiels byi ‘ ration io varying depths,
soaking in [term the siiriate dawn

. Waier can also rise lroni the soil water table
upwards, either by rloodinp, by capillary aeilon

   

leoiiiiniied on page 195

 

 

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