Table 21. Comparison Of Potassium Fertilizers

For 30 Lbs K2O/Acre
CharacteristicsValue Of Fertilizer, $/TonQuantities NeededN Added
K2O, %Energy Index, Gal/TonK2O, $N + P2O5, $Energy, $Total, $Typical Cost, $/Ton1Tons/AcreLbs/1000 Sq FtLbs/Acre
Organic
Fresh manure
Cow0.5202421265625060
Horse0.525252633523060
Pig0.418161926730090
Sheep132383344312050
Poultry manure
Cage layer0.520214213775230150
Broiler0.7642126680417090
Compost3401010416117004020
Hay1.880612821006228006040
Straw1.38047829340009025
Cocoa shells38310118610717004015
Fertrell Super N
4-2-44≤ 501335≤ 52≤ 8736022503050
Inorganic
Wood ashes518725100023(P2O5) 15
Granite dust5171785100023
Greensand7232312570017
Basalt2-10
Sul-po-mag, K-mag
0-0-21-11 Mg2170(Mg) 901602052406(Mg) 26
Potassium chloride
0-0-6060200200200832
Potassium sulfate
0-0-50501681681002

1 Basis of costs: hay, $1.25/40 lb bale; Fertrell Super N, $9/50 lb bag; greensand, $170/ton; sul-po-mag, $9/80 lb bag; 0-0-60, $8/80 lb bag. Magnesium is valued at $0.41/lb, based on the cost of magox at $19/80 lb bag.   [return to top]

© 2013 Robert Parnes

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