Rating chart for NPK after soil testing
Rating chart for NPK after soil testing
Soil fertility
levelOrganic carbon(%)Available N
(kg/ha)Available P2O5 (kg/ha)Available K2O
(kg/ha)
High(H)Above 0.75Above 450Above 90Above 350
Medium(M)>0.50-0.75>280-450>45-90>200-350
Low(L)Up to 0.50Up to 280Up to 45Up to 200
Rating chart organic carbon in particular situation after soil testing
Soil fertility
levelLand situation
Hill and forest soilTerai soilUpper situation of Red & Lateritic soil
High(H)Above 0.75Above 450Above 90
Medium(M)>0.50-0.75>280-450>45-90
Low(L)Up to 0.50Up to 280Up to 45
Soil reactionLess than 5.5 -Acidic soil
5.5-6.5 -Slighly acidic
6.5-7.5 -Neutral
7.5-8.5 -Slighly alkalineAbove 8.5 - Alkaline
Conductivity (in dS/m)
Below 1 -Normal
1-2 -Critical for germination
2-3 -Critical for growth of salt sensitive crops
Above 5 - Injurious to most plant
Sulphur(SO4= in mg/kg)Low 0-10
Medium >10-15
High Above 15
Micronutrients level of soilMicronutrientTesting ProcedureCritical level (mg/kg)
IronDTPA extract4.50
ManganeseDTPA extract1.00
CopperDTPA extract0.20
ZincDTPA extract0.60*
MolybdenumAmmonium oxalate0.05
BoronHot cacl2 extract0.36
* for rice and wheat the level is 0.86 mg/kg (DTPA extract)
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