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)