Green manure Nutrient Calculator
Value the N-P₂O₅-K₂O in green manure (dhaincha/sunhemp) (~0.5:0.1:0.3%) and the urea, DAP and MOP it replaces, with first-year nitrogen availability accounted for.
A 45–55 day dhaincha or sunhemp green manure incorporated before flowering adds 60–100 kg N/ha — much of it from biological fixation — plus organic matter. Incorporate succulent, before stems turn woody.
Indicative planning figures based on published research averages. Local soil tests, varieties and weather change actual requirements — confirm with your agronomist or extension officer.
Organic and integrated-nutrient farmers use the free Green manure Nutrient Calculator to put a rupee value on their green manure (dhaincha/sunhemp) and work out how much bagged fertilizer they can safely cut back.
About Green manure Nutrient Calculator
A short dhaincha or sunhemp green-manure crop, ploughed in before flowering, can add 60–100 kg N/ha — much of it biologically fixed — plus a surge of organic matter. This tool estimates the nitrogen and fertilizer value from the fresh biomass you turn in; incorporate it succulent, before stems go woody, for the highest credit.
How to use Green manure Nutrient Calculator
- 1Enter your green manure (dhaincha/sunhemp) application rate and field area.
- 2Read the total N, P₂O₅ and K₂O supplied and the fertilizer it replaces.
- 3Cut your bagged-fertilizer plan by the equivalents shown, then follow the application note.
Why use Green manure Nutrient Calculator?
- ✓Uses a realistic 0.5:0.1:0.3% N-P₂O₅-K₂O analysis for green manure (dhaincha/sunhemp)
- ✓Applies a 60% first-year nitrogen availability factor — organic N releases slowly
- ✓Converts the nutrients into urea, DAP and MOP equivalents and a rupee value
- ✓Free, instant and fully in-browser
Frequently asked questions
What is the nutrient value of green manure (dhaincha/sunhemp)?+
Green manure (dhaincha/sunhemp) typically analyses around 0.5% N, 0.1% P₂O₅ and 0.3% K₂O. Roughly 60% of the nitrogen is available in the first year; the rest builds soil over following seasons.
Why is only part of the nitrogen counted the first year?+
Organic nitrogen is locked in complex compounds that soil microbes mineralise gradually. About 60% becomes plant-available in year one for green manure (dhaincha/sunhemp); the carry-over keeps feeding later crops, which is why organic matter improves long-term fertility.
How and when should I apply it?+
A 45–55 day dhaincha or sunhemp green manure incorporated before flowering adds 60–100 kg N/ha — much of it from biological fixation — plus organic matter. Incorporate succulent, before stems turn woody.
Is this calculator free and private?+
Yes — completely free with no sign-up, and every calculation runs in your browser so nothing you enter is uploaded.
Related Agri tools
Tractor Fuel Consumption Calculator
Estimate your tractor's diesel consumption per hour from its horsepower, load and specific fuel consumption.
● LiveTractor Fuel Cost Per Acre Calculator
Convert your tractor's fuel use per hour into diesel litres and cost per acre for any field operation.
● LiveImplement Field Capacity Calculator
Calculate the effective field capacity (ha/h and acres/h) of any implement from width, speed and field efficiency.
● Live