Green Manure (Dhaincha / Sesbania) سبز کھاد
A living nitrogen factory — grown, then ploughed in before the main crop.
수치가 아닌 범위인 이유
Percentages are on an AIR-DRY biomass basis — fresh dhaincha is ~85% water, so per-tonne-fresh nutrients are far lower. eAgri/TNAU course material reports Sesbania aculeata at 2.6–3.2% N (dry basis) accumulating 130–185 kg N/ha; a published green-manure table gives 3.50% N, 0.60% P2O5, 1.20% K2O. Actual nitrogen added depends on biomass produced and incorporation timing.
범위 출처: www.eagri.org
What it is
Green manuring means growing a fast legume crop — dhaincha (Sesbania aculeata) is the classic choice in South Asian rice systems — and incorporating it into the soil at 45–60 days, before it turns woody. The legume fixes atmospheric nitrogen, and the incorporated biomass releases it as it decomposes.
Benefits
- Adds 130–185 kg N/ha of biologically fixed nitrogen (eAgri/TNAU figures)
- Adds large quantities of fresh organic matter, improving soil structure
- No transport or purchase cost — grown in situ
- Particularly valuable before transplanted rice
Precautions
- Takes land and water for 45–60 days — it competes with the cropping calendar
- Incorporating bulky biomass needs labour or machinery (plough/hydro-tiller)
- Nutrient percentages quoted are dry-basis; fresh-weight nutrients are ~6–7× lower
- Up to three-quarters of the fixed nitrogen can be lost in poorly managed lowland soils — incorporate into moist soil and transplant the next crop within 1–2 weeks
Application guidance
Sow dhaincha at ~20–25 kg seed/ha after the previous harvest. Incorporate at 45–60 days while still succulent (before flowering woodiness), preferably into standing water for rice fields. Transplant or sow the next crop 1–2 weeks after incorporation.