Manure Nutrient Application Rate
N-based rate = crop N need / (total N x availability).
Example
You enter
- Crop N need (lb/acre) 150
- Manure total N (lb/ton) 10
- First-year N availability (%) 50
- Manure P2O5 (lb/ton, optional) 5
- Manure K2O (lb/ton, optional) 8
You get
- Avail n per ton 5
- Application rate (N-based) 30
- P2o5 applied 150
Checked against published worked examples from: Penn State Extension.
Details, formula, and sources
ScopeWith the P2O5 and K2O delivered at that rate reported so phosphorus over-application is visible. 150 lb N/acre, 10 lb N/ton, 50% avail -> 30 ton/acre, delivering 150 lb P2O5/acre; composted manure (70%) drops it to 21.4 ton/acre. The nutrient-management plan governs.
Formula or tableavail_N_per_ton = total_N x availability%; rate = crop_N_need / avail_N_per_ton; P2O5_applied = rate x P2O5/ton; K2O_applied = rate x K2O/ton.
Source and editionNitrogen-based manure application rate and the co-applied P/K, per USDA NRCS Code 590 (Nutrient Management), by name.
Free accessThe N-based rate and the co-applied nutrient arithmetic follow the public USDA NRCS Code 590 nutrient-management method.
What governsEstimate. AHJ and licensed professional govern.
API field namescrop_n_need_lb_acre, total_n_lb_ton, availability_pct, p2o5_lb_ton, k2o_lb_ton, avail_n_per_ton, rate_ton_acre, p2o5_applied
- Available N total N x first-year availability; rate = crop N need / available NUSDA NRCS Code 590
- Co-applied P/K P2O5 and K2O = rate x their content per tonUSDA NRCS Code 590
- P over-application an N-based rate usually over-applies phosphorus; the plan governsscope of this tile