Starting in 2024 our compost, lagoon water, and manure reports have alignment marks on the soil nutrients section. (see below).
Suppose that i) you just purchased compost and had it tested by us; ii) the dairy nearby has a bunch of free manure they had tested and you plowed in 2 tons/acre last fall; and iii) you want to use a soil test from last fall instead of pulling a fresh soil sample.

Your soil test reads 11.3 ppm NO3-N and you need to add 186 lbs N/acre to hit your 30 tons/acre yield goal for Corn Silage. We have estimated mineralization rates for both manure and compost on their respective reports. We lay the compost report on bottom, then align the manure report on top of it, and the soil report on top of that.

So we need 186 lbs N/acre, we plowed in two tons of manure/acre providing 16.2×2 = 32.4 lbs/acre, then we added 1 ton of compost/acre which provides 5.4 lbs nitrogen/acre. 186 -32.4 -5.4 = 148.2 lbs N/acre is required from the fertilizer company.
Similar calculations can be performed for P2O5, K2O, and the micronutrients. Sometimes it is important to factor in the sulfur and minerals in irrigation water. Luckily we have packages for that.
We are full-circle at Weld Labs. We test the irrigation water, the soil, the compost, and the fertilizer to get your crops growing. During growth we test the plant tissue to determine if there are nutrient deficiencies that might affect the harvest. Then we test the harvested crop to determine protein, fat, fiber, and ultimately market value.