Fertilizer worksheet

1. Fertilizer product needed: 7.14 kg

1. The product is 28% nitrogen (N) by weight, so divide the target rate by that fraction

   $\frac{4}{\frac{28}{100}}$$=14.285714\text{\hspace{0.17em}g/m² of product}$

2. Multiply by your area to get grams, then divide by 1,000 to get kilograms

   $\frac{14.285714\times 500}{\mathrm{1,000}}$$=7.142857\text{\hspace{0.17em}kg}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{7.142857}{18}$$=0.396825$$=\text{round up →}1$

4. Check what you actually apply: the product times each nutrient's label percent (grade 28-6-9)

   $\text{N 2 kg, P₂O₅ 0.4286 kg, K₂O 0.6429 kg}$

2. Fertilizer product needed: 17.08 lb

1. The product is 24% nitrogen (N) by weight, so divide the target rate by that fraction

   $\frac{1}{\frac{24}{100}}$$=4.166667\text{\hspace{0.17em}lb per 1,000 ft²}$

2. Multiply by your area in thousands of square feet, since the rate is per 1,000 ft²

   $4.166667\times \frac{\mathrm{4,100}}{\mathrm{1,000}}$$=17.083333\text{\hspace{0.17em}lb}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{17.083333}{22}$$=0.776515$$=\text{round up →}1$

4. Check what you actually apply: the product times each nutrient's label percent (grade 24-6-9)

   $\text{N 4.1 lb, P₂O₅ 1.025 lb, K₂O 1.5375 lb}$

3. Fertilizer product needed: 56 kg

1. The product is 7% phosphate (P₂O₅) by weight, so divide the target rate by that fraction

   $\frac{7}{\frac{7}{100}}$$=100\text{\hspace{0.17em}g/m² of product}$

2. Multiply by your area to get grams, then divide by 1,000 to get kilograms

   $\frac{100\times 560}{\mathrm{1,000}}$$=56\text{\hspace{0.17em}kg}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{56}{20}$$=2.8$$=\text{round up →}3$

4. Check what you actually apply: the product times each nutrient's label percent (grade 24-7-8)

   $\text{N 13.44 kg, P₂O₅ 3.92 kg, K₂O 4.48 kg}$

4. Fertilizer product needed: 14.77 lb

1. The product is 22% nitrogen (N) by weight, so divide the target rate by that fraction

   $\frac{1}{\frac{22}{100}}$$=4.545455\text{\hspace{0.17em}lb per 1,000 ft²}$

2. Multiply by your area in thousands of square feet, since the rate is per 1,000 ft²

   $4.545455\times \frac{\mathrm{3,250}}{\mathrm{1,000}}$$=14.772727\text{\hspace{0.17em}lb}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{14.772727}{18}$$=0.820707$$=\text{round up →}1$

4. Check what you actually apply: the product times each nutrient's label percent (grade 22-6-10)

   $\text{N 3.25 lb, P₂O₅ 0.8864 lb, K₂O 1.4773 lb}$

5. Fertilizer product needed: 53.33 lb

1. The product is 12% potash (K₂O) by weight, so divide the target rate by that fraction

   $\frac{2}{\frac{12}{100}}$$=16.666667\text{\hspace{0.17em}lb per 1,000 ft²}$

2. Multiply by your area in thousands of square feet, since the rate is per 1,000 ft²

   $16.666667\times \frac{\mathrm{3,200}}{\mathrm{1,000}}$$=53.333333\text{\hspace{0.17em}lb}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{53.333333}{22}$$=2.424242$$=\text{round up →}3$

4. Check what you actually apply: the product times each nutrient's label percent (grade 26-3-12)

   $\text{N 13.8667 lb, P₂O₅ 1.6 lb, K₂O 6.4 lb}$

6. Fertilizer product needed: 22.5 kg

1. The product is 10% potash (K₂O) by weight, so divide the target rate by that fraction

   $\frac{5}{\frac{10}{100}}$$=50\text{\hspace{0.17em}g/m² of product}$

2. Multiply by your area to get grams, then divide by 1,000 to get kilograms

   $\frac{50\times 450}{\mathrm{1,000}}$$=22.5\text{\hspace{0.17em}kg}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{22.5}{22}$$=1.022727$$=\text{round up →}2$

4. Check what you actually apply: the product times each nutrient's label percent (grade 20-4-10)

   $\text{N 4.5 kg, P₂O₅ 0.9 kg, K₂O 2.25 kg}$

7. Fertilizer product needed: 112 lb

1. The product is 5% phosphate (P₂O₅) by weight, so divide the target rate by that fraction

   $\frac{1}{\frac{5}{100}}$$=20\text{\hspace{0.17em}lb per 1,000 ft²}$

2. Multiply by your area in thousands of square feet, since the rate is per 1,000 ft²

   $20\times \frac{\mathrm{5,600}}{\mathrm{1,000}}$$=112\text{\hspace{0.17em}lb}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{112}{16}$$=7$$=\text{round up →}7$

4. Check what you actually apply: the product times each nutrient's label percent (grade 21-5-12)

   $\text{N 23.52 lb, P₂O₅ 5.6 lb, K₂O 13.44 lb}$

8. Fertilizer product needed: 250 lb

1. The product is 4% phosphate (P₂O₅) by weight, so divide the target rate by that fraction

   $\frac{2}{\frac{4}{100}}$$=50\text{\hspace{0.17em}lb per 1,000 ft²}$

2. Multiply by your area in thousands of square feet, since the rate is per 1,000 ft²

   $50\times \frac{\mathrm{5,000}}{\mathrm{1,000}}$$=250\text{\hspace{0.17em}lb}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{250}{21}$$=11.904762$$=\text{round up →}12$

4. Check what you actually apply: the product times each nutrient's label percent (grade 22-4-11)

   $\text{N 55 lb, P₂O₅ 10 lb, K₂O 27.5 lb}$

9. Fertilizer product needed: 94.29 lb

1. The product is 7% potash (K₂O) by weight, so divide the target rate by that fraction

   $\frac{1}{\frac{7}{100}}$$=14.285714\text{\hspace{0.17em}lb per 1,000 ft²}$

2. Multiply by your area in thousands of square feet, since the rate is per 1,000 ft²

   $14.285714\times \frac{\mathrm{6,600}}{\mathrm{1,000}}$$=94.285714\text{\hspace{0.17em}lb}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{94.285714}{22}$$=4.285714$$=\text{round up →}5$

4. Check what you actually apply: the product times each nutrient's label percent (grade 18-4-7)

   $\text{N 16.9714 lb, P₂O₅ 3.7714 lb, K₂O 6.6 lb}$

10. Fertilizer product needed: 56 kg

1. The product is 4% phosphate (P₂O₅) by weight, so divide the target rate by that fraction

   $\frac{4}{\frac{4}{100}}$$=100\text{\hspace{0.17em}g/m² of product}$

2. Multiply by your area to get grams, then divide by 1,000 to get kilograms

   $\frac{100\times 560}{\mathrm{1,000}}$$=56\text{\hspace{0.17em}kg}$

3. Divide by the bag size, then round up, since you can only buy whole bags

   $\frac{56}{20}$$=2.8$$=\text{round up →}3$

4. Check what you actually apply: the product times each nutrient's label percent (grade 14-4-12)

   $\text{N 7.84 kg, P₂O₅ 2.24 kg, K₂O 6.72 kg}$