Time interval

(years)

Soil organic matter

(%)

Grain yield (kg∙ha−1)

Increase of grain yield due to the application of 200 kg FDA ha−1 (kg∙ha−1)

without FDA

with 200 kg∙ha−1 from FDA

1 - 5

4.80

3450

4674

1224

6 - 10

4.65

3348

4594

1246

11 - 15

4.21

3034

4349

1315

16 - 20

3.39

2377

3834

1457

21 - 25

3.67

2613

4019

1406

26 - 30

3.70

2638

4038

1400