The relation between N, P and K fertilisers and pH of the soil
| pH(water) of the soil | Efficiency (%)* of nitrogen sources | Efficiency (%) of phosphorus sources | Efficiency (%) of potassium sources |
| 4,50 | 35-30 | 20-25 | 30-35 |
| 5,00 | 50-55 | 30-35 | 50-55 |
| 5,50 | 70-75 | 45-50 | 70-75 |
| 6,00 | 85-90 | 75-80 | 100 |
| 7,00 | 100 | 100 | 100 |
* Efficiency as % of the source at pH(water) 7,00 which is seldom 100%.
The effect of different pH-leaves in the root zone on citrus production.
| pH | Yield kg/tree | Surface area of the canopy in m2 | Mass roots in kg per tree |
| 4,00 | 20 | 18,3 | 5,20 |
| 5,00 | 50 | 26,6 | 7,50 |
| 6,00 | 100 | 30,9 | 7,80 |
| 7,00 | 110 | 33,8 | 7,75 |
The effect of different concentrations of aluminium in the nutrient solution on the growth of citrus seedlings.
| Concentration Al in mg per litre | Plant length in mm | Leaf mass in gram | Stem mass in gram | Root mass in gram |
| 0 | 401 | 7,84 | 4,31 | 13,68 |
| 10 | 361 | 7,45 | 3,56 | 11,30 |
| 25 | 320 | 6,15 | 3,74 | 11,06 |
| 50 | 257 | 4,86 | 2,46 | 5,98 |
| 100 | 164 | 2,87 | 1,11 | 2,40 |
JGK CONSULTING