Regular soil testing is an important element in nutrient management. You can use soil tests as a diagnostic tool or to identify trends through time. Soil testing laboratories use different test methods, which may influence results and sufficiency ranges. Therefore, the sufficiency ranges in this publication are accurate only for the test methods listed.

Advances in micro-irrigation techniques, drip and under-tree sprinklers, have  facilitated more widespread adoption of fertigation,  especially for perennial  crops, including citrus.  It is well known that fertigation improves nutrient uptake efficiency.