*4.2.9 Sap analysis*

A refractometer gives general information about plant health, but for more information including nutrients balance, a sap analysis is necessary. Plant sap analysis provides 21 nutrients parameters values that enable farmers to optimize the crops' fertilization plan. The information is valuable because the uptake of plant nutrients are revealed in a few hours, the increasing performance can be tracked graphically, similar to the example shown in **Figure 3**. To a better understanding, one can compare a sap plant analysis with human blood analysis. A plant sap analyze tells the current

*Reducing the Effects of Drought and Degradation of Agricultural Soils, in the Context… DOI: http://dx.doi.org/10.5772/intechopen.104446*

**Figure 3.** *Example of the variation of the Brix index for tomato juice, for a period of 30 days.*

uptake of nutrients, excesses or deficiencies of nutrients long term before can be seen on a plant leaf, plant reserves of nutrients, nutrient imbalance in soil, what nutrient plant can use at that moment for its own growth, or even fruit quality [67]. Sap analysis laboratory in less than one week will provide the analysis sheet with a fertilizer plan recommended. A balanced mineral uptake increases plants' health that gets resistant to diseases and insects attack and crosses the drought.
