Update changelog

NEWS.md

@@ -5,14 +5,15 @@
 * The uppper limit for `D_BCS` is increased from 40 to 50
 * Switch on crumbleability
 * For `calc_phosphate_availability` the category `arable` is added for the crop categories
+* Changed evaluation of sulphur for arable fields #26
 
 ### Fixed
 * Fixed typo if mais in `ind_managment`
 * Fixed test for winderodibility
 * Use the correct correction factor in `calc_sealing_risk` #19
 * Fix for calculating `I_P_CEC` #24
 * Fix for calculating difficult values in `calc_sombalance` #25
-* Fix for `calc_sbal_arable` where combinations of soil type and region that do not exist in table 6.2 of Handboek Bodem & Bemesting gave a NA.
+* Fix for `calc_sbal_arable` where combinations of soil type and region that do not exist in table 6.2 of Handboek Bodem & Bemesting gave a NA #26
 
 ## Version 0.8.0 2019-08-02
 ### Added