Two types of finished compost, manure compost and spent mushroom compost, both significantly increased soil salinity.  However, with sufficient irrigation, the spike in electrical conductivity was reduced to within optimal levels by January (1.5 months after compost incorporation) and possibly earlier.  In a field with deficit irrigation, high EC levels were still measured in soil 7 months after compost incorporation.  This could lead to long term salt accumulation and resulting damage to plants.