Water Absorption by Hydrogel Using Fertilizers

It was sought, in this research, to evaluate the effects of fertilizer solutions on water retention by hydrogel as well as if the application methods and fertilizers affect water retention when the hydrogel is added to the soil. In laboratory works (experiment 1), the completely randomized design was used taking into account four treatments: distilled water; Urea (UR – 2.0 g L-1 ) and Magnesium Sulfate + Monoammonium Phosphate (MS + MAP – 2.0 g L-1  each). Regarding the experiment 2, considering soil columns, a 2x3x2 factorial was used, corresponding to two hydrogel application methods: dry and mixed to the soil or diluted in water and concentrated in the center of the column; three fertilizer solutions: distilled water, UR (2.0 g L-1 ) and MS + MAP (2.0 g L-1  each) with two cycles and three repetitions. An additional witness (hydrogel free) was also added. Total water volume absorbed by hydrogel, volume stored in the soil after each cycle, pH and electrical conductivity (EC) of leached solutions were all analyzed. The MS solution was the one who impacted the most the water absorption by the hydrogel, principally when the hydrogel was not present in the soil. The pH and EC of leached solutions evidenced the fertilizer solutions salinity.