Zeolite effects on soil water content on spinach (Spinacia oleracea L.) growth and yield: first results

Zeolites, microporous crystalline aluminosilicate minerals, are used in many fields as catalysts and sorbents. In agriculture, zeolites are considered soil conditioner because they can improve soils' ability to retain water as well as their cation exchange capacity. To assess the amendment effect of a coal fly ash zeolite, previous described by Belviso et al. (2022), on spinach (Spinacia oleracea L. cv ‘Lorelay’) growth and yield, an experiment was conducted in controlled conditions at the Agronomy laboratory of the University of Basilicata. Polypropylene plastic pots having a volume of 5 liters were used to cultivate the spinach plants propagated by seeds. Pots were filled with a silty-loam soil, previously air-dried and passed through a 2-mm to have 2 experimental treatments: 1) silty-loam soil plus zeolite at a percentage of 1% (Zeo 1) and 2) silty-loam soil without zeolite as control (Zeo 0). To monitor moisture content of the soil, Watermark probes were installed in pots. During the experiment, reading the watermark data, plants were watered to restore the field capacity. On plants, greenness index of leaves were measured by using a spad meter and gas exchange parameters were measured using a LI-6400 portable photosynthesis system. At the end of the trial, per each pot, some measurements were conducted on plants to have the leaf area, the fresh and dry weight, and the dry matter content. Our results confirmed the capacity of zeolite to hold water improving the ability of the soil to be moister. Moreover, dry matter content and greenness index of leaves of plants cultivated on the Zeo1 soil were higher than the control ones.