Growth and fresh yield response of Swiss chard (Beta vulgaris L. Var. Cicla) CV. Ford Hook Giant to zeolite soil amendment

Abstract

Vegetable and other crop producers face numerous challenges, including high input costs, water shortages, and soil degradation. Zeolite, a microporous aluminosilicate mineral with high cation exchange capacity and water retention properties, is receiving a growing research interest due to its positive effects as a soil amendment on various crops, including vegetables, however, specific studies on its impact on Swiss chard are relatively limited. This study investigated the effects of zeolite application on the growth and yield of Swiss chard (Beta vulgaris L. var. cicla) cv. Ford Hook Giant under greenhouse conditions over two growing seasons (2018 and 2019). Zeolite was applied at weight-to-weight ratios of 0:10, 1:9, 2:8, and 3:7 to sandy soil. Growth parameters (plant height, leaf area, and chlorophyll content) were monitored weekly, and fresh and dry yields were measured at 59 days after transplanting. Results indicated that zeolite application improved (p≤0.05) leaf area, leaf number, fresh and dry yield in the second growing season, including their growth rate per week. These improvements were linked to improved soil quality due to zeolite application. The initial season exhibited inconsistent trends, likely due to the integration period required for zeolite to stabilise in the soil system. Swiss chard leaf moisture also reduced (p≤0.05) with increased zeolite application in the second season, this was linked to Swiss chard cultivated under the zeolite-amended treatments having higher leaf growth which may have encouraged greater transpiration losses. Furthermore, chlorophyll content index and leaf moisture percentage showed limited direct correlation with yield, suggesting that growth parameters such as plant height and leaf area are better indicators of yield potential in Swiss chard. These findings demonstrate zeolite's potential to enhance vegetable production, emphasising the need for a stabilisation period in sandy soils. Future research should explore the long-term effects of zeolite application on crop performance and soil health.