Impact of organic mulch and exposure to shallow groundwater levels on Cnidoscolus aconitifolius in a tropical wetland, South Sumatra, Indonesia

Agricultural land in Indonesia is decreasing due to its conversion for various non-agricultural interests, which are economically more profitable. The remaining land available for agricultural activities is a suboptimal wetland. The reduction in cultivable areas has led to the evaluation of alternative crops in suboptimal land conditions. Chaya (Cnidoscolus aconitifolius) is a fast-growing perennial plant, its leaves are edible and rich in vitamins, minerals, and dietary fiber. However, the chaya plant has not been intensively tested for its adaptation to shallow groundwater tables in tropical lowlands. This study aimed to assess chaya’s adaptability to shallow groundwater table conditions and the benefits of using organic mulch. This research consisted of two separate parts, one part was related to organic mulch benefits (planting media without watering, with organic mulch but not watered, and with organic mulch and watering), while the other one was related to shallow groundwater table tolerance. The study followed a randomized complete block design consisting of three replications. Results showed that chaya plants negatively responded to the shallow groundwater table conditions. Growth retardation due to shallow groundwater levels is reflected in the averages of leaf length, leaf width, leaf area, canopy diameter, and canopy area; fresh and dry weight of stem, petiole, and leaf blade; development of roots; SPAD value at 7 weeks after transplanting and it was based on visual appearance. However, despite the increase in substrate humidity due to the application of organic mulch, the effects were not significant on most of the measured morphological traits. In conclusion, chaya plants are not able to adapt to shallow groundwater levels and do not require organic mulch on the soil surface.