No abstract

The sampling was carried out in two sampling sites; Chenderoh Reservoir, Malaysia and Jatiluhur Reservoir, Indonesia. These reservoirs are the initial of cascade reservoirs on Perak River and Citarum River. The aquatic plants distribution and abundance were recorded, and water quality parameters were measured. A total of 23 aquatic plant species from 14 families were identified. The populations of water hyacinth (Eichhornia crassipes) and giant salvinia (Salvinia molesta) were recorded in all sampling points of both reservoirs. Based on the TSI (Chl a), Chenderoh Reservoir was subjected to a mesotrophic, whereas, Jatiluhur Reservoir was subjected to an eutrophic reservoir. E. crassipes and S. molesta which were abundant in those reservoirs were listed in the 100 world worst invasive alien species.

A sub-irrigated planter (SIP) is a container irrigation technique in which water is supplied to the crop from the bottom, stored in a saturated media-filled reservoir beneath an unsaturated soil, and then delivered by capillary action to the root zone. The aim of this study was to optimize the water management and to assess the performance of this technique in terms of water use efficiency, soil moisture, and solute distribution in comparison with surface irrigation in a Mediterranean greenhouse. The experiment consisted of four SIP treatments, with a constant water level in the bottom reservoir in order to evaluate the effect of two different irrigation salinities (1.2 and 2.2 dS m−1) and two depths of substrate profiles (25 and 15 cm). The results showed that SIP is capable of significantly improving both water-use efficiency and plant productivity compared with surface irrigation. Also, a 24% average reduction in water consumption was observed while using SIP. Moreover, SIPs with a higher depth were recommended as the optimum treatments within SIPs. The type of irrigation method affected the salinity distribution in the substrate profile; the highest salinity levels were registered at the top layers in SIPs, whereas the maximum salinity levels for the surface treatments were observed at the bottom layers. SIPs provide a practical solution for the irrigation of plants in areas facing water quality and scarcity problems.