The response by selected rice genotypes to organic ameliorants in tidal swampland which is affected by Fe toxicity

Ferrous Fe toxicity in rice has been reported to be one of several major limitations in terms of wetland rice production. Previous studies have reported a decrease in paddy rice yields of between 12–100% due to this problem. A study was conducted in order to determine the growth and yield factors for selected rice genotypes as a response to the presence of organic ameliorants, and their interaction in controlling ferrous Fe toxicity levels in rice which is grown in tidal swampland. Experiments formed part of this study, with these being conducted in tidal swampland around Danda Jaya village and Belandean village in Barito Kuala Regency, South Kalimantan. The experiment was arranged in a split-plot design to test the organic ameliorant treatments (the control was fresh Salvinia sp, with the compost being formed of Salvinia sp, plus rice straw, and cow manure as the main plots, and sub-plots being formed of rice genotypes (TOX-4136, Inpara-1, Inpara-2, Inpara-4, and IR-64). Results from the experiments revealed the fact that organic ameliorants could reduce ferrous Fe toxicity levels, as well as Fe content in plant tissues, while plant height and the number of tillers also decreased. Rice genotypes which are medium tolerant or fully tolerant to ferrous Fe toxicity when organic amelioration treatments are added can serve to decrease ferrous Fe toxicity and increase the number of filled grains and yield. Applications of fresh Salvinia and Salvinia compost were as effective as an application of rice straw and cow manures when it came to successfully increasing the yield of rice grown in tidal swampland. Ferrous iron toxicity in rice which has been produced in tidal swampland can be overcome by using tolerant genotypes (Inpara-1 and Inpara-4), or organic ameliorants (Salvinia sp).