Peatland in Indonesia has a potential for maize cultivation, but it has constraints that low of soil pH and of nutrient availability. Use of ameliorants from coastal sediment and salted fish waste was an alternative to improve peatlands productivity and maize yields. Objective of the study was to examine effects of coastal sediment and salted fish waste on growth and yield of maize at three kinds of soil of peatlands of Kubu Raya, West Kalimantan. This research was conducted  in  field  using  Inter-area analysis  design.  The  first  factor  was  combination  of  each ameliorants  which consisted of 5 levels, namely: 1) treatment under farmer custom at the sites (control); 2) coastal sediment of 20 Mg ha-1 + 0.75 Mg of salted fish waste ha-1; 3) coastal sediment of 40 Mg ha-1 + 1.5 Mg of salted fish waste ha-1, 4) coastal sediment of 60 Mg ha-1 + 2.25 Mg of salted fish waste  ha-1. The second factor was soil types which consisted of three levels, namely: Typic Haplohemists, Typic Sulfisaprists and Typic Haplosaprists. Each treatment was repeated 5 times. The results showed that combination of 40 Mg ha-1 of coastal sediment and 1.5 Mg ha-1 of salted fish waste was the best combination for all soil type. It increased plant height (33% - 44%), shoot dry weight (74% - 75%), number of seeds per cob (31% -110%), weight of 100 seeds (58% -71%) and dry grain weight per plant (136 % -160 %) at each soil. The highest yield was found in soil of Typic Haplosaprists (219.54 g), followed by Typic Sulfisaprists (210.72 g) and Typic Haplohemists (208.82 g).Keywords: Coastal sediment, maize, peat soils, salted fish waste [How to Cite: Denah S, BH Sunarminto, D Shiddieq and D Indradewa. 2014. Use of Ameliorants to Increase Growth and Yield of Maize (Zea mays L.) in Peat Soils of West Kalimantan. J Trop Soils 19: 35-41. Doi: 10.5400/jts.2014.19.1.35]

The correlation of major growth parameters with the yield of cassava in different growth phases was investigated in 2013 and 2014. This experiment was conducted to assess the effect of two cassava varieties and the different growth phases to the yield and yield components. In experiment, the varieties as treatment were arranged in a randomized complete block design (RCBD) with three replications. Two varieties consisted of superior Adira-4 and local varieties Singgah were used. The growth parameters (plant height, stem diameter, leaf number) and yield components (number of tuber, weight per tuber and tuber yield) in early growth phase, maximum vegetative growth phase and charging tuber phase, were observed. Based on the correlation results, the growth parameters and the yield highly affected to the final outcome of cassava tubers at different growth phases. In the early growth phase, occurs high demand to assimilate with the expense of storage root. However, from the maximum vegetative phase, growth parameters began to show a significant positive contribution to the tuber weight. Weight of fresh tuber in both varieties increased at the charging of tubers phase and thereafter (enlarged bulb). The early growth phase and maximum vegetative phase might not generate a significant contribution to the final yield of cassava tuber. Making those two periods were not suitable time for optimum harvesting result, and it still depended on the variety and its allocation.

This study aims to find out the soil morphology diversity at the southern flank of Mt.Merapi Yogyakarta, Indonesia. The field research was conducted using purposive sampling method where each site of geomorphological unit as representing of the cone, upper, middle and lower slopes of Mt.Merapi. Poligenesis of the soil morphology was observed at pedon P1 with composition of the upper and buried soil was Typic Hapludands-Typic Hapludands, P3 (Andic Eutrudepts-Vitrandic Udorthents), P4 (Vitrandic Udorthents -Typic Hapludands), and P5 (Andic Eutrudepts-Andic Eutrudepts). Whereas the monogenesis of the soil morphology was observed at pedon P2, P6, P7 and P8 with subgroups of Typic hapludands, Andic Eutrudepts, Andic Dystrodepts and Typic Udorthents, respectively. Soil morphogenesis diversity (polygenesis) shown by the presence of a pedon having more than one soil profile was not a limiting factor for crop roots growth, so the agro-ecosystem recovery process was relatively fast.

Iron (Fe) poisoning can cause problems on growth, the formation of saplings, and the filling of grains. These problems lead to and plant death or decrease in productivity. The inhibition of growth and production is increasingly higher in susceptible varieties. The distribution of iron concentration varies in different regions and locations of swamp rice farming. Various adverse effects of iron poisoning on rice have been widely reported, but the spatial distribution of iron in tidal fields is still rare. Iron distribution in various soil profile depths has not been widely investigated and data availability to avoid Fe poisoning in tidal swamps has not been widely reported. Spatial distribution of Fe concentrations is needed as a reference for rice cultivation in tidal swamps. This study has been conducted in November 2015 until August 2017 using the survey method in the Barito River area, South Kalimantan, Indonesia. The use of thematic maps such as tidal height difference (Δ), tidal flood type, and thickness of mud map. The results showed that the spatial concentration of Fe is highest in the zone I which has the highest difference (Δ) of high tide maximum and low tide maximum. While on the soil profile, the highest of Fe concentration is in layer 1 and the lowest concentration is in layer 3. Based on the overflow type, the highest Fe concentration is typed A and type B especially close to the estuary. To prevent iron poisoning, rice seedlings should reach layer 2 (> 10 cm) and choose the safe zone that is zone II, III, or IV to produce optimal rice production.

Mujiyo M., Sunarminto B.H., Hanudin E., Widada J., Syamsiyah J. (2017): Methane production potential of soil profile in organic paddy field. Soil & Water Res., 12: 212−219.The use of organic fertilizers in the organic paddy/rice field can increase methane (CH 4 ) production, which leads to environmental problems. In this study, we aimed to determine the CH 4 production potential (CH 4 -PP) by a soil profile from samples using flood incubation. Soil properties (chemical, physical, and biological) were analyzed from soil samples of three different paddy farming systems (organic, semi-organic, and conventional), whilst soil from teak forest was used as the control. A significant relationship was determined between soil properties and CH 4 -PP. The average amount of CH 4 -PP in the organic rice field profile was the highest among all the samples (1.36 µg CH 4 /kg soil/day). However, the CH 4 oxidation potential (CH 4 -OP) is high as well, as this was a chance of mitigation options should focus on increasing the methanotrophic activity which might reduce CH 4 emissions to the atmosphere. The factor most influencing CH 4 -PP is soil C-organic (C org ). C org and CH 4 -PP of the top soil of organic rice fields were 2.09% and 1.81 µg CH 4 /kg soil/day, respectively. As a consequence, here the mitigation options require more efforts than in the other farming systems. Soil with various amounts of C org reached a maximum point of CH 4 -PP at various time after incubation (20, 15, and 10 days for the highest, medium, and the lowest amounts of C org , respectively). A high amount of C org provided enough C substrate for producing a higher amount of CH 4 and reaching its longer peak production than the low amount of C org . These findings also provide guidance that mitigation option reduces CH 4 emissions from organic rice fields and leads to drainage every10-20 days before reaching the maximum CH 4 -PP.