High acidity level and low nutrient availability are the most challenging factors of shallot production in peat soils. The purpose of this study was to find out the best lime material and the level of NPK fertilizer on shallot production in peat soil in Central Borneo, Indonesia. The experiment used was a Split Plot Design with three replications. The main plot was three types of lime material: 3 t ha−1 dolomite, 3 t ha−1 agriculture limestone and 1.5 t ha−1 calcium hydroxide. The subplots were ten combinations of NPK fertilizers. The results showed that lime materials and doses of NPK fertilizer had a significant effect on shallot growth and yield. Hydrated lime doses 1.5 t ha−1 and NPK fertilizer dose 100 kg N ha−1, 100 kg P2O5 ha−1 and 100 kg K2O ha−1 gave the highest bulb yield (7 t ha−1) compared to other trials. However, this bulb yield was lower compared to different adaptive cultivars from previous studies. Further experiments using higher levels of lime and adapted varieties are necessary to get the optimum bulb yield.

Shallot farming on peatland has physical, chemical and biological constraints which does not support crop growth properly. These constraints can usually be treated with amelioration. It is therefore important to understand the effects of applying ameliorant on soil properties and shallots productivity. The study was conducted in Central Kalimantan Province of Indonesia from April to August 2017. In this study, ameliorant such as 10 t ha−1 mineral soil + 4 t ha−1 dolomite + 5 t ha−1 manure has been applied into 0 – 20 cm soil depth. Furthermore, NPK fertilizer, peat fertilizer, bio fertilizer, mulch and or a combination thereof had been added as the treatments. The results showed that application of mineral soil + dolomite + manure was able to improve the physical, and chemical properties of soil on all treatments such as increases in bulk density, mineral content, pH, Ca, Mg, K, base saturation, and P, so that the improved soil condition can support the shallots growth properly. The shallot dry weight production ranged from 9.60 to 15.49 t ha−1. As a comparison, Indonesia’s national average shallots productions is 9.31 t ha−1. This finding indicates that shallots farming can be considered as the alternative for peatlands utilization.