Abstract

The problem of soil lacking fertility is an important factor affecting sugarcane production in Thailand, especially in sandy soil area. The use of soil conditioners is one of the methods to increase nutrients to the sandy soil. Humic acid is able to extract the positive charge of nutrients and reduce the evaporation of water from the soil and is an important property for sandy soil and contains important nutrients for plants such as nitrogen and sulfur. The objective of this experiment was to determine the effect of humic acid appication rate on germination rate, growth and yield components of sugarcane cultivar Khon Kean 3 in sandy soil conditions. The experiment was arranged in a randomized complete block design (RCBD) with 3 replications with 5 treatments, which consisted of 1. Chemical fertilizer as using in normal farm rate 50kg/rai; (Control), 2. (Control) + Filter cake rate 3,200 kg/rai; (FC), 3. (Control) + Humic acid rate 0.32 kg/rai; (0.32kg), 4. (Control) + Humic acid rate 0.64 kg/rai; (0.64kg) and 5. (Control) + Humic acid rate 1.28 kg/rai; (1.28kg). The results showed that fresh and dry weight yield, tiller number, leaf area and root length of sugarcane were not statistically significant in all treatments. However, 1.28 kg tended to show low number of leaves and leaf area. While, 0.32 kg tended to show high number of leaves and leaf area. Therefore, the humic acid application of 0.32kg was a suitable treatment, not only use low application rate of humic acid, but also gave plant growth closed to other treatments.