Utilization of Marginal Soils with Application of Phosphorus and Ethephon for Sweet Corn (Zea mays L. saccharata) cultivation

Abundance of marginal soils is among the major constraint to achieve high yield for crop production due to unsuitable physical and chemical properties of the soils. Commonly, farmers would manage the marginal soil by adding soil amendment, compost and fertilizer which increase the cost of production. Alternatively, application of fertilizer together with plant growth regulator (PGR) during crop management can be practiced to utilize the marginal soil effectively. The aim of this experiment was to determine effects of phosphorus (P) fertilizer and PGR namely ethephon on growth performance of sweet corn grown in three marginal soils namely Rasau, Kuah and Dampar. The treatments were arranged as factorial randomized complete block design with four rates of P fertilizer and standard rate of ethephon replicated four times. The results indicated that the physical properties of the marginal soils vary which Rasau dan Kuah series have low content of silt (10.30% and 36.10%), respectively and clay (9.40% and 11.86%) while Dampar series has low sand content (21%). Consequently, Dampar series depicted highest soil moisture content (18.80%) compared to Rasau and Kuah with high content of silt and clay at 42.43% and 36.43%, respectively. At tasseling stage, where application of P fertilizer with combination of ethephon at 0 and 15 kg P2O5 ha-1 there were significant difference between soil series on root length, total biomass wet and dry weight but exception for total biomass dry weight at 0 kg P2O5 ha-1. Moreover, at 45 kg P2O5 ha-1 there were significant difference among soil series on leaf number and total biomass dry weight whereas at highest P rate of 60 kg P2O5 ha-1 only root length and root volume were affected. Most of the results were observed highest on Rasau soil series which contain highest sand particle instead of silt and clay compared to Kuah and Dampar series. However, the addition of ethephon and several P rates did not affect plant height among soil series. The results suggest that, the marginal soil can be utilized for sweet corn production by addition of combined P fertilizer at low rate and PGR.