Combined application of mulches and organic fertilizers enhance shallot production in dryland
Department of Agrotechnology, Faculty of Agriculture, Tadulako University, Jl. Soekarno-Hatta Km 9, ID 94118 Palu, Central Sulawesi, Indonesia
The objective of this study was to determine the type of mulch and organic fertilizer that can induce suitable changes in the microclimate and chemical properties of soil for the promotion of growth and yield of shallot on dryland. A factorial randomized block design experiment with two factors and three replications was constructed. The first factor was mulches consisting of rice straw, coconut husk, silver-black plastic mulch, and without mulch. The second factor was the organic fertilizers composed of either composted cow manure, Gliricidia leaf compost (each applied at 5 t ha-1), and no organic fertilizer. Among all treatments tested, straw mulch with 5 t ha-1 cow manure (L1P1) decreased the soil temperature from 36 °C to 30 °C and increasing the soil moisture from 7% to 37%. This, in turn, increased the cation exchange capacity by 24.32 meq 100 g-1, pH by 6.83, C organic from 0.74 to 2.72%, C/N ratio by 13.27%, total N by 0.29%, total P from 20.02 to 28.86 mg 100 g-1 and K2O by 39.16 mg 100 g-1. In addition, the growth and yield of shallot were positively affected, as assessed by plant height, leaf number, root length, root dry weight, total leaf area, number of bulbs per hill, bulb diameter, weight of fresh bulbs, and bulb yield. The yield of bulbs increased from 4.27 to 10.22 t ha-1 after L1P1 treatment. This study demonstrates the application of straw mulch and 5 t ha-1 cow manure could enhance the yield of shallot cultivation on drylands.