Evaluation of soil characteristics and infiltration capacity under Dimocarpus Longan Fruit-tree based agroforestry in Selopamioro, Imogiri, Bantul, D.I.Yogyakarta

Abstract

Abstract Selopamioro village in Imogiri sub district, Bantul-D.I. Yogyakarta is located along southern mountains of Java. Nowadays, this village is developing agro-ecotourism through fruit-tree based agroforestry for improving household economy while keeping environment of hilly areas. The main objective of this study was to explore and evaluate physical characteristic of soil and infiltration capacity under Dimocarpus longan fruit-tree based agroforestry in Selopamioro village. Total area of Dimocarpus longan fruit-tree based agroforestry is 0,48 hectare with total 52 trees. The soil characteristics were focused on bulk density (ρb), particle density (ρs), porosity, textures, structure, soil moisture, content of organic material (COM), and lime content. The empirical models of infiltration, Kostiakov, was adopted to define soil infiltration capacity. The measurement of infiltration rate in the field was carried out by using Double-ring Infiltrometer method. The soil sampling and infiltration measurement were conducted in three different characteristics of slope, i.e., upper, middle, and lower slopes. The soils were taken from three points and two depth (0-40 cm and > 40 cm) per slope category, whereas the infiltration test was conducted solely in each points of slopes. A regression and correlations method were applied to evaluate the soil characteristics and infiltration capacity. The slope of upper, middle, and lower in Dimocarpus longan land were 30°, 17°, and 39° respectively. The Dimocarpus longan fruit-tree based agroforestry in middle slope was mixed with rainfed rice, the lower was nuts, while the upper slope was dominated by weeds. The soil was characterized as clay, sub angular blocky structure, bulk density (ρb) 1,26-1,46 gr/cm3, particle density (ρs) 2,04-2,10 gr/cm3, porosity 28-40%, soil moisture 36,90-42,00%mass, COM 1,16-1,78%, and lime content 2,69-3,46%. The average of infiltration capacity was 265,10 mm/hours which classified as very fast categories. The strongest relation between physical characteristic of soil and the infiltration capacity was owned by the soil textures. It had correlation coefficient -0,621, while the water content 0,883.