The impact of horticulture farming practices in Andisols forest on organic-P content, Tawangmangu, Central Java

Abstract

This research aimed at studying the change of organic-P status as an impact of horticultural farming in Andisols forest. Horticulture is an alternative agricultural practice which mainly develops in upland nowadays. However, the presence of this agricultural practice significantly influences on soil chemical properties, at most organic P-content. This research was conducted at five observation sites in the southern slope of Lawu Mountain, Tawangmangu, Central Java. Horticulture farming in this area has been developed for more than 25 years with organic manure application mainly derived from cow dung. This organic manure is applied for 15–25 Mg Ha−1yr−1. The Andisols in Lawu forest is mostly covered by Pine (Pinus merkusii) and the predominant horticulture vegetation developed in this area is Carrots (Daucus carota). The soil sampling was conducted through five replications for each site. The results showed a significant decreasing of organic P-content in the horticulture farming with more than 15 years of cultivation. The decreasing of organic-P content was correlated with the decreasing of organic-C content. There was a positive correlation between organic-P content and organic-C content as well as Fe-humus contents. However, the correlation between organic-P content and pH (H2O) remained negative.