Soil and climate description of benchmark sites for lowland rice-based cropping systems research in the Philippines and Indonesia

Soil morphological, physical, chemical and mineralogical properties are described at five locations in major rice (Oryza sativa L.) growing areas of the Philippines (two sites) and in Indonesia (three sites) which were selected for lowland rice-based cropping systems research. The data were used to classify the soils into the local soil series, soil taxonomy and The Australian Soil Classification systems. These data were intended to facilitate transfer of knowledge of improved farming systems technology to other lowland rice growing areas in the regions. The soils were classified as Andsisols, Inceptisols and Vertisols, and were characterised by clay contents ranging from 370 to 870 g kg ˇ1 and cation exchange values ranging between 17 and 68 cmol (pa )k g ˇ1 for whole soil. pH values were neutral to mildly alkaline. Land surface and root zone attributes were qualitatively evaluated for limitations to post-rice crop production by interpretation of modified surface and sub-soil properties associated with rice production. Leakiness of bunds was also examined and mainly attributed to biological activity and for the development of drainage channels. Climatic data are presented for each of the five sites and the characteristics for potential rainfall incidence are given for the post-rice dry season crop period. The soil sites selected have a range of properties which are deemed to represent large areas of soils used for rice production in these two countries. # 2000 Elsevier Science B.V. All rights reserved.