VOLUME 12 NUMBER 1 (January to June 2019)

by Virginia C. Cuevas^*1, Cirilo A. Lagman, Jr.^2,3, Xavier Anupo², Joey I. Orajay^2,4, and Frances G.E. Malamnao⁵

¹Institute of Biological Sciences, College of Arts and Sciences
     University of the Philippines Los Baños
²University of the Philippines Los Baños Foundation, Inc.
³Department of Soil Science, College of Agriculture, Benguet State University,
     La Trinidad, Benguet
⁴Del Monte Philippines, Bukidnon
⁴University of the Philippines Los Baños Graduate School

This research evaluated the improvements in the rice yield of paddies contaminated with copper-rich (Cu-rich) mine tailings that had been applied with rice straw compost and Trichoderma microbial inoculum (TMI). A field trial with three replicates was conducted in two sites to evaluate the effect of varying rates of compost application on rice yield. Treatments were: 0, 1, 2, 4 kg m^-2 compost application. Dry weight of grains and number of productive tillers were monitored. Another study was conducted that served also as a field demonstration trial on using TMI alone and in combination with rice straw compost to improve yield in these Cu-contaminated rice paddies on the same sites for four seasons involving three pairs of paddy fields in each site. Two paddies compared were: TD0 (Technique Demonstrated) - TMI, 0 compost; TD1 – TMI + compost at 2 kg m^-2. Yield, changes on soil organic matter, soil Cu, and soil pH were monitored. Results of the field trial showed that 2 kg m^-2 application significantly improved yield and number of productive tillers, and this rate was found to be optimum for rehabilitation of Cu-contaminated paddies in the area. Field demonstration on other techniques that can increase yield in Cu-rich rice paddies showed that yield in paddy fields with TMI alone was higher when compared to no amendment shown in the first trial. Yield with TMI + compost was consistently higher compared to paddies with TMI alone.