A field experiment was conducted at Rubber Research Institute of Nigeria, Edo state Iyanomo during the cropping season to determine the effect of different soil amendments on the chemical properties of the soil, root colonization and the growth of rubber saplings.. The experiment was a 3 x 4 factorial and arranged in a randomized complete block design (RCBD) with three replicates. The field was partitioned into plots with each measuring 1m x 1m and 1m apart between the plots giving rise to a total of 36 plots. 30 cmx 30 cm plant spacing was adopted. The materials used were three strains of the mycorrhiza Glomus (M1, M2 and M3) applied at the rate of 5000 kg/ha each, NPK 15:15:15 at the rate of 112 kg/ha and poultry manure was also applied at the rate of 6000 kg/ha which gave rise to 12 treatments which is as follows: M1F0–Glomus mosseae, M2F0– Glomus clarius, M3F0–Glomus deserticola, M0F1– Chemical Fertilizer 15:15:15 (NPK), M0F2 – Poultry Manure, M1F1–Glomus mosseae + NPK 15:15:15, M2F1–Glomus clarius + NPK 15:15:15, M3F1–Glomus deserticola + NPK 15: 15:15, M1F2– Glomus mosseae + Poultry Manure, M2F2– Glomus clarius+ Poultry Manure, M3F2–Glomus deserticola + Poultry Manure and M0F0 which was the Control respectively. Plant data; girth and height were collected at monthly interval for seven (7) months. Soil samplings were obtained before and after application of soil treatment at 0-15cm depth. Also, the roots of Hevea saplings were also harvested and subjected to chemical analysis for root colonization. The result showed general improvements in the chemical properties after application of treatments in organic matter, nitrogen, pH, calcium, Avail phosphorus, ECEC and base saturation. The treatments of Glomus clarius + NPK 15:15:15 showed a higher root colonization than the other treatments with values of 38.70 arbuscules and 42.70 vesicles, invariably the same treatment recorded a higher growth response of rubber saplings height and girth than the other treatments with values of 45.1, 57.2, 78.3 and 140.3cm in the second, third, fourth and seventh month while 10.42 and 11.52cm on the sixth and seventh month respectively, which connotes that root colonization favours the growth of rubber saplings.
Keywords: Mycorrhizae, Root Colonization, Rubber Saplings