Basalt is naturally available and well known as parent material of fertile and highly productive soils. This implies that the conditions of good soil properties and high productivity could be restored by applying basalt. For rice husk, the annual world output is about 116 million tones and is mainly distributed in the rice mills as the main by-product and agro-waste that cause serious environmental problems. However, rice husk may be used as an environment-friendly source of soil amendment and at the same time solves environmental problems. The objective of this study was to restore properties of the poor upland soil (Oxisol) and to promote crop growth using natural basalt and composted rice husk. Three series of experiments were carried out: 24 months soil incubated with various rates of finely ground basalt or composted rice husk in the laboratory, 15 months pot experiment used basalt or rice husk treatment and grown with cocoa in the glasshouse, and 24 month field experiment used combination of basalt and rice husk treatments and grown with cocoa. The long term effect of treatments were assessed by periodically sampled the soil and measured the changes in soil pH, variable charge property (point of zero charge or pH0), total organic C (TOC), carbon functional groups as revealed by 13C nuclear magnetic resonance (NMR) and various ion compositions of in situ soil solution. No in situ soil solution study was carried out for field experiment due to lack of soil moisture. The agronomic observations were plant height, stem diameter and dry matter weight (DMW). The statistical analyses used SAS (1999) soft ware package. The application of finely ground basalt showed all rates (5 to 80 t/ha) significantly increased soil pH values varying from 3.8 to 6.5 for laboratory, from 4.0 to 5.1 for glasshouse and from 4.3 to 4.8 for field experiment, depending on application rates and duration of application. In all cases, the pH values were still significantly higher at the end of experiments compared the control treatment, indicating the basalt has long residual effects on soil pH. Similarly, rice husk compost (RHC) application increased soil pH but only at 20 to 80 t/ha rates and the magnitude was lower than the basalt. The residual effects could take place 12 months for laboratory and glasshouse and 9 months for field experiments. The application of basalt and rice husk, either singly or in combination decreased pH0, indicating that basalt and rice husk have the ability to generate soil negative charge, which in turn increased soil capability to retain cations. This is extremely expected to prevent intensive cation leaching in Oxisols (poor soils). Composition of in situ soil solution showed the basalt or CRH application significantly increased the concentration of Ca, Mg, K, Na and Si ions compared to the control treatment (0 t/ha) and their trends increased with increasing duration of application periods (2 to 6 factors for basalt and 1.5 to 4 factors for rice husk). In contrast, the Al and Mn concentrations in soil solution were significantly suppressed to nontoxic levels. In all cases during the experiment, the organic C content significantly increased with increasing RHC application rates but consistently decreased with increasing duration of application periods. Using the regression equations obtained from relationship between soil organic C and application periods, it could be predicted that every 3 months the organic C decrease 0.02-0.04, 0.12-0.18 and 0.21-0.52 units (depends on application rates) under laboratory, glasshouse and field conditions, respectively, indicating RHC decomposition in soils is very slow. The solid state cross polarization magic angle spinning (CP/MAS) 13C NMR spectra of rice husk-treated soils showed dominant very sharp and well resolved resonance peaks of O-alkyl and di-O-alkyl C and minor proportion of alkyl C, indicating RHC mainly consisted of cellulose. The cellulose and alkyl C of RHC are resistant to microbial degradation and it may account for the slow decomposition rate. This finding indicates the organic C derived from rice husk has a long resident time in the soil, which is beneficial for many regions where organic C decomposed rapidly. Basalt or CRH treatments clearly improved cocoa growth as revealed by the significant increase in plant height, diameter and dried matter weight (DMW) compared to the control treatment. The implication of these studies is properties of poor soils (highly weathered soils) can be restored using basalt or/and CRH as a natural soil amendment and more environmentally accepted to promote crop growth.