The development of technologies that provide rapid acidity amelioration of the soil profile through the surface application of amendments and phosphogypsum, such as no-till (NT) systems, is extremely important to provide adequate chemical conditions in tropical soils with low natural fertility, which limits the grain yield of upland rice (Oryza sativa L.). Thus, this study aimed to evaluate the effects of surface applications of lime, silicate, and phosphogypsum, applied individually or in mixtures, on the chemical properties of the soil profile in an NT system and to determine their effects on the nutrition, yield components, and grain yield of upland rice. The experiment was designed as a completely randomized block with eight treatments replicated four times. The combination of phosphogypsum with lime and/or silicate improved the surface and subsurface soil chemical properties 12 months following application. The mixtures increased the concentrations of K, Ca, Mg, N-NO 3 − , and S-SO 4 2− in the subsurface layers. The sulphur concentration in the flag leaves of upland rice was higher with phosphogypsum application. The number of panicles per m 2 and grain yield of upland rice were positively influenced by the surface application of soil acidity amendments and phosphogypsum mixtures.

Core Ideas Soil acidity limits crop production in tropical regions. Soil amendments mixture can be a strategy to alleviate subsoil acidity. Subsoil profile acidity reduces common bean grain yield. The movement of surface‐applied lime to subsurface soil layers is slow, and, consequently, liming requires a long period of time to become effective. Thus, it is important to develop strategies to increase the efficiency of acidity amendments practices in order to improve the chemical properties of tropical acid soils in no‐till systems. The aim of this study was to evaluate the effects of applying mixtures of silicate, lime, and phosphogypsum to the soil surface in tropical no‐till systems on soil chemical properties and leaf nutrient concentrations, yield components, and grain yield of the common bean (Phaseolus vulgaris L.). A field experiment was performed during two growing seasons (2004 and 2005) in a field with Typic Acrustox soils. Among the treatments, the silicate–phosphogypsum mixture was more effective for ameliorating soil acidity at a depth of 0 to 0.20 m over a short period of time (6 mo). The application of soil amendments separately or in mixtures increased the soil pH to 0.40 m depth 18 mo after application. Combining the surface application of phosphogypsum with lime and/or silicate effectively increased the NO3−–N, SO42−–S, and Ca2+ levels at soil depths of up to 0.40 m over a relatively short period of time, resulting in a higher base saturation in the deepest layer evaluated (0.20–0.40 m). Compared with the control treatment, the mixtures of soil acidity amendments and phosphogypsum resulted in greater Ca, S, and Si concentrations in the leaves and increased the grain yield of the common bean by >22% over two growing seasons. Long‐term studies are required to establish the frequency of reapplication and the residual effects of soil amendment mixtures.