EFFECTS OF STONEMEAL WITH ORGANIC FERTILIZATION ON TROPICAL SOILS
This paper presents partial results of research whose main goal is to investigate the potential of using rock dust for soil remineralization. Five types of rocks were evaluated (kamafugite, carbonate-bearing mica schist, hydrothermal metamorphic rock, fresh basalt and weathered basalt) with, or without, the addition of organic compost (bovine manure). Experimentation took place near the city of Planaltina, in the Federal District area of Brasilia, Brazil. Testing occurred over a two-year period on five agricultural crops (corn, beans, garlic, carrots and okra), on a minimum of two harvests, using crop rotation. Preliminary results show that different rock types present different behaviors in regards to varying fertility levels, as well as agricultural productivity. Nevertheless, all results were highly positive when compared to control plots. The rock type that showed the highest level of performance was carbonatebearing mica schist. Despite this, plots containing only stonemeal showed superior productivity compared to control plots. Furthermore, fertility parameters (pH, Cation Exchange Capacity and Total Organic Capacity) also underwent positive alteration through rock use. The availability of key macronutrients (K, P, Ca and Mg) increased in all plots. These indicators show that the use of stonemeal for food production in tropical soils may contribute to the eradication of poverty and food sovereignty in Brazil, as well as ensure food production without the use of chemical fertilizers.
