Nutritional Diagnostic in Upland Rice Production in Some Municipalities of State of Mato Grosso, Brazil

Abstract

Nutrient deficiency is one of the most important yield limiting factors in crop production in cerrado soils in Brazil. A survey was conducted with the objective to evaluate soil fertility and nutritional status of upland rice plants in 43 sites, covering 33 rural properties, in three Municipalities of the Chapada dos Parecis Region, State of Mato Grosso, Brazil. Grain yield of upland rice was also determined where soil and plant samples were taken for nutritional evaluation. Grain yield of upland rice varied from 975 to 7853 kg ha−1 with an average value of 3595 kg ha−1. Soil analysis showed average value of pH 5.5, organic matter (O.M.) 21.5 g dm−3, phosphorus (P) 4.1 mg dm−3, potassium (K) 31.6 mg dm−3, calcium (Ca) 17.7 mmol dm−3, magnesium (Mg) 8.4 mmol dm−3, and aluminum (Al) 1.8 mmol dm−3. Average micronutrients levels in the soil were 0.51 mg dm−3 of copper (Cu), 2.4 mg dm−3 of zinc (Zn), 61.6 mg dm−3 of iron (Fe), and 4.79 mg dm−3 of manganese (Mn). Similarly, average base saturation was 28%, Al saturation was 8%, Ca saturation was 18%, Mg saturation was 9%, K saturation was 0.82%, Ca/K ratio was 24, Ca/Mg ratio was 2.23 and Mg/K ratio was 12. Plant analysis showed average values of N 30.3 g kg−1, P 1.68 g kg−1, K 19 g kg−1, Ca 3.87 g kg−1, Mg 2.66 g kg−1, Zn 22 mg kg−1, Cu 8 mg kg−1, Mn 120 mg kg−1, and Fe 106 mg kg−1. Based on soil fertility analysis there were low levels of P, K, base saturation, Ca saturation, Mg saturation, K saturation and deficiencies of Cu, Zn, and Mn in some samples. Plant analysis showed deficiency of P, followed by deficiency of K and N. Among micronutrientes, plant analysis showed deficiencies of Zn, Cu, and Mn in some samples.