Effects of Secondary and Micronutrients on Nutrient Uptake and Yield of Rice (Oryza sativa L.)

Market availability and final consumption are ultimately determined by regional and cultural preferences, as well as the need for stability during storage and transportation. Together with calories, rice has minimal fibre and fat content but is a good source of iron, magnesium, phosphorus, manganese, selenium, thiamine, and niacin. A field experiment was conducted to evaluate the effects of integrated application of macronutrients, secondary nutrients (S and Mg), and micronutrients (B and Zn) on yield, yield components, and nutrient uptake of rice (Oryza sativa L.) variety Legon One in the semi-deciduous zone of Ghana. The study was carried out on Awaase sandy loam soils at Adwaase in the Atwima Kwanwoma District. Initial soil properties indicated moderately acidic conditions (pH 5.61) with low fertility, including low total nitrogen (0.10%), organic matter (1.58%), available phosphorus (7.03 ppm), and deficiencies in S, Mg, Zn, and B. The experiment was arranged in a randomized complete block design with 20 fertilizer treatments and four replications. Treatments were formulated from NPK blends enriched with secondary and micronutrients, with N applied at 90–150 kg ha⁻¹, P at 30–90 kg ha⁻¹, K at 20–90 kg ha⁻¹, and varying levels of S, Mg, Zn, and B. Results showed that integrated nutrient application significantly (p < 0.05) improved plant height, tiller number, 1000-grain weight, grain yield, straw yield, and nutrient uptake. However, panicle length and uptake of P and Mg were not consistently affected. The combination of NPK with sulfur (T2) produced the highest grain yield, straw yield, and 1000-grain weight, highlighting the importance of Sin rice production. Treatments incorporating secondary and micronutrients further enhanced yield components and nutrient uptake efficiency. Maximum uptake of N, P, K, and S occurred under T10, T14, T18, and T21, while Mg uptake was highest in Mg-amended treatments (T19 and T21). Overall, T14 and T21 were identified as the most effective and economically viable treatments. The study underscores the importance of balanced fertilization for improving soil fertility and sustaining rice productivity in tropical soils.