Quality and antioxidant activity of rice grown on alluvial soil amended with Zn, Cu and Mo

• Application of micronutrients increased macronutrients contents in the plants.
• Micronutrients enhanced the grain quality, chlorophyll and protein contents of rice with antioxidant activities; phenolic and flavonoid contents in rice grain.
• Comparatively higher values of antioxidant activities were found in the de-husked grain compared to those of milled rice in micronutrient applied treatments. The application of micronutrients enhanced rice yield via uptake of nutrients, attributed to increase physiological performance, leading to higher harvest index and grain quality.
• This study focused about the effects of Zn, Cu and Mo in the riverine alluvial soils cropped to rice, not only in Malaysia, but also in the other parts of the globe so as to obtain better grain quality and higher yield of rice.

Insufficient micronutrients are a common phenomenon in Malaysian soils derived from riverine alluvium, which affect the growth and quality of rice. A study was conducted on such soils at Kelantan, Malaysia to evaluate the effects of applying Zn (5 kg ha− 1),Cu (4 kg ha− 1) and Mo (0.5 kg ha− 1) along with the recommended N, P, K and S at 120, 30, 50, 10 kg ha− 1, respectively on rice plant growth, grain yield, quality and antioxidant activity. Any single micronutrient or in combination with macronutrients had positive effects on the growth, chlorophyll contents, grain quality, and protein content of rice. Application of micronutrients increased phenolic compound by 40% and flavonoid content by 71.54% in rice grain compared to the control, particularly, Zn and Cu had positive effects on grain protein percentage. Furthermore, the application of micronutrients increased Zn, Mo, and Cu content in grain and straw. Higher values of antioxidant activities were found in the de-husked grain compared to those of the milled rice in micronutrient applied treatments. The application of the micronutrients to the riverine alluvium soil enhanced rice yield by 18% via uptake of nutrients, attributed to increased physiological performance, leading to higher harvest index and grain quality.