Magnesium and zinc fertilisation improves rice yield and yield component responses to nitrogen, phosphorus, and potassium

The aim of this study was to assess the effects of magnesium (Mg) and zinc (Zn) on the response of rice to nitrogen (N), phosphorus (P), and potassium (K) application. Two sets of field experiments were carried out in Benin. A Box Behnken Design with eight replications per year with treatments of N, P, potassium (K), Mg, and Zn was used for the first experiment, while a randomised complete block design with five treatments varying in Mg and Zn was used for the second experiment. Co-application of major nutrients with Mg and/or Zn significantly increased rice yield and nutrient use efficiencies. Co-application of N and Mg increased grain yield, filled grain rate, and 1 000 grains weight by 53.5, 7.10, and 7.34%, respectively. Likewise, the co-application of N with Zn increased rice yield, panicles per plant, and spikelets per panicle by 35.69, 14.78, and 6.06%, respectively. When P was co-applied with Zn, grain yield, spikelets per panicle, and the 1 000 grains weight increased by 27.21, 5.71, and 6.20%, respectively. The co-application of K with Mg led to an increase of grain yield and filling of grain by 24.28, and 5.71%, respectively. This study revealed the positive effects of Mg and Zn on rice yield response to the application of N, P, and K.