Impacts of Silicon Foliar Spraying and Nitrogen Application Techniques on Quantitative and Qualitative Parameters of Rice at Different Planting Spaces

The silicon (Si) foliar application along with timely application of nitrogen (N) can be help to increase the quantity and quality of crops. Also, planting spaces is an agronomic technique that can affect yield and quality of rice. The objective of this study was to evaluate the effects of Si foliar application and N application techniques on yield components, grain yield and accumulation of Si and N in rice grains at different planting spaces. The experiment was conducted as a split-split-plot in a randomized complete block design with three replications during two crop years of 2018 and 2019. The experimental treatments included the main plot assigned to planting spaces (25×10 cm, 20×10 cm), the sub-plot assigned to N application techniques (N application as 33.3% at basal + 33.3% at panicle initiation + 33.3% at full heading, N application as 40% at basal + 40% at panicle initiation + 20% at full heading), and the sub-sub-plot assigned to foliar application of Si (control or non-use of Si, Si foliar application). The results indicated that the reducing planting space (20×10 cm) resulted in an increase in the number of panicle number m–2 by 9.3%, followed by an improvement in grain yield by 9.7% compared with planting distance of 25×10 cm. The plants that received N in three equal splits had higher grain yield (6993.1 kg.ha–1 ). The Si-treated plants showed both higher yield parameters and greater physiological characteristics when compared with control plants. We observed an increase in grain yield (10%), N concentration (7%) and uptake (14.3%) in grain, protein content (6.8%), and nitrogen use efficiency (7.1%) by supplying Si fertilizer. Overall, our results revealed that foliar application of Si could be an effective technique for increasing rice grain yield and improving rice nutritional quality.