Silicon enhances yield and nitrogen use efficiency of tropical low land rice

Abstract

High nitrogen (N) rate often leads to low yield of rice due to lodging and mutual shading. This study was conducted to ascertain whether silicon (Si) could enhance yield response of rice to higher N rate by enhancing rigidity of plant parts and improving photosynthesis. The effects of Si and N on crop growth, photosynthesis, N use efficiencies and yield of rice were investigated during wet season (June to November) in sub-humid tropical region of India. An increasing trend in crop growth rate with Si at all levels of N was observed. Silicon reduced the flag leaf angle making the leaf more upright and enhanced flag leaf N content. Leaf chlorophyll concentration and single leaf photosynthesis rate were higher with Si compared to without Si at flowering stage. Both N and Si significantly affected panicle number and grain filling.Application of 200 kg SiO 2 ha −1 and 100 kg N ha −1 produced the highest number of panicle per square meter, filled grain per panicle and yield. Significant yield increases ranging from 8.2-16.9% were observed with Si compared to without Si. Both N and Si treatments had significant effects on N uptake and N use efficiency. Agronomic N use efficiency and N recovery efficiency were higher with Si compared to without Si. The highest physiological N use efficiency was recorded with 200 kg SiO 2 ha −1 and 80 kg N ha −1 . Silicon may enhance yield response of rice to higher N rate by improving source (photosynthetic) capacity and sink (reproductive organ) strength.Abbreviations: DMA, dry matter accumulation; FL, flowering; HI, harvest index; MT, maximum tillering; NRE, nitrogen recovery efficiency; NUE a , agronomic nitrogen use efficiency; NUE p , physiological nitrogen use efficiency; PFP N , partial factor productivity of nitrogen; PI, panicle initiation; PM, physiological maturity.

Silicon Amendment Enhances Agronomic Efficiency of Nitrogen Fertilization in Maize and Wheat Crops under Tropical Conditions

“…However, most studies related to Si-amendment sources application focused on soil chemical shifts instead of plant growth promotion, and nutrient uptake and imbalance. The application of various forms of Si (i.e., slag materials, silica powder, silicates, among others) could improve plant growth and development with greater nutrient uptake in different crops [ 16 , 19 , 20 , 21 ]. Haddad et al [ 22 ] indicated a beneficial effect of Si treatment in alleviating damage associated with nitrogen (N) deficiency in rapeseed ( Brassica napus L.).…”

“…Liang et al [14] reported that Si content in Oxisols in the tropical zone can be less than 1% due to intense weathering processes. Highly weathered tropical and subtropical soils under continuous cropping systems are generally low in available Si content due to heavy desilication of primary silicate minerals, release and leaching of basic cations with decreased base saturation, and crop removal [3,7,15,16]. Therefore, the decrease in Si availability in tropical soils might have significant impacts on cropping systems if not properly managed.…”

Silicon-Mediated Priming Induces Acclimation to Mild Water-Deficit Stress by Altering Physio-Biochemical Attributes in Wheat Plants

“…Si provision improved the yield of rice by increasing the mobilization of photoassimilates and amino acids from vegetative tissues to grain and nitrogen use efficiency. It redirected the primary metabolism by acting as a signaling factor under unstressed conditions (Pang et al, 2019;Mohanty et al, 2020).…”

Silicon attenuates abiotic stress caused by ammonium toxicity but not nitrogen deficiency in cotton plants

“…A strategy to mitigate nutritional disorders of N is to utilize silicon (Si), as it mitigates the symptoms of stress caused by N deficiency (Deus et al, 2020) and toxicity (Gao et al., 2014). Furthermore, Si has beneficial uses such as increasing the efficiency of N utilization linked to an overall increase in chlorophyll abundance and photosynthesis (Mohanty et al., 2020). However, a more parsimonious explanation is that Si prevents or mitigates the strains imposed by stress, which is then reflected in a reduced induction of oxidative stress (Coskun et al., 2019).…”