Status and Distribution of Plant Available Silicon in Relation to Some Soil Properties and Response of Rice (Oryza sativa L.) to Silicon Nutrition in the Intensively Rice Growing Soils of Kanyakumari District, Tamil Nadu, India

Silicon (Si) is well known as a beneficial element which is extremely essential for sustained rice productivity. Therefore, an attempt was made in the present study to assess the status of plant available Si in the intensively rice growing blocks of Kanyakumari district, Tamil Nadu, India. A total of two hundred and ten geo referenced surface soil samples representing three major rice growing blocks of Kanyakumari district (42 villages @ 5 samples /village) were collected using GPS and analysed for available silicon. Overall, 52 per cent of the rice soils were low (< 67 mg kg− 1), medium (67–95 mg kg− 1) and high (> 95 mg kg− 1) in Si status. The available Si had significant positive correlation with soil reaction, clay and cation exchange capacity and negatively correlated with soil electrical conductivity, coarse sand, sesquioxide and iron oxide. A field experiment was conducted with graded levels of two Si sources (0, 50, 100,150,200 kg Si/ha as calcium silicate and rice husk ash) and the results showed that soil application of 150 kg Si ha− 1 as calcium silicate was sufficient to increase growth, physiological parameters, yield attributes, grain yield of rice and post harvest soil available silicon in the study area.