Relationship of surface soil temperature on rice (Oryza sativa L.) yield under high density planting in tropics of India

Abstract

Rice is one of the most important food crops of India. Soil temperature is an important weather parameter and changes in soil temperature may influence the rice yield. To study this impact, a field experiment was conducted during the late Samba (September-January) season of 2018-19 at Tamil Nadu Agricultural University, Coimbatore. The experiment was arranged in Randomised Complete Block Design with three replications. The surface soil temperature was recorded at weekly interval from 13 Days after transplanting (DAT) to 111 DAT during four time intervals (0600 hrs, 1000 hrs, 1400 hrs and 1800 hrs) of day at weekly interval. The result revealed that surface soil temperature was higher in closer spacing levels during 0600 hrs and 1000 hrs compared to all other wider spacing levels. However, at 1400 hrs and 1800 hrs, surface soil temperature was maximum in widely planted rice plants. The grain yield of rice was higher in wider planted treatments compared to closer spacing planted rice. Correlation between soil temperature and yield during early hours (0600 hrs and 1000 hrs) was negative, but was positive in later hours (1400 hrs and 1800 hrs).