Different micro-climate response of indica rice population to nitrogen fertilizer

Field experiment was carried out from 2014 to 2016 to clarify the micro-climate response of indica rice population to nitrogen fertilizer. R498, R816 and R499 were used as representatives of drooping panicle, semi-erect panicle and erect panicle indica rice, respectively and 3 nitrogen fertilizer levels (N0 - 0 kg N/ha; N1 - 150 kg N/ha; N2 -150 kg/ha) were set for each panicle of indica rice. Results showed that the erect panicle indica rice (R499) improved the environment of temperature, relative humidity and light of rice population under heavy nitrogen fertilizer, and built a healthier micro-climate environment for rice population, especially at the middle position of rice population. Comparing with drooping panicle indica rice (R498), erect panicle indica rice performed better under heavy nitrogen fertilizer, with a higher micro-climate response index to nitrogen fertilizer at middle and lower position in rice population. In comparison of R498, the yield of R499 increased by 0.10-0.11 t/ha under N1 treatment, while it increased by 0.93-0.96 t/ha under N2 treatment; thus, the suggestion for farmers is to plant erect panicle indica rice in heavy fertilizer area or to use more fertilizer in moderate fertilizer area.