关键词: 水稻, 施肥, 生理特性, 保护性酶, 产量

Abstract: In order to explore the effects of different manure nitrogen (N) input ratios on the physiological characteristics in plant leaves and grain yield of early and late rice, this paper established a field experiment in Ningxiang county of Hunan province, and investigated the protective enzyme activities and photosynthetic characteristics of early and late rice leaves, and grain yield of early and late rice. The experiment included five different fertilization treatments: without N fertilizer input as a control (M0), chemical fertilizer (M1), 30% N of organic matter plus 70% N of chemical fertilizer (M2), 50% N of organic matter plus 50% N of chemical fertilizer (M3), and 100% N of organic matter (M4). The results showed that: The activities of superoxide dismutase (superoxide dismutase, SOD), peroxidase (peroxidase, POD) and catalase (catalase, CAT) in rice leaves of M1, M2, M3 and M4 treatments were increased when compared with M0 treatment at different main growth stages of early and late rice. Meanwhile, compared with M0 treatment, the malondialdehyde (malondialdehyde, MDA) and proline (Pro) contents in rice leaves of M1, M2, M3 and M4 treatments were decreased at different main growth stages of early and late rice, respectively. ANOV indicated that the activities of SOD, POD and CAT in leaves of rice plant with M1 and M2 treatments were significantly (P＜005) higher than that of the M0 treatment, and the MDA and Pro contents in leaves of rice plant with M1 and M2 treatments were significantly (P＜005) lower than that of the M0 treatment at different main growth stages of early and late rice, respectively. Meanwhile, the net photosynthetic rate, transpiration rate, stomatal conductance in leaves of rice plant with M1, M2, M3 and M4 treatments were significantly (P＜005) higher than that of the M0 treatment at different main growth stages of early and late rice, respectively. In 2017 and 2018, the grain yield of early rice with M1 and M2 treatments were significantly (P＜005) higher than that of the M0 treatment, and the grain yield of late rice with M1 and M4 treatments were significantly (P＜005) higher than that of the M0 treatment, respectively. Compared with M0 treatment, the grain yield of M1 and M2 treatments were increased by 2 0408 and 1 9728 kg·hm-2 in early season in 2017 and 2018, the grain yield of M1 and M4 treatments were increased by 2 1724 and 2 0060 kg·hm-2 in late season in 2017 and 2018, respectively. As a result, it was an effective way for improving protective enzyme activities and photosynthetic characteristics in leaves of rice plant by taken manure N input practices, which was the physiological mechanism to obtain higher grain yield of rice.

Key words: rice, fertilizer management, physiological characteristics, protective enzyme, yield