[Effect of fertilization on the absorption, partition and accumulation of carbon and nitrogen of rice under the equal N conditions].

ABSTRACT

In this study, the assimilation, partition and accumulation of carbon (C) and nitrogen (N), as well as the relationship between C and N accumulation of rice, were studied from typical paddy ecosystems under long-term fertilizer applications with equal N inputs in subtropical China. The results showed that chemical fertilizer plus low organic manure (LOM) could promote effectively the distribution of C in the rice plant. The N content in the stem-leaf and grain of rice under organic-inorganic fertilization was 8.9-10.2 g x kg(-1) and 11.9-14.8 g x kg(-1) respectively. It was much higher than under other treatments, with about 13% - 53% and 9% - 19% higher than under the chemical fertilization (NPK), separately and 12% - 77% and 23% - 32% higher than under the control treatment (CK), respectively. The C and N storages of rice were mainly accumulated in the aboveground part. Organic-inorganic fertilization treatment possessed higher storages of C (3467.8-4 323.9 kg x hm(-2)) and N (120.3-135.2 kg x hm(-2)) in the rice grain,which was about 13% - 23% of C and 26% - 45% of N higher than under NPK treatment. It indicated that rice grain was the main sink of C and N. The organic-inorganic fertilization was in favor of C accumulation and N absorption in the rice plant and it still possesses an obvious potential in C and N sequestration and absorption in subtropical paddy field.