The efficiency of fertilizer nitrogen in irrigated, direct seeded rice (O. sativa L.) in Europe
1994
Stutterheim, N.C. | Barbier, J.M. | Nougaredes, B.
Data from 35 experiments with direct seeded rice, performed between 1981 and 1991 by national research institutes in five major rice growing countries of Europe were analyzed to estimate the average efficiency of fertilizer nitrogen (N). Pooled data from a four year regional survey (1984-1988) on rice-based farming systems in the Camargue-region (43 degrees 20'-43 degrees 40' N) in the south of France, were used to perform a similar analysis. Experimentation during two years (1989-1990) was carried out to assess the value of the N-utilization efficiency within the range of N-limited growth and to obtain information on the N-efficiency under controlled conditions. At reduced basal dressing of N on soils with high soil organic matter content, the apparent N-recovery was estimated at 0.21 to 0.32 kg N uptake per kg N applied. Average agronomic efficiency ranged from 12 to 17 kg grain dry mass per kg N applied. High basal N-application on these soils resulted in yield loss. No consistent yield response to fertilizer-N input was found on soils with less than two percent organic matter, irrespective of fertilizer timing. These results confirm the important role of soil organic matter in rice cultivation. An average apparent N-recovery of 0.18 was obtained with split application of N under controlled experimental conditions in the Camargue. Using a controlled release fertilizer, values of 0.58 and 32 kg.kg-1 were obtained for the apparent N-recovery and agronomic efficiency, respectively. Hence, disregarding the economic feasibility, considerable scope exists for improving N-efficiency in European rice cultivation.
显示更多 [+] 显示较少 [-]