NITROGEN USE EFFICIENCY OF RICE RECONSIDERED - WHAT ARE THE KEY CONSTRAINTS
NITROGEN USE EFFICIENCY OF RICE RECONSIDERED - WHAT ARE THE KEY CONSTRAINTS
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DOI：
10.1007/bf00025057
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发表时间：
1993-10-01
期刊：
影响因子：
4.9
通讯作者：
PENG, S
中科院分区：
文献类型：
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作者：
CASSMAN, KG;KROPFF, MJ;PENG, S
IRRI研究农场最近对灌溉水稻的田间研究表明，根据植株对施氮量的吸收(由氮素差异估计)，有效利用化肥-氮肥，并利用获得的氮素来提高粮食产量。这些发现与微区研究中的N-15吸收形成了对比，后者低估了添加化肥对植物N的实际增加。然而，除吸收效率外，其他限制因素可能制约着农民田地的化肥-N效率。在对吕宋岛中部44个农户田地的研究中，在没有添加化肥-N的情况下，水稻产量在2.5-6.2 t ha(-1)之间，吸氮量在35-95 kg N ha(-1)之间。农户施氮量为35~240 kg ha(-1)，但每个农户的施氮量与土壤有效氮素供应之间没有关系。氮素差异对肥料氮素吸收效率平均只有36%。我们的结论是，要提高农民的氮肥利用率，就需要一种信息密集型的管理策略，使氮肥投入更好地适应作物氮素需求和土壤氮素供应的季节性模式。
Recent field studies on irrigated rice at the IRRI research farm indicate efficient use of fertilizer-N based on plant uptake of applied N, (estimated by N difference), and utilization of acquired N for increased grain yield. These findings contrast with N-15 uptake in microplot studies which underestimate the actual increase in plant N from added fertiliser. Constraints other than uptake efficiency, however, may govern fertiliser-N efficiency in farmers fields. In a study of 44 farmers' fields in Central Luzon, rice yields ranged from 2.5 to 6.2 t ha(-1) and N uptake from 35 to 95 kg N ha(-1) in plots without fertiliser-N addition. Farmers applied from 35 to 240 kg N ha(-1), but there was no relationship between the N rate used by each farmer and the effective soil N supply. Mean N uptake efficiency from fertiliser by N difference was only 36%. We conclude that improved fertiliser-N efficiency by farmers will require a more information-intensive management strategy that makes N fertiliser inputs better fitted to the seasonal pattern of crop N demand and soil N supply.