How widespread are yield declines in long-term rice experiments in Asia?
How widespread are yield declines in long-term rice experiments in Asia?
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DOI：
10.1016/s0378-4290(00)00075-7
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发表时间：
2000-05-01
影响因子：
5.8
通讯作者：
Zhen, QX
中科院分区：
文献类型：
--
作者：
Dawe, D;Dobermann, A;Zhen, QX
本文分析了在亚洲热带和亚热带地区24个地点进行的30个长期试验（LTE）的产量趋势，这些试验采用了集约化水稻单作或水稻-旱地Clop系统。分析的目的是（1）调查在投入水平恒定的实验中产量下降的范围有多大，（2）研究产量趋势的大小与实验中初始产量水平之间的横截面关系。在水稻-水稻系统中，在IRRI以外进行的许多长期试验中，在最有利的气候季节（旱季）的产量保持稳定，大多数产量水平为4-7兆公顷（-1），并采用推荐的N、P和K施用量。在IRRI以外的21个数据集中，只有两个数据集在p小于或等于0.05时观察到统计学显著的产量下降，尽管IRRI的所有三个LTE都显示产量下降。一项旱季试验表明，产量在统计上有显著增加。在气候不太有利的季节（雨季），IRRI以外的14个数据集中只有两个显示出统计上显著的产量下降趋势，而IRRI的四个数据集中有三个显示出统计上显著的产量下降趋势。在水稻-旱地作物（通常是小麦）LTE中，仅在10个数据集中发现水稻产量显著下降。为了小麦。尽管产量有一次统计上显著的增加，但没有统计上显著的产量下降。产量下降幅度与初始产量水平呈负相关，但不显著。数据表明，虽然一些LTE存在产量下降，但它们不像以前认为的那样普遍，特别是在中等产量水平下。在产量下降的情况下，它们与长期土壤湿润或土壤养分耗竭影响土壤性质有关。(C)2000 Elsevier Science B. V.保留所有权利。
This paper analyzes yield trends in 30 long-term experiments (LTEs) conducted at 24 sites with intensive rice monoculture or rice-upland clop systems in tropical and subtropical regions of Asia. The objectives of the analysis were to (1) investigate how widespread yield declines are in experiments with constant levels of input and (2) study the cross-sectional relationship between the magnitude of yield trends and the initial yield level in the experiment. In rice-rice (-rice) systems, yields in the most favorable climatic season (dry season) have remained stable in many LTEs conducted outside of IRRI, mostly at yield levels of 4-7 Mg ha(-1) with recommended rates of N, P and K applied. Statistically significant yield declines at p less than or equal to 0.05 were observed in only two of 21 data sets outside of IRRI, although all thr et: LTEs at IRRI showed yield declines. One dry season experiment showed a statistically significant yield increase. In the less favorable climatic season (wet season), only two of 14 data sets outside of IRRI showed a statistically significant declining yield trend, while three of four at IRRI showed statistically significant yield declines. In rice-upland crop (typically wheat) LTEs, a significant yield decline for rice was found in only one of ten data sets. For wheat. there were no statistically significant yield declines, although there was one statistically significant yield increase. There was a negative correlation between the magnitude of yield decline and the level of initial yields, but it was not statistically significant. The data suggest that while yield declines exist in some LTEs, they are less common than previously thought, particularly at moderate yield levels. Where yield declines occured, they were related to soil properties affected by prolonged soil wetness or soil nutrient depletion. (C) 2000 Elsevier Science B.V. All rights reserved.