How extensive are yield declines in long-term rice-wheat experiments in Asia?
How extensive are yield declines in long-term rice-wheat experiments in Asia?
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DOI：
10.1016/s0378-4290(02)00219-8
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发表时间：
2003-02-20
影响因子：
5.8
通讯作者：
Hobbs, PR
中科院分区：
文献类型：
--
作者：
Ladha, JK;Dawe, D;Hobbs, PR
稻麦种植制度在南亚和中国的生产面积中占2 400万公顷，对粮食安全十分重要。监测作物产量的长期变化并确定与这些变化相关的因素对于维持和/或提高作物生产力至关重要。长期实验（LTE）提供了这些机会。我们分析了南亚印度-恒河平原（IGP）、印度非IGP和中国的33个稻麦LTE，以调查产量停滞或下降的程度，并确定产量下降的可能原因。在氮、磷、钾推荐用量下，水稻和小麦产量分别停滞在72%和85%的极限值，而水稻和小麦产量分别下降22%和6%的极限值，差异显著（P < 0.05）。在稻麦系统中，特别是在IGP中，水稻产量比小麦下降得更快。产量下降的原因大多是特定的位置，但土壤钾的耗竭似乎是一个普遍的原因。在90%以上的LTE中，所使用的肥料K用量不足以维持中性K投入-产出平衡。土壤C、N和Zn的耗竭以及P的可用性降低、种植延迟、太阳辐射减少和最低温度升高是产量下降的其他潜在原因。需要一个更有效的综合战略，收集详细的数据，以确定产量下降的具体原因。应利用改进的统计和模拟工具不断监测长期效应并分析数据，以揭示稻麦系统生产力和可持续性的因果关系。(C)2002 Elsevier Science B. V.保留所有权利。
The rice-wheat cropping system, occupying 24 million hectares of the productive area in South Asia and China, is important for food security. Monitoring long-term changes in crop yields and identifying the factors associated with such changes are essential to maintain and/or improve crop productivity. Long-term experiments (LTE) provide these opportunities. We analyzed 33 rice-wheat LTE in the Indo-Gangetic Plains (IGP) of South Asia, non-IGP in India, and China to investigate the extent of yield stagnation or decline and identify possible causes of yield decline. In treatments where recommended rates of N, P and K were applied, yields of rice and wheat stagnated in 72 and 85% of the LTE, respectively, while 22 and 6% of the LTE showed a significant (P < 0.05) declining trend for rice and wheat yields, respectively. In the rice-wheat system, particularly in the IGP, rice yields are declining more rapidly than wheat. The causes of yield decline are mostly location-specific but depletion of soil K seems to be a general cause. In over 90% of the LTE, the fertilizer K rates used were not sufficient to sustain a neutral K input-output balance. Depletion of soil C, N and Zn and reduced availability of P, delays in planting, decreases in solar radiation and increases in minimum temperatures are the other potential causes of yield decline. A more efficient, integrated strategy with detailed data collection is required to identify the specific causes of yield decline. Constant monitoring of LTEs and analysis of the data using improved statistical and simulation tools should be done to unravel the cause-effect relationships of productivity and sustainability of rice-wheat systems. (C) 2002 Elsevier Science B.V. All rights reserved.