A study on the productivity under the continuous maize cultivation in Sainyabuli Province, Laos I. Yield trend under continuous maize cultivation
A study on the productivity under the continuous maize cultivation in Sainyabuli Province, Laos I. Yield trend under continuous maize cultivation
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老挝沙耶武里省玉米连作生产力研究 一、玉米连作产量趋势
DOI：
10.1016/j.fcr.2017.12.016
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发表时间：
2018
影响因子：
5.8
通讯作者：
Shiraiwa Tatsuhiko
中科院分区：
文献类型：
--
作者：
Fujisao Kazuhiko;Khanthavong Phanthasin;Oudthachit Saythong;Matsumoto Naruo;Homma Koki;Asai Hidetoshi;Shiraiwa Tatsuhiko
老挝的玉米连作增加了。由于玉米是在没有肥料或任何土壤保护措施的情况下连续种植的，人们担心玉米产量正在下降。在这项研究中，我们进行了实地调查和对农民的访谈，以量化连续耕作下玉米生产的可持续性与老挝塞尼布利省农民田地的地形特征的关系。在为期两年的时间里，对40个农民田地的三个样点进行了产量调查，其中包括坡地和平地。此外，为了分析不同地形顺序位置对产量趋势的影响，将样点按坡度和相对高程分为4种地形顺序位置：坡地“上”、“中”、“下”，平地“平”。每块地玉米连作周期从1年到30年不等。每块地3个样地的平均产量在1.1~6.0 t ha−1之间变化，且随连作年限的延长有降低的趋势。对各地形序列位置的方差分析和回归分析表明，各田产量的下降趋势主要来源于坡地的上位。就玉米产量而言，购买种子、除草剂和外包耕作在玉米种植中需要1.7万亿 t ha−1。产量与连作年限的线性回归曲线表明，−0.06 t ha−1年−1玉米产量下降，但仍可维持43年的经济可行性。然而，36个田地中有6个的产量被评估为低于有利可图的水平，这表明迫切需要改善田地和作物管理，以可持续地生产玉米。
Continuous maize cropping has increased in Laos. Because maize is continuously cultivated without fertilizer or any soil conservation practices, there is a concern that maize yield is decreasing. In this study, we conducted a field survey and interviews with farmers to quantify maize production sustainability under continuous cultivation in relation to topographical characteristics in farmers’ fields within Sainyabuli Province, Laos. Yield was investigated over a two-year period at three sample sites in each of the 40 farmers’ fields, including sloped and flat fields. In addition, to analyze the difference in yield trend due to topo-sequential position, the sample sites were categorized into four topo-sequential positions per slope angle and relative elevation: “upper,” “middle,” and “lower” positions for sloped fields and “flat” for flat fields. The period of continuous maize cultivation in each field varied from 1 to 30 years. The average yield of the three sample sites in each field varied from 1.1 to 6.0 t ha−1and tended to be lower as the period of continuous cultivation was longer. ANCOVA and regression analysis for each topo-sequential position indicated that the decreasing yield trend in each field were mainly derived from the upper position of sloped fields. Cost of 1.7 t ha−1, in terms of maize yield, were required for purchasing seed, herbicide, and outsourcing plowing in maize cultivation. The linear regression line of the yield based on the period of continuous cultivation suggested that maize production decreased at −0.06 t ha−1year−1; but it could be economically viable for 43 years. However, yield in six of the 36 fields was evaluated as below profitable levels, indicating that urgent improvements in field and crop management are required to produce maize sustainably.