Soil conditions affect cotton root distribution and cotton yield under mulched drip irrigation
Soil conditions affect cotton root distribution and cotton yield under mulched drip irrigation
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土壤条件影响覆膜滴灌棉花根系分布和棉花产量
DOI：
10.1016/j.fcr.2020.107743
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发表时间：
2020-04-01
影响因子：
5.8
通讯作者：
Xian, Yang
中科院分区：
文献类型：
--
作者：
Chen, Wenling;Jin, Menggui;Xian, Yang
微咸水膜下滴灌技术在干旱区棉花生产中得到了广泛应用。充分考虑微咸水灌溉的前景，需要考虑棉花根系特征对土壤条件的依赖性。到目前为止，这些依赖关系非常复杂，而且很难理解。本研究比较了微咸水灌溉和淡水灌溉处理对棉花根系特征和产量的影响。棉花根质量、根长、根表面积和根体积分布的空间差异与土壤条件分布的差异相对应。棉花根长与根质量之间存在显著的线性关系。土壤温度对根系生长没有明显的控制作用。由于与BWT相关的土壤温度降低和土壤盐度升高，BWT的平均根密度比FWT低，根粗。BWT对盐胁迫的敏感性高于根系生长。灌浆处理的根密度和细根比例均高于灌浆处理。即浅覆盖区棉花根系较多，根系吸水速率和盐分积累量较高。本研究表明，棉花根质量可作为覆盖滴灌条件下根长测量的实用指标。在浅覆盖区设置滴灌带进行地下滴灌，可进一步促进棉花根系生长，实现微咸水灌溉棉花的可持续生产。
Film-mulched drip irrigation with brackish water has been used widely for cotton (Gossypium hirsutum L.) production in arid regions. Full consideration of the promise of brackish water irrigation requires consideration of the dependence of cotton root characteristics on soil conditions. To date, these dependences are complex and poorly understood. The present study compared the impacts of soil temperature, water and salinity on root characteristics on cotton yield for brackish water irrigation treatment (BWT) and fresh water irrigation treatment (FWT). Spatial differences were observed for cotton root mass, root length, root surface-area and root volume distribution that corresponded with differences in the distributions of soil conditions. There existed a strikingly linear relationship between cotton root length and root mass. Soil temperature did not exert clear control on root system growth. Lower average root density and coarser roots were observed for BWT than for FWT as a result of the reduced soil temperature and the elevated soil salinity associated with BWT. Cotton shoot growth was more sensitive than root growth to salt stress for BWT. Higher root density and fine root proportion for FWT than BWT led to higher cotton yield. That is, more cotton roots were observed in the shallow mulched zone, which corresponded with high root water uptake rate and salt accumulation. Our study indicated that the easily-measured cotton root mass could be used as a practical surrogate for root length under mulched drip irrigation. Subsurface drip irrigation with drip tapes set in the shallow mulched zone may further promote cotton root system growth, allowing for sustainable cotton production with brackish water irrigation.