Zhai Yaming, Yang Qian, Hou Maomao
Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China (Hohai University), Ministry of Education, Nanjing, China.
College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China.
PLoS One. 2015 Nov 5;10(11):e0142204. doi: 10.1371/journal.pone.0142204. eCollection 2015.
Saline water resources are abundant in the coastal areas of south China. Most of these resources still have not been effectively utilized. A 3-year study on the effects of saline water irrigation on tomato yield, quality and blossom-end rot (BER) was conducted at different lower limits of soil matric potential (-10 kPa, -20 kPa, -30 kPa, -40 kPa and -50 kPa). Saline water differing in electrical conductivity (EC) (3 dS/m, 4 dS/m, 4.5 dS/m, 5 dS/m and 5.5 dS/m) was supplied to the plant after the seedling establishment. In all three years, irrigation water with 5.5 dS/m salinity reduced the maximum leaf area index (LAIm) and chlorophyll content the most significantly when compared with other salinity treatments. However, compared with the control treatment (CK), a slight increase in LAIm and chlorophyll content was observed with 34 dS/m salinity. Saline water improved tomato quality, including fruit density, soluble solid, total acid, vitamin C and the sugar-acid ratio. There was a positive relationship between the overall tomato quality and salinity of irrigation water, as analyzed by principal component analysis (PCA). The tomato yield decreased with increased salinity. The 5.5 dS/m treatment reduced the tomato yield (Yt) by 22.431.1%, 12.628.0% and 11.727.3%, respectively in 2012, 2013 and 2014, compared with CK. Moreover, a significant (P≤0.01) coupling effect of salinity and soil matric potential on Yt was detected. Saline water caused Yt to increase more markedly when the lower limit of soil matric potential was controlled at a relatively lower level. The critical salinity level that produced significant increases in the BERi was 3 dS/m4 dS/m. Following the increase in BERi under saline water irrigation, marketable tomato yield (Ym) decreased by 8.9%33.8% in 2012, 5.1%30.4% in 2013 and 10.1%32.3% in 2014 compared with CK. In terms of maintaining the Yt and Ym, the salinity of irrigation water should be controlled under 4 dS/m, and the lower limit of soil matric potential should be greater than -20 kPa.
中国南方沿海地区咸水资源丰富。这些资源大多尚未得到有效利用。在不同的土壤基质势下限（-10 kPa、-20 kPa、-30 kPa、-40 kPa和-50 kPa）下，开展了一项为期3年的关于咸水灌溉对番茄产量、品质和脐腐病（BER）影响的研究。在幼苗定植后，向植株供应电导率（EC）不同（3 dS/m、4 dS/m、4.5 dS/m、5 dS/m和5.5 dS/m）的咸水。在这三年中，与其他盐分处理相比，盐度为5.5 dS/m的灌溉水使最大叶面积指数（LAIm）和叶绿素含量降低最为显著。然而，与对照处理（CK）相比，盐度为34 dS/m时，LAIm和叶绿素含量略有增加。咸水改善了番茄品质，包括果实密度、可溶性固形物、总酸、维生素C和糖酸比。通过主成分分析（PCA）分析得出，番茄总体品质与灌溉水盐度之间存在正相关关系。番茄产量随盐度增加而降低。与CK相比，5.5 dS/m处理在2012年、2013年和2014年分别使番茄产量（Yt）降低了22.4%31.1%、12.6%28.0%和11.7%27.3%。此外，检测到盐度和土壤基质势对Yt有显著（P≤0.01）的耦合效应。当土壤基质势下限控制在相对较低水平时，咸水使Yt增加更为明显。导致BERi显著增加的临界盐度水平为3 dS/m4 dS/m。在咸水灌溉下BERi增加后，与CK相比，2012年可销售番茄产量（Ym）下降了8.9%33.8%，2013年下降了5.1%30.4%，2014年下降了10.1%32.3%。在维持Yt和Ym方面，灌溉水盐度应控制在4 dS/m以下，土壤基质势下限应大于-20 kPa。
