亏缺灌溉下温室番茄生长生理指标对生物炭的响应

The Effects of Deficit Irrigation Combined with Biochar Amendment on Growth and Physiological Traits of Greenhouse Tomato

【目的】探究生物炭和亏缺灌溉对番茄生长生理指标及水分利用效率的影响,为西北地区温室栽培番茄提供灌水和生物炭施用依据。【方法】在温室内进行桶栽试验,设置3个灌溉水平(充分灌溉I1:75%θf~85%θf,中度水分亏缺I2:55%θf~65%θf,重度水分亏缺I3:40%θf~50%θf)和3个生物炭施用量(B0:0,B1:3%,B2:6%),共9个处理,每处理重复15桶,研究了不同灌溉水平和生物炭施用量对番茄不同生育期生理指标、地上部干物质量和水分利用效率(WUEL)的影响。【结果】适当的亏缺灌溉不会影响番茄植株生长关键期的光合能力,同时也能大幅提高叶片抗氧化酶(SOD、POD、CAT)活性,但地上部干物质量显著降低;充分灌溉下生物炭施用对植株光合产生负面效应,使PSⅡ系统开放比例(qP)降低,最终导致地上部干物质量和水分利用效率显著降低;亏缺灌溉下生物炭B2处理的qP和植株热耗散能力(NPQ)在生长关键期均有所提高,从而提高地上部干物质积累和WUEL。在干物质积累关键期,监测生理指标均与地上部干物质关系密切,其中抗氧化酶活性(POD和CAT)、净光合速率(Pn)和气孔导度(Gs)对地上部干物质积累的综合作用最大,提高叶片的光合能力和抗氧化系统的防御能力均能促进干物质的积累。与I2B0处理(55%θf~65%θf,无生物炭施用)相比,I2B2处理(55%θf~65%θf,生物炭6%施用量)的地上部干物质量和水分利用效率分别提高了6.1%(P>0.05)、30.9%(P<0.05)。【结论】I2B2处理是西北地区番茄栽培适宜的灌溉和生物炭施用组合。

【Objective】Deficit irrigation and biochar amendment have been increasingly used to increase irrigation water use efficiency and improve soil quality respectively.However,how their combination affects the growth and physiological traits of crops is an issue that is not well understood.The aim of this paper is to address this in an attempt to provide guidance to improve the management of greenhouse tomato production in northwest China.【Method】The experiment was conducted in a greenhouse.We compared three irrigation levels by keeping the soil water content at 75%~85%(I1),55%~65%(I2)and 40%~50%of the field capacity respectively.Added to each irrigation treatment were three biochar application rates:no amendment(B0),added 3%(w/w)(B1),and 6%(B2)of biochar.In each treatment,we measured the growth and physiological traits of the crop,as well as its ultimate shoot dry matter and water use efficiency at different growth stages.【Result】A moderate deficit irrigation did not reduce the photosynthetic rate at critical growth stage,but significantly increased the activities of antioxidant enzymes(SOD,POD,CAT)in leaves and reduced the final shoot dry matter.Biochar amendment combined with full irrigation reduced photosynthesis and the open ratio of photosystem II(PSⅡ),thereby resulting in a significant decrease in shoot dry matter and water use efficiency(WUEL).Combination of deficit irrigation and B2 biochar amendment enhanced the opening of PSⅡand heat dissipation capacity(NPQ)of the crop,thereby increasing the shoot dry matter and WUEL.Dry shoot matters were affected significantly by all physiological traits,especially antioxidant enzyme activities(POD and CAT),the net photosynthetic rate(Pn)and stomatal conductance(Gs),during the critical period when dry matter started to accumulate in the shoot.Improving the photosynthetic capacity of the leaves and defence capacity of the antioxidant system can promote dry matter accumulation.Compared with I2+B0,I2+B2 increased dry shoot matter and WUEL by 6.1%(P>0.05)and 30.9%(P<0.05),respectively.【Conclusion】I2+B2 was the optimal combination of irrigation and biochar amendment for greenhouse tomato in northwest China.