外源腐殖酸对栽培基质性状和辣椒生长发育的影响

Physico-chemical properties of a soilless substrate and growth of pepper influenced by exogenous humic acid

为研究添加外源腐殖酸对基于发酵床垫料蔬菜栽培基质的腐殖酸及其他理化性质的变化和辣椒生长发育的影响,本试验通过盆栽试验研究了添加5种水平(0 mg/kg、0.5 mg/kg、1.0 mg/kg、1.5 mg/kg、2.0 mg/kg)外源腐殖酸对辣椒栽培基质在定植期、苗期、开花坐果期和成熟期腐殖酸含量和理化性状的变化以及对辣椒在苗期、开花坐果期和成熟期的生长发育情况及产量的影响。结果表明,与对照相比,各外源腐殖酸添加量处理在定植期、苗期和开花坐果期能显著提高基质腐殖酸含量,并随外源腐殖酸施入量的增加而增加;各外源腐殖酸添加量处理在开花坐果期和成熟期,基质p H值有所增加,而在定植期、苗期、开花坐果期和成熟期,基质电导率均有不同程度下降,对基质的有机质和粗灰分含量影响不显著,在4个生育期基质的全氮、全磷、钾含量随外源腐殖酸添加量的增加而略有增加,而基质容重、总孔隙度和通气孔隙度有所降低。添加外源腐殖酸均能不同程度地增加辣椒植株在苗期、开花坐果期和成熟期的植株鲜质量、干质量、株高、根长和茎粗,其中添加量为2.0 mg/kg和1.5 mg/kg时增加效果较为显著,并提高开花结果期和成熟期辣椒SPAD值,提高光合能力,而且随外源腐殖酸添加量的增加辣椒单株产量显著增加。说明,添加外源腐殖酸在一定范围内可以增加基质中腐殖酸含量,提高基质总孔隙度和通气孔隙度,促进辣椒生长发育和提高单株产量。

A pot experiment was conducted to investigate the effect of exogenous humic acid on the contents of humic acid and physico-chemical properties of soil less substrate as well as the growth of pepper planted in the substrate. Five exogenous humic acid levels [0（ CK）,0. 5 mg/kg,1. 0 mg/kg,1. 5 mg/kg,2. 0 mg/kg]were set. Compared to CK,the contents of humic acid in the substrate increased significantly with the additions of exogenous humic acid at planting,seedling,flowering and fruiting stages. The p H values in the substrate were enhanced with the addition of exogenous humic acid at flowering and fruiting stage,and maturation,while EC droped at planting,seedling,flowering and fruiting,and maturation stages. The contents of organic matter and crude ash in the substrate stayed stable throughout the experiment. During the growth and development of pepper,the contents of total N,P and K in the substrate were slightly increased with the increase of exogenous humic acid,but the bulk density,total porosity,aeration porosity declined in some treatments.Exogenous humic acid additions improved fresh and dry weight,height,root length and stem diameter of pepper which were significantly（ P〈0. 05） different from those of control in 1. 5 mg/kg and 2. 0 mg/kg exogenous humic acid treatment. The SPAD of pepper leaves was increased at flowering and fruiting,and maturation stages,resulting in an improved photosynthetic capacity,and subsequenly a boost in fresh fruit weight of pepper. In summary,applications of exogenous humic acid in a certain range could increase the contents of humic acid in the substrate,improve total porosity and aeration porosity of the substrate,promote the growth and development of pepper,and increase pepper yield.