有机发酵基质理化性质变化及对甜瓜出苗的影响

Effects of organic fermentation substrates on the emergence of melon seedlings and change of physicochemical properties

为探究有机发酵基质的理化特性,本研究以树叶基质、草酸树叶基质、锯末基质和菇渣基质为材料进行甜瓜育苗,测定甜瓜出苗情况和基质理化性质变化。结果表明:锯末基质(T5)出苗率接近对照(CK),其余基质处理出苗率显著低于CK,出苗结束后甜瓜幼苗长势均弱于CK。育苗前,T5基质理化性质基本符合育苗基质标准要求,其余基质处理主要存在电导率(EC)值偏高问题。出苗后,容重和持水孔隙度菇渣基质(T6)降低,其余基质处理增加;总孔隙度T5和T6基质降低,其余基质增加;通气孔隙度和气水比均下降。pH值增减幅度在1.5%以内,EC值下降幅度超过27%(除T5基质处理)。树叶基质(T3)、草酸树叶基质(T4)和T5基质碱解氮含量增加,其余基质处理减少;有效磷含量均增加,速效钾含量均降低。研究发现,各处理基质甜瓜出苗效果弱于CK,出苗后基质理化性质相对育苗前均发生变化,其中T3、T4、T5和T6基质孔隙度和气水比变化幅度大,基质孔隙结构稳定性差;T3、T4、T5基质EC值大幅降低,基质离子易流失。

In order to investigate the physicochemical properties of organic fermentation substrates,the experiment of melon seed-ling was carried out with leaf substrates,oxalic acid leaf substrates,sawdust substrates and mushroom residue substrates as materials.The results showed that the seedling emergence rate of sawdust substrate was close to that of the control(CK),while the seedling emergence rate of the other substrate treatments was significantly lower than CK,and the growth of melon seedlings was weaker than CK at the end of seedling emergence.The physical and chemical properties of the sawdust substrate(T5)basically met the stan-dard requirements for seedling substrates before seedling establishment,while the rest of the substrate treatments mainly had high Electric Conductivity(EC)values.After seedling emergence,the bulk weight and water-holding porosity of mushroom residue sub-strate(T6)decreased and the rest increased;the total porosity of T5 and T6 substrate decreased and the rest increased;the ventilation porosity and air-water ratio decreased.pH value increased or decreased within 1.5%,EC value decreased by more than 27%(except for T5 substrate treatment).In all treatments,the content of available phosphorus increased and the content of available potassium decreased.However,the alkali-hydrolyzed nitrogen content decreased in the substrate of T6,and increased in other substrates.It was found that the seedling emergence of melon was weaker than CK in each treatment substrate,and the physical and chemical proper-ties of substrate changed after seedling emergence relative to the pre-sowling period,among which the porosity and air-water ratio of substrate of T3,T4,T5 and T6 substrate changed greatly,and the stability of substrate pore structure was poor.The EC value of T3,T4 and T5 substrate decreased greatly and the substrate ions were easy to be lost.