液态有机肥对酚酸胁迫下马铃薯生长发育和土壤酶活性影响

为明确液态有机肥对土壤酚酸导致马铃薯的连作障碍的缓解效应,采用盆栽试验,将阿魏酸与香草酸等量混合后按不同浓度(0,50,100,150 mg/kg)施加于马铃薯基质土壤中,模拟马铃薯连作分泌的有机酸自毒物质,并施加不同浓度梯度液态有机肥(0,225,450,675 kg/hm^2),探讨酚酸胁迫下液态有机肥对马铃薯生长发育以及土壤酶活性的影响。结果表明:单一施加外源酚酸对马铃薯株高、茎粗、叶面积以及干物质量皆有不同程度的抑制作用,随酚酸浓度增加,土壤中脲酶、酸性磷酸酶、蔗糖酶活性相对对照分别降低2.74%~10.95%,11.11%~20.55%,5.29%~12.96%,过氧化氢酶、多酚氧化酶活性升高,FDA水解酶活性表现为低促进高抑制。施加液态有机肥后提高了马铃薯株高、茎粗、叶面积以及干物质量,土壤酶活性均有提高,脲酶、酸性磷酸酶、蔗糖酶、过氧化氢酶、多酚氧化酶、FDA水解酶活性相对对照处理最高分别提高了10.80%,21.40%,18.20%,29.60%,37.69%,12.31%,但是液态有机肥浓度过高降低了其对磷酸酶、脲酶、过氧化氢酶的提升效果,抑制了FDA水解酶活性。因此合理施加液态有机肥可以促进马铃薯生长发育,提高土壤酶活性,增强马铃薯的抗逆性,从而缓解酚酸对马铃薯的胁迫作用。

Effects of Liquid Organic Fertilizer on Potato Growth and Soil Enzyme Activities Under Phenolic Acid Stress

A pot experiment was conducted to clarify the mitigation effect of liquid organic fertilizer on continuous cropping obstacle caused by phenolic acid in soil. Ferulic acid and vanillic acid were mixed equally and applied to potato substrate soil at different concentrations (0, 50, 100 and 150 mg/kg) to simulate the autotoxin substances secreted by potato continuous cropping, and different concentration gradients liquid organic fertilizer (0, 225, 450 and 675 kg/hm²) were applied to clarify the effects of liquid organic fertilizer on potato growth and soil enzyme activity under phenolic acid stress. The results showed that single exogenous phenolic acids reduced the potato plant height, stem diameter, leaf area and dry weight in different degree. With the increasing of phenolic acid concentration, the activity of urease, acid phosphatase and invertase in soil decreased by 2.74%~10.95%, 11.11%~20.55% and 5.29%~12.96% compared with the control, respectively, the activity of catalase and polyphenol oxidase increased, while FDA hydrolase activity showed low promotion and high inhibition. Applying liquid organic fertilizer improved the potato plant height, stem diameter, leaf area and dry weight. Soil enzymes activities all increased, the activity of urease, acid phosphatase, invertase, catalase, polyphenol oxidase and FDA hydrolase increased by 10.80%, 21.40%, 18.20%, 29.60%, 37.69% and 12.31% at most, respectively, compared with the control. But excessive concentration of liquid organic fertilizer decreased its enhancement of activity of phosphatase, urease and catalase, and inhibited the activity of FDA hydrolase. Therefore, reasonable application of liquid organic fertilizer could promote the growth and development of potato, improve soil enzyme activity and enhance the stress resistance of potato, thereby alleviating the phenolic acid stress on potato.