兰州百合连作土壤碳氮磷化学计量特征及酶活性研究

探究连作对兰州百合土壤碳氮磷生态化学计量学特征及酶活性的影响,为解析兰州百合部分连作障碍机制及农田养分的调控提供理论依据。通过对不同种植年限（1、2、3年）的兰州百合土壤生态化学计量学特征及酶活性进行测定和分析,结果表明：（1）随着兰州百合种植年限的增加,土壤pH呈下降趋势。土壤有机质、全氮、全磷、碱解氮、速效磷含量总体呈增加趋势,且种植3年后含量显著增加。土壤C/N、C/P呈增加趋势,种植2、3年较种植1年相比,C/N显著增加了18.91%、13.57%;C/P种植3年较种植1年相比显著增加了14.71%;N/P无显著变化。（2）土壤过氧化氢酶、蔗糖酶、脲酶、碱性磷酸酶活性随着兰州百合种植年限的增加呈U型变化趋势,其中,土壤蔗糖酶、脲酶、碱性磷酸酶活性各种植年限间差异显著,同种植1年相比,种植2、3年土壤的蔗糖酶活性分别降低了49.71%、38.79%,碱性磷酸酶活性分别降低了43.31%、14.17%,种植2年土壤的脲酶活性较种植1年降低了17.17%,种植3年较种植1年升高了15.15%,过氧化氢酶活性种植2、3年较种植1年相比分别降低了7.80%、4.92%;（3）土壤生态化学计量学特征与土壤酶活性间连续存在一定的相关性,其中C/N与土壤酶活性呈负相关关系,C/P与蔗糖酶、碱性磷酸酶呈负相关关系。（4）典型性相关分析结果显示,土壤理化性质对土壤酶活性存在明显的影响,pH与土壤养分含量呈负相关关系。研究表明,随着连作年限的增加,兰州百合土壤呈酸化趋势。短期连作能为兰州百合提供良好的养分环境,但养分趋于失衡。在对百合农田进行管理时,应注意调节酸碱度,合理施肥,平衡养分。

The Stoichiometric Characteristics and Enzyme Activities of Soil Carbon,Nitrogen and Phosphorus Under Continuous Cropping of Lilium davidii var.

Through exploring the effect of continuous cropping on the eco-stoichiometric characteristics of carbon, nitrogen and phosphorus and enzyme activities in Lanzhou lily soil, the study aims to provide a theoretical basis for analyzing the mechanism of partial cropping obstacles in Lilium davidii var. and the regulation of farmland nutrients. By measuring and analysis of soil eco-stoichiometric characteristics and enzyme activities of Lilium davidii var. of different cultivation years (1, 2 and 3 years), the results showed that: (1) with the increase of planting years, the soil pH decreased, while the contents of soil organic matter, total nitrogen, total phosphorus, alkali-decomposed nitrogen and available phosphorus generally increased, and the increase was significant after 3 years of planting; the soil C/N and C/P showed an increasing trend, compared with planting of one year, the 2 or 3 years’ planting increased C/N by 18.91% and 13.57 %, respectively, and C/P of 3 years’ planting increased by 14.71%, N/P had no significant change; (2) the activities of soil catalase, invertase, urease and alkaline phosphatase showed a U-shape change trend with the increase of planting years and the activities of soil invertase, urease and alkaline phosphatase had significant differences among the planting years; compared with one year planting, the activity of invertase of 2 and 3 years’ planting decreased by 49.71% and 38.79%, respectively, the activity of alkaline phosphatase decreased by 43.31% and 14.17%, respectively, and the activities of soil catalase decreased by 7.80% and 4.92%, respectively; the activity of urease of 2 years’ planting decreased by 17.17% compared with 1 year planting, while that of 3 years’ planting increased by 15.15%; (3) there was a continuous correlation between soil ecological stoichiometric characteristics and soil enzyme activity, the C/N was negatively correlated with soil enzyme activity and the C/P was negatively correlated with invertase and alkaline phosphatase; (4) the results of typical correlation analysis showed that the physical and chemical properties of soil had obvious effects on soil enzyme activities and the pH was negatively correlated with soil nutrient content. The research indicates that with the increase of continuous cropping years, the soil of Lanzhou lily shows an acidification trend, although short-term continuous cropping could provide good nutrient environment for Lanzhou lily, the nutrients tend to be out of balance. Therefore, in the management of lily farmland, attention should be paid to adjusting pH, reasonable fertilization, and balanced nutrients.