种植年限对设施菜田土壤pH及养分积累的影响

本试验以山东省寿光地区设施菜田为研究对象，分析了不同种植年限设施菜田土壤pH值以及有机质、无机氮、有效磷和有效钾含量状况。结果表明，寿光地区设施菜田各土层土壤pH值随着种植年限的增加而下降，与露地小麦土壤相比降幅达0.05～0.69个单位，其中尤以0～20 cm土层降幅最大，并且随着种植年限的增加，下层土壤pH值下降明显，种植10 a后20～40 cm土层土壤pH由8.67下降至7.99。0～20 cm土层土壤有机质随着种植年限的增加明显增加，1～3、4～6、7～9、≥10 a种植年限设施菜田土壤有机质与露地小麦土壤相比分别增加了6.1%、46.4%、66.5%、125.3%。土壤无机氮含量明显高于露地小麦土壤，但种植年限影响不大。各土层土壤有效磷和有效钾含量随着种植年限的增加显著增加，1～3、4～6、7～9、≥10 a种植年限设施菜田0～20 cm土层有效磷含量分别是露地小麦土壤的8.9、14.8、18.1、18.3倍，有效钾含量分别是露地小麦土壤的2.8、3.2、3.5、3.5倍。设施菜田各土层土壤pH值随种植年限的增加而下降，但与已有研究结果相比土壤pH值有上升趋势。

Effect of Planting Years on Soil pH and Nutrient Accumulation in Greenhouse Vegetable Fields

Taking greenhouse vegetable fields in Shouguang region，Shandong Province as research objective，this study analyzed the soil physiochemical properties，including pH value，soil organic matter，contents of available phosphorous and potassium in greenhouse vegetable fields with different cropping years．The results showed that the pH value in different soil layers decreased with the increase of cropping years，and compared with the open wheat field，the soil pH value in greenhouse decreased by 0.05 to 0.69 units，especially in 0-20 cm soil layers，the decreasing amplitude was the largest．Along with the increase of cropping years，the pH value of under layer decreased obviously．In 20-40 cm soil layers，the pH value decreased from 8.67 to 7.99，after 10 years of greenhouse vegetable production．While the content of soil organic matter in 0-20 cm layers significantly increased with the increase of cropping years by 6.1%，46.4%，66.5% and 125.3%，respectively with 1-3，4-6，7-9 and ≥10 years of greenhouse vegetable production，compared with open wheat field．The soil Nmin content was significantly higher than that in wheat field，but the cropping years did not have much influence．The contents of available phosphorous and potassium in different soil layers obviously increased with the increase of cropping years．In 0-20 cm soil layers with 1-3，4-6，7-9 and ≥10 years of greenhouse vegetable production，the contents of available phosphorous were 8.9，14.8，18.1 and 18.3-fold higher than those in open wheat field|while the contents of available potassium were 2.8，3.2，3.5 and 3.5-fold，respectively，compared with open wheat field．The soil pH value declined with the increase of planting years，but compared with previous research results，the soil pH value appeared rising trend．