不同种植年限设施西瓜土壤可溶性盐组分变化特征

采用田间取样及室内分析相结合的方法,研究了连续种植不同年限(0年-6年)西瓜的设施土壤可溶性盐含量及组分的变化。结果表明,与种植0年的麦地土壤相比,设施西瓜土壤pH显著降低(P < 0.01)；土壤碱解氮、速效磷和速效钾含量显著增加(P < 0.01)；电导率显著增加且随着设施西瓜种植年限的延长而显著增加趋势(R₂ = 0.90,P < 0.01)。设施西瓜土壤可溶性盐阳离子以Ca₂₊和Mg₂₊为主,阴离子以SO_42-和NO_3-为主。随着设施西瓜种植年限的增加设施西瓜土壤可溶性盐总量显著增加(R₂ = 0.93, P < 0.01),增加的可溶性盐主要为Ca₂₊、K₊、NO_3-和Cl_-,分配比例分别为31.3%、10.1%、23.6%和15.0%。相关分析表明,供试的设施西瓜土壤速效磷、速效钾与盐基离子Na₊、K₊、SO_42- 和Mg₂₊含量显著相关(P<0.05),土壤电导率(EC)与土壤可溶性盐总量相关关系达到显著水平(P<0.05)。

Effect of Planting Ages on Soil Salts Content in Facility Cultivation Watermelon Soil

To analyze the effects of watermelon planting years on changes of soil salts contents in facility cultivation watermelon soil, a field sampling in combination with analytical methods was carried out to measure the content and composition of soluble salts in soils with different facility cultivation planting ages. The results showed that soil pH value of facility cultivation watermelon soil significantly decreased compared with upland soil (P <0.05), while soil available nitrogen (AN), available phosphate (AP), available potassium (AK), andEC significantly increased (P <0.05). SoilEC was significantly increased with the increase of planting ages (R 2= 0.90，P <0.01). Ca2+ and Mg2+ were the major soluble salt cation, and SO42- and NO3- were the major soluble salt negative ions in facility cultivation watermelon soil. The content of soil total soluble salt were significantly increased with the increase of planting ages (R 2=0.93，P <0.01). The Ca2+, K+, NO3- and Cl- accounted for about 31.3%, 10.1%, 23.6% and 15.0% of the increased total soluble salt in soil. Correlation analysis indicated that soil available phosphate (P), available potassium (K) were important factor affecting the content of Na+ 、K+ 、SO42- and Mg2+. Soil electrical conductivity (EC ) could represent the level of soil secondary salinization.