渭河上游地区温室菜地土壤肥力演变特征研究

摘要

The effects of long-term continuous cropping greenhouse vegetables on soil pH ,total salt ,organic mat-ter ,and N ,P and K nutrients content of topsoil (0 ~ 20 cm) were studied through open field and greenhouse topsoil sampling during different cropping years in Wushan county Tianshui city located upstream of Weihe River .The results showed that pH of topsoil (0 ~ 20 cm) in greenhouse vegetable field during different cultivation years was all significantly lower than that of the open field ,and with the extension of cultivation years ,soil pH become declined significantly . Moreover ,soil pH was significantly negatively related with cultivation years ,0 .05 pH decline per year .In contrast ,the soil total salt content was significantly positively related to cultivation years with 0 .091% increase per year .For 14 years continuous cropping with greenhouse vegetables ,soil total salt content reached to 0 .34% ,6 .35 times as much as that in the open field .Soil organic matter ,total nitrogen ,available nitrogen ,total phosphorus ,total potassium ,available phos-phorus and available potassium contents were also gradually increased with the increase of cultivation years .After 14 years of continuous cropping with greenhouse vegetables ,soil available N ,available P and available K contents reached to 230 .17 ,342 .17 mg·kg - 1and 263 .00 mg·kg - 1 ,respectively ,significantly higher than those in the open field .%在陇东南渭河上游地区的天水市武山县，通过田间采样的方法，以不同种植年限的温室和露地的耕层土壤（0～20 cm）为研究对象，研究了长期连作温室蔬菜对土壤 pH 、全盐、有机质及氮磷钾养分的影响。结果表明：不同种植年限温室菜地的土壤 pH 都明显低于其露地大田，而且随种植年限的延长，pH 逐渐降低，与种植年限显著负相关，年均降低0．05个单位。而土壤全盐含量与种植年限呈显著正相关，年均增加0．091个百分点。连续14年种植温室蔬菜土壤全盐含量达到0．34％，是露地土壤的6．35倍。土壤有机质、全氮、碱解氮、全磷、全钾、速效磷和速效钾含量也随种植年限逐渐增加，与种植年限显著正相关，连续14年种植温室蔬菜后，土壤的速效氮、速效磷和速效钾含量分别达到230．17、342．17 mg·kg －1和263．00 mg·kg －1，显著的高于大田。