洞庭湖平原菜园土壤养分径流规律及其影响因素

Nutrient loss with runoff from vegetable soil derived from river alluvial in Dongting Lake Plain and its affecting factors

摘要:

通过定位大田和田间小区试验，研究了不同蔬菜类型及不同施肥结构对菜园土壤养分径流损失的影响。结果表明：菜园土壤养分径流损失以氮为主，钾素次之，磷素最少。种植辣椒作物由于施肥量大于南瓜，氮、磷、钾养分的淋失显著高于南瓜地。白菜地磷、钾养分的淋失显著高于甘蓝地。春、夏季蔬菜地氮、磷、钾养分的淋失高于秋、冬季蔬菜地。在茄子生育前期，当地菜农习惯施肥处理（CK₂），氮、磷养分的淋失较其他处理严重，单施化肥处理（NPK），钾养分的淋失较其他处理严重。白菜、甘蓝地前2次径流水样中，习惯施肥和单施化肥处理氮、磷、钾养分的淋失较其他处理严重。施用有机肥料，在蔬菜生育后期氮、磷、钾养分的淋失大于其他处理，维持较高的水平。不施肥处理，也存在着养分的损失，且数量较大，在生产实践中应加强土壤养分资源的管理和高效利用。

Abstract:

Through long-term stationary field and plot experiments, effects of vegetable type and fertilization structure on nutrient loss with runoff were studied. Results show that nitrogen was the main nutrient element lost from vegetable field with runoff, and followed by potassium and phosphorus. NPK leaching was significantly higher in hot pepper field than in pumpkin field, because the former received a higher rate of fertilizer. P and K leaching was obviously higher in Chinese cabbage field than in cabbage field. NPK leaching from vegetable fields was higher in spring and summer than in fall and winter. At the early growth stage of eggplant, N and P leaching was more serious in CK₂ (local custom fertilization treatment) than in any other treatments. K leaching was higher in Treatment NPK (chemical fertilization) than in any other treatments. In the water samples from the first and second runoffs from Chinese cabbage and cabbage fields, N, P, K contents were higher in CK₂ and Treatment NPK than in any other treatments. At the later growth stage of vegetables, NPK leaching was higher in Treatment OM (organic manure) than in any other treatments and remained high. In Treatment CK₁ (No fertilization), nutrient loss still existed and was quite high, too. It is, therefore, recommended that the management of soil nutrient resources should be intensified to make efficient use of them in the production.