摘要:设施黑土菜田由于过量施肥和灌溉导致磷素淋溶损失严重，亟待优化水肥管理模式以减少设施黑土菜田磷素淋溶。本研究依托黑土设施菜田淋溶监测试验，设置常规灌溉量与施肥量（WF）、常规灌溉量+80%常规化肥量（W80% F）、80%常规灌溉量+常规肥处理（80% WF）3个处理，对土壤磷储量、速效磷动态变化、磷素淋失量进行分析，研究了不同水肥处理对黑土设施茄子土壤磷素淋失风险和淋失量的影响。结果表明：经种植1季茄子后，WF、W80% F和80% WF处理0~100 cm土体磷储量分别为9.69 t·hm-2、9.36 t·hm-2和8.84 t·hm-2，分别比移栽前增加26.5%、27.5%和7.1%。随着茄子生育期延长，0~20 cm土层速效磷含量呈先升高后降低的趋势，80% WF处理速效磷含量较其他两个处理高，变幅为145.17~224.55 mg·kg-1；20~40 cm土层，WF处理速效磷含量基本保持不变，80% WF处理速效磷含量整体呈上升趋势，W80% F处理速效磷含量先升高后降低再升高，除盛果期外均显著高于另两个处理。WF、W80% F和80% WF磷素淋失量分别为17.84 kg·hm-2、17.47 kg·hm-2和9.02 kg·hm-2，其中有机磷淋失量占磷素淋失总量的90%以上。磷素淋失量与磷储量增加量、盛果期0~40 cm土层速效磷含量、拉秧期0~20 cm土层速效磷含量之间均存在显著的相关性（P < 0.05），可通过磷储量增加量来预测生育期内磷素淋失量。与常规水肥处理相比，减少化肥施用量对磷素淋失量和淋失风险无明显影响，但减少灌溉量能显著减少磷素淋失量，降低磷素淋失风险。研究结果可为设施黑土菜田磷素淋溶阻控提供技术支撑，为新阻控技术的研发提供理论指导。
关键词:设施黑土菜田/
磷淋溶/
磷储量/
减施化肥/
减少灌溉量
Abstract:Excessive fertilization and irrigation have led to phosphorus leaching in Mollisol vegetable fields, and optimization of these practices is critical for reducing phosphorus pollution. A leaching monitoring experiment was performed in a Mollisol eggplant field using the following three treatments: standard irrigation and chemical fertilizer amounts (WF), standard irrigation + 80% chemical fertilizer (W80%F), and 80% irrigation + standard chemical fertilizer (80%WF). The soil phosphorus storage, available phosphorus dynamics, and phosphorus leaching amounts were analyzed to determine the effects of irrigation and fertilization treatments on phosphorus leaching. After one growing season, phosphorus storage in the 0–100 cm soil layers were 9.69 t·hm-2 (WF), 9.36 t·hm-2 (W80%F), and 8.84 t·hm-2 (80%WF), which were 26.5%, 27.5%, and 7.1% higher than before planting, respectively. These results showed that phosphorous accumulation occurred, which increased the leaching risk. During the extended eggplant growing period, the available phosphorus in the 0–20 cm soil layer increased and then decreased, and was highest in the 80%WF treatment, ranging between 145.17–224.55 mg·kg-1. The available phosphorus in the 20–40 cm soil layer did not change under WF treatment and increased under 80%WF treatment. The available phosphorus fluctuated with W80%F but was significantly higher than that in the other treatments, except during the full fruit period. The phosphorus leaching amounts were 17.84 kg·hm-2 (WF), 17.47 kg·hm-2 (W80%F), and 9.02 kg·hm-2 (80%WF). Organic phosphorus leaching was more than 90% of the total phosphorus leaching, differing from other soil types. There were significant positive correlations between phosphorus leaching and increased phosphorus storage, available phosphorus in the 0–40 cm layer at the full fruit stage and in the 0–20 cm layer at the withering stage (P < 0.05). This indicates that changes in phosphorus storage and the available phosphorus content may help predict phosphorus leaching in Mollisols. After one growing season, phosphorus storage in the 0–100 cm layer increased in all treatments; the smallest increase was in the W80%F treatment, indicating that reduced irrigation lowers the phosphorous leaching risk. Reducing chemical fertilizers did not affect phosphorus leaching or the leaching risk. These results provide information for preventing phosphorus leaching, which may be used to develop new techniques for Mollisol vegetable fields.
Key words:Facility vegetable field of Mollisols/
Phosphorus leaching/
Phosphorus storage/
Reducing chemical fertilizers application/
Reducing irrigation
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