青藏高原东部设施农业区土壤肥力演变和氮磷淋失风险特征  

Evolution of soil fertility and nitrogen/phosphorus leaching risk in protected agriculture of the eastern Qinghai-Tibet Plateau

作　　者：宋明丹 李月梅[1,2] 塔林葛娃 李凤桐[1,2] SONG Mingdan;LI Yuemei;Talin Gewa;LI Fengtong(Academy of Agriculture and Forestry Sciences,Qinghai University,Xining 810016,China;Xining Observation and Experiment Station of National Agricultural Environment,Xining 810016,China)

机构地区：[1]青海大学农林科学院,西宁810016 [2]国家农业环境西宁观测实验站,西宁810016

出　　处：《应用与环境生物学报》2022年第4期877-882,共6页Chinese Journal of Applied and Environmental Biology

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0303)资助。

摘　　要：设施农业的高水肥投入必然引起土壤环境变化,了解该种植方式下土壤肥力的变化及带来的环境风险对该区的生态环境保护具有重要意义.在青藏高原东部农业区百亩以上规模的设施基地按种植年限(≤3年,3-5年,5-10年,10-20年)采集土壤样品,研究土壤肥力随种植年限的变化规律,评估潜在氮磷淋失风险.结果显示:(1)该区土壤有机质和全氮含量平均为17.1和1.3 g/kg,含量中等;碱解氮、速效磷和速效钾含量平均为160.9、72.0和191.2 mg/kg,含量丰富.(2)随种植年限增加,土壤有机质、全氮、碱解氮和速效磷含量均呈增加的趋势,设施种植10年后显著提高,种植10-20年比种植≤3年提高了41.6%、44.2%、26.5%和67.4%,土壤速效磷增加最明显.(3)土壤速效钾含量和pH值均随种植年限呈降低的趋势,速效钾在种植5年以后显著降低,5-10年比≤3年降低了32%;土壤pH值在种植3年以后显著降低,3-5年比≤3年显著降低2.3%.(4)设施种植10-20年,土壤潜在氮磷淋失强度最大,氮磷淋失概率分别达0.74和0.84.综上,青藏高原东部设施农业区种植3-5年后,土壤速效钾含量和pH值明显降低,应及时补充钾素和有机肥投入;种植10-20年,土壤有机质和氮磷含量有明显提升但氮磷淋失风险加剧,需严格控制氮磷肥投入.(图4表2参30)Understanding changes in soil fertility and soil environmental risks in protected agriculture with high irrigation and fertilizer inputs are of great significance for ecological protection. In this study, soil samples in the plow layer were collected from greenhouses >100 acres in the eastern Qinghai-Tibet Plateau after different durations of planting time(either ≤ 3, 3-5, 5-10, or 10-20 years) to assess the changing pattern of soil fertility indicators and the potential leaching risk of nitrogen and phosphorus. The results showed that soil organic matter(OM) and total nitrogen(TN) contents in protected agriculture were 17.1 and 1.3 g/kg, respectively,which suggests moderate content levels. Meanwhile, soil alkali-hydrolyzed nitrogen(AN), available phosphorus(Olsen-P), and available potassium(AK) contents were 160.9, 72.0, and 191.2 mg/kg, respectively, which suggests abundant content levels. As the number of planting years increased, the contents of soil OM, TN, AN,and Olsen-P increased significantly, especially after 10 years, with 41.6%, 44.2%, 26.5%, and 67.4% increases,respectively, compared to ≤ 3 years. As seen, Olsen-P had the most marked increase. In contrast, soil AK and pH decreased with planting years, and soil AK after 5 years decreased by 32% compared to ≤ 3 years.Moreover, the soil pH value in 3-5 years decreased by 2.3% compared to that of ≤ 3 years. The leaching risk of soil nitrogen and phosphorus was intensified after 10-20 years, and the probability of leaching was 0.74 and 0.84,respectively. This study indicated that, in protected agriculture, soil OM, AN, and Olsen-P contents improved,accompanied by a high risk of N and P loss, and AK and soil pH values decreased. It is recommended that the input of nitrogen and phosphorus fertilizers should be controlled, and the input of potassium fertilizer should be increased for more than 10 years of facility cultivation. This study provides a scientific basis for the rational fertilization of agricultural facilities. The findings indicate that a

关 键 词：氮素 磷素 淋失 临界值 风险评价 设施农业 土壤肥力 

分 类 号：X71[环境科学与工程—环境工程] S158[农业科学—土壤学]