| 摘要: |
| 【目的】评价陕西不同地区日光温室系统养分平衡及土壤养分累积状况，为当地日光温室土壤养分管理提供技术指导。【方法】2013年7月和2014年7月连续2年分别在陕西杨凌（土娄土）、安塞（黄绵土）和靖边（风沙土）3个区县调查了193个日光温室的施肥状况，分析日光温室的养分总投入量、养分携出量及表观养分盈余量变化；并采集日光温室土壤样品，测定土壤养分含量及基本理化指标。【结果】（1）研究区域日光温室养分总投入量因地区而异，年均氮（N）、磷（P2O5）、钾（K2O）养分总投入量分别为1 933.3，1 587.2和1 799.2 kg/hm2，而养分携出量仅占氮、磷、钾养分总投入量的22%，7%和36%；年均氮、磷、钾的表观盈余量分别高达1 503.2，1 473.1和1 155.2 kg/hm2。（2）研究区域日光温室土壤有机质含量整体处于中、低水平，这与研究地区土壤基础肥力低有关；杨凌、安塞和靖边地区温室土壤0～200 cm土层硝态氮累积量分别达到1 451.5，1 647.2和498.5 kg/hm2，0～60 cm土层硝态氮累积量分别仅占0～200 cm硝态氮累积量的37.8%，36.9%和37.9%，其中0～2 m土层土壤剖面累积的硝态氮有60%以上分布在60～200 cm土层，难以被作物根系吸收利用；研究区土壤速效磷、钾多处在高及较高水平，其中土壤速效磷含量处于中、高水平（≥50 mg/kg）的样本所占比例达77%～91%，土壤速效钾含量处于中、高水平（≥150 mg/kg）的样本数所占比例为35%～91%。（3）温室土壤pH整体偏碱性，这与土壤发育于黄土母质及碳酸盐含量高有关；不同土层相比，表层土壤pH明显小于下层土壤；土壤电导率整体低于蔬菜生长临界值600 μS/cm，不同土层相比，表层土壤电导率显著高于下层土壤。（4）与杨凌土娄土及安塞黄绵土相比，靖边风沙土养分含量相对较低，故日光温室生产中应注意有机肥及化肥的有效施用。【结论】陕西不同地区日光温室系统普遍存在过量施肥问题，导致土壤中氮、磷、钾养分过量累积，由此带来的环境问题值得关注，同时适当控制日光温室养分投入应是陕西不同地区日光温室养分管理的重点。 |
| 关键词: 日光温室 过量施肥 养分平衡 土壤养分累积 环境风险 |
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| 基金项目:国家“十二五”科技支撑计划项目（2012BAD15B04）；高等学校学科创新引智计划资助项目（B12007）；中英农业国际合作项目 |
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| Nutrient balance and accumulation in soil of solar greenhouse in Shaanxi |
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CAI Hongming,WANG Shichao,LIU Yan,et al
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| Abstract: |
| 【Objective】This study evaluated nutrient balance and soil nutrient accumulation in greenhouse systems at different areas of Shaanxi to provide technical support for the nutrient management in local greenhouses.【Method】The application of fertilizers in 193 greenhouses over two consecutive years from July 2013 to July 2014 in Yangling,Ansai,and Jingbian was surveyed for analyzing the changes of total nutrient input,crop yield,and apparent nutrient surplus in greenhouse system. Nutrient contents and basic physical-chemical properties in greenhouse soils were also determined.【Result】(1) Total nutrient inputs from manures and chemical fertilizers varied with regions.The average annual input amounts of N,P2O5 and K2O were 1 933.3,1 587.2 and 1 799.2 kg/hm2,respectively.The N,P2O5 and K2O uptake amounts by crops accounted for only 22%,7% and 36% of nutrient inputs,resulting in surplus of N 1 503.2 kg/hm2,P2O5 1 473.1 kg/hm2 and K2O 1 155.2 kg/hm2 in greenhouse system.(2) The contents of organic matter in soils were in medium or low levels,which was related to low soil fertility.Nitrate-N accumulations in 0-2 m soil profile of Yangling,Ansai and Jingbian greenhouses were 1 451.5,1 647.2 and 498.5 kg/hm2,and 37.8%,36.9% and 37.9% of the accumulated nitrate in the three regions were distributed in 0-60 cm soil layer.More than 60% of nitrate accumulation in 0-2 m soil profile was distributed below 60 cm layer,which was difficult to be absorbed by crops.Soil available P and K contents were at high levels,and 77%-91% and 35%-91% of soil available P and K contents were higher than the critical value (≥50 mg/kg P2O5 and ≥150 mg/kg K2O).(3) Soil pH was weakly alkaline,which was related to local soil developed from loess parent material with high carbonate content.Soil pH in topsoil was significantly lower than that of the subsoil.The soil electrical conductivity was lower than 600 μS/cm,which is the critical value influencing growth of vegetables.Electrical conductivity of topsoil was significantly lower than that of the subsoil.(4) Compared with the Lou soil and Loessal soil,the nutrient contents in aeolian sandy soil was relatively low.Therefore,attention should be paid to the effective application of organic manure and chemical fertilizers in this soil in Northern Shaanxi.【Conclusion】Excessive fertilization is a problem in sunlight greenhouse systems at different areas of Shaanxi,leading to large surplus of nitrogen,phosphorus and potassium nutrient in soil and causing environmental problem.Decreasing nutrient inputs properly in greenhouse should be the focus of nutrient management at different areas of Shaanxi. |
| Key words: solar greenhouse excessive fertilization nutrient balance soil nutrient accumulation environmental risk |
