崇明岛农林土壤养分分布特征及其影响因素研究

Study on distribution characteristics and influencing factors of agricultural and forestry soil nutrients of Chongming Island

科学评价崇明岛农林土壤养分储存状况,阐述其空间分布特征,对于崇明岛农林生态可持续发展具有重要意义。针对上海崇明岛4种主要农林种植方式(粮田、菜田、果园和生态林)及3种代表性土壤类型(水稻土、潮土和滨海盐土),采集0~20 cm土壤样点100个,分析崇明岛农林土壤养分分布特征及其影响因素。结果表明:崇明岛农林土壤pH均值为7.99,电导率(EC)均值为0.56 mS/cm;有机质平均含量为17.29 g/kg,属于中下水平;全氮平均含量为1.91 g/kg,属于丰富水平;全磷平均含量为1.33g/kg,属于中上水平。崇明岛的农林土壤基本呈碱性,中部的EC较低;土壤有机质含量在南部和中部较高,在东部偏低;全氮含量整体处于较高水平,中部偏高,西部偏低;全磷含量呈现出中部偏高,从南部向东北、东南方向逐步降低的分布格局。不同种植方式下各土壤养分指标均有显著性差异,粮田有机质含量最高,为19.20 g/kg;粮田与菜田全氮含量均较高,分别为2.09、2.17g/kg;土壤EC与全磷含量表现为菜田>果园>粮田>生态林。不同类型土壤的全氮、全磷含量表现为水稻土>潮土>滨海盐土;潮土的有机质含量最高,为18.00 g/kg,EC最低。崇明岛农林土壤养分分布受种植方式的影响显著,选择粮田种植方式有助于崇明岛农林土壤养分提升。

It is of great significance for the sustainable development of the agriculture and forestry ecology of Chongming Island in Shanghai to scientifically evaluate the storage status of agricultural and forestry soil nutrients and expound their spatial distribution characteristics.According to four main agricultural and forestry planting types(grain field,vegetable field,orchard and ecological forest)and three representative soil types(paddy soil,tidal soil and coastal saline soil),100 soil samples of 0-20 cm were collected to analyze the distribution characteristics and influencing factors of agricultural and forestry soil nutrients of Chongming Island.The results showed that the average pH and electrical conductivity(EC)values of agricultural and forestry soils of Chongming Island were 7.99,0.56 mS/cm,respectively,and the average organic matter content was 17.29 g/kg,belonging to the lower middle level;the average total nitrogen content was 1.91 g/kg,belonging to the rich level;and the average total phosphorus content was 1.33 g/kg,belonging to the upper middle level.The agricultural and forestry soil of Chongming Island was basically alkaline,with lower EC value in the central part,higher soil organic matter in the southern and central part and lower in the eastern part.Total nitrogen content was at a relatively high level in the middle and low in the west.The distribution pattern of total phosphorus was higher in the middle and decreased gradually from south to northeast and southeast.There were significant differences in soil nutrient indexes under different planting methods.Grain field had the highest organic matter content(19.20 g/kg)and vegetable field had the highest total nitrogen content(2.17 g/kg).Soil EC value and total phosphorus content were in the order of vegetable field>orchard>grain field>ecological forest.The contents of total nitrogen and total phosphorus in different soil types were paddy soil>tidal soil>coastal salt soil,while the highest organic matter content of tidal soil was 18.00 g/kg,with the lowest EC value.The distribution of agricultural and forestry soil nutrients of Chongming Island was significantly affected by planting methods.In summary,the selection of rice planting mode is conducive to the improvement of agricultural and forestry soil nutrients of Chongming Island.