生物炭添加对酸化土壤中小白菜氮素利用的影响  

EFFECT OF BIOCHAR APPLICATION ON PAKCHOI(BRASSICA CHINENSIS L.)UTILIZING NITROGEN IN ACID SOIL

作　　者：俞映倞[1] 薛利红[1] 杨林章[1] 何世颖[1] 冯彦房[1] 侯朋福[1] 

机构地区：[1]江苏省农业科学院农业资源与环境研究所,南京210014

出　　处：《土壤学报》2015年第4期759-767,共9页Acta Pedologica Sinica

基　　金：江苏省农业科技自主创新项目(CX(13)3039);水体污染控制与治理科技重大专项(2012ZX07101-004);江苏省太湖水环境综合治理科研课题(20130209)资助

摘　　要：针对菜地土壤酸化趋势显著、氮肥利用率低下等突出问题,以小白菜为供试作物,设置了前3季连续施用化肥氮及后2季不施化肥氮的5季盆栽试验,研究生物炭添加对酸化土壤上连续多季种植小白菜的产量、氮肥利用率以及土壤供氮能力的影响。结果表明:在连续添加化肥氮的条件下,生物炭添加显著增加了小白菜的产量及氮素累积量,有效降低了土壤速效氮含量,并提高了土壤速效氮中NO3--N含量比例,缓解了土壤酸化趋势,降低了小白菜中硝酸盐含量,增加了氨基酸含量,提高了氮肥利用率;在停止施用化肥后,生物炭添加处理仍能保持较高的土壤速效氮含量,提高土壤固持氮素的有效性,促进植株对氮素的吸收利用,从而使产量维持在施氮条件下的高水平。研究表明生物炭添加对土壤氮素具有"削峰填谷"的调节功能,能够有效促进氮素的吸收转化,从而有利于维持高产。Excessive application of nitrogen （ N ） fertilizer is a widespread problem in vegetable field in Taihu Lake basin, which would not only cause severe non-point source pollution, but also induce soil acidification, and hinder vegetable growth, too. A number of studies have demonstrated that having a strong N adsorption capacity, biochar is able to affect N recycling in the soil and regulate soil pH in various ecosystems, but little is known about effects on vegetable soils and vegetable production. In this study, impacts of biochar application on vegetable growth, N absorption N utilization, N transformation, soil readily available N and soil pH are explored. A pot experiment was carried out using acidified garden soil collected from Taihu Lake region and biochar prepared out of wheat straw under 450℃. The experiment was designed to have four treatments： biochar and urea （BC＋U） , only urea （U） , only biochar （BC） , and no N fertilizer treatment （ NO, control ） and 6 replicates for each treatment. Five continuous croppings of pakchoi （Brassica chinensis L. ） were planted. For the first three croppings, urea （ N 100 kg hm^-2） was applied into related treatments, i.e. Treatments BC＋U and U; and for the following two croppings, no N was applied soil N as designed as N depletion period. Biomass of and N accumulation, nitrate and amino acid contents in pakchoi and dynamics of soil readily available N was measured during the harvest season. Soil pH was determined at the end of the experiment. Results show that application of biochar significantly promoted vegetable growth, and yield of and N accumulation in the vegetable of the 2rd and 3rd cropping was increased by over 70% and 60%, respectively, in Treatment BC＋U as compared with that in Treatment U. In the last two croppings without N fertilization, the yield of and the N accumulation in the vegetable in Treatment BC＋U still remained quite high, almost twice as high as that in Treatment U, thanks to the presence of biochar in the

关 键 词：氮素利用率 土壤酸化 小白菜 生物炭 

分 类 号：S157[农业科学—土壤学]