摘要
在连续少免耕１１年的定位试验田里，研究了少免耕土壤的供肥特性和水稻吸肥规律。结果表明：（１）少免耕有利于土壤有机质、全氮和速效钾等在上层富集和积累，耕翻有利于氮素的矿化，提高前拥有效氮的供应，后期则较低；（２）连续少免耕植株含氮率前期较高，后期较低，易出现早衰现象，并不是土壤真正缺氮，而与７～１４ｃｍ土层容重和穿透阻力增加，障碍层上移，可能影响水稻根系生长和吸收能力等有关；（３）连续多年少免耕植株累积吸氮量明显低于常耕，施肥区少免耕平均比常耕低１８．２％，不施肥区低４０％，不利于水稻植株生长。
The characteristics of soil fertility and rice absorbed nitrogen were investigated in continuonsminimurn or no tillage for 11 years.The results show that:(1)The contents of soil organic matter,totaI ni-trogen and avallable potassium were enriched in the surface soil in continuous minimum or no tillage, but conventional tillage soil was favorable to soil nitrogen mlneraliztion,Therefore, the supply of available nitrogenwas raised in the early stage of rice growth,but reduced in the late stage for conventional tillage.(2)Thecontent of nitrogen in rice plant was higher in the early stage,but lower in the late stage for continuous mini-mum or no tillage.SO rice was likely to be premature. It resulated from increasement of bulk densitv andponetration reslstance in 7 ～ 14cm soil layer,and moving up of the hinder horizon,the growth of rice rootsand their absorbing capabllity being lirnlted,not from the lack of nitrogen in soil.(3 )Compared with theconventionaI tillage,the alnounts of nitrogen accumulated in rice plants is lowed by 18.2%and by 40% re-spectively in applying nitrogen fertilizer and no fertilizer treatments,which was disadvantageous to ricegrowth.
出处
《江苏农学院学报》
CSCD
1995年第2期77-80,共4页
Jiangsu Agricultural Research
基金
江苏省科委应用
关键词
水稻
少耕
土壤肥力
氮
吸收
rice
minimal tillage
soil fertllity
nitrogen+absorption
