摘要
随着酸雨的蔓延和化学氮肥用量的增加,土壤酸化日趋严重,钙流失不断加剧,而含钙肥料却因高浓度复合肥比重的增加(磷铵取代含钙磷肥)而不断下降,使钙供应与植物需要的矛盾日渐突出.文中简述了钙对植物抗酸、盐、氨、重金属、渍害、冷害、热害、病害及酸雨等能力的影响,以及维持土壤钙供应的措施,指出植物生长过程中分泌的酸是施肥引起土壤酸化的主要原因.根系分泌酸能力强的田菁改良盐碱土的重要机理之一是促进土壤钙的活化,增强后季作物的抗盐能力.降水中氮素含量的增加,促进了林木的生长,并使其他元素缺乏,易加剧根际酸化,可能是一些工业化地区森林退化的重要机制.基于钙在植物抗逆中的作用,建议在肥料试验设计中增加施钙的空白对照区,以便将钙的效应从其它处理效应中区分出来.磷铵不应作为我国磷肥工业的发展方向.
Calcium loss from soil has dramatically increased for decades due to the increase of nitrogen input and/or the extension of acid rain,while calcium input into soil has declined substantially for the replacement of superphosphate by ammonium phosphate in fertilization,which intensified the imbalance of calcium input and output in agro-ecosystems,and needed to be solved in the near future for the sustainability of agriculture in such a country like China where the arable land resource is very limited.In recent years,the intensified soil acidification is mainly attributed to the root proton secretion stimulated by fertilization,and the nitrogen input from precipitation near industrialized regions promotes plant growth but results in other nutrients deficiency,which in turn acidifies soil and causes tree death.One of the most important mechanisms of saline soil bioremediation by sesbania is the activation of soil calcium by sesbania's proton secretion and the increase of soil calcium supply for subsequent crops.The present paper summarized the roles of calcium in plant tolerance to the stresses like acidosis,toxic metals,osmosis,ammonium toxicity,drought,extreme temperature (cold or heat shock),anoxia and pathogen infection,and the measures for maintaining soil calcium fertility.It was suggested that the production of ammonium phosphate should not be a pursued target for China's phosphorus fertilizer industry,and the roles of calcium in plant growth should be taken into account in fertilization experimental designs to make the experiments more accurate.
出处
《应用生态学报》
CAS
CSCD
北大核心
2005年第5期971-976,共6页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(39370422
3937041)
国际原子能机构资助项目(CPR8478).
关键词
钙
植物
土壤肥力
逆境胁迫
抗性
Calcium, Plant, Soil fertility, Stress, Stress tolerance.
