有机物料对酸性红壤铝毒的缓解效应

利用盆栽试验研究了施用不等量稻草对酸性红壤旱耕地铝毒的缓解效应。结果表明,添加不等量的秸秆碳(C)后,土壤pH值显著提高,土壤交换性铝和吸附态羟基铝的含量则明显降低,土壤有机络合态铝的含量也呈增加趋势。添加铝盐并不影响秸秆碳对降低土壤交换性铝和吸附态羟基铝含量的作用。在本研究中,土壤pH值与土壤交换性铝和土壤吸附态羟基铝均呈显著负相关,方程分别为y=-2193.9x+11545,R2=0.9798**,y=-655.34x+9748,R2=0.7837**。土壤交换性铝和吸附态羟基铝与玉米主根长,地上部磷、钾含量均呈显著负相关,是抑制玉米吸收养分的主要限制因素,土壤吸附态羟基铝是次于交换性铝的又一活性较大的铝化合物。

Alleviation of organic manure on aluminum toxicity in acid red soil

Aluminum is the most abundant metal that makes up 7% of the earth's crust and occurs in a number of different forms in the soil.If the soil pH <5 or even 5.5,as is now the case accounted for 40% of the arable lands in the world, the harmless oxides and aluminosilicates could be solubilized into toxic forms, generally referred to Al3 ,which is a primary factor limiting plant growth.A possible alternative to ameliorate Al toxicity is the application of organic manure such as rice straw.A pot experiment was conducted to investigate the alleviation of straw on aluminum toxicity in acid red soil.The result revealed that adding 0.5%,1% and 1.5% organic straw carbon significantly increased soil pH value and active exchangeable aluminum;while decreased adsorbent hydroxy aluminum. Soil pH negatively correlated with soil exchangeable aluminum and adsorbent hydroxyl aluminum.with the correlation equations being y=2193.9x 11545,R2 = 0.9798** and y=-655.34x 9748,R2 = 0.7837** respectively.Soil exchangeable aluminum and adsorbent hydroxyl aluminum were significantly negative correlated to root length and P and K content in the ground parts.It is the main limiting factor controlling nutrients uptake.