磷含量和秸秆添加量对褐土锌吸附—解吸的影响

采用室内培养的方法,通过人为添加不同量的玉米秸秆和磷,研究不同含量磷和作物秸秆对土壤锌吸附—解吸的影响,以探讨磷—锌在土壤中的交互作用机制。结果表明:低锌(Zn10:添加Zn2+浓度为10 mg L-1)条件下,土壤对Zn2+的吸附量随土壤速效磷含量的增加而逐渐降低,表明在石灰性土壤中,随磷含量的增加提高了土壤锌的有效性;而Zn2+的解吸量随土壤中磷含量的增加先升高后降低,添加Zn2+浓度为80 mg L-1(Zn80)条件下,土壤对Zn2+的吸附量明显大于Zn10条件下。土壤中添加不同秸秆量对不同浓度Zn2+吸附时,低锌(Zn10)处理下,在相同磷含量情况下,土壤对Zn2+的吸附量随秸秆添加量的增加而减少,而土壤对Zn2+的解吸量随秸秆量的增加而增加。在不同磷水平下,不同秸秆添加量对Zn2+的吸附趋势差异较大。高锌(Zn80)处理下,土壤对Zn2+的吸附量在不同秸秆量处理下趋势大致相同,且Zn2+吸附量随磷含量的提高先升高后降低;在同一磷水平下,土壤对Zn2+的吸附趋势和Zn10时相似。利用KNO3进行解吸Zn2+时,不添加秸秆和低量秸秆处理变化趋势相同,均在添加磷量为360 mg kg-1时解吸量达到最大,分别为363.5 mg kg-1、424 mg kg-1,而高量秸秆处理下,Zn2+解吸量随磷含量的增加先升高后降低。

Effects of P and Straw Application Rates on Zinc Adsorption & Desorption in Cinnamon Soil

To elucidate the interaction mechanism of P and Zn in soil system,this study investigated the effects of different rates of phosphorus and straw on Zn2+ adsorption and desorption in Cinnamon soil.The results showed that the Zn2+ absorption amount decreased with P content increase in low content Zn treatments(Zn10 treatment),which indicated that the Zn availability was increased with P content increase;and Zn2+ desorption amount increased at first and then decreased.And in Zn80 treatment,the Zn2+ adsorption amount was significantly higher than that of Zn10 treatment.As for different rates of straw addition,in low amount Zn treatment(Zn10 treatment),the Zn2+ adsorption amount decreased with straw application rates increase and Zn2+ desorption amount increased with straw application rates increase under the same P level.But under different P levels,the Zn2+ adsorption amount was significantly different among all straw application treatments.Under high Zn amount treatments(Zn80 treatment),the trend of Zn2+ adsorption was almost the same in different straw application treatments,and Zn2+ adsorption amount increased at first and then decreased with P content increase.Under the same P level,the trend of Zn2+ adsorption was the same as Zn10 treatment.When using KNO3 to desorb Zn2+,the Zn2+ desorption trend was the same in non-straw treatment and low rates of straw treatment,and the desorption amount reached the maximum at 360 mg kg-1 of P,and the desorption amounts were 363.5 mg kg-1 and 424 mg kg-1,respectively,but in high straw application treatment,Zn2+ desorption amount increased at first and then decreased with P content increase.