硅藻土、改性海泡石对氮磷钾吸附和缓释作用的研究

Adsorption and Slow-release Effect of Diatomite and Modified Sepiolite on NPK

为了提高土壤中氮磷钾肥的利用率,通过恒温振荡试验研究了硅藻土、改性海泡石对氯化铵、磷酸二氢钙和氯化钾的吸附作用。通过盆栽试验,测定了玉米不同生长时期土壤中氮磷钾含量,研究了硅藻土、改性海泡石对氮磷钾的缓释作用。研究结果表明,在25℃条件下恒温振荡4 h,氯化铵和氯化钾的初始浓度为60 mg/L时,硅藻土对氮、钾的吸附率分别达到最大值12.80%和17.26%;改性海泡石对氮、钾的吸附率分别达到最大值19.22%和14.75%。当磷酸二氢钙的初始浓度为60 mg/L时,恒温振荡6 h,硅藻土、改性海泡石对磷的吸附率分别达到最大值35.42%和13.42%。对玉米盆栽试验土壤中氮磷钾含量的测定结果表明:硅藻土、改性海泡石对氮磷钾具有良好的缓释作用。该试验获得了硅藻土:改性海泡石:尿素:过磷酸钙:氯化钾的优化质量比为3:3:17.3:9.3:9.6,为缓释肥的研制奠定了基础。

In order to improve the using efficiency of NPK fertilizer, an oscillation experiment was conducted tostudy the adsorption effect of diatomite and modified sepiolite on NH4 Cl, Ca（H2PO4）2 and KCl. And a potexperiment was also conducted to study NPK content in soil in different growth stages of maize and the slow-release effect of diatomite and modified sepiolite. The results showed that when the oscillation continued for 4hours at 25℃ under the initial concentration of NH4 Cl and KCl of 60 mg/L, the adsorption rates of diatomite toN and K reached the maximum of 12.80% and 17.26%, the adsorption rates of modified sepiolite to N and Kreached the maximum of 19.22% and 14.75%. When the oscillation continued for 6 hours under the initialconcentration of Ca（H2PO4）2 of 60 mg/L, the adsorption rates of diatomite and modified sepiolite to P reachedthe maximum of 35.42% and 13.42%. The results of the pot experiment showed that diatomite and modifiedsepiolite had good slow-release effect on NPK. This study obtained the optimum proportion of diatomite：modified sepiolite： urea： calcium superphosphate： potassium chloride as 3：3：17.3：9.3：9.6, which could lay afoundation for the development of slow-release fertilizer.