长期定位施肥对非石灰性潮土钾素状况的影响

利用22年肥料长期定位试验,研究施肥对土壤钾素状况的影响。结果表明,1978年到2000年,土壤钾素收支平衡的状况为:氮钾肥处理钾盈余57.72kg/hm2,氮磷钾肥处理钾亏缺192.90kg/hm2。以氮钾肥处理提高土壤中水溶性钾、非特殊吸附钾、特殊吸附钾、矿物钾最多,依次分别比对照提高5.49倍、1.13倍、2.47倍和1.11倍。氮磷钾肥和氮钾肥处理在土壤中积累各形态钾总量分别占施钾量的19.18%、20.01%。氮钾处理和氮磷钾处理土壤速效钾和土壤缓效钾含量高,在土壤剖面中分布以0—20cm含量高,20cm以下逐层降低。用X-射线衍射测定长期施钾和不施钾的土壤粘土矿物组成为:氮磷钾处理土壤粘土矿物中蒙脱石峰值高;而氮磷处理土壤粘土矿物中蛭石峰值高。

Effect of long-term fertilization on the status of potassium in noncalareous fluvo-aguic soil

Balance status of potassium in soil with 22 years long-term fertilization were studied. The results showed that the potassium surplus was 57.72 (kg/hm²) in NK treatment and deficit of 192.97 (kg/hm²) in NPK treatment during the 1978 to 2000 years. The water soluble potassium, non-specifically absorptive potassium, specifically absorptive potassium and mineral potassium increased by 5.49, 1.13, 2.47 and 1.11 times with NK reatment, respectively. The potassium forms percentage in soil of total K were 19.18% and 20.01% in NPK and NK treatments and the available potassium and slow-release potassium in 0—20cm soil layer of NK and NPK treatments was higher than that in 20—100cm soil layer. The X-ray diffraction diagrams indicated that the clay mineral composition of soil had significant change with and without application of potassium, the peak value of montmorillonite was higher in NPK treatment and vermiculite was higher in NP treatment.