Influence of Long-term Nitrogen,Phosphorus Fertilizers and Organic Complex Fertilizations on Cinnamon Potassium Balance and Forms

Based on the experiment by 20 consecutive years of nitrogen and phosphorus fertilizations with organic fertilizer on the cinnamon soil,the effect of nitrogen and phosphorus fertilizer with organic fertilizer on the tilth soil potassium balance,content and proportion of K was studied.The results show that all treatments could increase crop yield and improve potassium absorption of the aerial crop.In single applied high quantity organic fertilizer treatment,soil potassium was surplus and the others deficit.With the increase of organic manure,profit and loss of soil potassium reduced.In the only nitrogen and phosphorus fertilizer treatments,water soluble K and non-exchangeable K content increased and then declined with the increase of nitrogen and phosphorus chemical fertilizer.Potassium contents of other forms showed no obvious change.In complex nitrogen and phosphorus fertilizer with organic fertilizer treatments,potassium content of various forms showed ascendant with the increase of organic fertilizer.In the only nitrogen and phosphorus fertilizer treatments,the proportions of water soluble K,non-exchangeable K and mineral K in total potassium declined first and later increased with the increase of nitrogen and phosphorus chemical fertilizer.In complex nitrogen and phosphorus fertilizer with organic fertilizer treatments,water soluble K,the proportions of non-specifically adsorbed K and specially adsorbed K showed ascendant with the increase of organic manure,but mineral K ratio decreased.Non-exchangeable K change rule was not obvious.Long-term nitrogen and phosphorus fertilizer with organic fertilization could also slow down the soil total potassium content consumption.