2种常用肥料在马铃薯种植条件下肥力转化速率研究

Study on Fertility Conversion Rate of Two Common Fertilizers Under Potato Planting Conditions

[目的]研究2种肥料在土壤中的转化时间,从而判断养分供给时间和能力,为确定科学施肥时间提供数据支持。[方法]以马铃薯生产中常用的2种肥料为处理,分别是硫酸钾、磷酸二铵。并设置3个土壤含水量处理,分别为25%、35%、45%。设定取样时间,测定肥料剩余量并计算肥料的溶解量和溶解率。[结果]磷酸二铵和硫酸钾分别在施肥后第5天和第56天时溶解量超过或接近50%,可将其标定最佳养分吸收期。磷酸二铵施入21 d后,肥料不再转化,整体上随着土壤水分含量的提高,磷酸二铵溶解能力增强,养分供应能力变大,但持续供养能力变弱。试验周期内硫酸钾养分释放比较平均,在土壤含水量25%和35%条件下,施肥后28 d内为养分高效供应期,28 d后养分供应趋于稳定。在土壤含水量45%条件下,施肥后49 d内为养分高效供应期。整体上看,含水量45%更有利于硫酸钾高效供养时间的延长。[结论]可将磷酸二铵和硫酸钾的溶解能力作为肥料养分供应的指标,但只能应用于矿质元素类肥料,因有机肥料溶解后还涉及矿质化过程,对有机类肥料不具备指导意义。

[Objective]To determine the conversion time of two fertilizers in soil,so as to determine the nutrient supply time and ability,and provide data support for determining the scientific fertilization time.[Method]In this experiment,two fertilizers commonly used in potato produc-tion were used as treatment,namely potassium sulfate and diammonium phosphate.Three soil moisture treatments were set,respectively 25%,35%and 45%.Sampling time was set and fertilizer residual amount and fertilizer dissolution amount and dissolution rate were determined.[Re-sult]The dissolved amounts of diammonium phosphate and potassium sulfate exceeded or approached 50%on the 5th and 56th day after fertili-zation,respectively,and could be labeled as the best nutrient absorption period.After the application of diammonium phosphate for 21 days,the fertilizer did not transform.On the whole,with the increase of soil moisture content,the dissolution capacity of diammonium phosphate was en-hanced,and the nutrient supply capacity was increased,but the sustainable support capacity was weakened.The release of potassium sulfate nu-trient was relatively average during the experiment period.Under the conditions of 25%and 35%soil water content,the nutrient supply period was efficient within 28 days after fertilization,and the nutrient supply tended to be stable after 28 days.Under the condition of 45%soil mois-ture content,the nutrient efficient supply period was within 49 days after fertilization.On the whole,45%water content is more conducive to prolonging the effective feeding time of potassium sulfate.[Conclusion]The solubility of diammonium phosphate and potassium sulfate can be used as the index of nutrient supply of fertilizer,but it can only be applied to mineral element fertilizers.Because organic fertilizers also involve mineralization process after dissolution,it has no guiding significance for organic fertilizers.