相對濕度對硝磷基及錏磷基複合肥料吸濕程度之影響

本研究係針對不同溫度下的相對濕度對於不同型態的氮混合型肥料，硝磷基複合肥料及錏磷基複合肥料之吸濕性的影響，分別探討兩類複合肥料在20℃、25℃、30℃、35℃及40℃下的臨界相對濕度(critical relative humidity, CRH)、30℃時錏磷基及硝磷基各配方複合肥料臨界相對濕度的探討、錏磷基及硝磷基各配方複合肥料在30℃ CRH+3% 維持24小時後的吸濕率、CRH各增加3%、2%、1%及減1%、2%環境下第24小時吸濕率趨勢及CRH正負1%濕度肥料吸濕量變化。結果顯示，溫度的提升大多會加強肥料吸濕能力，無論是硝磷基或錏磷基複合肥料皆有相同趨勢。此外，針對各配方30℃時的CRH深入了解增減相對濕度時的吸濕能力變化，可以看出不同型態的氮素來源在吸濕後表現有明顯不同，可從組成原料各溶解度解釋吸濕能力與溶解度對複合肥料的具體影響。如上所述，本研究建議硝磷基複合肥料含水率降至1.5%以下。散裝肥料須放置於有空調之倉庫，並調整溫、濕度至肥料CRH以下。降低肥料袋水分滲透率，將PP (polypropylene)編織袋提升為BOPP(biaxially oriented polypropylene)淋膜袋。運輸過程中加裝遮蔽物，避免肥料溫度變化過大。儲存時間盡可能縮短。堆疊時底部放置棧板，及堆疊重量不超過2噸重。發現破包時，分包成小包裝。可有效降低因吸濕結塊造成農民施灑複合肥料的不便性。

關鍵字

相對濕度；複合肥料；硝磷基；錏磷基；吸濕

並列摘要

This study was conducted to investigate the effect of relative humidity at different temperatures on the hygroscopicity for different types of nitrogen-mixed fertilizers, nitrophosphate-based compound fertilizers and ammonium phosphates-based compound fertilizers. The critical relative humidity (CRH) of two types of compound fertilizers at 20°C, 25°C, 30°C, 35°C, and 40°C were analyzed, separately. Furthermore, for nitrophosphate and ammonium phosphates-based of compound fertilizers, the comparison of CRH of each formula at 30°C, the ability to absorb moisture after 24 hours for each formulation by increasing 3% humidity at 30°C CRH, the trends of the moisture absorption ability after 24hr at different CRH increased by 3%, 2%, 1%, and 1%, 2%, and the variation of the moisture absorption at different CRH by increasing and decreasing 1% moisture will be discussed, separately. The results indicated that when increasing the temperature, the ability of absorb moisture of fertilizers will increase, either nitrophosphate-based or ammonium phosphates-based compound fertilizers have the same trend. Furthermore, the ability of absorb moisture when increasing or decreasing relative humidity at 30°C CRH was also investigated. The results indicated that different types of nitrogen sources have distinctly different developments after moisture absorption. It can be explained from the raw materials for the specific impact absorption capacity and solubility for the compound fertilizer. In conclusion, this study suggests that the water content of nitrophosphate compound fertilizer should be reduced to less than 1.5%. Bulk fertilizer should be placed in an air-conditioned warehouse and the temperature and humidity should be adjusted below the fertilizer CRH. Reduce the moisture permeability of the fertilizer bag and upgrade the P.P. woven bag to a B.O.P.P. laminating bag. Install a shield during transportation to avoid excessive changes in fertilizer temperature. Storage time is as short as possible. The stack is placed at the bottom of the stack, and the stack weight does not exceed 2 tons. When it is found that the package is broken, it is subcontracted into a small package. It can effectively reduce the inconvenience caused by farmers to apply compound fertilizer due to moisture absorption and agglomeration.