堆肥有效養分潛能估測之研究

Abstract

如能適當的估算堆肥的有效養分潛能(PAN, Potentially available nutrient)，並巧妙地配合作物生育特性，將使堆肥的效益發揮至最恰當。本研究目的在於評估利用化學萃取法，估算堆肥有效養分潛能之可行性。供試之化學萃取劑包括1M (N H4)2 CO3, 0.1M NaOH , IM Na2CO3及1M (NH2)2CO等四種，經由多種有機材質製成的不同堆肥之玉米盆栽試驗結果顯示，利用碳酸銨萃取堆肥所得之可利用性有機氮量與施用相同種類堆肥之淨有效氮量可用1nY=Ina+b/X (X：碳酸銨萃取堆肥之有效性氮潛力，Y：堆肥淨有效氮量）迥歸程式描述碳酸銨萃取堆肥所得可利用性有機氮量與施用相同種類堆肥的淨有效氮量之關係，其相關性(r2=0.673**)可達極顯著水準，因此碳酸銨萃取法以估測堆肥之有效養分潛力頗具可行性。 The most efficient way to understand availability of nutrient of organic fertilizers is to determine their PAN(potentially available nutrient) and manage their mineralization rates to match the amounts of nutrients needed for the aim crops. The objectives of this research was to deveolope a chemical extracting method for estimating of the PAN value of composts. Pot experiments with different levels of composts added were conducted to evaluate four chemical extracts (0.1 M NaOH, 1M Na2CO3, 1M (NH4)2CO3, 1M Urea) for estimating the PAN value of composts. Results inducated that the best correlation was between the amount of net available N and organic N extracted by the ammonium carbonate which could significantly be described by lnY=lna+b/X (X:potential available N of compost, Y: estimated net available N, r2=O.673**). It is concluded that the ammonium carbonate extraction method is effective on evaluating the PAN value of composts.