土壤表殼對萌芽種子阻力之田間量測計的開發

Development of a Field Penetrometer for Measuring the Impedance of Soil Crusts upon Emerging Seedlings

朱元南(Yuan-Nan Chu) ； Charlie G. Coble ； Wayne R. Jordan

《農業機械學刊》 1卷4期 (1992/12) Pp. 22-30

https://doi.org/10.30062/JAM.199212.0003

摘要

本研究發展出一種新型的土壤阻力計，可模擬種子在土中萌芽之狀態，量測土壤表層5公分內土壤對種苗之阻力。其原理為利用一個粗0.95公分的半圓弧鉤，由苗床側邊旋轉插入土中直到其尖端由土壤表殼下方穿出為止。鉤端的力量轉換器可量測出穿透過程中的表殼阻力。鉤端的位置由一個電位計量出。阻力和位置的資料由一個可攜式記錄器收集，並可傳送至其他電腦以作資料分析。此一阻力計可量測1～45N之阻力，量測之不準度為±0.05N，安全係數為2。田間每次量測所需之時間少於四分鐘。本阻力計有助於研究田間土壤表殼阻力之變化以及種苗發芽過程中土壤表殼阻力與芽的位置之關係。

關鍵字

土壤表殼 ； 阻力 ； 量測計

並列摘要

A new field penetrometer was developed for measuring the impedance of soil crusts upon emerging seedlings in the surface 5cm of the seedbed. The penetrometer simulated emerging seedlings by using a half-circle hook made from a 0.95cm diameter stainless steel rod to penetrate and rotate through the side of seedbed until the tip of the hook emerged from below the crust. Crust impedance on the tip of the hook was measured by a tiny load cell within the tip. A potentiometer measured the position of the tip during the penetration. The impedance and position data were collected by a portable datalogger and may be transferred to mainframe or personal computers for further analysis. The penetrometer measured forces on the tip of the hook from about 1N up to 45N with an accuracy of ±0.05N and a factor of safety of 2. Field measurements of crust impedance using this device took less than 4 minutes per sample. The new field penetrometer may be used for the field investigation of the crusting phenomena and allowed the study of the relationship between the crust impedance and the penetration distance by the seedling.

並列關鍵字

Soil crust ； Impedance ； Penetrometer