Using single-site augering to determine root distribution of rice
1993
Kumar, K. | Meelu, O.P. | Yadvinder-Singh | Bijay-Singh (Punjab Agricultural Univ., Ludhiana 141004, Punjab (India). Soils Dept.)
Simple auger sampling method is generally used to determine root distribution of field-grown plants. A method for determining average root mass density (RMD) of rice using single-site sampling (SSS) was formulated and tested. RMD was greatest close to the plant base and decreased with increasing distance to a point, then RMD increased again due to contribution of roots from the adjacent row. RMD distribution for all treatments and stages followed the same pattern. A quadratic polynomial generally best explained the relationship between horizontal root distribution and distance. The position for centering the auger for SSS, computed from interpolation of average RMD on the horizontal root distribution curve, was between 3 and 4 cm from the plant box for both soils irrespective of sampling stage and treatment. Results suggest that horizontal root distribution in the top 10-cm soil layer may be sufficient for determining the sampling site for centering the auger. In puddled and flooded soils, a small ring should be hammered around the sampling site a day before sampling and the water removed from within. Single-site augering estimates of RMD are very close to those of monolith excavations. The simplicity and precision of the single-site auger method allows more replications and rapidity of sampling - with reduced labor and destruction of experimental plots - than do other methods
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