Dear Wei
There is an assumed value of  2.65 for miniral bulk density  for all mineral
soils, it can range from 2.6 to 2.75. I have the publication  of Dr Rawls
and Brakensiek titled "Estimation of soil water retention and hydraulic
properties" , and they use this value of 2.65
Hope this helps
Regards
Eugenia Munaro

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Sent: Wednesday, November 02, 2005 2:39 AM
Subject: DSSAT Digest - 25 Oct 2005 to 1 Nov 2005 (#2005-72)


> There is one message totalling 20 lines in this issue.
>
> Topics of the day:
>
>  1. soil bulk density calculation
>
> ----------------------------------------------------------------------
>
> Date:    Wed, 2 Nov 2005 09:12:28 +0800
> From:    xiongw <[log in to unmask]>
> Subject: soil bulk density calculation
>
> Dear Colleagues
>
> We need to calculate the bulk density from the soil survey with sampling
> points across China, we used the function of Rawls and Brakensiek (1985,
> 1989) which used in DSSAT4, BD = 100 / (SOM% / 0.224 + (100 - SOM%) /
> mineral BD). While the mineral BD is not the available input value. the
> reference of Rawls and Brakensiek is quick old literature which is not
> available in China. Does anyone knows how to estimate the mineral BD from
> soil texture information, Or there are lastest references.
>
> Thank you very much in advance.
>
> Wei
> Institute of Environment and Sustainable development for Agriculture
> Chinese Academy of Agricultural Sciences
> 100081, P.R. China
>
> ------------------------------
>
> End of DSSAT Digest - 25 Oct 2005 to 1 Nov 2005 (#2005-72)
> **********************************************************
>