Re: Soil moisture and organic fertilizers

David Leonard (newsgate.duke.edu!solaris.cc.vt.edu!newsfeed.internetmci.com!feed1.news.erols.coDavid Leonard)
Thu, 1 May 1997 11:43:24 LOCAL

In article <5kad5c$ld2@ds2.acs.ucalgary.ca> thodges@freenet.calgary.ab.ca (T Hodges) writes:
>
>We have been doing experiments growing potato/corn/wheat on coarse
>sand (95%) with native OM of less than 0.5% for several years. The area
>is stabilized dunes with substantial relief. Before we started the
>ridges were leveled exposing subsoil with zero measureable OM.

>The OM has gradually increased probably to 0.6 or 0.7% (still lower
>in the leveled areas) and the water holding capacity probably has
>increased by 15-20%. That may not seem like a big deal but it is
>noticeable and significant for our irrigation scheduling. Also
>other hard to identify problems perhaps due to pH swings are becoming
>less severe in the leveled areas.

>I am definitely a strong believer in doing almost anything to increase
>soil organic matter (OM). Many benefits. BTW this is in the desert
>area of south central Washington (USA).

>Tom

Tom,

Point well taken. I didn't mean to imply that organic matter has no
other benefits for sandy soils. When you consider the improvements to
exchange capacity, leaching losses, buffering effects, beneficial soil
microbial life, and extra nutrients, organic matter does wonders for even
sandy soils, and these factors may have something to do with a perceived
improvement of 15-20% in your whc or at least boost these effects..

Regards

David Leonard
Training and extension specialist in hillside-farming systems
Tucson