Subject: Re: Fertilizer FAQ

From: [email-masked] (Ronald Florence)
Date: Tue, 17 Aug 1993 13:51:14 GMT

[email-masked] writes:

   Besides carbon, hydrogen and oxygen, the essential minerals for
   most plants are:
			  Chemical
	   Element        Symbol     Available form:
   MACRO  Nitrogen        N          NH4+, NO3-
	  Phosphorus      P          HPO4-, H2PO4-
	  Potassium       K          K+

   SECONDARY
	  Sulfur          S          SO4--
	  Calcium         Ca         Ca++
	  Magnesium       Mg         Mg++

   MICRONUTRIENTS
	  Iron            Fe         Fe++, Fe+++
	  Manganese       Mn         Mn++
	  Boron           B          H2BO3
	  Copper          Cu         Cu++
	  Zinc            Zn         Zn++
	  Molybdenum      Mo         MoO4--
	  Chlorine        Cl         Cl-

The FAQ was clearly intended for rec.gardens, and not for misc.rural,
but it might be useful to add that boron is an important element in
assuring growth of forage legumes like alfalfa and ladino clover.

One other mineral which can be important to the health of animals fed
on forage is selenium.  The soils in many areas of the United States
are low in selenium; animals raised on hay or pasture from these soils
can suffer from selenium/vitamin-E defficiency (White Muscle Disease),
a chronic muscular dystrophy that ultimately affects the heart
muscles.  The condition can be relieved by injections of vitamin-E and
selenium, or by diet supplements.  I don't know whether selenium can
be added to deficient soils.

These comments are only a shepherd's nit-picks to a very useful FAQ.
--

				Ronald Florence
				[email-masked]

---

From: [email-masked] (Paul Harvey)
Date: 21 Aug 1993 21:19:17 UTC

In article <[email-masked]> 
[email-masked] (Ren Tescher) writes:
>In article <[email-masked]> 
[email-masked] (Marc T. Kaufman) writes:
>>On the other hand, large amounts of California wetlands are considered
>>toxic sites because of the Selenium concentrated by field drains over the
>>years.  Too much selenium causes deformities in birds.
>As I recall the land surrounding these 'wetlands' was originally arid.
>and naturally high in selenium.

It was originally a large lake, the Tulare Lake, just west of
Visalia. The Kings, Kaweah, Tule and Kern rivers flowed into it instead
of into the San Joaquin valley and out to the San Francisco Bay. The
Tulare Lake basin is arid with under 10 inches of rain per year, hence
like most deserts, the soil has accumulated salts, one of them being
selenium.

>Irragation of these lands for farming
>washed the selenium out of the soil and into the drainage system (wetlands).

The rivers were diverted and the basin converted to premium farmland.
However, like many desert regions, drainage is a problem. Water does not
readily percolate into the subsoil and instead irrigation produces an
elevated water table which must be drained. In addition, salts such as
selenium, which rise to the surface because of irrigation of the desert,
must be regularly leached with water in order to continue cultivation.
Thus, in typical desert irrigation cultivation, one has fresh water
coming in and drain or salty water going out - which is the problem. In
the Colorado valley, the drain water is typically dumped back into the
river on the assumption that Mexico can deal with the salts - in fact as
part of a treaty arrangement, the US helps a little by running a
desalination plant at the border. [As a side note, at one time the
Colorado drained into the Imperial valley which produced the Salton Sea
of southern California.] Anyway, back to the Tulare Lake Basin. The
obvious place to dump drain water is the ocean since that's were we dump
everthing else anyway plus for the most part salt isn't a problem for
the ocean. And so a big drain project was begun, the idea being to dump
the drain water into the SF bay where it would flow out to sea. But, the
SF bay is not the ocean and the drain water would have been a severe
contaminate. So, the drain was halted at Lake Kesterson which was a man
made wetland - just one problem - the selenium which was killing
waterfowl for whom the wetland was made as a substitute for all the
drained wetlands of the San Joaquin Valley and Tulare Lake Basin. The
drain was stopped and Kesterson sits today as a selenium polluted lake
from which birds must be continuously chased away. In the meanwhile,
farming in the Tulare basin continues with more conservation of input
water to minimize drain water and the drain water being evaporated in
large evaporation ponds which destroys the land underneath with selenium
and other salts. Bottom line: we can make the desert bloom, but for how
long and at what cost? The classic reference on this subject is Cadillac
Desert by Mark Reisner.

>The area I refer to is near Silicon Valley.

Nope, different story. The problem in the Santa Clara Valley is
industrial, (primarily TCE/TCA), contamination and the threat of
leaching into the underground aquifer which is the primary source of
drinking water in the SCV aka Silicon Valley. The SCV is unique in that
a land owner doesn't own the water under one's land, it is a valley
resource. The SCV is on the forefront of ground water control. In the
Western US, water is the key element. Where you see a large development,
whether rural or urban, there is a large source of water somewhere that
is fueling it. In the SCV, that large source of water is the underground
aquifer which is largely replenished by rivers which flow into the
valley. Pollution of that aquifer would be the end of SCV "civilization."

>IBM was 'blamed' for dumping
>the selenium and 'volunteered' to help clean up (denying any responsibility)
>before the real cause of the high selenium levels was found.

No, IBM has ground water pollution problems in its south SJ disk
manufacturing plant which they are working on cleaning up. The other
major SCV pollution site is a huge plume from Moffet Field/Fairchild/AMD
and others in Sunnyvale. The SCV has the largest concentration of EPA
Superfund sites in the US, but probably because the issue is so urgent
and much effort has been expended in finding the sources.

>	So my question is, did these 'wetlands' exist before irragation?

Hopefully answered. Prior to European colonization, the SCV, Sacramento,
San Joaquin and Tulare Lake Basin had extensive wetlands because of a
high water table from runoff from the nearby mountains. There is a lot
of water in California, it's just not naturally where the people live
and it's not always there from year to year due to frequent drought.