Hi! TaChung Huang, We have an extreme case in some quartz sand soils on Eyre Peninsula, South Australia, where long term use of acid fertilizer has lowered the pH to around 4.1 - 4.2, which means the crops are struggling and mineral deficient. They have developed liquid fertilisers and folar sprays, so are really growing broad acre grain crops hydoponicly and not very well.
Gil tachung_h wrote: > Hi Lyoyd: Thank you for the kind assistance and explanations. It is very > helpful. > > What does it mean when people say that long term usage of inorganic > fertilizer will cause the soil to become acidic? Is it because the > fertilizer itself is acidic? Or is it because the calcium is bonded with > other ions and leached away? > > Regards > TaChung Huang > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:owner-bdnow@;envirolink.org] On > Behalf Of Lloyd Charles > Sent: Thursday, October 10, 2002 8:49 PM > To: [EMAIL PROTECTED] > Subject: Re: Nutrient blockers > > ----- Original Message ----- > From: tachung_h <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, October 11, 2002 7:39 AM > Subject: RE: Nutrient blockers > > > > > HI Lloyd : In what form does Al exist when the PH is above the cutoff > > point? > > The basic framework of the clay particles in soil is Aluminium Al(OH)6 > and Silica SiO4 . a strong acid soil solution breaks down some of the > clay structure and Aluminium becomes soluble - plant available as Al+++ > > > > How does calcium get depleted? Does it leach away like the inorganic N > > > ? > > We export it from the farm in the bones of animals, in milk, in grains > and hay sold off farm. We change the nutrient ratio balance by adding > other things like potassium fertiliser, or we lock up calcium by adding > acid phosphate fertilisers that combine with soil calcium, and yes it > leaches down the profile out of the root zone. Many agronomists disagree > with this last bit but if you dig deep enough most any where you will > find a layer of accumulated calcium Cheers Lloyd Charles. > > > > Regards > > TaChung Huang > >
