----- 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 >
