STUDIES ON POTASSIUM AVAILABILITY IN DIFFERENT SOIL SERIES OF CHANDRAGIRI MANDALAM
Loading...
Files
Date
1990
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ANDHRA PRADESH AGRICULTURAL UNIVERSITY HYDERABAD
Abstract
The present investigation was aimed at the studying
of availability of potassium with respect to fonns of
potassium, indices of potassium availability, o/I parameters,
k-release characteristics and k uptake, in seven
soil series belonging to Chandragiri Mandal.
The soils were neutral to alkaline in reaction, free from
salanity problem with low organic carbon. The clay and silt
varied from 14.70 - 35.50. and' 12.80 - 25.00 per ce~t respectively.
Water soluble, exchangeable, non-exchangeable, lattice and
total-k ranged from 0.8-3.2, 11.60-17.80, 37.60-66.06, 630-1326
and 700-1400 mg 100 g-l soil respectively. With regard to depth,
the water soluble and exchangeable - k decreased with depth
whereas the non-exchangeable, lattice and total-k did not show
any trend.
Of the nine extractants tried, the extracting efficiency
was of the order: lN HN03 > Hunter and Pratt's) Amer's>
NH40A.c > Hunter) Morgan•s ) Benjminwolf > Woodruff and
Mc Intosh > water.
increasing depth.
The ability of extraction decreased with
The equilibrium activity ratio (ARK
0
) varied from 0.50-
5.40 (mML-1)~. The light textured soils of Mariyanapalle and
Thogotepalle series recorded the higher values of K AR0 • The
PECK ranged from 50.60-210.00 {c mol kg-l CmML-1)~~,. The
heavy textured soil series of Kalya.ni recorded higher PBCK
while in the Perur series, though cl~y content was not higher,
it recorded higher PBCK value due to higher amount of smectite.
The -AF varied from -3.09 to -4.50 K Cal mol-1 • The heavy
textured soils of Kalya~. and Tirupati series recorded higher
-AF values.
Tirupati and Mekalaswamypalle series recorded highest
cumulative and step-K, while Perur and Thogotepalle series
recorded the lowest values (lN HN03 and O.OlM cac12 method).
It was observed the soil profiles with high clay and silt
content had released higher amounts of cumulative and step-K.
The constant rate-K was attained at the end of 6th extraction
with HN03 the magnitude of release less in light textured soils
than the heavy textured ones.
In pot culture stu.d. ies Mek~ laswamypalle series recorded .
higher dry-matter (2.51 g pot-1) and K uptake (4{59 K mg kg-~
soil). With regard to depth, the drymatter and K uptake
decreased with increasing depth.
Among the numerous indices of K availability tried,
extractants based on water soluble and exchangeable-k like
water, NH40Ac and Amer's methods, labile-k ~r extractants
based on non-exchangeable~k like HN03 and Hunter and Pratt's
were proved to be better indices of k-availability in the
soil series of present investigation as they had shown
higher significant correlation with k uptake in the crop.
These could be bett er utilised for further stu~ies to
evaluate k availability calibrated with crop response and
recommended k fertilizer dressing to crops.
Description
Keywords
null