TROPSOILS-Indonesia
Center for Soils Research
Field Research Brief No. 28
May, 1986

TITLE: Lime Reaction Rate and Effectiveness, us 1002, 1103, 1404

RESEARCHERS: Mike Wade and Al-jabr[

OBJECTIVES: 1. Determine the rate of reaction of applied lime
in field conditions,
2. Study the effect of lime on various soil
chemical parameters and their interaction, eg
pH, Al, Al+H, Ca+Mg, O.M.
3. Evaluate methods of predicting lime require-
ments of soybeans,
4. Study the above objectives on three major soils
in the Sitiung area, ie ultisol, oxisol and
inceptisol.


SOIL: Ultisol, LCeak, forest station, cleared in 1964, 1st crop
Oxisolf Ceak Sitiung IVb, cleared in 1980, abandoned
Inceptisol, Cak, Sitiung Ia, cleared in 1976, barren


Soi l'
Ultisol

Oxisol

Inceptisol


Pre-Treatment
Depth PB
0-15 4.2
15-30 4.4
0-15 4.4
15-30 4.3
0-15 4.7
15-30 4.8


Soil Analysis
A1+H Ca+Ms
1.9 1.2
1.7 0.8
2.6 0.3
2.6 0.3
3.0 0.9
4.2 0.8


TREATMENTS: RCB, 3 replications, 4 X 6m plots
Lime rates-0, .75, 1.5, 2.25, 3.0, 4.5, 6.0 t/ha
Sampling dates-0, 3, 7, 15, 30, 60, 120, 240, 360
days after application

CROP: Corn (4th), cv. C-l, plant spacing 25x80 cm, planted end
of Dec 1985 and harvested early April 1986. Seed treated
with Ridomil for downy mildew prevention, and carbofuran
applied in dibble hole (1 kg a. i./ha) for prevention of
stem borer. Base fertilizers: 300 kg urea applied
in 3 applications (100 each at planting, and at 3 and 5
weeks after planting), 20 kg P and 100 kg K/ha.

RESULTS: This is the fourth crop grown in this trial. The first
three were soybeans, but corn has been included in order to
estimate its' tolerance to soil acidity. The corn grew and
produced well at all three locations. The response to the
residual lime (corn planted at 330 days after initial lime appli-
cations) is shown in Figure 1. Quadratic regression equations
best fit the response at all three locations. The previous


. M.
5.2
-
4.6

3.3






soybeans had generally shown a linear-plateau type response, but
the corn did not form a clear plateau.

Figure 2 shows the relationship between relative yield of
the three locations and acid saturation (relative yield is the
treatment means calculated as % of the maximum yield at each
location). The linear-plateau model indicates a critical level
of 29% AS. It should be noted, however, that the critical level
is not clearly defined by the data points. Between the levels of
10 and 40% there is a tendency for the yields to decline. In
fact the equation Y=97-0.00986x2 gave a better fit, with an
RL=0.94. However such an equation is difficult to use for
predictive purposes.

The vegetative growth of the corn (stover yield) showed a
distinct yield plateau at each location (Figure 3), yet grain
yields continued to increase somewhat even at the higher rates as
indicated by the quadratice regressions. One (the) reason for
this appears to be related to ear size. Figure 4 indicates a
fairly strong relationship between exchangeable Ca+Mg and ear
size. Only the Oxisol site showed a maximizing of ear size,
whereas the other two indicated a linear increase in ear size
throughout the range of Ca+Mg. So despite the lack of vegetative
response beyond the 3t/ha rate, the increasing ear size caused a
continued increase in overall grain yields.

Tolerance of corn to acid saturation of 30% is relatively
consistent with other reports, but needs further verification
under Indonesian conditions. The tendency for yields to decline
from 0% AS in this experiment suggests that varietal :olerances
may be important. Although high yielding, the C-l may be
exceptionally susceptible to soil acidity.

The recently cleared Ultisol site gave a slight, though
significant, response for the first time. This is somewhat
unexpected as the three previous crops were all soybean, which is
usually more susceptible to soil acidity than corn. The actual
acid saturation levels still have not changed (50-60% in the
unlimed plots), but the suspected benefit of organic acids may
well be declining as it has now been 1 1/2 years since clearing.













Co) ODis.L : 3.0 + 1.5Yr o./5?n
(y) WU Lsdl = 3.7 6 .3/x 03260 Z
(.) ZIncep. = 1.96+ /.o.z -o. //6(0


o i.s 3-.0 V.5 Q,
Lime Rade UA/hk)

F;r,-e 1. Cffec4 dsf 4
Co rn GC r.-;
'

S zo Y2.0 0 o
ACID- SritAr,.4VqC )

Fighn2.. Rl&4.jiois4;p hleu 'ek
Red.iLve CGs^ Garc Yzields o-i
i-elod Schu^-iA's^.


R: .9
,^: .c9/


.0


(: Ie/a ~n







g


3=L
4/ u

r
u

\n


Livile W~~e ( /


F-i`Sjw'. *3.
Rco:eS 6~


OxiscJ


mI Hisol


T"Cepo6.soI


i I& --
o 2- A 0


&cbaa eaL le


Fl IL /-e q.


oL+in (Ci~o/IML4I)


L ebfweo 4
,Lvkd Loc W-;' hvt.


L7 A
0



s0,
xJ
/:; ce


'4J


qo


A5