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Archives (2001)
Coping with acidic
soils
by Junelyn S. de la Rosa |
July-September
2001
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Since the early 80s, most farmers used lime
as an all-around remedy for all kinds of acidic soils. However,
recent studies indicate that too much of lime could aggravate
the poor condition of acidic soils.
A study commissioned by the Philippine Sugar
Research Institute Foundation Incorporated (PHILSURIN) confirmed
the findings of the study and said that the liming rate set
by the Sugar Regulatory Administration (SRA) increased the
calcium content of the soil to 2000ppm and did not do much
to neutralize acidic soils.
To evaluate the SRA liming rates that are still
used by most farmers as a standard for very acidic soils,
Mr. George Malam from SRA-LGAREC and Dr. Wilfrido Cosico of
the Soil Science Department of the University of the Philippine
at Los Baños (UPLB) conducted an experiment on very
acidic soils that are grown to sugarcane.
Entitled: Field Evaluation of the SRA Lime Recommendation
for Sugarcane (Saccharum officinarum), the researchers studied
the effect of lime on the growth and yield of sugarcane and
its effects on soil acidity and the availability of other
essential nutrients in the soil such as aluminum, iron, manganese,
nitrogen, phosphorus and potassium.
Results showed that 6 tons/ha calcitic lime
favored the growth of sugarcane (Phil8839). This liming rate
produced the tallest plants with the second highest number
of tillers and the longest cane stalks six months after planting.
The scientists explained that 6 tons per hectare of calcitic
lime could have been sufficient enough to reduce or minimize
the inhibitory effect of Aluminum injury on the growth of
sugarcanes on very acidic soils.
However, over-liming is not good for the growth
of sugarcane. Increasing the lime rate to 9 or 12 tons/ha
calcitic lime decreased plant height, number of tillers, stalk
length and diameter at harvest. This is consistent to the
research findings of Miller (1995) which stated that excess
lime is often detrimental to plant growth. He said that this
could be due to the reduced solubility of boron, zinc and
other micronutrients that are needed by the plants. Similarly,
the higher the amount of lime is added to the soil, the bigger
is the corresponding increase in soil pH. Higher liming rate
also reduced exchangeable manganese and aluminum. This could
be avoided by following specific recommendations depending
on soil and crop type. Excess lime not only affects the growth
of the crop and the availability of the essential elements
in the soil but alters the growth of beneficial microorganisms
in the soil. Over-liming could destroy the nourishing capacity
of the soil in the long run.
The researchers recommend that farmers apply
6 tons/ha of calcitic lime for very acidic soils that are
planted to sugarcane. This validates SRA's liming recommendation
that is widely used by sugarcane farmers in the countryside.
Also, farmers could gain from liming. Economic
analysis showed that farmers could get an additional income
of P10,576.42 as a result of the application of 3 tons/ha
calcitic lime and P6, 527.92 for 6 tons/ha calcitic lime.
While scientists agree that liming is necessary for very acidic
soils (Manapla sandy clay loam) that are planted to sugarcane,
they said that it is very important that farmers apply lime
according to the results of a soil test. That is---too much
lime can be as harmful as too little. 
(For particulars, contact: Mr. George L. Talam (SRA- La
Granja Agricultural Research and Extension Center SRA-LGAREC)
and Dr. Wilfrido Cosico (Department of Soil Science, UPLB-CA,
College, Laguna).
More Articles:
Vol. 3 No. 3 July-September 2001
»»
USM recommends high-yielding rubber clones
»» GMA okays
P2B R&D Fund
»» New
sciences to produce more food
»» Five
cacao clones now ready for farmer use
»» NIRDEAP
for rubber: stretching opportunities for rubber industry
»» Rubber:
the oozing tree
»» Village
processing technologies: approach to solve low production of rubber
»» Smallholder
rubber farming system "no break" in farmers' income
»»
NIRDEAP for coffee: perking up the coffee sector
»» Clonal
propagation in coffee: a promising technology
»» How
to raise healthy cacao seedlings
»» Earning
more from canes
»» Coping
with acidic soils
»» Muscovado:
the promise of the 'other sugar'
»» Rock
candy: a 'tasteful' example of a profitable home business
»» Propagating
cacao by nodal grafting
»»
Making vinegar a business venture
»» The
Philippine coffee industry: a profile
»» Prospects
in cocoa
[More
2001 Articles]
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