Malaysian Journal of Soil Science (MJSS)
Abstracts
Vol. 1
Effect of Azolla Green Manure on Wetland
Rice and Available of Azolla-N
A pot experiment and a field experiment were conducted to
investigate the effect of Azolla pinnata, applied alone or
in combination with urea, on rice plants under Malaysian conditions.
Result of the pot experiment show that application of Azolla
significantly increased the number of tillers and panicles,
dry straw weight and grain yield over the control; similar
results were obtained from the application of urea. There
was no significant difference between the various Azolla treatments.
In the filed, the recovery rate with Azolla application at
30 DAT was higher than when applied at transplanting; results
with urea-N application were similar.
Assessment of the Availability of Phosphate
to Corn (Zea mays L) Using 32P Isotope
dilution Technique
This study investigate the effectiveness of two phosphate
rocks (PRs), an unreactive phosphate rock from China (CPR)
and a reactive phosphate rock from North Carolina, USA (NCPR)
compared to triple superphosphate (TPR), a highly water-soluble
phosphate fertilizer. These fertilizers were tested using
three crops of corn (Zea mays L) grown consecutively on a
Serdang series soil (Typic Paleudult). 32P isotope dilution
technique was used to access their P availability. The rate
of P used was 100 kg P ha-1, applied once at the beginning
of the experiment. NCPR was as efficient as TSP in providing
P to the first crop, while CPR showed the lowest percentage
of utilization. In the second crop, NCPR was the superior
source of P. However, in the third crop all three sources
showed very poor percentages of utilization. The total amount
of P taken up by the three crops of corn was 13.65, 18.04
and 8.56 kg ha-1 from TSP, NCPR and CPR respectively. Thus
this study suggests that NCPR is an effective source of P
for corn and can be used as a substitute for the water-soluble
phosphate fertilizers. CPR is not a suitable phosphate source.
Extraction of Potassium by Sulphuric Acid
in Selected Particle Size-fraction of Five Malaysian Soils
The research of potassium (K) was investigated by leaching
clay, silt, and coarse + fine sand fraction from five soils
with different physical and chemical properties with sulphuric
acid (H2SO4). The results showed that the exchangeable K in
each of the size fractions was easily depleted. The amount
of K extracted increased with acid concentration in the following
decreasing order; clay > silt > coarse + fine sand.
The effective amount of K released per unit weight of soil,
express as a percentage of total release, was 49, 33, and
18% for clay, silt, and + fine coarse sand, respectively.
The release of K was closely associated with the amount of
Al exchange sites but also from the mineral structures which
underwent slow dissolution in acid conditions. In soils with
appreciable amounts of k-bearing soil K status was suggested
to be a better method.
Overland Flow and Soil Erosion in Sloping
Agricultural Land
A study was conducted to investigate runoff rate, its temporal
distribution and soil loss on four 0.1-ha plots (treatments)
in cocoa cultivation with slopes ranging from 14% to 19%.
Treatments Ti and T2 were intercropped with bananas and Gliricidia.
Ti was kept chemically weed-tree, T2 was allowed to establish
Indigofera spicata and grasses Treatments T3 and T4 were not
intercropped. T3 was kept chemically weed-free; on T4 Indigofera
spicala was established with grasses Surface cover influenced
total runoff and runoff rate At banana planting, the surface
cover for Ti, T2, T3 and T3 was 45, 40, 73 and 77%, respectively
and the corresponding peak runoff rates for a large event
on September 28 were 64, 37, 30 and 15 mm h-1. The planting
of bananas drastically altered the soil surface Sediment concentrations
in Ti and T2 increased from 0 4 kg/ms to 6 1 and 12 7 kg/ms
respectively. Pass-through sediment or suspended load constituted
more than 50% of total soil loss, indicating a high loss of
the finer soil material Soil loss as pass-through sediment
and as trapped sediment or bedload was related to runoff rate,
cover management and cropping. Large soil losses are attributed
to high runoff rates on surfaces without adequate contact
cover. In soils where pass-through sediment is a major component
of total soil loss, these losses are accompanied by a serious
reduction in soil quality.
Fertility Improvement of Fluvial Paddy
Soils of Kelantan Plain by Organic Matter Addition
To investigate the effect of OM on the CEC of Kelantan plain
soils. bum soil series in a toposequence, namely Tok Yong,
Chempaka, Laung and Jabil. were used Calibrated amounts of
OM-CEC and yield-CEC models of POMES were added to the soil,
which were then incubated anaerobically. The increase in CEC
of the soils corresponded more or less to the expected CEC
of 16 cmol, kg-1 as predicted by the model This study shows
that the organic matter POMES could be used to increase the
nutrient retention capacities 01 the less fertile soils of
the Kelantan plain. There was a strong indication that the
increase in CEC was dependent on the physico-chemical properties
of the soils in relation to the amount of organo-mineral complex
that could he formed
In a field experiment conducted at Mulong Lating, Kelantan
to evaluate the effect of OM addition on rice performance,
six levels of organic matter (POMES) and three levels of N
with optimum levels of P and K fertilizers here used in the
treatment combinations A significant yield enhancement was
obtained with OM incorporation corresponding to 0 5% C, irrespective
of N levels, with an average yield increase of 1 t ha-1, that
would provide a regional yield increase of 33,000 t per season.
Rate of Water Absorption by Soil Clods
under Confined and Unconfined Conditions
Experiments were conducted to study the rate of water absorption
by clod of different sizes and initial moisture content using
the capillarity method. Clods were prepared by molding wet
clay soil into cubes for easy contact with the wet surface
of a water-conducting material. Prepared samples ex-posed
to wetting were examined by cutting 5-mm thick slices, starting
the base. For confined conditions, a measured load was applied
on every clod tested. The results of the clod-wetting experiments
show that the rate of water absorption by capillarity was
greatest when clods were initially very dry and that smaller
clods tended to absorb water faster than bigger cloths confined.
However, confining had no significant effect on absorption
when the initial condition was very wet.
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