| Material Information
||Mg fertilization for annual food crops
||TropSoils field research brief
||3 leaves : ill. ; 28 cm.
||Wade, M. K ( Michael Karl )
Aribawa, I. B
Lembaga Penelitian Tanah
Soil Management Collaborative Research Support Program
||Soil Management Collaborative Research Support Program, North Carolina State University
||Place of Publication:
||Soil management -- Indonesia ( lcsh )
Soils -- Magnesium content -- Indonesia ( lcsh )
Food crops -- Indonesia ( lcsh )
||Statement of Responsibility:
||researchers, Mike Wade, Dan Gill, and I.B. Aribawa.
||At head of title: TropSoils-Indonesia, Centre for Soil Research.
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 156976375
Centre for Soil Research \ 4 scuj T-
Field Research Brief No. 26 _ES_ _
TITLE: Mg Fertilization for Annual Food Crops
RESEARCHERS: Mike Wade, Dan Gill and I. B. Ariba.a
EXPERIMENT NO.: 1105
1. To study crop response to Mg fertilization for
a low input system (rice and pearrt rotation)
and a high input system (corn and soybean rota-
2. To determine critical Mg soil test levels
for the crops in the rotations being studied,
3. To compare the effects of yearly applications
vs. per-crop applications of Mg cn yields and
soil test levels,
4. To monitor Mg movement within the soil profile
under low and high input systems.
SOIL: Dystropept (FCC: Cak) Cleared from virgin forest by
bulldozers in 1976, abandoned to grass and bush fallow
The following rates of Mg fertilizer, as kieserite-
MgSO4.H20, and base fertilizers were applied:
4 per crop
8 per cr:o
2.5 ((40% Al sat)
50 (rice only)
40 + 10/crop
5.0 ((1C. Al sat)
150 (corr- only)
160 + 20 crop
Elemental sulfur (flower of sulfur).was applied tc balance the S
that was applied as SO4 in the kieserite to a co-stant rate of 62
kg S in the Low Input and 83 kg S in the High Input system.
CROP HISTORY: Upland rice (an experimental line from SARIF) was
planted in 20 x 25 cm hills and corn (cv. C-1) in 25 x 75 cm
hills on October 9, 1985. Weed control was done manually and
carbofuran was applied at planting with both crops for initial
insect control. No further insecticides were used on the corn,
but rice was sprayed periodically with diazinon and sevin. The
rice suffered rather extensive rat and bird damage during grain
fill, such that yields were erratic and modest. Corn suffered
rather severe short-term drought stress right at flowering that
impaired pollination and subsequent grain yield.
RESULTS: Early growth of the corn was strongly influenced by the
Mg fertilization. Figure 1 shows a strong response to Mg rates
up to 32 kg/ha. Visual symptoms in the field also reflected this
response, as the unfertilized corn had leaves with severe
yellowing and intervenal chlorosis. Progressive rates of Mg
reduced the deficiency but only at rates of 32 and 64 kg/ha were
the leaves completely normal. The rice however showed only
modest response to the Mg (Figure 1), and no visual symptoms were
apparent in the field.
As indicated in crop history, the corn tassied and
pollinated during the only extended dry period of the entire
season. This had adverse effects on grain yield, which did not
respond to the Mg fertilizer (Figure 2). By the end of the
season, the visual deficiency symptoms had greatly diminished and
even dry matter yield (data not shown) did not respond to the
fertilizer treatments. Likewise, rice yields did not respond to
Mg (Figure 2). The rice suffered from bird and rat damage and
yields were modest but even so there was no apparent response,
visually or otherwise, to the applied Mg fertilizer.
Soil analysis is pending, and so no information or
conclusions can be made at this time regarding the effect of the
treatments on soil Mg or correlation with plant growth and yield.
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