physicochemical

MALLA REDDY et. al.
producing grain yield. Soil application of ZnS04 gave
significantly higher seed yield than foliar spray of 0.5
% ZnS04 at 25 DAS in cluster bean during kharif at
Gwalior (Sharma et al., 2004). Foliar sprays of Zn
can not be compared with soil application.
Soil application of ZnS04 @ 22.4 kg ha -1 significantly
increased the grain yield of rice over control in sodic
soils at Ludhiana (Sharma et al., 1982).
Significantly higher straw yield (8621 kg/ha) was
recorded with basal application of Biozinc @ 50 kg/
ha + foliar spray @ 3 g/l at 30 DAT and 22.6% higher
over control (7029 kg/ha) and was at par with basal
application of Biozinc @ 50 kg /ha (8530 kg/ha),
basal application of ZnS0 4
@ 50 kg /ha + foliar spray
@ 3g/l at 30 DAT (8281 kg/ha) and basal application
of ZnS0 4
@ 50 kg/ha (8185 kg/ha) during 2009. There
was no significant difference between foliar spray of
Biozinc (7682) and ZnS04 (7794) @ 3 g/l at 30 and
45 DAT during 2009. The straw yield was not
significantly influenced by zinc nutrition during 2008
(Table 3).14.1 and 17.6 % increase in straw yield
was observed with basal application of ZnS04 and
Biozinc, respectively over control. During 2009, 9.8
and 8.5 % increase in straw yield recorded with foliar
spray of ZnS04 and Biozinc, respectively over control.
In addition to basal application, foliar spray by ZnS04
and Biozinc increased the straw yield by 15.1 and
18.5 %, respectively over control.
There was no significant difference between
sources of Zn i.e., ZnS04 and Biozinc in producing
tillers, yield attributes and yield in low land rice during
both the years. On the other hand, significant
difference observed between method of application
i.e., basal and foliar spray during both the years in
producing tillers, yield attributes and yield.
The DTPA-Zn in the soil after harvest of the
crop was not influenced by zinc nutrition. There was
not much change in the values (ppm) of soil zinc
during two years (Table 4). However, the DTPA-Zn
was higher in plots where zinc was applied (0.8 to
1.1 ppm) compared to control (0.7 ppm).
Basal application of 50 kg Biozinc/ha + foliar
spray @ 3 g/l at 30 DAT has recorded high net returns
during 2008 and 2009 (Rs.51,212 and 62,344/ha,
respectively), followed by basal application of 50 kg
ZnS0 4
/ha + foliar spray @ 3 g/l at 30 DAT (Rs.49,584/
ha) during 2008 and basal application of 50 kg Biozinc/
ha only (Rs.61,240/ha) during 2009 (Table 3). There
was very little difference between foliar spray of ZnS0 4
(Rs.44, 641 and 54,515/ha) and Biozinc (Rs.45,550
and 53,359/ha) compared to basal application of
ZnS0 4
(Rs.46,470 and 57,830/ha) or Biozinc
(Rs.47,961 and 61,240/ha) alone during 2008 and
2009,repectively.
Growing of zinc sensitive varieties like MTU
1001, MTU 1010 etc. coupled with high soil available
P, resulted in Zn deficiency. This is very frequent in
sodic soils. Thus, the findings indicated that for Zn
sensitive varieties, basal application of Biozinc or
ZnS0 4
@ 50 kg/ha and foliar spray @ 3 g/l at 30 and
45 DAT are essential in low land rice for getting higher
profitable yields in alkali/sodic soils of Andhra
Pradesh.
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