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An experiment entitled " Secondary and micronutrient management for soil health and productivity in upland rice " was conducted with
medium duration rice variety Uma, to investigate the effect of secondary and
micronutrient application under organic and integrated nutrient management
practices, on nutrient uptake, soil health and productivity of upland rice. The field
experiment was carried out at farmer‟s field, Venganoor, Thiruvananthapuram,
during Virippu, 2017-„18.
The experiment was laid out in a randomized block design with three
replications and ten treatments viz. absolute control (T1), KAU PoP + lime (T2),
KAU PoP + dolomite (T3), KAU PoP for organic farming (T4), foliar application
of micronutrient solution or KAU sampoorna multimix along with lime (T5 and
T6), dolomite (T7 and T8) and organic farming treatment (T9 and T10). Foliar
sprays of 0.5 % micronutrient solution (containing FeSO4.7H2O 0.1%,
ZnSO4.7H2O 0.25%, borax 0.1%, MnSO4. H2O 0.025%, and CuSO4. 5H2O
0.025%) and 1 % KAU sampoorna multimix (containing Zn 7%, B 4.5%, Cu
0.5%, Fe 0.2%, Mn 0.2% and Mo 0.02%) were given during the critical growth
stages viz. active tillering, panicle initiation and one week after flowering.
The soil of the experimental site before the crop was very strongly acidic
with normal EC, sandy clay loam in texture, medium in organic carbon and
available N, high in available P and K, sufficient in available Fe, Mn, Cu, Zn,
exchangeable Ca and Mg and deficient in available B.
The results of the study revealed that foliar application of micronutrient
solution or sampoorna multimix along with KAU PoP (dolomite or lime)
significantly increased the total and productive tillers per m2 with T7 giving the
highest value. Root length, dry weight and volume were highest for all the organic
farming treatments.
Foliar application of micronutrients produced significant increase in yield
and yield attributes with T8 recording the highest value for panicle weight (2.41
g), length of panicle (23.43 cm), per cent filled grains (87.17 %) and thousand
grain weight (23.53 g) resulting in the highest grain yield (4158 kg ha-1). T8 was
on par with treatments T5, T6 and T7. Highest straw yield was recorded by T5
(4897 kg ha-1) which was on par with the other micronutrient applied treatments
(T6 to T8) and KAU PoP receiving lime or dolomite alone.
Application of liming materials alone or along with foliar micronutrients
gave significantly higher contents of N, P and K in index leaf at panicle initiation
stage with T6 giving the highest value for N and P and T7 for K. Treatment T2
gave the highest Ca content of index leaf, which was also on par with all the
micronutrient applied treatments. Mg content was highest in the dolomite applied
treatments and was on par with the lime applied ones. Fe, Mn, Cu, Zn and B
contents in index leaf were also found to be higher for the treatment receiving
foliar micronutrients along with KAU PoP (dolomite or lime), with the highest
values recorded by T5 for Fe, T7 for Mn and Zn, T6 for Cu and T8 for B.
Higher N, P and K content in straw and grain were observed for treatments
T5 to T8 which were on par with KAU PoP (lime or dolomite). Ca content of straw
was highest for T2 and was on par with all the treatments except T4 and T1.
Highest grain Ca was observed for T5 which also gave significantly higher Mg
content in grain and straw compared to absolute control and the organic
treatments. Uptake of N, P, K, Ca, Mg, Fe, Mn, Cu, Zn and B by straw and grain
was also found to be the highest for the treatments receiving micronutrients along
with KAU PoP (lime or dolomite).
Soil available N and K were on par for all the treatments except organic
treatments and absolute control. Available P was on par for all the treatments
except T1. The increase in organic carbon due to integrated nutrient management
was not significant. Liming materials significantly increased the soil Ca level
whereas soil Mg was increased by the application of dolomite. Integrated or
organic management increased the soil Fe, Mn and Zn levels. In general organic
treatments gave significantly lower values for Cu and B.
Foliar application of micronutrients along with KAU PoP (dolomite or
lime) was more economical, resulting in significantly higher B: C ratio with the
highest value (1.43) given by T8.
Based on the study, it can be concluded that foliar micronutrient
application (sampoorna multimix or micronutrient solution) along with KAU PoP
(lime or dolomite) significantly enhanced the growth, yield and nutrient uptake in
upland rice.