Nutrient management in semi-dry rice for North-Coastal A.P
Loading...
Files
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Acharya N.G. Ranga Agricultural University
Abstract
A field experiment entitled “Nutrient management in semi-dry rice for North-
Coastal A.P” was conducted on sandy loam soils of Agricultural College Farm, Naira
during kharif, 2015. The treatments consisted of four levels of NPK viz., 120-75-60 kg
NPK ha-1 (L1), 160-90-75 kg NPK ha-1 (L2), 120-75-60 kg NPK ha-1 with dhaincha as
brown manuring (L3) and 160-90-75 kg NPK ha-1 with dhaincha as brown manuring
(L4) which were assigned to main plots and four time of application of nitrogen viz.,
four equal splits at 15, 45, 60 and 75 DAS (S1), 10% of N at 15 DAS, 20% at 45 DAS,
30% at 60 DAS and 40% at 75 DAS (S2), five equal splits at 15, 45, 60, 75 and at 90
DAS (S3) and 10% of N at 15 DAS, 20% at 45 DAS, 25% at 60 DAS, 25% at 75 DAS,
20% at 90 DAS (S4) assigned to sub plots. The design adopted was split-plot with three
replications.
The tallest plants, maximum number of total tillers m-2 and dry matter
accumulation were observed at all intervals of sampling with the application of the
highest dose of NPK with dhaincha as brown manuring (L4). While, the lowest values
for all these parameters were recorded with L1. Scheduling of N in four equal splits (S1)
registered significantly higher values for all the growth parameters, while they were
significantly lower with S4, except in case of plant height at 30 and 90 DAS where, S2
registered the shortest plants. The interaction effect was found significant in case of
total tillers m-2 only at 90 DAS. Significantly higher values for total tillers m-2 were
registered with L4 at S1, which was however, comparable with L3 at S1. While, the total
number of tillers m-2 was minimum with L3 at S4, which was however, comparable with
L1 and L2 at S4 and L3 at S2.
Significantly more number of days to 50% flowering and days to maturity were
noticed with the application of the lowest level of NPK (L1), while application of the
highest dose of NPK with dhaincha as brown manuring (L4) took significantly lesser
number of days. Scheduling of nitrogen in five splits 10% of N dose at 15 DAS, 20% at
45 DAS, 25% at 60 DAS, 25% at 75 DAS, 20% at 90 DAS (S4) took more number of
days to 50% flowering and days to maturity, while a declining trend was observed with
S1 (Four equal splits at 15, 45, 60 and 75 DAS) and S3 (Five equal splits at 15, 45, 60,
75 and 90 DAS), which were however, found on par with each other.
Larger yield structure, comprising of productive tillers m-2, panicle length,
number of filled grains panicle-1 and test weight and significantly higher grain (5599 kg
ha-1) as well as straw (6788 kg ha-1) yield were associated with the highest level of NPK
with dhaincha as brown manuring (L4), while they were the lowest with the lowest level
of NPK (L1) tried. Application of nitrogen in four equal splits (S1) produced
significantly superior yield parameters, grain and straw yields. While the lowest values
were associated with S4 except in case of test weight, which was minimum with S2. The
interaction effect was found absent for all the yield parameters, except number of
productive tillers m-2. Significantly superior values for number of productive tillers m-2
and grain as well as straw yield were associated with L4 at S1, while they were found to
be significantly lower with L3 at S4 except grain yield, which was minimum with L1 at
S4. Harvest index was not markedly altered either due to graded levels of NPK or due to
different times of application of nitrogen, while the interaction effect was also not
statistically measurable.
Significantly higher uptake of N, P and K at flowering and maturity (by grain
and straw) were associated with application of L4 except in case of N uptake by straw
where, L3 resulted the highest uptake, while the uptake of these three major nutrients
was minimum with the lowest level of NPK tried (L1). As regards the time of
application of N, maximum uptake of N, P and K at flowering and maturity were
observed when N was scheduled in four equal splits (S1), while the lowest uptake of N,
P and K were found with S4. The N, P and K uptake by grain was found to be
significantly higher with L4 when N supplied in four equal splits (S1), while it was
minimum with L1 at S4.
Significantly higher NHI was associated with L4, which was however,
comparable with L3, while the NHI was the lowest with L1. Varied times of application
of nitrogen as well as the interaction effect between graded levels of NPK and N
scheduling treatments did not alter the NHI significantly.
Maximum gross returns, net returns and benefit-cost ratio were obtained with
application of the highest dose of NPK with dhaincha as brown manuring (L4), while it
was minimum with the lowest level of NPK (L1) tried. As regards the time of N
application, significantly higher gross returns, net returns and benefit-cost ratio were
noticed with the application of N in four equal splits (S1), while it was minimum with
S4. With regard to interaction effect between graded levels of NPK and time of
application of N, maximum gross returns, net returns and benefit-cost ratio were
observed with the highest dose of NPK with dhaincha as brown manuring (L4) and
when N was supplied in four equal splits (S1). While, these parameters (gross returns,
net returns and benefit-cost ratio) were significantly lower with L1 at S4.
Significantly higher amount of post-harvest soil N status was observed with
application of the highest level of NPK with dhaincha as brown manuring (L4) while, it
was minimum with L1 (120-75-60 kg NPK ha-1) which was however, found statistical
parity with L2 (160-90-75 kg NPK ha-1) and L3 (120-75-60 kg NPK ha-1 with dhaincha
as brown manuring). Varied levels of NPK as well as different time of application of N
did not alter post harvest soil P and K status to a statistically detectable magnitude
From the present investigation, it can be concluded that application of 160-90-75
kg NPK ha-1 with dhaincha as brown manuring (L4) and scheduling nitrogen in four
equal splits at 15, 45, 60 and 75 DAS (S1) was the best nutrient management package
for semi-dry rice grown in North Coastal A.P as it resulted in significantly higher grain
yield as well as economic returns.
Description
D5384
Keywords
null