Agriculture Reference
In-Depth Information
TABLE 8.8
Grain Yield (kg ha
−
1
) of Lowland Rice as Affected by Nitrogen Timing Treatments
Treatments
a
1st Year
2nd Year
3rd Year
Average
T
1
4677.66b
4069.44d
4486.66c
4411.26d
T
2
6934.00a
5069.44bc
4763.19bc
5588.87c
T
3
6605.67ab
5402.78b
5298.75abc
5769.06bc
T
4
8065.00a
4708.33bcd
4730.69bc
5834.67bc
T
5
6890.00a
5001.38bc
4884.72bc
5592.03c
T
6
6782.33a
4583.22cd
4627.22c
5330.96c
T
7
7256.66a
6250.00a
5790.97a
6432.54ab
T
8
7174.33a
6305.55a
5555.55ab
6345.14ab
T
9
8347.00a
6527.77a
4818.33bc
6564.37a
T
10
7086.33a
5416.67b
4953.05abc
5818.68bc
T
11
7776.33a
4583.33cd
4475.69c
5611.78c
Average
7054.12a
5265.28b
4944.07c
F-test
Year (Y)
**
N timing (NT)
**
*
Y × NT
CV (%)
7.97
a
T
1
= control (0 kg N ha
−1
), T
2
= 150 kg N ha
−1
(total at sowing), T
3
= 150 kg N ha
−1
(1/2 at sowing + 1/2 at 45
days after sowing), T
4
= 150 kg N ha
−1
(1/3 at sowing +1/3 at 45 days after sowing + 1/3 at initiation of
panicle primordial), T
5
= 150 kg N ha
−1
(1/4 at sowing + 1/2 at initiation of tillering + 1/4 at 45 days after
sowing), T
6
= 150 kg N ha
−1
(2/3 at sowing + 1/3 at 45 days after sowing), T
7
= 200 kg N ha
−1
(total at sow-
ing), T
8
= 200 kg N ha
−1
(1/2 at sowing + 1/2 at 45 days after sowing), T
9
= 200 kg N ha
−1
(1/3 at sowing
+1/3 at 45 days after sowing + 1/3 at initiation of panicle primordial), T
10
= 200 kg N ha
−1
(1/4 at sow-
ing + 1/2 at initiation of tillering + 1/4 at 45 days after sowing), and T
11
= 200 kg N ha
−1
(2/3 at sowing + 1/3
at 45 days after sowing).
*,**Significant at the 5% and 1% probability level, respectively. Means followed by the same letter in the same
column are not significantly different at the 5% probability level by Tukey's test.
nitrification inhibitor properties. Similar results were also reported by Agarwal et al. (1980) and
Singh and Singh (1986).
Nash et al. (2013) reported that over a 3-year study, conducted at one location, NT/injected anhy-
drous ammonia with nitrapyrin at preplant produced at least 2 Mg ha
−1
higher corn grain yields
than all other management systems with a fall in N application. De Datta and Buresh (1989) and
Campbell et al. (1995) reported that generally less than 40% of N applied to lowland rice is recov-
ered. Most of the losses are through ammonia volatilization, leaching, and denitrification. This loss
can be significantly reduced by the use of urease inhibitors (Fillery and De Datta, 1989).
8.3.6 f
olIar
f
ertIlIzatIon
Foliar application of nutrients is an important crop management strategy in maximizing crop yields.
It can supplement soil fertilization. When nutrients are applied to soils, they are absorbed by plant
roots and are translocated to aerial parts. In case of foliar application, the nutrients penetrate the
cuticle of the leaf or the stomata and then enter the cells (Fageria et al., 2009). Hence, crop response
occurs in short time in foliar application compared to soil application. The rate at which an ion
passes through the cuticle, and generally the epidermal tissues of the leaves, depends on many fac-
tors, including the concentration and the physical and chemical properties of the sprayed ion. In
