RESPONSE OF WHEAT TO K2SO4 AND KNO3 FOLIAR APPLICATION SOWN
DIRECT SEEDING ON RIDGES AT SALT-AFFECTED SOIL
Muhammad Arshadullah , A. Ali, S. I. Hyder , I.A. Mahmood, and B. Zaman
Land Resource Research Institute, National Agricultural Research, Pakuistan.45500
ABSTRACT
A field experiment was conducted to investigate the effect of foliar (2 and 4 % KNO3, 2 and 4 %
K2SO4, 2% KNO3+2% K2SO4 ,4% KNO3+2% K2SO4,2% KNO3+4% K2SO4 ,4% KNO3+4%
K2SO4 ) on growth of wheat variety (cv. Watan) at SSRI, Farm, Pindi Bhattian during Rabi
season, 2007. Treatments were assigned using randomized complete block design (RCBD) with
three replications. The crop was harvested at maturity, data on tillering, plant height, spike
length, number of grains spike-1, 1000- grain weight, straw and wheat yields were recorded.
Tillering, number of grains spike-1, 1000- grain weight and paddy yield significantly (P≤ 0.05)
increased by different levels of doses. However, maximum average number of spike length
(11.33) was recorded with 4 % K2SO4 foliar application and 4003 kg ha-1 straw yield was noticed
in control. Maximum plant height (95.33 cm) was also observed in 2% K2SO4 and lowest plant
height in control. 2% K2SO4 and 4% K2SO4 improved the tillering capacity of wheat than
control. The combination of 2% KNO3+4% K2SO4 attained the highest grain yield (2825.33 kg
ha-1) which was statistically at par with 2% K2SO4 (2795 kg ha-1). It could be concluded from
this study that foliar application of K to wheat crop at 30 and 45 days after sowing is quite better
than control that of soil application at the time of sowing
Keywords; Foliar application, K2SO4, KNO3 , Wheat and Soil
INTRODUCTION
Wheat (Triticum aestivum L) is the principal food crop of Pakistan. It is an important cereal crop
and is used as staple food grain in Pakistan. It is mostly preferred as human food than any other
cereal grain. The straw and by products of flour milling and industries are important sources of
feed for livestock. The fast growing population of the country makes it imperative to achieve
matching increase in the rate of wheat production. Wheat is cultivated on an area of 8578
thousand hectares with a total production of 23294 thousand tons during this year (GOP, 2007).
Majority of Pakistani soils are calcareous in nature with pH greater than 8.5 that affects K
availability. The major fraction of potash fertilizer directly applied to soil gets fixed with clay
fraction and becomes unavailable to crop plants (Ali et al. 2005a; 2005b; 2007). Further, the
price of K fertilizers is getting higher day by day and becoming unaffordable to farmers (NFDC,
2005). The application of balanced fertilizers is one of the most important factors for increasing
crop yields. Researchers generally agree that with intensive cultivation, the need for K fertilizer
increases. In the Wheat cultivation, the farmers are bestowing much attention only to N
fertilization and very often P and K application are partially or completely ignored. This practice
of imbalance and inadequate fertilizer application affects the soil productivity in general
(Cassman et al. 1996). The practice of correct dose and timely application of fertilizers nutrients
plays an important role in efficient use of fertilizers as well. Nutrient management practices
determine the sustainability of the most intensively cropped system (Flin and De Datta, 1984:). K
utilization by plants through foliar application is well recognized and is being practiced in
agricultural advanced countries. Hence, there is a need to provide the required K through foliar
application as well. Therefore, this study was planned to compare different concentration of
K2SO4 and KNO3 for foliar application to obtain optimum wheat yield under different wheat
planting techniques.
MATERIALS AND METHODS
A field experiment was conducted to investigate the effect of foliar (2 and 4 % KNO3, 2 and 4 %
K2SO4, 2% KNO3+2% K2SO4 ,4% KNO3+2% K2SO4,2% KNO3+4% K2SO4 ,4% KNO3+4%
K2SO4 ) on growth of wheat variety (cv. Watan) sown direct seeding on ridges with rabi drill at
SSRI, Farm, Pindi Bhattian during rabi season, 2007. treatments were assigned using randomized
complete block design (RCBD) with three replications was followed. The treatments planned for
this study were as under:
T1=Control (Soil application)
T2=2% KNO3 foliar spray at 30 and 50 DAS
T3=4% KNO3 foliar spray at 30 and 50 DAS
T4=2% K2SO4 foliar spray at 30 and 50 DAS
T5=4% K2SO4 foliar spray at 30 and 50 DAS
T6=2% KNO3+2% K2SO4 foliar spray at 30 and 50 DAS
T7=4% KNO3+2% K2SO4 foliar spray at 30 and 50 DAS
T8=2% KNO3+4% K2SO4 foliar spray at 30 and 50 DAS
T9=4% KNO3+4% K2SO4 foliar spray at 30 and 50 DAS
Basal dose of P @ 80 kg ha-1 was applied to all treatments at sowing. Nitrogen application @
100 kg N was applied was applied at two stages. ½ of the nitrogen was applied at the time of first
irrigation and remaining ½ at tillering stage. The crop was irrigated with tubewell water
throughout the growth period. Necessary plant protection measures were done whenever
required. The crop was harvested at maturity and data on tillering, plant height, spike length,
number of grains spike-1, 1000-grain weight, straw and wheat yields were recorded at the time of
harvesting. Soil samples were analyzed for particle size distribution by hydrometer method
(Gee and Bauder, 1986), for CaCO3 by acid neutralization method (FAO, 1980), and for
soil organic matter by Walkley and Black procedure (Nelson and Sommers, 1982). Soil
pH was measured in soil: water suspension (1:1 ratio). Electrical conductivity of the soil
suspension was measured using conductivity meter. Extractable P, K and Zn were determined
using AB-DTPA extractant (Soltanpour and Workman, 1979). Total K in plant samples was
determined using wet digestion (nitric acid + perchloric acid in 2:1 ratio) (Rhoades, 1982).
Data were analyzed statistically and treatment differences determined using LSD (Gomez
and Gomez, 1984).
RESULTS AND DISCUSSION
Growth and Yield
Data in Table III indicate that there was no significant effect of foliar application on spike length
and straw yield under Rabi drill sowing. However, maximum average number of spike length
(11.33) was recorded with 4 % K2SO4 foliar application and 4003 kg ha-1 straw yield was noticed
in control. Foliar application of 4 % KNO3+2% K2SO4 significantly improved tillering capacity.
Maximum plant height (95.33 cm) was also observed in 2% K2SO4 and lowest plant height in
control.2% K2SO4 and 4% K2SO4 improved the tillering capacity of wheat than control. The
combination of 2% KNO3+4% K2SO4 attained the highest grain yield (2825.33 kg ha-1) which
was statistically at par with 2% K2SO4 (2795 kg ha-1). Ali et al. (2005) reported that foliar
application of 1.5% K2SO4 produced better paddy and straw yield as compared to KNO3 and KCl
alone. Many researchers have reported the positive response of K2SO4 foliar application to rice
and wheat crops as well as higher plants (Malik et al. 1988; Hussain and Jilani, 1991 and Ramos
et al. 1999; Ali et al. 2005; 2007).
Potassium concentration in wheat was significantly affected by foliar application at various
concentrations of K2SO4.The highest concentration (0.69 %) was recorded when 2%KNO3+2%
K2SO4 solution was sprayed which was statistically equal to 4% K2SO4, 4%KNO3+2%
K2SO4 and 2% KNO3+ 4% K2SO4 (0.67, 66 and 65 % respectively). Rest of the treatments
showed comparatively less K concentration in plant tissues being minimum (052%) in case of
control. The K concentration in straw was also significantly affected by different K 2SO4
and KNO3 application treatments.. Control and
4% KNO3+4% K2SO4 spray again exhibited
the lowest K concentration in wheat straw (Table IV). The K uptake by paddy was also
significantly affected by foliar application at different K2SO4 and KNO3 concentrations
(Table IV).. A consistent increase in K uptake by wheat was observed due to different
concentrations of K2SO4 and KNO3 foliar application. Maximum uptake (18.75 kg ha-1)
was recorded with 2%KNO3+2% K2SO4 foliar application which was statistically equal 2%
KNO3+ 4% K2SO4.The K uptake by straw was also significantly affected
with
different
concentrations of K2SO4 and KNO3 foliar application. However, uptake pattern was not
similar as noticed in K uptake by wheat. Similar findings regarding significant effect of K
application have also been obtained by various researchers (see Howard et al. 1998; Arabi
et al.2002; Ali et al.2005a & b).
Table I: Physico-Chemical Analysis of the Soil at SSRI FARM
Parameters
Unit
pH (1:1)
Value
8.52
ECe (1:1)
dSm-1
5.32
SAR
(m.mole L-1)1/2
18.87
CaCO3
%
23.01
OM
%
1.02
Sand
%
63
Silt
%
17
Clay
%
20
Texture Class
Sandy Loam
Table I I : Water analysis of Tubewell
Parameters
Unit
Value
pH )
8.1
ECe
dSm-1
1.7
RSC
meq L-1
15.2
HCO3
meq L-1
17.5
Table III: Effect of K2SO4 and KNO3 foliar application on number of tillers, plant height,
spike length, number of grain per spike, 1000-grain weight, straw and grain yield of wheat
at SSRI, Pindi Bhattian.
Treatments:
No
of Plant
Tillers
height
Spike
No
length
grain
(cm)
of
per
1000 grain
Straw yield
Grain yield
weight (g)
(kg ha-1
(kg ha-1)
)
spike
Control
128.67 cd
85.33 e
9.33
4533 e
48.37 d
4003NS
1929 e
2% KNO3
129.33 cd
94.33 ab
11.00
67.33 abc
48.73 d
3220.67
2485 bcd
4% KNO3
132.00 bcd
89.00 cde
11.33
70.00 a
51.43 c
3281
2715 ab
2% K2SO4
132.67 bcd
95.33 a
11.00
68.33 ab
57.67 a
2833
2795 a
4% K2SO4
127.67 cd
87.00 cde
10.33
61.33 cd
59.43 a
2705
2434 cd
2%KNO3+2%
139.67 abc
85.67 de
10.67
74.33 a
56.17 abc
3210
2718 ab
145.00 a
89.33 cde
10.33
69.00 ab
56.87 ab
3400
2392 d
144.67 ab
91.00 bc
10.00
57.33 d
52.20 bcd
3020
2825 a
K2SO4
4%KNO3+2%
K2SO4
2% KNO3+ 4%
K2SO4
4%
KNO3+4%
123.33 d
90.00 cd
11.00
65.00 bc
54.77 abc
2857
2661 abc
K2SO4
Means followed by different letter (s) within the columns differ significantly at 5% level of
significance.
Table IV: Effect of K2SO4 and KNO3 foliar application on Potassium contents (%) and
Potassium uptake (Kg ha-1) at SSRI, Pindi Bhattian
Potassium Contents (%)
Potassium uptake (Kg ha-1)
Treatments
Wheat
Wheat
Control
0.52 bc
1.56d
9.83de
52.45c
0.57 b
1. 66bc
14.16 c
53.45c
0.63ab
1.72b
17.10 a
56.43ab
0.64ab
1.77a
17.89 a
49.94cd
0.66a
1.69b
16.06 b
46.16d
0.69 a
1.79a
18.75 a
58.42a
0.67a
1.63c
16.02 b
56.42ab
Wheat straw
Wheat straw
2% KNO3
4% KNO3
2% K2SO4
4% K2SO4
2%KNO3+2% K2SO4
4%KNO3+2% K2SO4
2% KNO3+ 4% K2SO4
0.65a
1.82a
17.56a
6245a
15.97b
45.14d
4% KNO3+4% K2SO4
0.60 b
1.58d
Means followed by different letter (s) within the columns differ significantly at 5% level of
significance
CONCLUSION
It could be concluded from this study that foliar application of different sources K to wheat crop
at 30 and 45 days after sowing with direct seeding on ridges and Rabi drill sowing is quite better
than control that of soil application at the time of sowing.
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