IMPORTANCE OF GYPSUM, ORGANIC MANURE APPLICATION AND NITROGEN, ZINC FERTILIZATION FOR WHEAT CROP IN SALINE SODIC SOILS.

INTRODCTION
Wheat is the most important food crop in Egyptian Agriculture. Wheat
higher yield is the major purpose and it is a function of some important
variables; i.e. soil salinity and sodicity, irrigation water, plant variety and
reclamation as well as fertilization sources. Gypsum is recommended for
sodicity reclamation and its application ahead of some crops planting would
be better for their productivities. It was indicated that the beneficial effect of
gypsum application prior to crops planting in slightly to moderately sodic
soil, on yields would be due to amelioration effect brought about i.e.
modifying various soil physicochemical characteristics and enhancing N,
Ca, Zn and Mn availability to plants (Genaidy, 2011). The remediation of
saline soil using chelating agents such as gypsum (CaSO4 2H2O), calcite
(CaCO3), calcium chloride (CaCl2) and organic matter (farmyard manure,
green manure, organic amendment and municipal solid waste), is a fruitful
topic of investigation and can be applied worldwide, being low cost,
effective and simple to implement (Mitchell et al., 2000; Hanay et al., 2004;
Sharma and Minhas, 2005; Tejada et al., 2006 and Mokoi & Verplancke,
2010). The physical, chemical and biological properties of salt affected soil
are improved by the application of gypsum and/or FYM as remediation for
sustainable land usage and crop productivity, leading to enhanced plant
growth and development (Ghafoor et al., 2001; Choudhary et al., 2004 and
Wong et al., 2009).
Investigation about organic manure indicated some important facts
about the role of organic matter as a source of many nutrients i.e. N, P, K,
Ca, Fe, Zn, etc. besides its role of increasing the solubility of some nutrients
and subsequently their better availability to plants absorption (Genaidy and
Hegazy, 2001and Genaidy, 2011).
Nitrogen as a macronutrient is considered a limiting factor in
Egyptian soils. In saline-sodic soils, availability and absorption of plant
nutrients is severely limited to sustain high crop production due to ion
interactions, especially low nitrogen (N) because of its leaching as NO3,
volatilization and de-nitrification losses (Marschner, 2011). Overall, all
these factors individually or in combination with each other limit N-useefficiency
(NUE) and the extent of this limitation depends on the
J. Product. & Dev., 23(2),2018 345
salinity/sodicity levels, crop types and species and soil physicochemical
properties (Grattan and Greeve, 1999). Tayebeh (2011), indicated that the
different N rates (120, 240 and 360 kg ha-1) had a significant effect on wheat
grain yield with increments of (46% at N120, 72% at N240, and 78% at
N360) compared to control. The increase in grain yield was due to increase
in the yield attribute as the level of nitrogen increased. Also, several studies
indicate that N fertilization can increase both wheat grain yield and grain
protein content (Subedi et al., 2007; Gorjanovic and Kraljevic-balalic, 2008
and Majid, 2010).
Zinc deficiency is most widespread micronutrient deficiency
worldwide (Graham et al., 1992 and Welch et al., 1991). Thus, many
researches approved crop responses and realizing higher yields by adding
the optimum recommended rates as ZnSO4.7H2O.These responses would be
related to Zn-deficiency in such salt-affected soils. Prerna et al. (2014)
revealed that the Zn increased the contents of N, K, Zn significantly in both
grain and straw whereas, phosphorus content was decreased significantly.
Also, the comparative reduction in grain and straw yield of wheat as well as
contents of P and Zn of grain and straw was less at higher doses of zinc
sulfate when the level of ECiw increased in irrigation water. Moreover,
Hazardous effects of saline water on wheat can be mitigated to some extent
by applying zinc sulfate at the rate of 15 mg Zn kg-1 soil.
Accordingly, the objective of this presented research is to indicate the
main effects of gypsum application; organic manuring rate (as compost); Nfertilization
rate as ammonium sulfate and Zn-fertilization as Zinc sulfate as
well as the interaction effects on wheat yield and wheat grains – N, Zn and
protein concentration in saline-sodic soils.
MATERIALS AND METHODS
Two factorial field experiments on wheat crop (Triticum aestivum, L.)
var.Msr2 have been conducted at Sakha Agric. Res., Station during
(2015/2016); (2016/2017) growth seasons, at two different locations, in
fulfillment of the purpose of the presented work. The factors involved
gypsum application rates (0 and 100% GR) × organic manure (as compost)
fertilization rates (0 and 20 m3 fed-1) × nitrogen fertilization rates (0 and 100
kg N fed-1) × Zinc fertilization rates (0 and 5 kg Zn fed-1) × 4 replicates. The
soils of the two experimental locations have the fertility properties as shown
in (Table 1), which have been determined according to Richards (1954);
Black (1965) and Jackson (1972).
346 GENEDY et al.
J. Product. & Dev., 23(2),2018 347
The statistical completely randomized block design with plot area of 6
m2 was followed. Gypsum and organic manure treatments have been
ploughed in soil during tillage processes.
The physico- chemical characteristics of the tested compost have been
indicated in (Table 2).Wheat crop (Triticum aestivum, L.) var. Msr2 as high
yielding cultivar has been sown on 19/11/2015 and 23/11/2016. Planting
irrigation was applied directly after wheat sowing for the two seasons,
respectively. Nitrogen fertilization (as ammonium sulfate source) with the
afore mentioned rates has been added in two equal doses; the first dose was at
mohayah irrigation (30 days after sowing); and the second dose was at the
second irrigation, 30 days after the first one; for the two seasons, respectively.
Table (2):Some physico-chemical characteristics of the tested organic manure
at the two of experimental locations of the two growth seasons.
Zinc fertilization (as zinc sulfate source) with the above mentioned
rates has been added in one addition (with the first N-dose). Irrigation
water requirements and irrigation intervals as well as all the agronomic
practices, have been applied according to the recommended methods of
wheat applied researches. Wheat harvesting has been carried out on
17/5/2016 and on 14/5/2017; for the two seasons, respectively. Wheat yield
and yield components have been determined, and wheat-grains have been
analyzed for N, Zn concentrations and protein content according to standard
methods mentioned by Chapman and Pratt ( 1961).The statistical field design
and analysis of variance have been applied according to Snedecor and
Cochran (1971).
Organic manure
characteristics
Location 1 ( 1st
season)
Location 2 ( 2nd
season)
Moisture content (%) 28.52 29.63
Bulk density ( g cm-3) 0.402 0.425
Organic matter (OM) % 39.01 43.38
Organic carbon (C) % 22.63 25.16
Total nitrogen (N) % 1.19 1.21
C/N ratio 19.02 20.79
pH ( 1 : 10 extract) 7.68 7.77
ECe ( 1 : 10 extract) 1.63 1.57
Total –P ( % ) 0.43 0.51
Total –K ( % ) 1.83 2.68
Total –Zn ( mgkg-1 ) 0.87 1.98
348 GENEDY et al.
RESULTS AND DISCUSSION
Ι- Effects of the main variables:
1- Gypsum application Effects:
As shown in Table (3); wheat grain and straw yields have been
significantly increased by applying the GR treatments, while the increases
of grain / straw ratio were nonsignificantly.The parallel increments were
(33.9,32.4 and 2.4 %) S1 and (35.5, 33.1 and 0.0 %) S2 over control treatment
(GR0.0) and for the two seasons, respectively. These results are in
accordance with those obtained by Choudhary et al.(2004); Hammad et al.
(2007) and Wong et al. (2009).
With respect to wheat grains- N and Zn concentrations as well as
protein content (%), gypsum application increased significantly their values.
The obtained increases were (4.6, 16.7, and 5.2 %) S1 and (3.5, 17.9 and 4
%) S2 over (GR0.0) treatments and for the two seasons, respectively. These
findings are in harmony with those recorded by Genaidy (2011).
2- Organic fertilization effectss:
The same Table (3) indicates that wheat grains and straw yields have
been significantly increased by adding organic manure rate of 20 m3 fed-1.
The obtainable increments were (16 and 15.2 %) S1 and (17.1 and 15.5 %) S2
over control (OM0.0) treatment and for the two seasons, respectively. Also
the results showed that organic fertilization had no effect on grains / straw
ratios for the two seasons. Regarding wheat grains-N Zn concentrations and
protein content, organic fertilization resulted in significant increments of
(3.3, 7.6 and 3.6 %) S1 and (3.5, 6.5 and 4 %) S2 over (OM0.0) treatments and
for the two seasons, respectively. Abou El-Enein et al. (2008) obtained
similar results.
3- Nitrogen fertilization effects:
As shown in the same Table (3), wheat grains and straw yields have
been significantly affected by adding the optimum N –fertilization rate of
100 kg N fed-1 and there is no significant effects on grains / straw ratios.
The gained increases were (19,16.6 and 2.4 %) S1 and (20.3,18.5and 0.0 %)
S2 over the control treatments (N0.0) and for the two seasons, respectively.
Regarding the wheat N and Zn grains concentrations as well as protein
content, nitrogen fertilization gave significant effect with increases of (14.5,
42.2 and 14.9%) S1 and (12.5,41.2 and 12.8%) S2 over (N0.0) treatments and
for the two seasons, respectively. These results are in agreement with those
realized by Subedi et al. ( 2007); Gorjanovic and Kraljevic-balalic ( 2008)
and Majid (2010 ).
J. Product. & Dev., 23(2),2018 349
350 GENEDY et al.
4- Zinc fertilization Effects:
As shown in the same Table (3), zinc fertilization rate of 5kg fed-1
increased wheat grains and straw yields, but grains / straw ratios have been
not affected. The significant increases of grains and straw yields were
(8.7and 8.8 %) S1 and (8.7and 8.1%) S2 over the control treatments (Zn0.0)
and for the two seasons, respectively. With respect to grains-N Zn
concentration, and protein percentage, Zn- fertilization resulted in
significant increments of (6, 17.4 and 6.1%) S1 and (5.7, 15.2 and 5.7%) S2
over the (Zn0.0) treatments and for the two seasons, respectively. Similar
results are in accordance with those stated by Sharaf (2008) and Ali et al.(
2011) who obtained positive values of wheat yield and nutrient uptake when
zinc was applied to the soil. Also, the present results are in agreement with
that obtained by Prerna et al.( 2014) who said that hazardous effects of
saline water on wheat can be mitigated to some extent by applying zinc
sulfate at the rate of 15 mg Zn kg-1 soil.
Π- Interaction Effects:
Table (4) reveals the significant interaction (gypsum application ×
organic fertilization × N fertilization × Zn- fertilization) effects on the wheat
characters. With regard to wheat grain and straw yields, the higher values
have been resulted by applying the treatments of (GR × OM20 × N100 × Zn5)
and (GR × OM20 × N100 × Zn0.0) with obtainable increases of [(87, 82%) S1,
(96, 87%) S2] gr.y. and [(73, 69%) S1, (80, 74%) S2] st. y. over the control
treatments (GR0.0 × OM0.0 × N0.0 × Zn0.0) and for the two seasons,
respectively. With respect to wheat grains-N Zn concentrations and protein
content; the higher values have been obtained by applying of (GR × OM20 ×
N100 × Zn5) and (GR × OM20 × N100 × Zn0.0). The parallel increments were
[(37, 30%) S1, (31, 21%) S2] N, [(111, 85%) S1, (98, 80%) S2] Zn, and [(37,
30%) S1, (31, 21%) S2] prot. over the control treatments and for the two
seasons, respectively.
Conclusions:
According to the above mentioned results; it could be concluded that:
1- For salt affected soil(saline-sodic soils or sodic) a double purpose could be
realized at the same time (a) optimizing soil condition to improve physicochemical
properties and (b) increasing the availability of most nutrients
for wheat plants such as nitrogen, zinc, and subsequently better yields.
Therefore, the addition of gypsum with 100% (GR) prior wheat
J. Product. & Dev., 23(2),2018 351
352 GENEDY et al.
cultivation resulted in higher wheat yield due to reaction in depressing soilpH,
soil-EC, soil-ESP and increasing the availability of most nutrients.
2- Better wheat yield have been obtained by organic manure fertilization (20
m3.fed-1) as a result of lowering soil-pH, soil-ESP and increasing N and
Zn-use efficiency whether from soil or fertilizer sources.
3- Zinc sulfate fertilization of 5 kg Zn fed.-1 led to higher wheat yields out
of Zn-unavailability due to higher soil-pH and soil-ESP.
4- The significant interactions revealed that the efficiency of gypsum
application or zinc sulfate fertilization have been affected with each other
and with organic fertilization, that have been increased their efficiencies.
Therefore, the co-addition of the variables resulted in higher values of wheat
yield and wheat grains- N Zn as well as protein concentration