**4. Application of inorganic amendments to agricultural crops to mitigate salinity effects**

#### **4.1 Exogenous application of sulfur**

Salt affected soil has many salts in it and each salt has a differential contribution to salt stress. There are different salts such as Na2SO4, NaCl, Na2CO3, CaSO4, MgCl2, KCl but the most important of these is NaCl [69–73]. For the regulation of cell metabolism and hormone signaling pathway, Sulfur plays a very important role. For regulating seed germination its acts as a biochemical agent [74, 75]. For the

**121**

*Interactive Effect of Organic and Inorganic Amendments along with Plant Growth Promoting…*

synthesis of protein, chlorophyll, vitamins, and glutathione which are helpful to tolerate various stresses, sulfur plays a very important role [76]. Sulfur compounds are also present in many amino acids and their composition changes by the application of sulfur [77]. To improve plant growth by improving its cellular functions especially in saline soil, the addition of sulfur is beneficial [78]. Different approaches are being applied to mitigate the deleterious effects of salinity on health of plants. The exogenous application of inorganic salts and osmo-protectants are cost efficient approach to reduce the negative effects of salt stress on plant growth [79, 80].

toxicity, silicon (Si) has ameliorative features. It can

and low concentration of K+

ratio vary in plants [84]. Due to elevated level of

and decreasing Na<sup>+</sup>

and Ca+2

uptake [86].

toxic-

uptake.

and reduces Na<sup>+</sup>

**4.2 Use of silicon nutrition to alleviate the salt stress in maize**

help plants to grow on saline soil. For industrialized counties, it can prove costeffective. Under biotic stress, silicon can improve plant growth also reduces radiation effects on it. It is helpful in reducing water loss up to 30% [81]. The exogenous application of Si for different salt-tolerant plant species has been reported [82, 83]. Under saline environment, Si uptake by plats increases root activity and inhibits transpiration. But in the plasma membrane, it increases the activity of ATPase and PPase. This can result in decrease in Na uptake and an increase in K uptake [84, 85].

*4.2.1 Silicon-mediated mechanisms underlying increased crops tolerance to salinity*

 *uptake by plant roots due to Si application*

and Na+

Thus, research studies determined that Si application resulted in reduced Na+ buildup in the roots [86]. Si as phytolith, accumulates different parts of plant bod-

Application of Si plays a protective role to improve antioxidant activity.

**5. Role of PGPRs in alleviation of salinity stress in maize crop**

 and overproduction of ROS, plant metabolism is being changed [85] Research studies demonstrated that Si can reduce ion toxicity which is resulted from the

Under the saline conditions, studies have determined the enhanced production of antioxidant due to the application of Si [87]. Effects of Si on the antioxidants depend upon different factors like the severity of saline stress, time, plant species, and the concentration of Si. Thus, studies determined that application of Si can regulate antioxidant defense system by reducing salinity effects. This also resulted in decrease lipid peroxidation and regulate membrane integrity. It also can decrease permeability of plasma membrane. The research studies determine that non-Sitreated and Si-treated plants show different responses under saline conditions.

In the semi-arid environment, salinity pose negative effects on the growth and production of various crops. It also affects aggregate stability of soil. Soil structure

transport in upper regions and increasing the K<sup>+</sup>

/K+

ies. Si deposits underneath cell walls of roots to bind the Na<sup>+</sup>

*4.2.1.2 Stimulation of antioxidant defense system in crops*

Si application can directly influence growth of plants by diminishing the transport

ions while indirectly activating physiological processes under saline conditions.

and Cl−

*DOI: http://dx.doi.org/10.5772/intechopen.99063*

In contrast to Na<sup>+</sup>

of Na+

Na+

*4.2.1.1 Reduced Na<sup>+</sup>*

Due to high concentration of Cl<sup>−</sup>

saline condition. It is also helpful in increasing K+

in the saline environment, Na+

ity by decreasing the Na+

*Interactive Effect of Organic and Inorganic Amendments along with Plant Growth Promoting… DOI: http://dx.doi.org/10.5772/intechopen.99063*

synthesis of protein, chlorophyll, vitamins, and glutathione which are helpful to tolerate various stresses, sulfur plays a very important role [76]. Sulfur compounds are also present in many amino acids and their composition changes by the application of sulfur [77]. To improve plant growth by improving its cellular functions especially in saline soil, the addition of sulfur is beneficial [78]. Different approaches are being applied to mitigate the deleterious effects of salinity on health of plants. The exogenous application of inorganic salts and osmo-protectants are cost efficient approach to reduce the negative effects of salt stress on plant growth [79, 80].

#### **4.2 Use of silicon nutrition to alleviate the salt stress in maize**

In contrast to Na<sup>+</sup> and Cl− toxicity, silicon (Si) has ameliorative features. It can help plants to grow on saline soil. For industrialized counties, it can prove costeffective. Under biotic stress, silicon can improve plant growth also reduces radiation effects on it. It is helpful in reducing water loss up to 30% [81]. The exogenous application of Si for different salt-tolerant plant species has been reported [82, 83]. Under saline environment, Si uptake by plats increases root activity and inhibits transpiration. But in the plasma membrane, it increases the activity of ATPase and PPase. This can result in decrease in Na uptake and an increase in K uptake [84, 85].

#### *4.2.1 Silicon-mediated mechanisms underlying increased crops tolerance to salinity*

Si application can directly influence growth of plants by diminishing the transport of Na+ ions while indirectly activating physiological processes under saline conditions.

#### *4.2.1.1 Reduced Na<sup>+</sup> uptake by plant roots due to Si application*

Due to high concentration of Cl<sup>−</sup> and Na+ and low concentration of K+ and Ca+2 in the saline environment, Na+ /K+ ratio vary in plants [84]. Due to elevated level of Na+ and overproduction of ROS, plant metabolism is being changed [85] Research studies demonstrated that Si can reduce ion toxicity which is resulted from the saline condition. It is also helpful in increasing K+ and decreasing Na<sup>+</sup> uptake [86]. Thus, research studies determined that Si application resulted in reduced Na+ buildup in the roots [86]. Si as phytolith, accumulates different parts of plant bodies. Si deposits underneath cell walls of roots to bind the Na<sup>+</sup> and reduces Na<sup>+</sup> toxicity by decreasing the Na+ transport in upper regions and increasing the K<sup>+</sup> uptake.

#### *4.2.1.2 Stimulation of antioxidant defense system in crops*

Under the saline conditions, studies have determined the enhanced production of antioxidant due to the application of Si [87]. Effects of Si on the antioxidants depend upon different factors like the severity of saline stress, time, plant species, and the concentration of Si. Thus, studies determined that application of Si can regulate antioxidant defense system by reducing salinity effects. This also resulted in decrease lipid peroxidation and regulate membrane integrity. It also can decrease permeability of plasma membrane. The research studies determine that non-Sitreated and Si-treated plants show different responses under saline conditions. Application of Si plays a protective role to improve antioxidant activity.

#### **5. Role of PGPRs in alleviation of salinity stress in maize crop**

In the semi-arid environment, salinity pose negative effects on the growth and production of various crops. It also affects aggregate stability of soil. Soil structure

*Landraces - Traditional Variety and Natural Breed*

**salinity effects**

**3.1 Organic matter**

**3.2 Biochar**

**3. Application of organic amendments to agricultural crops to mitigate** 

There is an excess of salts in water which is used for irrigation purposes. It can reduce the crop yield due to its increased salt concentration [59]. Soil electrical conductivity is being increased due to the continuous increase of salts in it [60]. Water which is used for irrigation having excess salts in it resulted in negative impacts on plant physiology, soil water plant relationships, and limits the production of crops [61]. By application of organic manure in soil, the toxicity of salts can be minimized, and soil properties can be improved as cost-effective approaches [62]. There are agricultural practices that are used for the management of saltaffected soil [63]. Addition of organic martial is beneficial as a fertilizer which can modify and improve the soil characteristic. For recovery of saline soil, organic amendments like organic manure and compost are being tested as efficient methods [64]. Application of organic matter for the reclamation of sandy soil is an effective method to improve the physical properties of soil [65]. Researchers determined that poultry manure, farmyard manure (FYM), crop residues as compost are being used for the addition of nutrients in the soil. It is beneficial for improving plants' health. It can also modify physiochemical properties of plants [66]. Farmyard manure is the most commonly and easily available source of organic matter. There are different factors which can affect the efficiency of farmyard manure such as nature of feed consumed by the animal, type of animal and waste management methods [67].

There are different long-term and short-term methods for reclamation of saltaffected soil, but short-term management approaches are useful as a management strategy that are cost effective and high-income generating methods [68]. The biochar is an effective method for organic amendment of salt-affected soil that results in

**4. Application of inorganic amendments to agricultural crops to mitigate** 

Salt affected soil has many salts in it and each salt has a differential contribution to salt stress. There are different salts such as Na2SO4, NaCl, Na2CO3, CaSO4, MgCl2, KCl but the most important of these is NaCl [69–73]. For the regulation of cell metabolism and hormone signaling pathway, Sulfur plays a very important role. For regulating seed germination its acts as a biochemical agent [74, 75]. For the

• Soil physicochemical and biological properties are improved

• Stomatal conductance and phytohormones can be regulated

• Effects on plant growth, photosynthesis and biomass

• Reduction in oxidative stress

• Increase in mineral nutrient uptake

• Na ion toxicity in plants is reduced

**4.1 Exogenous application of sulfur**

**salinity effects**

**120**

stability has important for improvement of soil properties. The soil microbial communities such as free-living or symbiotic organisms play an immense role to improve soil structure. It is proved that the activities which microbes performed to soil aggregate stability are very advantageous [88]. It can efficient solution for saline soil and make it fit for agricultural practices. PGPRs can help in inducing plant tolerance to various abiotic stresses including salt stress. In saline environments, PGPR-crop interactions improved the plant growth. It can also promote plant survival in adverse conditions [89]. PGPR promote the growth and development of plants by providing nitrogen, phytohormones soluble phosphates, and iron [90]. The plant is being protected against various soil-borne diseases, and it is known that most of these diseases are caused by pathogenic fungi [91].
