Effect of NPS Fertilizer, Spraying Nano-NPK+TE and Cerium Oxide NPs on Growth and Yield of Rice (Oryza Sativa L.)

The aim of this research was to identify the effects of NPS fertilizer with the spraying of Nano-NPK+TE and Cerium Oxide NPs on the growth and yield of (Amber 33) rice. This field study was carried out in the Tali’a region, 41-Husainiya, Hilla city, Babylon province, Iraq, from 14/6/2022 to 25/11/2022, The study treatments were randomly distributed on the experimental units according to a simple and one-way experiment by a randomized complete block design (RCBD). The study treatments consisted of adding NPS fertilizer at four levels (0, 100, 200, and 300 kg ha-1) and spraying with nanomaterials of Nano-NPK+TE and Cerium Oxide NPs at concentrations of (2.5 ml L-1) and (50 mg L-1), respectively, with four sprays for each of them. A total of 16 experimental units were used. The statistical analysis using Duncan’s test revealed to us that the process of fertilizing with NPS fertilizer and nanomaterials led to the highest improvement for plant height with a value of (130.43 cm) achieved by the combination of (NPS 300 kg ha-1 + spray CeO2 NPs + Nano-NPK+TE), This combination also achieved the highest chlorophyll index of (41.6 SPAD), as well as the highest response in biological yield (21.19 Meg ha-1), grain yield (5.89 Meg ha-1) and the index of yield harvesting (27.8%). Moreover, this treatment achieved high response for the weight of 1000 grains at (21.31 g). Additionally, the bi-combination of spraying with CeO2 NPs and Nano-NPK+TE had the highest agronomic efficiency at (381.61 kg kg-1).


Introduction
Rice (Oryza sativa L.) is most important cereal crop that is widely grown in many countries, particularly in tropical and subtropical regions with warm and moderate temperatures.It is cultivated in over 114 countries [1] and is an essential food for over half of the world's population, with a global production of approximately 480 million tons [2].China and India are the leading producers and consumers of rice, accounting for 50% of global consumption [3].Furthermore, an estimation of 422.5 thousand tons of rice production was recorded locally during the summer season of 2021, which is a 9.0% decrease from the previous season's estimate of 464.2 thousand tons.The total cultivated area for rice in 2021 was approximately (384.9 thousand dunums), with Al-Diwaniyah Governorate ranking second in total production with around (158.8 thousand tons), following Al-Najaf Governorate, which produced an estimated 241.8 thousand tons [4].Rice is a grain crop that generally needs large amounts of nutrients, mineral fertilizers, and large amounts of water during the various stages of growth.Because of immersion irrigation methods [5] large amounts of conventional fertilizers are exposed to washing, volatilization, and fixation in the soil in a way that is not able to be absorbed by the roots of the plant, especially Soils with a clay texture, and this causes material losses due to the large consumption of fertilizers [6], in addition to the imbalance of the amounts of nutrients needed by the plant in the soil, especially the microelements [7].or trying to find a balance of nutrients and compensate for the lost ones by adding larger quantities of fertilizers, so Fertilization Balanced means achieving available soil nutrients and creating an ideal environment for plant growth and organisms in the soil, so it requires ensuring that the amount of the nutrient reaches the optimum level in the soil [8], and some soils have a high content of basic elements N, P, K, S and in such these cases [9], the addition of mineral fertilizers to these soils in large quantities is not required except for the quantities added to compensate for the shortage of the cultivated crops, then the lost is compensated with different forms of a single elemental fertilizer, a compound or a mixture fertilizer [10], and these additions are considered necessary, especially when cultivating grain crops such as corn Yellow and rice that absorbed large quantities of soil nutrients, especially nitrogen, as the soil then needs additional urea fertilizer to be added in two or three batches gradually in order for the plant to benefit from it in the largest possible quantities and reduce the amounts of volatilized and washed from it, as more than 40% of the urea is lost added [11].Agricultural soils are exposed to consumption and depletion of nutrients in them as a result of the development in the production of improved crop varieties and the increase in their consumption with the continuous population increase.Adding fertilizers in larger quantities [12], and the increasing requirements for traditional mineral fertilizers often cause unregulated or unbalanced use of fertilizers in a way that causes groundwater pollution and soil salinity increase [13].so fertilizers are a critical element that affects production per unit area [14].Nano fertilizers are considered a modern technology that has entered the agricultural scientific fields and the fertilizer industry, and play an effective role in improving the balance and rationing of the use of fertilizers, which contributes to improving food production and quality and reducing the resulting environmental pollution, especially for improved, high-quality varieties that are highly responsive to fertilizers [15], and nanometer-sized fertilizers have the ability to penetrate the plant body and improve the uptake efficiency of the roots and leaves (for foliar spray) [16], and improve the release of nutrients in a slow and balanced manner so that they are able to improve nutrients availability in the soil and the rhizosphere zone on a regular basis.Nano fertilizers are widely used for crops by foliar application of micro nutrients and bio stimulators, as this method is considered highly efficient in delivering the necessary nutrients into the plant body and reducing waste, and it is also considered a more effective method than application on the soil or to the root zone [17].The use of nanoscale cerium oxide (CeO2) by foliar spraying of rice (Oryza sativa L.) can bring about important changes in the plant and increase the proportions of some nutrient compounds in rice grains, where the nanometer size of particles used as fertilizers plays a major role in the biological activity within the plant`s body, especially within the limits of (5 -100) nanometers, because it is absorbed, transported, and represented within the plant body with high efficiency, with nutrients released slowly and according to the plant's need [18].Cerium increases plant resistance to drought by reducing oxidative damage to the cell as explained by the research of [19], in addition to increasing the activity of antioxidant enzymes, and cerium can act as a catalyst for the redox process in electron transfer.In the first and second photosystems, in addition to improving plant resistance to biotic and abiotic stresses in general, while providing the rest of the necessary growth elements and requirements, and thus improving grain quality [20].Among the qualitative indicators of rice grains are the active substances that enter into the nuclear structure of the seed and its compounds and give it its aromatic smell [21,22].In general, the use of nano-Fertilizers as a modern technology and most effective ways to provide the plant with its needs and reduce losses, and is less harmful to the ecosystem compared to traditional chemical fertilizers.In addition to the role of these characteristics in enhancing economic benefits, their joint use with traditional mineral fertilizers contributes to creating a balance Continuous feeding at different stages of plant growth and finding a better medium for absorbing nutrients in the plant, in 3 addition to reducing dependence on chemical fertilizers, which is what the current study aims to identify by evaluating the fertilizer combinations used from NPS fertilizer with three levels as an addition through soil, integrated Nano-NPK+TE fertilizer, and Cerium Oxide NPs by foliar spraying on the vegetation of Amber-33 rice with the aim of knowing: 1.The effect of adding mineral fertilizer NPS and spraying Nano-NPK+TE fertilizer and Cerium Oxide NPs on some growth and yield indicators of rice crop.2. The combinations effect of levels NPS fertilizer and the spraying of Cerium Oxide NPs and Nano-NPK+TE fertilizer in some quantitative and qualitative standards for rice grains.3. Determine the optimal treatment or combination to increase production from an economic point of view.

Experiment Location
This field experiment was carried out in Tali'a region, 41-Husainiya, Hilla city, Babylon province, Iraq, in the interval between 14/6/2022 to 25/11/2022, Within the geographical coordinates of latitude (N-3560050) and longitude (E-481907), which is the required time period for the completion of all growth stages in the rice plant.

Experience Design
The experiment of current study was carried out with randomly distribution of the study treatments on the experimental units according to a simple and one-way experiment by a randomized complete block design (RCBD), and the number of treatments reached ( 16) within each replicate with three replicates for the field experiment, Consequently, the total number of experimental units increased to 48 [23].The treatments consist of adding NPS fertilizer at four levels (0, 100, 200, and 300 Kg ha -1 ) and spraying with nanomaterials of Nano-NPK+TE and Cerium Oxide NPs at concentrations of (2.5 ml L -1 ) and (50 mg L -1 ), respectively, with four sprays for each of them.
Table 1.Provides a list of the fertilizers and nanomaterials utilized in the experiment with their respective components.

Experiment Field Preparations
The experimental field unit was selected from agricultural land and subjected to perpendicular tillage, smoothing, and leveling processes.A representative sample for field soil was taken at a depth of 20 cm from five locations surrounding and the center of experimental field, to characterize the classification of agricultural soil, that was classified as Entisols according to the latest American classification [24] with clay loam texture.Also we found that soil have the following properties: Electrical Conductivity (Ec) = 3.02 ds m -1 , pH = 7.56, N= 21.11 mg N Kg -1 soil, Available P= 9.32 mg P Kg -1 soil, Available K= 261.24 mg K kg -1 soil, available S = 297.53mg S Kg -1 soil, Organic matter = 1.44%.The total study area of the field was (300 m 2 ), the area divided into three equal replicates, each containing 16 experimental units.The area of each experimental unit was 4.5 m 2 (3 x 1.5 m), with waterways and sewers were dug to irrigate the experimental unit plots and to drain any surplus water.

Plantation and Crop Management
The dry rice seeds of (Ambar-33) variety, were approved by Rice Research Station located in Al-Mishkhab District of Al-Najaf governorate, for planting directly into previously prepared soil on (14/6/2022), at a rate of 120 Kg ha -1 .The soil was covered after planting to prevent erosion by irrigation water and consumption by birds.During the patching stage (1-4/8/2022), irrigation water depth was maintained at approximately (10 cm) to ensure adequate water availability for the plants to attain full maturity, in addition to weeding while doing the patching process.Irrigation of the field was stopped for 14 days before harvesting and weeding while doing the patching process.

Fertilization
The soil of experimental units were initially fertilized with Tron fertilizer NPK (20:20:20) at a rate of (200 kg ha -1 ), then the fertilization process with NPS fertilizer at four levels (0, 100, 200, and 300 kg ha -1 ) applied to the soil (Table 3).The calculated quantities of addition were depending on the area of the experimental unit.In addition, the foliar spraying with nanomaterials combine of Nano-NPK+TE fertilizer at a concentration of (2.5 ml L -1 ) and Cerium Oxide NPs at a concentration of (50 mg L -1 ).The process of spraying Nano-materials was carried out according to concentrations with four sprays, and the period between one spray and another was 7 days, starting from pre-flowering stage to 50% flowering.These foliar sprays were carried out at the crack of dawn applying at a proportion of (400 liters ha -1 ) (Table 3).The size of particles of Nano-NPK+TE and Cerium Oxide NPs was determined using scanning electron microscope (FE-SEM), this analysis was performed at the physics department's central laboratory of the University of Tehran.to confirm that the particle size was within the Nano-dimension range (1-100 nm).

Harvest
On 11/25/2022, the rice crop was harvested at full plant maturity for all treatments.Moisture percentage in grain at harvest was measured to be within the range of 18-25%, as mentioned in [25].

Plant Height (cm)
At 100% flowering stage, plant height was determined using a tape measure to measure the distance from the soil surface to the highest point of the plant, for ten randomly selected plants from every experimental unit.The values of plant height were calculated by dividing overall plant height values for each treatment by the number of measured plants, as stated in [26].

Chlorophyll Leaves Index (SPAD)
Before the flowering stage of the plants, the chlorophyll content of the leaves was assessed using a portable (Model: SPAD-502) chlorophyll device to obtain accurate and fast estimates of leaf chlorophyll content in real-time in the field [27].The chlorophyll leaves readings were taken randomly from ten plants within each experimental unit, and the mean values was calculated by dividing the total chlorophyll content of leaves by its respective number of leaves.

Biological Yield (Meg ha -1 )
The biological yield represents the weight of the total dry matter of the plants above the soil surface per square meter of each experimental unit.The weight is calculated by weighing the harvested plants for each experimental unit, then exposing them to air to air-dry them for 10 days to get rid of excess moisture.Then the dried plants are weighed for each treatment in kilograms, then the dried plants are weighed for each treatment in kilograms, then convert it mathematically to the unit (Meg ha -1 ) according to [28].

Grain Yield (Meg ha -1 )
The grain yield of rice is calculated per one square meter for every experimental unit, after that, the harvested plants for each treatment were air-dried for ten days to get rid of excess moisture, after that, the grains were separated from the vegetable yield, weight the grain measured in kg m² for each treatment, then It is computed mathematically to the unit of Mega grams per hectare (Meg ha -1 ), and these steps after confirming from moisture content of grains by 14% using the moisture device measuring owned by the laboratory of Muradia Research Station in the Directorate Agriculture of Babylon [28].

Harvest Index (%)
Harvest index for rice crop yield is calculated from the means of grain yield and biological yield for each treatment by the following equation [28]: The harvest Index= Grain yield /Biological yield x100 2.8.4.1000 Grain Weight (g) For estimating the values of this trait, a thousand raw grains of rice were calculated for each treatment with the grain counting device of Al-Muradia Research Station in the Directorate Agriculture of Babylon, after estimating the moisture content of the grains, which reached 14%, then 1000 grains were weighed using an electronic scale sensitive for small weights, for each treatment.

The Content of Nitrogen Percentage (%)
The nitrogen content of the yield was determined by utilizing the method of [29], and subsequently calculated using the following formula:

The Content of Protein Percentage (%)
Two grams of a pulverized and desiccated grain sample were subjected to digestion using the procedure outlined by [29], subsequently, the nitrogen percentage was determined using the Kjeldahl process.The protein percentage was then calculated using the following formula: Protein (%) = Nitrogen (%) x 5.95 2.8.7.Netting Percentage % (100) grams of raw rice grains were taken for each treatment, then these grains were milled by using a Japanese-made milling machine owned by Ghammas Rice Silo Factory, after milling process for the grains was completed, we put grains in a Stone husking machine (Satake Japanese-made) for husking rice and removing lemma, the percentage of netting grain of rice was calculated as mentioned at the equation: [30]   = ℎ    ()  ℎ ()  100

Statistical Analysis
The data of the obtained results were assessed using statistical methods by variance analysis (ANOVA), using the tabulation program, and the statistical analyses of the data included the Analysis ToolPak, then the differences between the averages of treatments were assessed by using Duncan test, the least significant difference test, at the level of probability (P ≤ 0.01) and (P ≤ 0.05), to determine the significant differences, as mentioned in [23].

Plant Height (cm)
Through the results in Table (3), we can notice a significant difference in the treatments for this trait with the excellence for treatment (NPS (300) +NPK+TE +CeO2), which was distinct from the rest of the treatments with a value of (130.43 cm), and about bi-combinations, the treatment (NPS (200) +NPK+TE) achieved a significant difference over its counterparts by a value of (128.87 cm) in comparing with the comparison treatment that recorded a value (120.17cm), while the treatments for foliar spraying of Nano-fertilizers by the combined treatment (NPK+TE + CeO2) achieved the highest value (125.83cm).

Biological Yield (Meg ha -1 )
We can observe the treatment (NPS (300) +NPK+TE +CeO2) with a value of (21.196Meg ha -1 ) was distinct from all other treatments for the studied trait.Significant values were also observed in the treatments with combined nanomaterials (NPK+TE +CeO2) by recording (16.66 Meg ha -1 ) in comparing with the control treatment, which recorded a value of (11.55 Meg ha -1 ).

The Weight of 1000 Grains (g)
From the results in Table (4) we noted that the highest significant response for weight of 1000 grains trait exhibited in the tri-treatment (NPS (300) +NPK+TE +CeO2) which recorded (21.31) g when comparing with the control treatment with a value of (18.43 g), and the bi-combinations (NPS (300) +NPK+TE and NPS (200) +NPK+TE and NPS (300) +CeO2) also recorded a significant response with values of (21.11, 21.07 and 20.95) g, respectively.4) explain to us that the triple combination (NPS (300) +NPK+TE +CeO2) had a distinct value of (68.73%) in this trait, the other combination treatments (NPS (200) +NPK+TE +CeO2 and NPS (300) +NPK+TE and NPS (100) +NPK+TE +CeO2) recorded significant differences (68.56, 68.46 and 68.16) % respectively.And the single treatment of addition NPS at level (300 kg ha -1 ) also showed high significant value of (67.93%) when comparing with the control treatment with the value (65.10%).

Nitrogen Concentration in Grains%
By observing the results shown in Table No. (4), that there are a significant different for the treatments at the trait of Nitrogen content in grains, with distinct of the treatment (NPS (300) +NPK+TE +CeO2) and achieved a significant response comparing with the readings of other treatments by recording value of (1.428%), and the other combined treatments (NPS (200) +NPK+TE +CeO2, NPS (300) +NPK+TE, NPS (200) +NPK+TE) also recorded high significant mean with values (1.286, 1.245 and 1.232), in comparing with the comparison treatment which recorded a value (0.943%), while the treatments of foliar spraying of Nano-fertilizers with (NPK+TE +CeO2) recorded highest value of (1.123%).

Agronomic Efficiency (A.E) (kg kg -1 )
Through the results shown in (Table 4), we observed that the treatment of spraying CeO2 NPs achieved the highest significant difference value recording (5325 kg kg -1 ).Then the combined treatment of nanomaterials (NPK+TE +CeO2) achieved value (381.61kg kg -1 ) which also recorded significant difference.

Discussion
From the results shown, we conclude that the use of the mineral compound fertilizer NPS with Nano-NPK+TE and Cerium Oxide NPs achieved the highest responses of increase at the studied traits on plant, due to the role played by the NPS fertilizer added on the soil by increasing the availability of the basic elements for growth, especially phosphorus and sulfur [32], This is reflected in the improvement of photosynthetic and respiratory activities, as well as the efficacy of plant hormones, in addition to the effect of spraying nanomaterials and providing the plant with macro and micro nutrients.The reason for this due to the fact that nanoparticles are possess by a very high specific surface area that leads to an increase in chemical and biological reactions within the plant [33].In addition to the role of Cerium Oxide nanoparticles in stimulating the activity of antioxidant enzymes, and thus reducing the harmful oxidative effects caused by the accumulation of reactive oxygen species (ROS), as well as improving the activity of catalase, and with the direct absorption of macro and micro nutrients provided by Nano-NPK+TE fertilizer with the ground supply of nitrogen and phosphorus and sulfur to the plant to increase the growth of plant cells, increase the cellular divisions of plant tissues, promote IOP Publishing doi:10.1088/1755-1315/1259/1/01201510 the growth of vegetative plants, and delay the aging of cells [34], and thus increase the dry matter weight, increase plant height and the biological yield of the plant [35].Foliar spraying of nanomaterials (Nano-NPK+TE and Cerium Oxide NPs) improves plant growth, by improving metabolic processes related to photosynthesis, carbon metabolism, and the activity of enzymes involved in primary and secondary metabolism.As a result of improving cell growth and enhancing chlorophyll concentration in leaves, and thus the dry and wet vegetable crop [36], this is due to the use of Cerium nanoparticles while providing the plant with other nutrients necessary for vital interactions and growth.The high surface area of the nanoparticles resulted in an expansion the area of biological reactions and improving the activities of enzymes and their rates, and this leads to the production of cell components, protoplasm, and unprocessed materials sufficient for the sustainability of cell proliferation and encourages the plant to directly absorb, larger quantities of nutrients through the plant leaves in comparing with soil fertilization, as a result to the size of the added Nano-nutrients, and the increase in plant leaf area and their numbers, and thus increased leaf chlorophyll (SPAD) [37], so this explain to us the reason for this improvement through the results that show an increase in biological yield [38,39], and the consequence of supporting soil additions with nano nutrients that have consequential role in enhancing the capability of plants to absorb and grow [40].In addition to achieving the highest responses in grain yield under the influence of tricombinations of ground additives NPS and nanomaterials that rich in nutrients and the stimulating effect on plant growth (NPK+TE + CeO2).These achieved results show the high importance of applying these combined fertilizers by their role in affecting cell growth and division and thus affecting the yield [41]. Through the results showed about the increase in grain yield with the highest significant improvements obtained (5.891 Meg ha -1 ) in comparing with the plants of the comparison treatment, we can confirm the important role of Nano fertilizers as a promising technology for sustainable agriculture and environment, because it works in smaller quantities and the use of higher efficiency compared to traditional fertilizers with a slow release, in addition to the smart targeting of the sites of absorption in the plant with a high speed in nutrient release, transport and representation within the plant, which enhances and promotes a high response for optimal growth and the good quality of yield [42][43][44].Agricultural efficiency is based on the quantity and effect of the add-ons to the plant, so it's considered as an indicator of the efficiency of the materials used, and through the results of values achieving to the agricultural efficiency, we can observe the role and effect of Nano-fertilizers, so this signifies a novel approach towards the utilization of nanotechnology as opposed to the conventional means of fertilizer application and traditional fertilizers combinations with less efficient.

Conclusions
The results of the current study showed that high significant responses were recorded for studied traits on rice plant in comparing with untreated treatment, and the highest improvements were obtained by the effect of the tri-combinations of mineral fertilizer NPS at its three levels, foliar spraying of Nano-NPK+TE and Cerium Oxide NPs.This shows the role of the combined fertilizers in providing the plant with nutrients necessary for growth in an integrated and continuous form.The bi-combinations also achieved for the ground additions, especially at the higher level of addition, and nanomaterials, high and significant responses for grain yield, biological yield and the rest of the studied traits of rice growth and productivity (Amber-33).Therefore, these combinations of Nano-fertilizers can contribute to reducing the large quantities of traditional fertilizers applied to increase crop production, in addition to their negative impact on biodiversity in cultivated soils, as well as reducing risks to the environment and water pollution due to the large quantities of these added fertilizers, in addition to wrong agricultural practices.Therefore, it is necessary to increase interest in these nanotechnologies used as Nano-fertilizers providing nutrients for plants, and need for more studies and researches, aiming to reach a clear physiological and molecular understanding and the effects resulting from these fertilizers, especially the application of Nano-fertilizers on rice plants and the effects on yield, noting that the agricultural efficiency through the results, gave An important indicator when spraying nanomaterials individually, due to the small size and the least quantities used.

Figure 1 .
Figure 1.Particles of Cerium Oxide NPs by FE-SEM scanning electron microscope.

Table 2 .
A description of Soil Fertilization Treatments with ground NPS fertilizer and levels of dosages, the nanomaterials used, the concentration employed and Number of Sprays.

Table 3 .
Effect of NPS and spray of Nano-NPK+TE fertilizer and Cerium Oxide NPs on Plant height, Chlorophyll index, Biological yield, Grain yield and Harvest index.

Table 4 .
Effect of NPS and spray of Nano-NPK+TE fertilizer and Cerium Oxide NPs sprays on weight of 1000 grains, clearance percentage %, Nitrogen concentration in grains %, Protein content in grain % and agronomic efficiency.