Revolutionizing Maize Farming with Potassium Silicate Foliar Spray and Water Management Techniques

By integrating various irrigation and agriculture management techniques, it is possible to considerably improve water productivity. In order to examine the impact of irrigation scheduling (1.0 and 1.2 pan evaporation coefficient), planting method (ridge and raised bed), and potassium silicate foliar application (0 ppm and 100 ppm) on maize (Zea mays L) growth, yield, and water-related factors, a two-season field experiment was conducted in a hot-dry climate region of southern Egypt during 2017 and 2018. The results showed that the seasonal irrigation requirement and consumptive use were higher at 1.2 than the 1.0 pan evaporation coefficient, irrespective of the planting methods. Raised bed planting method saved about 19% of applied water (two seasons average) compared to the ridge planting method. Plants treated with potassium silicates attained higher yields compared to the control, irrespective of the irrigation level and planting method. Moreover, irrigation at 1.2 pan evaporation resulted in the lowest daily ETc values, i.e., 3.15, 6.0, 6.7, and 2.8 mm for plant growth stages, i.e., ini, dev, mid and late. This resulted in the lowest Kc values (0.47, 0.91, 1.16, and 0.61) at different plant growth stages (ini, dev, mid and late). Based on the study findings, it is recommended to use a deficit irrigation of 0.15% based on accumulated pan evaporation values of 1.2, coupled with raised bed planting method and the application of 100 ppm potassium silicates, for optimal maize water productivity and net return.


Introduction
Water availability is the main limiting factor for the agriculture production and food security, in particular in arid and semiarid regions.Climate change and the rapid increase in human population increase the pressure on the already available water resources, popularizing the concept of crop per drop "water productivity" rather than land unit productivity.Climate change is expected to increase the frequency, length, and severity of drought events, through increasing the rainfall variability, thus adversely affects crop yield and water productivity [1][2][3][4].
The increase in food demand for ever increasing population will increase the necessity of irrigated agriculture, because of the expected decline in rainfed agriculture productivity due to expected increase in rainfall variability [5].Due to the increased dependence on irrigated agriculture, limited water for irrigation and the adverse impacts of climate change, it is urgent to maximize the amount of food produced for every drop of water.Though, water crisis is a global issue, but water availability varies region to region, thus there is need of developing region-specific water management strategies to deal with.
It is rich-established that raised-beds planting method has the advantage for increasing crop productivity, compared to ridge-and flat planting method.It saves suitable root zone and more soil volume, which improve root rhizosphere and increasing soil porosity [6] .The raised-beds cultivation also decrease the production costs, energy inputs and environmental impact [7].Raised-beds cultivation attains saving in the applied irrigation water because planting on both edges of the raised bed results in one wetting front [8].However, in ridge planting method, the plants are at located at the center, which results in two wetting fronts.Thus, raised-beds cultivation could introduce the solution to socioeconomic, biophysical, and environmental problems related to irrigation; save the irrigation water and increase water productivity [9,10].
Potassium (K) is an essential mobile macronutrient that enhances the photosynthetic rate, improves gas exchange parameters, and regulate plants water uptake and therefore improve plant growth and productivity [11].The K roles start with seed germination and proceed with numerous plant physiological stages [12].Potassium is involved in many physiological processes, i.e., an integral part of many metabolic activities of plants [13,14], an activator for more than sixty enzymes, a biomaterial transporter [15], transfers of light energy into chemical energy [16], involves in protein synthesis [17,18], a key enzyme in sugar transport [19] and sugar accumulation [20].It is the main osmotic solute  in plants, assists in the opening and closing of stomata, and plays an important role in water use [21].Potassium is known as a stress alleviator, where it improves the water relations under water stress by helping the plant absorb more water to attain turgidity [22,23].Silicon (Si) is still debated as a plant bio-stimulant, fertilizer, or protectant [24], or all together.Si has the ability to decrease biotic and abiotic stresses, increase resistance to diseases and insect pests, and maximize plant growth and yield [25].Although of its effect, Si is still not routinely used [26].Si plays a buffer role to adjust internal plant balances.Adepts the concentration and activities of different hormones, amino acid and enzyme, transpiration rates and gene expression change under stress condition [24].Potassium silicate as a source of both potassium (K) and silicon (Si) can be applied through the foliar application, which is low-cost and more effective than soil fertilization [27] .
Maize is a strategic and adaptable crop that can grow over an extended period of the year, especially under in the southern of Egypt.Because of the apparent and irreplaceable role of maize in milk, meat, poultry and fish production, besides the industrial role in oil, starch, and energy production [28].Maize is coming secondly cultivated crop globally [29] .While there is a wide gap between maize production and need, its self-sufficiency ratio is about 50% locally at Egypt [30].
Water use grew at almost twice the rate of population increase [29].The Egyptian population was lower than 21 million in 1950 and it is rapidly increasing to exceed 100 million in 2020 (World Popul ation Prosp ects -Popul ation Divis ion -Unite d Natio ns), while our main water resources are approximately the same.About 85% of the total water resources in Egypt are consumed by the agricultural sector.
Because of its scarcity, water always is the core attention of most agronomists and on-farm irrigation specialists [31] .As a result of an unfavorable change in environmental conditions and an extreme increase in global temperatures, there is a large need to apply untraditional methods that could mitigate that harmful effects and sustain the agricultural production, especially in arid and semi-arid regions, which already suffering from water shortage and evapotranspiration raising.Therefore, the objective of this research was to evaluate the effect of irrigation scheduling, cultivation method and foliar application of potassium silicates on maize yield and water productivity.

Materials and Methods
A two-season field experiment was conducted during the summer season of 2017 and 2018 at El-Mattaena Agricultural Research Station, (25 º 18/ latitude and 32 º 34/ longitude), Luxor Governorate, southern Egypt.Monthly means of maximum and minimum temperature ( º C), relative humidity (%), wind speed (m sec −1 ), daily sunshine (hours day −1 ) and Reference evapotranspiration ET 0 (mm day −1 ) for the experimental site during the two growth seasons of 2017 and 2018 are presented in Table 1.The ET 0 values were computed using ET 0 _Calculator_V3.2[32].The soil of the experimental site is clay loam in texture, non-saline and slightly alkaline.Physical and chemical properties of the experimental field at different depths (0-15, 16-30, 31-45, and 46-60 cm) are presented in Tables 2 and 3.

The Experiment Design and Treatments
The experiment was laid out in a Split-Split Block Design (Stripes) under (RCBD) using four replicates.The experiment included 3 factors in which irrigation, planting method and potassium silicate were distributed in the main-plot, subplot, and sub-sub plot, respectively.The field was divided into 32 plots (8 treatments; two irrigation levels × two planting methods × two rates of potassium silicates).Plants were irrigated either at 1.0 or 1.2 pan evaporation coefficient.Under each irrigation level, two planting methods were investigated (ridge Vs raised bed).Within each planting method, the foliage of the plants was treated with potassium silicates (100 ppm) in addition to the control.Each experimental units consisted of 8 ridges or 4 raised beds   4).Maize (Zea mays L.) cv.Giza 168, was planted on July 5th of both growing seasons (2017 and 2018) and harvested on the 22nd and 19th of October 2017 and 2018 growing seasons, respectively.Maize was planted on the ridge center or the two edges of the raised where every two planted ridges have the same plant density as one raised bed (Fig. 1).Potassium silicate was applied as a foliar application with the rate of 100 ppm at 30, 45, 60 and 75 days after sowing.

Plant, Soil, and Water Relationships
The experiment has been implemented under a hybrid furrow irrigation system where the water passes through a closed pipe or small network from the water source to the experimental unit, in order to maximize the conveyance efficiency.

Time of Irrigation
Daily evaporation data were obtained from a standard Class-A-Pan located near the experimental field.The recorded readings were and multiplied by an evaporation pan coefficient of (1.0 and 1.2).Then irrigation time is determined by setting the cumulative pan evaporation to be equal to the allowable available soil moisture depletion (50%).

Irrigation Requirement Computation (Applied Water)
The experimental plots have been given volumes of water to raise the moisture of the top 60 cm of the soil layer to the field capacity (+ 0-5%) to ensure a high uniform distribution of the water through the plots at the ridge planting system and (−15%) of ridge water volumes were given at raised-bed planting system.
Soil samples at four depths (0-15), (15-30), (30-45) and (45-60 cm) were collected directly before irrigation and 48 hours after irrigation.The quantity of water for each irrigation treatment was computed according to the following formulas: For ridge planting system: For raised beds planting system: Where.
Q is the quantity of water (m 3 ).R is the area that would be irrigated (m 2 ).D is the soil depth required to be irrigated (m).Bd is the bulk density of the soil (g cm −3 ).F.C is the field capacity of the experimental field (%).S.M.I is the soil moisture (%) before irrigation.

Evapotranspiration (ET), Amount and Rates
The quantities of ETc were calculated for 60 cm soil depth using the following equation: Where.
ET is the evapotranspiration (m 3 ).Ө 2 is the soil moisture after irrigation (%).Ө 1 is the soil moisture before the next irrigation (%).Bd is the bulk density (gm cm −3 ).D is the soil depth in (m).A is the area of the plot (m 2 ).

Water Application Efficiency
The water application efficiency was calculated according to [39,40], using the following equation

Crop Coefficient
The Kc was calculated according to [22].

Crop Water Productivity (WP)
The WP was calculated as the ratio between the grain yield and the total volume of water applied [41] and expressed as (kg m −3 ).

Statistical Analysis
Data obtained were analyzed using the statistical package [42].Mean values were compared to each other using the Least Significant Differences (LSD) at the probability level of 0.05.

Irrigation Requirement (Applied Water, m 3 /Ha)
The irrigation requirements as affected by irrigation scheduling, planting method and the foliar application of potassium silicate in the two seasons are presented in

WP = grain yield Seasonal ETc
Regarding the effect of planting methods on irrigation requirements, the results revealed that raised beds planting method saved on the applied irrigation water under 1.0 and 1.2 accumulated pan evaporation by 46.8 and 45.12% in 2017 and by 45.12 and 44.88% in 2018, respectively as compared to its values under ridge planting method in Table 5.Thus, raised beds planting method saved approximately 45.8% of applied water averaged over the two studied seasons, as compared to the ridge planting method.

Maize Evapotranspiration (ET crop; m 3 )
The seasonal evapotranspiration (m 3 ) as affected by irrigation scheduling, planting method and potassium silicate foliar application in the two seasons are presented in Table 6.
The actual consumptive water use (ET c ) for maize in 2017 and 2018 was higher under irrigation with 1.2 pan evaporation coefficient (Figs. 2 and 3 and Table 6).
The daily ETc gradually raised to reach the peak after 50 to 80 days after planting, thereafter, declined until the end of the season (Figs. 2 and 3).The application of potassium silicates slightly effected the periodical and ETc reduction.However, clear variances attributed to differences in soil moisture availability in I2-ridge planting method and climate parameters in 2018.The daily ETc obtained during 2017 and 2018 at different stages of plant growth stages (initial, development, mid and late) and under the best treatments; I2 irrigation treatment, 100 ppm Potassium silicate and raised bed planting method were (3.1, 5.9, 6.4 and 2.6) and (3.2, 6.2, 7.0 and 3.0) while it has increased (3.8, 5.9, 6.7 and 3.5) and (4.0, 6.5, 7.3 and 3.9) under ridge planting method in 2017 and 2018, respectively.On the other hand, potassium silicates played a thermal buffering role.The relationship between Potassium silicate and ET reduction percentage reflects a strong linear relationship in Fig. 4. The maximum reduction percentages (3.30 and 2.10%) have been found with 2018 under bed and ridge respectively, where the average temperature degree reached 33.0 o , while the minimum values (1.10 and 0.90%) have been found with 2017 under bed and ridge respectively, where the average temperature degree reached to 30.85 o .These results highlight the promoting and buffering effect of spraying Potassium silicate to control the harmful impact of climate parameters variability.

Water Application Efficiency WAE (%)
WAE (%) was calculated from the amount of water applied and water stored in the root zone (Tables 5 and 6).The experiment has been implemented under a hybrid surface irrigation system where the water passes through a closed pipe or small network from water source to the experimental unit, in order to maximize the conveyance efficiency.The raised beds planting method recorded a higher WAE value (75.4%) than the ridge planting method (69.9%), as an average over the two studied seasons.

Maize Crop Coefficient (Kc)
Crop coefficient (K c ) values were calculated as ratios of measured maize ET C to that of ET o estimated at different stages of plant growth.The average values of maize K c under Fig. 2 Periodical ETcrop (mm) under bed planting method at the two studied seasons the irrigation scheduling treatments (I1 and I2) in the two studied seasons are presented in Figs. 5 and 6.
The Kc values varied from one growth stage to another in both growing seasons.These values were low at the initial stage because the plant vegetation growth was not established, and the loss of moisture is mostly by evaporation from the soil surface.As the plant developed, a gradual increase was observed in the crop coefficient.The crop coefficient reaches its peaks in the mid-season growth stage.
Then, the crop coefficient decreased during the late season of plants.
Results revealed that crop coefficient (Kc) values obtained during 2017 and 2018 at different stages of plant growth stages (initial.,development, mid and late) and under the best treatments; I2 irrigation treatment, 100 ppm K-Si and raised bed planting method were (0.47, 0.91, 1.15 and 0.60) and (0.47, 0.92, 1.17 and 0.63).While, under the same circumstances, but replacing ridge by raised beds planting

Crop Water Productivity (CWP)
CWP is evaluated in terms of the ratio of dry matter yield to seasonal evapotranspiration (kg/m 3 ) as affected by irrigation scheduling at (1.0 and 1.2) values of accumulated pan evaporation, planting method (raised bed and ridge) and different potassium silicates fertilization levels (0 and 100 ppm) in the two studied seasons are presented in and Table 7.
Concerning irrigation treatments, the results indicated a significant effect between the different irrigation treatments.Therefore, irrigation according to 1.2 accumulated pan evaporation gave the highest mean WP values (1.55 and1.35), while the lowest mean values (1.08 and 0.89) were obtained from irrigation 1.0 accumulated pan evaporation in the two studied seasons, respectively.The values of CWP of I2 method increased significantly by 11.9% in the 2017 season, and by 15.3% in the second season, compared to the irrigation according to the I1accumulated pan evaporation.
Regarding planting methods, it has a significant effect on this property; the highest mean value (1.37) was obtained from planting raised bed in 1st season while the lowest mean value (1.04) was obtained from planting a ridge in the 2nd season.Results indicated that the raised bed planting method produced WP (28.5%) in 1st season and (30.7%) in the 2nd season compared to the ridge planting method.Concerning the effect of different foliar application of potassium silicates on maize, results indicated that K-Si application enhanced crop water productivity, the highest mean values (1.35) was obtained from 100 ppm K-Si application in the 1st season, while the lowest mean values (1.05) was obtained from zero K-Si application in the 2nd season.The use of 100 ppm K-Si led to a significant increase in this characteristic by 8.5% in the 2011 season, and by 13.3% in the second season, as compared to zero K-Si application.

Economic Evaluation
Enterprise cost and net return (L.E./ha.) of maize as affected by irrigation scheduling at (1.0 and 1.2) values of accumulated pan evaporation), planting method (raised bed and ridge) and different potassium silicates foliar application levels (0 and 100 ppm) in the two studied seasons (summer 2017 and summer 2018) are presented in and Tables 8 and 9.As it is cleared in Table 8, the ridge planting method under I2 recorded the highest seasonal cost of maize per hectar (13,605 L.E./ha.), while the Fig. 5 Maize Kc values for I1 and I2 over maize growth stages for the two studied seasons under raised bed planting method lowest seasonal cost (12,690 L.E./ha.) has been recorded by raised bed planting method and I1 irrigation treatment.As for the net return of maize per feddan (L.E./ha.), all experimental factors have a significant effect on this property.Concerning irrigation treatments, the data indicated a significant effect between the different irrigation treatments.Therefore, irrigation according to 1.2 gave the highest mean net return values (8775 and 7479 L.E./ha.), while the lowest mean values (6243 and 4806 L.E./ha.)obtained from irrigation 1.0 of accumulated pan evaporation in the two studied seasons, respectively.The values of net return of irrigation according to the I2 method increased significantly by 40.6% in the 2017 season, and by 55.6% in the second season compared to the irrigation according to the I1 method, respectively.
Regarding planting methods, it has a significant effect on this property, the highest mean values (21,751.2 and 8818.4L.E./ha.) were obtained from planting raised bed while the lowest mean values (14,289.6 and 10,665.6L.E./ha.) were obtained from planting ridge in both seasons respectively.
Results indicated that the raised bed planting method increased the net return by (52.2%) in 1st season and (76.5%) in the 2nd season compared to the ridge planting method.
Furthermore, the Potassium silicate application enhanced the net return of maize per feddan (L.E./ha.), the highest mean value (18,787.2L.E./ha.) was obtained from 100 ppm Potassium silicate application at the 1st season, while the lowest mean value (13,478.4L.E./fed.) was obtained from zero Potassium silicate application at the 2nd season.
The use of 100 ppm Potassium silicate led to a significant increase in this characteristic by 8.9% in the 2011 season, and by 18.7% in the second season, as compared to zero Potassium silicate application.

Discussion
In the last five decades, the arid region of Egypt has experienced a significant expansion of its arable area due to the continuous exploitation and extension of oases towards the deserts.Nonetheless, this has also resulted in a deterioration of the environment due to the scarcity of water resources and the overexploitation of groundwater.The agricultural use of water has further worsened ecological conditions.The transformation of deserts into irrigated farmlands has led to a high dependence on chemical fertilizers and extensive flooding irrigation to compensate for the low fertility and sandy texture of the soil, which has resulted in poor efficiency of water and fertilizer use.Hence, it is essential to develop irrigation and fertilization techniques that are more efficient and to find ways Fig. 6 Maize Kc values for I1 and I2 over maize growth stages for the two studied seasons under ridge planting method to increase soil fertility, as well as to improve the use of water and fertilizers for sustainable management of newly cultivated oases.
In the current study, there were differences in weather between the two seasons mentioned in Table 1, which in turn had an impact on water requirements for crops or plants.Specifically, the second season (2018) was hotter than the first season (2017) and required more applied water.This makes sense, as higher temperatures can increase the rate of evapotranspiration (the combined processes of water evaporation from soil and plant surfaces, and water transpiration from plant leaves), leading to greater water loss from the soil and plants [5].In order to compensate for this increased water loss and maintain healthy growth, crops or plants may require additional water to be applied.It's important to note that other factors beyond temperature can also influence water requirements, such as humidity, wind, and precipitation [22].However, based on the information given, it seems likely that the temperature difference between the two seasons played a significant role in the observed difference in water requirements [43].
The argument suggests that there was a relationship between irrigation and seasonal irrigation requirements, with the highest requirement observed at an irrigation coefficient of 1.2 and the lowest at an irrigation coefficient of 1.0, as measured by accumulated pan evaporation.This indicates that as the available soil moisture decreased in the root zone, the amount of water required for irrigation also decreased.In other words, when less water was applied, plants were able to make more efficient use of the available soil moisture [44,45].Also highlights the importance of irrigation in Egypt, with approximately 100% of the country's old lands being irrigated and contributing to more than 80% of the total cultivated area in Egypt.This underscores the critical role that irrigation plays in supporting agriculture and food production in the country.
Given the arid and semi-arid climate of much of Egypt, irrigation is necessary to provide the water needed to support crop growth and maintain agricultural productivity [17,46].Unfortunately, the majority of these areas are traditional irrigated systems with 50% Irrigation application efficiency [47].Consequently, there is an urgent need to increase water-saving, water use efficiency and water productivity in agriculture.
The study results indicated that these management practices were effective in achieving several desirable outcomes.These included water savings, increased water application efficiency, improved water productivity, and higher net returns of maize per feddan (an Egyptian unit of land area).Water-saving practices, such as deficit irrigation scheduling, can be important in regions where water resources are limited or in areas where water is expensive or difficult to obtain.The raised bed planting method is often used in areas with poor drainage, as it can help improve soil aeration and water drainage.The raised beds planting method had a higher WAE value (75.4%) compared to the ridge planting method (69.9%) on average over two seasons.While ridge planting led to increased soil moisture, it was crucial for maize to access deep soil water to avoid drought [48].Planting pattern significantly impacted root growth at shallow soil levels, with positive correlations between soil water conditions and root growth [49] .Raised beds improved root growth at different soil levels, leading to enhanced water absorption by maize [50].Higher soil water storage during maize growth from vegetative to reproductive stages promoted root activity, plant transpiration, and avoided drought stress, leading to improved photosynthesis and dry matter accumulation [51].Ridge planting significantly increased WUEGY and WUEDM, indicating that it improved both soil water use and crop productivity [52].As a result, RT had a notable impact on dry matter accumulation after V12.The study suggests that the combination of deficit irrigation scheduling, raised bed planting, and the application of potassium silicates can be an effective strategy for improving maize production while conserving water resources and maximizing economic returns.Potassium silicates can be used as a fertilizer to help improve crop growth and yield, particularly in soils that are low in potassium [12] .The application of K-silicate externally has been shown to have a positive impact on plant growth, root length, and architecture.This can mitigate the harmful effects of salinity in the rhizosphere of maize by increasing microbial biomass, ultimately leading to the synthesis of soil enzymes [53].In addition, K-silicate can stimulate the availability of soil nutrients like N, which has a direct positive relationship with the activities of soil enzymes [54].Maize is an important staple C4 food crop, appears a positive correlation or link between assimilation processes and WP [55].So, increasing available water has a direct effect on maize yield increasing (Fig. 7).These results are on par with those of Jin et al., [56] who found that under full irrigation summer maize yield increased significantly and also WP improved.In the same trend, the net return of maize (L.E./ ha.) increased.Besides, the cost of irrigation and some agromanagement practices like weeding and hoeing for the traditional method was higher compared to the raised method.Which are in agreed with that mentioned by [57][58][59][60].On other hand, raised bed planting method has a clear role in increasing yield (Fig. 7) and water productivity at the same time (Table 7), these results are in harmony with those of [61,62].It is the most efficient traditional surface irrigation method [63] .Reduces the number of irrigated ditches and consequently reduces the moisture zone [64].Maximizes plant productivity by producing higher root length density and root mass density [65,66] .The highest effect of Potassium silicates on WP comes from its effect on maize yield increasing (Fig. 7) these results are in accordance with [31,67].As for the relationship between potassium silicates application, ET and climate variability, Hasanuzzaman et al. [12] cleared that Potassium stimulates root and vegetative growth and controls stomata movement and water status.While Meena et al. [68] and Guntzer et al., [69] reported that Si forms a double silica layer which reduces the diameter of stomatal pores, decreases stomata opening, reduces leaf transpiration and limits water losses without affecting plant growth.Si helps to keep the plant cell membrane integrity and stability against biotic or abiotic stress [70,71] and reduces stress as a resistance elicitor in biochemical processes, [72].Which explains why potassium silicates plays a thermal buffering role.

Conclusion
The recent research suggests that to obtain the best maize water productivity in the Luxor Governorate of Upper Egypt, a combination of management techniques would be necessary.The techniques recommended by the study comprise of irrigating according to an accumulated pan evaporation coefficient of 1.2, implementing a deficit irrigation of 0.15%, utilizing raised bed planting, and applying potassium silicates through foliar application.Collectively, the study exhibited that by adopting these practices, it was feasible to achieve excellent water productivity while simultaneously conserving water resources and maximizing economic returns.The study's results are especially significant in areas such as Upper Egypt, where water resources are restricted, and agriculture is a crucial economic sector.The study proposes that these management practices could be implemented by farmers in the region to enhance maize production and encourage sustainable agriculture, despite water scarcity and other environmental challenges.

Fig. 3 Fig. 4
Fig. 3 Periodical ETcrop (mm) under ridge planting method at the two studied seasons

Table 2
Soil physical properties of the experimental site

Table 3
Some soil chemical properties of the experimental site

Table 4 The
Wstored in root zone (mm) volume of water applied (mm) × 100

Table 5
3/ha . in 2018 under the same respective irrigation treatment.While under 1.2 accumulated pan evaporation, the values were 7394.4,and 8786.4 m 3 /ha.in 2017 and 7394.4 and 8786.4 m 3 /ha.in the second season, respectively.

Table 5
Irrigation requirements (m 3 /ha.)as affected by irrigation scheduling, planting method and Potassium silicate application in the two studied seasons

Table 6
Seasonal ET (m 3 ) and application efficiency as affected by irrigation scheduling, planting method and foliar application by Potassium silicate in the two studied seasons

Table 7
Water productivity (Kg/m 3 ) as affected by irrigation scheduling, planting method and potassium silicates application in the two studied seasons NS, *, ** indicate not significant, significant at 5% (p ≤ 0.05) and significant at 0.1% (p ≤ 0.001) probability level, respectively.Different lowercase letters indicate statistically significant differences between treatments (p ≤ 0.05), as performed by the least significant difference (Fisher's LSD) test

Table 9
Net return of maize per feddan (L.E./ha.)under different irrigation scheduling, planting method and Potassium silicate applications in the two studied seasons NS, *, ** indicate not significant, significant at 5% (p ≤ 0.05) and significant at 0.1% (p ≤ 0.001) probability level, respectively.Different lowercase letters indicate statistically significant differences between treatments (p ≤ 0.05), as performed by the least significant difference (Fisher's LSD) test