Effect of Irrigation Schedule and Organic Fertilizer on Wheat Yield, Nutrient Uptake, and Soil Moisture in Northwest India

Abstract

Indiscriminate and injudicious application of inorganic fertilizers and irrigation, respectively, cause declines in crop productivity as well as environmental pollution. Therefore, judicious use of organic manures and proper scheduling of irrigation are required for sustainable production of wheat crops. A two-year (2014–2015 and 2015–2016) study was conducted to determine the wheat nutrient uptake, soil moisture, and grain yield as a result of organic manures and irrigation schedule. The experiment was set up with four treatments of organic manure in four subplots with repellents and five irrigation planning treatments in the main plot. The results showed that an irrigation/water ratio of 0.9 irrigation water depth/cumulative pan evaporation (I₂) increased grain yield, soil moisture content, and nutrient uptake of wheat (I₃) compared to 0.6 IW/CPE during the vegetative period and 0.8 IW/CPE during the reproductive period. According to statistics, it was found that the vegetative period is maintained at 0.8 IW/CPE, and the reproductive period is maintained at 1.0 IW/CPE (I₅). Applying 7.5 Mg ha⁻¹ of farmyard manure (FYM) plus 3 Mg ha⁻¹ of vermicompost while employing organic manure increases grain output, soil moisture content, and nutrient content and absorption compared to the control treatment. Therefore, it is concluded that irrigation either at I₂ or I₅ + FYM at 7.5 Mg ha⁻¹ + vermicompost at 3 Mg ha⁻¹ could be recommended for enhancing grain of wheat cultivation, particularly in the semiarid regions of northwestern India.

1. Introduction

The main food crop in the world is wheat [1]. It is grown in a wide range of climate and soil conditions. It is India’s second-largest produced food crop after rice. It is a very healthy diet consisting of approximately 78% carbohydrates, 12% protein, 2% fat, minerals, and many vitamins [2]. India holds the noteworthy distinction of being the second-largest contributor to global wheat acreage and production. Due to limited available space, the country faces a challenging predicament when it comes to expanding its wheat cultivation area. As a result of this constraint on acreage growth and stagnant or declining production levels, wheat farming in India is facing serious challenges. Suboptimal crop management practices, imbalanced fertilization techniques, inadequate nutrition extraction methods, and water limitations directly affect wheat production [3]. Likewise, natural rainfall cannot meet crop water needs and irrigation is needed to support crop yields [4]. Therefore, judicious use of irrigation and plant nutrients could prove to be crucial inputs for improving wheat productivity [5].

To ensure crop yield, irrigation is a priceless and scarce input that is essential to ensure turgidity, nutrient absorption, and plant metabolism. Therefore, irrigation planning is a crucial part of water management, ensuring the right amount and timing of water application [6]. Many approaches have been developed for irrigation scheduling under different crops. These approaches are based on soil water regime, plant indices, and climatological parameters. Many researchers have reported that IW/CPE ratio (climatological approach) was found to be better in terms of enhancing crop productivity and saving water [7,8,9]. In general, irrigation is being scheduled on the basis of the climatological approach (IW/CPE ratio) during the entire period of crop, irrespective of the stage of growth, but proper scheduling of irrigation is necessary in both vegetative and reproductive phases to maintain the optimum moisture regime for better growth and development of crop in the changing climatic scenario where abrupt variation in temperature takes place. The irrigation water/cumulative pan evaporation (IW/CPE) approach synchronizes supply and demand for water, which ultimately leads to excellent crop growth and increased grain output [10].

Nutrient management also plays an integral role in agriculture production. India has incorporated the unbalanced and indiscriminate use of chemical fertilizers into its agricultural practices to satisfy the varied food demands of a growing population and to realize a desire to extract larger returns from agricultural land. Yet, overuse of chemical fertilizers has reduced crop yields, reduced soil fertility, increased greenhouse gas emissions, and decreased groundwater pollution. Additionally, an excessive reliance on chemical fertilizer-based nutrient management led to nutrient depletion, nutrient mining, and low nutrient use efficiency, especially nitrogen (30–40%) and phosphorus (10–20%), which has become a limiting factor in raising food productivity and sustainability [11]. Hence, applying nutrients from organic sources has a greater potential to increase agricultural output, improve soil health, and reduce environmental pollution. By adding nutrients from organic sources such as farmyard manure (FYM) and vermicompost, grain yield, soil physical, chemical, and biological qualities have reportedly increased [12].

Irrigation planning and nutrient management in wheat production have been extensively researched, but few studies have examined the combined effects of organic nutrition management and IW/CPE irrigation scheduling. The specific outcomes of integrating organic nutrition management with IW/CPE irrigation scheduling remain relatively unexplored despite positive results when implemented separately. Further research is needed to better understand the potential synergies and benefits that may result from combining these practices in wheat farming. Studying this area comprehensively will provide valuable insight into enhancing sustainable agricultural practices and optimizing wheat production. This study suggests that improving wheat yield and nutrient uptake requires careful timing of irrigation planning and organic manures. The goal of the study is to determine how wheat is impacted by organic products and irrigation schedules.

2. Materials and Methods

2.1. Description of Study

The two-year experiment was carried out in the Instructional Unit, SKN Agricultural University, Jobner, during the rabi seasons of 2014–2015 and 2015–2016. At 26.05° N latitude and 75.28° E longitude, 45 km west of Jaipur, and 427 m above mean sea level is where the experiment was conducted. This area is located in the Rajasthan agroclimatic zone III-A. According to the information given, the area has a semiarid climate, which indicates that it is typically dry and receives 350 to 450 mm of total annual precipitation. The rainiest months are July through September. Temperatures in the region can vary widely, reaching high temperatures in summer and dipping below freezing in winter. The soil in this region is loamy sand in texture, which means it has a mixture of sand, silt, and clay. The soil is also alkaline in reaction, which means it has a pH above 7.0. It has a medium quantity of potassium but is poor in organic carbon and has little accessible nitrogen and phosphorus according to critical limit of soil.

2.2. Treatments and Design of Experiment

The irrigation scheduling variable had five treatments, while the organic manure variable had four levels. A random number table, a device used to produce a random sequence of numbers, was used to randomly allocate these treatments to various plots [13]. The experiment had a total of 20 treatment combinations, which were replicated four times. This means that there was a total of 80 plots used in the experiment.

Table 1. Presentation of the experimental design.

Treatments	Symbol
A. Irrigation Scheduling
1. Irrigation at critical stages	I1
2. 0.9 IW/CPE ratio	I2
3. 0.6 IW/CPE ratio at vegetative + 0.8 IW/CPE ratio at reproductive phase	I3
4. 0.6 IW/CPE ratio at vegetative + 1.0 IW/CPE ratio at reproductive phase	I4
5. 0.8 IW/CPE ratio at vegetative + 1.0 IW/CPE ratio at reproductive phase	I5
B. Organic Manures
1. Control	M0
2. FYM at 15 Mg ha−1 *	M1
3. Vermicompost at 6 Mg ha−1 *	M2
4. FYM at 7.5 Mg ha−1 * + vermicompost at 3 Mg ha−1 *	M3

* Mg ha⁻¹ = 1 t ha⁻¹ (1 t = 1000 kg; 1 kg = 1000 g; therefore, 1 Mg = 10⁶ g).

lists the therapies along with the accompanying symbols. Generally, irrigation is applied at a 0.9 IW/CPE ratio throughout the crop period irrespective of growth stage. This treatment may be considered a control base treatment to compare against other treatments (schedules of irrigation), whereas irrigation was applied at different ratio and growth stages to estimate savings of irrigation. Common doses of fertilizers were applied as per recommended, but for control treatment (M₀), no manure was applied. Diammonium phosphate (DAP) was used to apply the necessary dosages of nitrogen, 90 kg/ha, and phosphorus, 30 kg/ha, respectively. When planting, we applied a sufficient amount of phosphorus and half the amount of nitrogen as base fertilizer and covered twice the amount of remaining nitrogen. Farmyard manure (FYM) and vermicompost were provided by the College’s farm and vermicomposting units, respectively. Vermicompost was added before sowing, and FYM was placed on the appropriate beds in accordance with the treatment two weeks prior to planting. The FYM was thoroughly absorbed into the soil. The N content of each manure source was used to determine the dosages of organic sources. Following routine irrigation to a depth of 45 mm, irrigation treatments were implemented. Details of the total number of irrigations performed during the first and second years of the experiment, the amount of water used, and the date of each irrigation performed for the different treatments were allotted. Daily pan evaporation values from a USWB Class A open pan evaporimeter were used to calculate cumulative pan evaporation (CPE) using standard procedure prescribed for the instrument. Near the experiment plot, the evaporimeter was installed in a meteorological observatory. Using a Parshall flume with a 7.5 cm wide throat, the amount of irrigation water used for irrigation was calculated. A fixed water depth of 45 mm was used for each irrigation treatment, based on the IW/CPE ratio. The ratios used were 0.6, 0.8, 0.9, and 1.0, and the corresponding CPE values were 75 mm, 56.25 mm, 50 mm, and 45 mm, respectively. This means that when the CPE values approached these levels, the irrigation treatments were given with the corresponding amounts of water based on the IW/CPE ratios.

2.3. Crop Management

Raj-4037, a wheat variety with early maturation and resistance to stem rust disease, was chosen for the experiment. Seeds were seeded on November 2015 for both years at 100 kg/ha, at a depth of 5 cm and with 22.5 cm between rows. The crop was shielded from disease and insect pests through the application of plant protection techniques. Seeds were treated with Bavistin at dosages of 2.5 g/kg seed seeds before sowing to protect them from soil and seed-borne diseases. In order to defend against termite infestations, the crop was also treated with Chlorpyriphos at a rate of l/ha. Plants from the boundary rows were taken out of the field during harvest and the net plots were collected separately. The harvested crop was wrapped and weighed to calculate the grain and straw yields, which were indicated in Mg ha⁻¹ after being sun-dried for 4–5 days. Crop threshing was accomplished with the AL-MACO Pullman Thresher. The yield was measured in Mg ha⁻¹ after the grains had been washed and weighed. By deducting the seed weight from seeds plus straw, straw weight was estimated and expressed in Mg ha⁻¹.

2.4. Soil Moisture Sampling and Studies

Soil moisture studies were conducted throughout the entire duration of the wheat crop, from sowing to maturity. For all treatments, the soil moisture was measured twice: right before irrigation and 24 h later. When soil moisture was at field capacity (1/3 bar) using pressure plate apparatus, four distinct soil depths were used for the measurements: 0–15, 15–30, 30–45, and 45–60 cm, respectively. For the purpose of studying soil moisture, soil samples were taken. In each treatment’s net plot area, soil samples were taken all around a fixed site that was chosen at random. In order to avoid moisture loss, the soil sample was then immediately moved to aluminum soil moisture boxes and covered. As soon as possible, the soil sample moisture boxes were taken to the lab for weighing and drying. Soil samples collected in boxes were quickly weighed and then placed in a heated, temperature-controlled oven. The samples were dried at 105 °C for 8–10 h while maintaining their weight and the moisture percentage was calculated using the following formula [14]:

$$\mathrm{Moisture} \mathrm{percentage} (\mathrm{oven} \mathrm{dry} \mathrm{weight} \mathrm{basis}) =\frac{{\mathsf{W}}_1-{\mathsf{W}}_2}{{\mathsf{W}}_2}\times 100$$

where

• W₁ = Weight of moist sample (in grams);
• W₂ = Weight of dried sample (in grams).

2.5. Moisture Depletion

The area of soil where plant roots are actively growing and absorbing moisture is known as the root zone, which was divided into four levels according to depth, namely, 0–15, 15–30, 30–45, and 45–60 cm. The soil moisture depletion was assessed using these layers. The quantity of moisture that was removed from each layer for a short period of time (such as a day or a week) was calculated and the short-term depletion values for each layer were added up over the course of the full growing season until crop maturity.

2.6. Plant Sampling and Nutrient Uptake

Plant samples were taken at harvest and baked in an oven at 70 °C for 24 h. Air-dried grain samples and dried plant samples were ground to pass through a 40-mesh sieve. Seed and straw samples of 0.5 g were taken from each treatment for nutritional analysis. Measurement of nitrogen in plant samples was carried out using the colorimetric technique (Nessler’s reagent) [15]. By employing the Vanadomolybdophosphoric yellow color method, P in plant materials was measured using a method for determining the phosphorus content of a sample by measuring the absorbance of a yellow-colored complex formed by reacting phosphate ions with a mixture of vanadate and molybdate ions. The absorbance is proportional to the amount of phosphorus in the sample. This method is commonly used for soil and plant analyses [16]. A flame photometer is an analytical instrument used to determine the concentration of certain elements including potassium by measuring the intensity of light emitted by the element when it is vaporized in a flame. The concentration of the element in the sample immediately correlates with the intensity of the light that is emitted. In this case, the potassium content in the plant samples was measured directly using a flame photometer. To determine the total nutrient uptake, the nutrient concentrations in the plant samples were multiplied by the corresponding yield for each component (grain and straw). The nutrient uptake of each component was then summed to obtain the total nutrient uptake of the plant.

2.7. Statistical Investigation

Statistical analysis of the results was performed using the F-test. The F-test with a 5% probability level was used to compare significant differences between treatments [17]. Comparisons were made using SEm⁺ and CD standard abbreviations in statistical analysis. Pooled analysis of the data was performed following the standard norms of the ANOVA. Pearson correlation analysis and principal component analysis (PCA) were accomplished using R software (R version 3.5.1, Jaipur, India) to depict the correlations among the various parameters and their relationships with the different treatments.

3. Results

3.1. Yield of Grains and Moisture Content

Due to different irrigation scheduling techniques, wheat grain production has greatly risen (

Table 2. Influence of irrigation schedule and organic manures on grain production and moisture content both prior to irrigation and at 1/3 bar moisture content.

Treatments	Grain Yield (Mg ha−1)	Moisture Prior to Irrigation (%)	At 1/3 Bar Moisture Content (%)
Irrigation Scheduling
I1	4.24 bc	5.60 ab	15.83 ab
I2	4.45 a	6.06 a	17.07 a
I3	3.78 d	4.77 d	14.14 d
I4	4.14 b	5.21 c	15.00 c
I5	4.37 a	5.78 a	16.43 a
SEm±	0.071	0.110	0.241
CD (p = 0.05)	0.203	0.322	0.714
Organic Manures
M0	3.48 c	3.91 c	13.54 c
M1	4.29 ab	6.01 a	16.34 a
M2	4.43 a	5.90 ab	16.14 ab
M3	4.57 a	6.11 a	16.76 a
SEm±	0.060	0.072	0.154
CD (p = 0.05)	0.181	0.191	0.423

The values followed by the different lowercase letters in the table are significant according to Ducans multiple range test at p = 0.05.

and Figure 1). In comparison to other irrigation schedule treatments, wheat grain production was higher when irrigation was provided in treatment I₂. Treatment I₂ enhanced grain yield by 17.7% in comparison to I₃. The treatment of I₂, remained unchanged statistically (I₅). The grain yield for treatment I₃ was noticeably lowest, with corresponding values of 3.78 Mg ha⁻¹. When FYM and vermicompost were added at 7.5 Mg ha⁻¹ and 3 Mg ha⁻¹, respectively, when using organic manures, grain yield increased by 31% in comparison to the control.

Compared to treatments I₃, I₄, and I₁, treatment I₂ reported significantly higher moisture content irrigation and 1/3 bar. Treatment M₃ outperformed M₀, while they were still on par with M₁ in terms of the maximum preirrigation moisture content estimate and 1/3 bar (Table 2).

3.2. Amount of NPK in Grain and Straw Yield

The irrigation system had no effect on the nitrogen, phosphorus, and potassium contents in grain and straw. However, the I₂ treatment recorded the highest NPK content in grain (0.367 and 0.484%) and straw (0.497, 0.126, and 1.694%) except for N content in grain. The results showed that the treatment with the highest concentration of N, P, and K in grain and straw was M₃. Nevertheless, M₃ was superior to M₀ in all respects except grain nitrogen content and straw potassium concentration (

Table 3. Influence of irrigation schedules and organic fertilizers on the nutrients’ levels in grain and straw.

Treatments	Amount of Nutrients in Grain (%)			Amount of Nutrients in Straw (%)
	N	P2O5	K2O	N	P2O5	K2O
Irrigation Scheduling
I1	1.65	0.342	0.464	0.473	0.118	1.546
I2	1.64	0.367	0.484	0.497	0.126	1.694
I3	1.69	0.318	0.437	0.463	0.117	1.499
I4	1.66	0.325	0.452	0.461	0.121	1.571
I5	1.66	0.340	0.455	0.481	0.123	1.613
SEm±	0.04	0.009	0.008	0.009	0.003	0.051
CD (p = 0.05)	NS	NS	NS	NS	NS	NS
Organic Manures
M0	1.40 d	0.288 c	0.427 d	0.429 d	0.111 c	1.354 d
M1	1.67 bc	0.339 ab	0.455 c	0.475 c	0.122 ab	1.550 c
M2	1.73 b	0.357 a	0.467 b	0.492 b	0.124 a	1.660 b
M3	1.83 a	0.370 a	0.482 a	0.503 a	0.126 a	1.774 a
SEm±	0.03	0.007	0.006	0.008	0.001	0.038
CD (p = 0.05)	0.09	0.021	0.018	0.022	0.003	0.107

NS = nonsignificant. The values followed by the different lowercase letters in the table are significant according to Ducans multiple range test at p = 0.05.

).

3.3. Intake of NPK in Grains and Straw

The consumption of NPK (nitrogen, phosphorus, and potassium) in both grain and straw is influenced by the combination of irrigation techniques and the application of organic fertilizers. In particular, treatment I₂, which was equivalent to I₅, exhibited significant improvements compared to treatments I₁, I₃, and I₄ in terms of N, P, and K absorption in both grain and straw. Furthermore, when compared to the control group, the application of organic fertilizers had a significant impact on the uptake of N, P, and K in both grain and straw. In terms of irrigation, the M₃ treatment resulted in significantly higher NPK absorption in both grain and straw compared to the M₀ and M₁ treatments, while the M₂ treatment showed similar results. Notably, treatment M₃, which displayed the highest nitrogen uptake in grain, outperformed the other treatments in terms of overall performance (

Table 4. Influence of irrigation schedules and organic fertilizers on nutrient intake from grain and straw.

Treatments	Nutrients Uptake by Grain (kg/ha)			Nutrients Uptake by Straw (kg/ha)
	N	P	K	N	P	K
Irrigation Scheduling
I1	70.01 ab	14.54 ab	19.71 ab	28.70 ab	7.15 bc	93.77 ab
I2	74.41 a	16.35 a	21.61 a	31.49 a	7.98 a	107.50 a
I3	64.10 d	12.02 d	16.53 d	26.70 d	6.74 d	83.48 c
I4	69.03 c	13.46 bc	18.74 abc	27.91 bc	7.31 ab	95.12 ab
I5	72.53 a	15.14 a	19.91 a	30.06 a	7.68 a	100.81 a
SEm±	1.38	0.44	0.56	0.66	0.15	3.40
CD (p = 0.05)	4.04	1.34	1.72	1.99	0.44	10.23
Organic Manures
M0	48.87 d	10.06 c	14.92 c	22.01 c	5.68 c	69.46 c
M1	71.91 c	14.60 ab	19.68 ab	29.79 ab	7.64 ab	97.27 ab
M2	76.79 b	15.86 a	20.82 a	31.63 a	7.96 a	106.74 a
M3	84.04 a	16.89 a	22.01 a	33.01 a	8.25 a	116.29 a
SEm±	1.12	0.42	0.52	0.62	0.12	3.24
CD (p = 0.05)	3.14	1.26	1.58	1.88	0.38	9.76

The values followed by the different lowercase letters in the table are significant according to Ducans multiple range test at p = 0.05.

and Figure 2 and Figure 3).

3.4. Utilization of All NPK by Grain and Straw

Treatment I₂ performed on par with I₅ and much better than the other treatments, with equivalent values of 105.86, 24.34, and 129.11 kg/ha for total nitrogen, phosphorus, and potassium uptake. Total uptake of N, P, and K was significantly lower in treatment I₃ (89.90, 18.77, and 100.01 kg/ha, respectively). The experiment’s organic manures had an impact on how much total nitrogen, phosphorus, and potassium were absorbed, according to data analysis (

Table 5. Influence of irrigation schedules and organic fertilizers on total nutrient uptake through grain and straw.

Treatments	Total Nutrients Uptake in Seed and Straw (kg/ha)
	N	P	K
Irrigation Scheduling
I1	98.71 ab	21.69 ab	114.48 ab
I2	105.86 a	24.34 a	129.11 a
I3	89.90 d	18.77 d	100.01 c
I4	96.84 bc	20.78 bc	112.86 ab
I5	103.64 a	22.83 a	120.72 a
Sem±	2.17	0.57	3.36
CD (p = 0.05)	6.54	1.73	10.12
Organic Manures
M0	70.88 c	15.75 c	82.38 c
M1	102.70 b	22.25 ab	118.95 ab
M2	110.62 a	23.83 a	128.56 a
M3	114.85 a	25.15 a	137.03 a
Sem±	1.48	0.52	3.28
CD (p = 0.05)	4.49	1.59	9.87

The values followed by the different lowercase letters in the table are significant according to Ducans multiple range test at p = 0.05.

and Figure 4). Treatment M₃, which outperformed all other treatments while remaining on par with M₂ (vermicompost at 6 Mg ha⁻¹, outperformed all other treatments while measuring at significantly higher levels (114.85, 25.15, and 137.03 kg/ha) of total nitrogen, phosphorus, and potassium uptake. The values with the obviously lowest total NPK uptake under M₀ were 70.88, 15.75, and 82.38 kg/ha.

3.5. Soil Moisture Depletion Pattern

Data analysis revealed that the 0–15 cm depth was where the majority of moisture was removed for all irrigation schedule treatments, followed by the 15–30 cm depth. As irrigation water increases, more water is extracted from the soil surface (0–15 cm), but less water is extracted from deeper soil layers (

Table 6. Influence of irrigation timing and organic usages on soil moisture depletion at different depths.

Treatments	Different Soil Depth
	0–15 cm	15–30 cm	30–45 cm	45–60 cm
Irrigation Scheduling
I1	37.09 c	29.47 c	20.72 c	13.04 c
I2	37.31 a	29.59 a	20.79 a	13.12 a
I3	36.90 e	29.32 e	20.58 e	12.88 e
I4	36.97 d	29.37 d	20.66 d	12.96 d
I5	37.24 b	29.54 b	20.75 b	13.08 b
Organic Manures
M0	37.28 a	29.60 a	20.79 a	13.22 a
M1	36.73 d	29.32 d	20.61 d	12.69 d
M2	36.79 c	29.40 c	20.67 c	13.06 c
M3	37.03 b	29.51 b	20.74 b	13.09 b

The values followed by the different lowercase letters in the table are significant according to Ducans multiple range test at p = 0.05.

). According to the data analysis in the above table, the irrigation depths of M₀, 37.03, 37.03, 0–15, 15–30, 30–45, and 45–60 cm are, respectively, 37, 9%, 29.6%, 20.8%, and 13.2%. They were 29%, 51%, 20.74%, and 13.09% under M₃, 36.79%, 29.40%, 20.67%, and 13.06% under M₂, and 36.73%, 29.32%, 20.61%, and 12.69% under M₁.

4. Discussion

4.1. Yield of Grains and Moisture Content

Treatment I₂ (4.45 Mg ha⁻¹) considerably outperformed treatments I₁, I₃, and I₄ in terms of wheat grain production and it was comparable to treatment I₅, whereas treatment I₃ had the significantly lowest grain yield (3.78 Mg ha⁻¹). Treatments I₂ and I₅ demonstrated promising results in improving wheat development and yield. Tillage efficiency, increased grain yield, longer ears, and increased test weight are some of these traits. Grain yields are higher when these factors are combined. In addition, nitrogen (N), phosphorus (P), and potassium (K) are more readily available to plants when irrigation is applied more frequently. Watering increases nutrient movement through the soil profile, which increases plant dry matter accumulation. A higher irrigation level has been found to positively impact wheat production in addition to nutrient availability. In order to increase root growth and nutrient absorption, adequate irrigation reduces the soil’s mechanical strength. By providing the necessary water for metabolic activities, it also promotes increased respiration and enhances photosynthesis. Together, these findings emphasize the importance of optimizing irrigation practices and ensuring an adequate supply of nutrients, particularly N, P, and K. It is possible to improve crop development, yield traits, and grain yields through efficient irrigation and nutrient management [18]. Another factor that may have contributed to the increase in yield is irrigation scheduling, which extended the reproductive time and increased the photosynthetic surface and regenerative storage capacity to yield of grain with a higher proportion of net photosynthetics [19,20,21,22]. On the other hand, treatment I₃ recorded the noticeably lowest grain. Unsaturated soil moisture conditions may be to blame for the lowest grain yield; when the roots are under water stress, their turgor pressure causes a vapor gap to form around them. Dry matter production and nutrient absorption through the roots would be greatly reduced, if ever present, because of less contact between the roots and the water particles. The limited soil water levels create unfavorable conditions for cell division and growth, leading to reduced uptake of photosynthetically active radiation and a lower net photosynthetic rate. The lower yield attribute values observed in treatment I₃ may be attributed to this factor. The plant’s internal water status, which is linked to various physiological processes, helps explain the significant reduction in grain output when water resources are limited. According to [23], water conditions and plant cycles are related to soil water supply and its absorption capacity, highlighting that plants reduce the yield or quality of harvested crops. Due to the detrimental effect on all development and yield parameters, the grain yield may have dropped as a result. The yield obtained under I₁ and I₄ was, likewise, not similar to that obtained under I₂ or I_5, it was further revealed, even if the same amount of water was used under I₅ and during crucial stage (I₁). However, there was a difference in yield between the treatments. This may be the case because water was applied in I₂ and I₅ at the correct IW/CPE ratio during both the plant and reproductive stages to meet atmospheric evaporation needs, regardless of crop stage. In order to counteract evapotranspiration losses under I₁, the number of irrigations was provided at critical stages of cultivation without taking into account actual water needs. Because of this, despite using the same amount of water, there was a noticeable difference in the yield. The authors of [24,25,26,27] also reported similar outcomes. The largest moisture content was reported by treatment I₂, which performed on par with I₅ and much better than the other treatments, at 1/3 bar and prior to irrigation. The significantly lowest moisture content was maintained by I₃ (Table 1). The more frequent watering utilized throughout the crop’s whole growth period contributed to the treatment I₂ maximum moisture content. The crop may have been under moisture stress due to longer intervals when the lowest moisture content was estimated under I₃ [16,28]. The complex interactions between physiological and biochemical processes that alter the architecture and morphology of growing plants result in crop production. Throughout the crop growth period, wise use of the available nutrients is a fundamental requirement for the efficient operation of all physiological processes. The significantly greater grain yield was produced by treatment M₃, which outperformed the other treatments and was comparable to M₂. It is well known that adding FYM and vermicompost to soil can boost the soil’s ability to bind cations and anions, especially phosphates and nitrate, as well as the amount of micronutrients present. The crop then benefits from these nutrients as they are gradually released over the course of its full growth period. According to [29], humic acids in vermicompost increase the availability of natural and soil-added micronutrients, thereby improving production characteristics and yields [30,31,32]. The moisture content measured in M₃ (16.76%) at 1/3 bar and before irrigation (6.11%), as affected by organic manure, was substantially higher than that of M₀ and M₂, according to the results for moisture content at 1/3 bar and before irrigation (Table 1). M₃ remained at parity with M₁, however, and M₀ and M₂ were significantly lower than M₃. It should not need stating that organic manures increase soil’s ability to retain water and also serve as a barrier to lessen deep percolation and surface evaporation. Consequently, plots treated with organic manure may have had higher moisture contents than control plots [33,34].

4.2. Amount of NPK in Grain and Straw

The watering schedules had no discernible impact on the NPK content of grain or straw (Table 3). The application of organic fertilizers significantly increased the total grain and straw supply and the content of nitrogen, phosphorus, and potassium. The N, P, and K contents of grain and straw increased significantly after the application of FYM and vermicompost. The increased nutrient environment in the root zone and plant system seems to be responsible for the good effect of organic fertilizers on N, P, and K [35,36].

4.3. Intake of NPK from Grain and Straw

When the IW/CPE ratio was 0.9, the uptake of N, P, and K in grain and straw from the I₂ treatment was much higher than that of the other treatments and equal to that of the I₅ treatment. The least amount of nitrogen, phosphorus, and potassium was absorbed when I₃ was used. It is assumed that nutrient uptake is influenced by yield and the amount of grain and straw present [25,27]. The application of organic fertilizers significantly increased the content and uptake of nitrogen, phosphorus, and potassium in grain and straw. Nitrogen, phosphorus, and potassium content in grain and straw increased significantly after the application of FYM and vermicompost. The increased uptake and accumulation of nutrients in the vegetative fraction is thought to result from higher yields, improved cellular metabolic processes, and the availability of these nutrients in the root zone. Due to possible increased metabolism, nitrogen, phosphorus, and potassium moved from crop’s vegetative sections more quickly than before and into the reproductive organs [37].

4.4. Total Amount of NPK Uptake by Grain and Straw

While preserving parity with I_5, the wheat in treatment I₂, which had a 0.9 IW/CPE ratio, absorbed much more total nitrogen, phosphorus, and potassium than the other treatments. Treatment I₃ exhibited the lowest absorption of nitrogen, phosphorus, and potassium compared to other treatments. Increased intake of these nutrients in wheat crops is associated with higher grain and straw production and improved nutritional content. Studies have shown that the application of organic fertilizers, such as farmyard manure (FYM) and vermicompost, significantly increases the total concentrations of nitrogen, phosphorus, and potassium in both grain and straw. Organic fertilizers positively affect the availability and uptake of these nutrients, leading to improved nutrition within the root zone and the entire plant system. Higher N, P, and K contents in plants and increased grain and straw yields indicated that different treatments increased N, P, and K uptake by crops, and the authors of [32,38,39] reported the same results.

4.5. Soil Moisture Depletion Pattern

According to the moisture extraction pattern, the soil moisture extraction steadily decreased with soil depth in all irrigation schedules (Table 6). More frequent (I₂) irrigation of wheat crops restored more soil moisture from the upper soil layer than less frequent irrigation. This is most likely a result of the soil profile having more moisture available, which increased potential and increased stomatal conductance. When water was scarce (I₃), it was harder for plants to obtain moisture from upper layers, so they had to obtain more from the deeper layers [40,41,42]. According to soil moisture patterns affected by organic manure, soil moisture increased in M₁, M₂, and M₃ compared to the control. The FYM or vermicompost alone, or even both of them, contributed to the plant’s improved physical health and root development.

5. Conclusions

In a two-year experiment, when irrigation was timed at a rate of 0.9 IW/CPE throughout the growth period or 0.8 IW/CPE during the vegetative phase + 1.0 IW/CPE during the reproductive phase, wheat crop showed a significant increase in yield, moisture content, and nutrient uptake. To save irrigation water, the optimal irrigation ratio was 0.8 IW/CPE in the vegetative period and 1.0 IW/CPE in the reproductive period. This schedule also produced nearly identical yields, increased nutrient uptake, and reduced the need for one irrigation. Grain yield, moisture content, and nutrient uptake improved with 7.5 Mg ha⁻¹ FYM + 3 Mg ha⁻¹ vermicompost or 6 Mg ha⁻¹ fertilization with vermicompost. However, the most productive treatments were treatments with equal amounts of FYM and vermicompost, for example, 7.5 Mg ha⁻¹ FYM + 3 Mg ha⁻¹ vermicompost or 15 Mg ha⁻¹ complete FYM.