The Effect of Inoculum with the Glomus mosseae and Palm Frond Detritus on the Yield of Millet (Panicum miliaceum L.) and the Ratio of Protein to Proline under Varying Irrigation Levels

This study aimed to determine the effect of Gloums Mosseae fungus and palm fronds detritus (compost) on the yield of millet crop (panicum miliaceum L.) and the ratio of protein to proline at various irrigation levels. A field experiment was conducted in one of the fields in the Sumer District of the Al-Diwaniyah Governorate during the summer of 2022. A Randomized Complete Block Design (RCBD) was used in this experiment with three replications. The treatments were distributed randomly. Two levels of fungal inoculation (F1 = inoculation with Glomus Mosseae, F0 = control), three levels of compost (C1 = application of 3 tons of palm frond compost, C2 = application of 5 tons of palm frond compost, C0 = control) and three irrigation duration (R1 = irrigation every ten days, R2 = irrigation every fifteen days, R3 = irrigation every twenty days). The results present a significant increase in all the studied traits (grain yield, biological yield, grain protein content, leaf proline content) 2.408 t h-1, 17.926, t h-1 16.10%, 13.16%, and 1.617 mmol gm-1, respectively, compared to with the control treatments that resulted in the least values for the studied traits, respectively, 1.123 t h-1 10.099 t h-1, 8.62%, 6.66%, 0.807 mmol gm-1.


Introduction
Bio inoculums are natural substances that contain one or more varieties of non-genetically modified beneficial microorganisms.They are essential for enhancing soil fertility and supplying plants with nutrients continuously and sustainably, thereby decreasing the use of chemical fertilizers and lowering production expenses [1].The world is turning to clean farming techniques to reduce chemical fertilizers utilization through natural materials such as bio-inoculums and organic fertilizers [2].Mycorrhiza fungus is one of the bio inoculums that play a role in supplying the plant with nutrients, protecting it from pathogens, and increasing its tolerance to water stress and drought.Therefore, this fungus is considered a symbiotic organism with the plant because it benefits both the fungus and the plant [4,5].Furthermore, organic matter improves soil properties, whether plant or animal waste, as it promotes growth and nutrient production [6].Utilizing organic matter reduces the excessive use of chemical fertilizers.It also reduces salts in irrigation water and enhances soil aeration, oxygen movement, and the availability of nutrients [7].Organic farming is his transition from plant feeding to soil feeding methodology.Treating the soil as a 1259 (2023) 012026 IOP Publishing doi:10.1088/1755-1315/1259/1/012026 2 vibrant body, not just a plant fixation medium.Organic agriculture is considered less harmful to the environment for several reasons, such as contributing to cleaning the environment of waste and recycling [8].Compost is a word derived from the English term Composting, which means industrial, municipal waste produced through aerobic or anaerobic fermentation of plant and animal residues or both.It is an organic matter decomposed by microorganisms in moist and warm environmental conditions [9].The decline in cultivated area, soil fertility, agricultural activities, and agricultural output is attributable, in part, to a lack of available water.Therefore, it has become necessary to optimally invest water resources in the correct scientific and practical manner through the use of modern methods of irrigation, including molecular irrigation, magnetic irrigation, and irrigation at intervals, which is the focus of our research to provide sufficient quantities of irrigation water that contribute to increasing the agricultural area [10].Proline is one of the freely available amino acids and contains an associated secondary amine group, distinguishing it from the other amino acids.Proline accumulates due to the inability of plant tissues to build protein and its breakdown.Because proline acts as a reservoir for metabolites that regulate osmosis, the extensive accumulation of proline in plant leaf cells alters the osmotic potential of the plant tissue, thereby enhancing the plant's ability to absorb water from the soil.Proline has an effective osmotic protective action [11].It accumulates in osmotically stressed plants by stimulating their regeneration and stopping catabolism [12].It is one of the most common amino acids formed in response to harsh and abnormal conditions that plants are exposed to [13,14].The local millet (Panicum miliaceum L.), Proso millet, ranks sixth among the cereals in terms of economic importance [15.It is the main protein and energy supply crop for more than a billion people in semi-arid regions.Commercially, it is one of the most used crops for feeding birds [16].In addition, its seed oil is used medicinally for hair and skin care [17].Because there is a real crisis in water scarcity and to reduce its effects on the plant, the study aimed to know the effect of bio-inoculants and organic residues on the percentage of yield of millet plant, as well as knowing their effect on the percentages of protein and proline in different irrigation durations.

Materials and Methods
The local millet plant (Panicum Miliaceum L.) was sowed in the summer of 2021-2022.They determined the effect of biological inoculants and organic residues on the percentage of millet plant yield and their effect on the percentages of protein and proline in different irrigation durations.The experiment was conducted in one of the fields of Sumer district -Diwaniyah Governorate in a sandy loam mixture soil.The field land was prepared well before starting the fieldwork, as it was modified and leveled, and weeds and bushes were removed.More than one soil sample was randomly taken from different locations in the field to conduct the necessary physical, chemical, and biological analyses and measurements before starting work.A biological inoculum, mycorrhiza fungus, consisting of spores + infected roots + soil, was used.Glomus Mosseae was obtained from the Agricultural Research Department of the Ministry of Science and Technology in Al-Zafaraniya for use in the experiment.It was applied to the plots before sowing and distributed evenly on the field plots within the upper 5 cm below the seeds.

Experimental Design and Distribution of Treatments
The complete random block design (RCBD) was used in the experiment.The field was divided into three replicates with 45 experimental units, and each sector included 18 treatments.The treatments were distributed randomly in the field.The area of the experimental unit was 6 square meters, and its dimensions were 2×3.An isolation distance was left between the sectors of m 2 and between the experimental units 1m, and a distance of 2m was left on both sides of the field.The experimental treatments were as follows: fungus inoculation treatment F (F0 = control F1 = inoculum application) and organic residue treatment C (C0 = control, C1 = application of 3 tons ha, C2 = application of 5 tons ha) and irrigation intervals treatment R (R1 = irrigation every 10 days, R2 = irrigation every 15 days, and R3 = irrigation every 20 days).

Grain Yield (t ha)
The grain yield was estimated by harvesting each experimental unit, after which the harvested plants were dried [18], then the grains were extracted from the inflorescences, cleaned well, and then the yield was weighed.

Biological Yield (t ha)
It was estimated from the weight of the harvested plants per (1 m 2 ) from the center of the board, where stems, leaves, and inflorescences were weighed after drying.

Grain Protein Percentage (%)
Two grams of dried and crushed samples of seeds were taken and digested according to the method of [19], then the percentage of nitrogen was estimated using the Micro Kjeldahl apparatus.The percentage of protein according to the following equation: Protein % = Nitrogen % x 6.25

Proline Content (µmol gm -1 )
The method of [20] was used to estimate proline content in green plant tissues.First, ten milliliters of aqueous sulfosalicylic acid, a concentration of 30%, was added to 5 g of the sample taken from the plant leaves; the sample was mashed and then filtered.Next, two milliliters of the filtrate were taken, 2 ml of Ninhydrin reagent and 2 ml of Glacial acetic acid were added, and the sample was heated in a water bath for an hour.Next, the sample was cooled, and 4 ml of toluene was applied; then, the sample was shaken and left at room temperature.Then the toluene layer separates, carrying the proline on top of the mixture.Finally, 1 ml was taken from this layer, and its absorption was measured using a spectrophotometer at a wavelength of 520 nm.

The Influence of Applying Glomus Mosseae Inoculum, Organic Residues, and Irrigation Durations on Grain Weight (ton ha -1 )
The results of Table 2 show a significant increase in grain yield.Inoculation with fungus resulted in the highest value, 1.941 t ha -1 .Compared to the non-inoculated treatment, 1.744 t ha -1 .It is also the case in the average organic waste, where the application of compost resulted in the highest value in the application level of treatment C1, 2.022 tons ha -1, compared with the treatment of the control treatment, 1.567 tons ha -1 .The irrigation average was significant with the irrigation treatment every ten days R1 2.073 tons ha -1 and the irrigation average every fifteen days R2 2.028 tons ha -1 compared to the irrigation treatment every twenty days R3, which resulted in the lowest value 1.426 ton ha -1 .The increase is due to the fungus Glomus Mosseae increases the availability of nutrients and secrete a growth-regulating substance, which increases the ability of the plant to absorb nutrients and water and thus increases growth parameters [21].
The binary and triple interactions were significant in increasing grain yield values.The two-way interactions that are, inoculation with fungus and inoculation with irrigation, durations resulted in the highest value with treatment F1R1 (inoculation with fungus + irrigation every ten days) 2.205 t ha -1 compared to F0R3 treatment (no inoculation with fungus + irrigation every twenty days) which resulted in the lowest value of overlap 1.335 ton ha -1 .This is due to the positive role of bio inoculum, as microorganisms have many characteristics that promote growth, including their ability to fix atmospheric nitrogen and increase the solubility of phosphorus and make it more available [22].
As for the bilateral interaction between irrigation and compost durations, it had a significant effect on the yield.For example, treatment C1R1 (compost 3 tons + irrigation every 10 days) resulted in the highest value of interactions, 2.294 tons ha -1, compared to treatment C0R3 (no compost application + irrigation every twenty days), which produced the lowest overlap value of 1.228 tons ha -1 .The reason is that organic fertilizers increase the availability of nutrients and soil fertility and improve their properties.
The dual interaction between mushrooms and compost also significantly affected yield.The treatment F1C1 was the most significant overlap of 2.168 ton ha -1 compared to the treatment F0C0, which resulted in an overlap of 1.442 ton ha -1 .This is attributed to organic fertilizers' direct and indirect role in plant growth.The direct role is represented by increasing the availability of the elements and increasing the absorption of them.In contrast, the indirect role is represented in the fact that they increase the activity of microorganisms in the soil and thus improve the soil's physical, chemical, and biological properties and increase the soil's water retention.All these factors and indicators affect growth and increase [23].
As for the three-way interaction between the factors of the study, it was significant in terms of grain yield, as the treatment F1C1R1 resulted in the highest value of interference, 2.408 tons ha -1 compared to the comparison treatment F0C0R1, which resulted in the most negligible value of interference 1.123 tons ha -1 .(3) present that inoculation with G.mosseae resulted in a significant increase in the biological yield of the millet plant.The inoculation treatment resulted in 15,215 tons ha -1 compared to the control treatment of 14,294 tons ha -1 .The same Table also shows that the compost had a significant effect, as the treatment C1 15.594 ton ha -1 was significantly superior, while the comparison treatment had an average of 13.722 ton ha -1 .The increase is due to the role of organic fertilizer in increasing the decomposed organic matter in the soil, which in turn works to improve soil properties and increase nutrient concentrations [24].The effect of irrigation durations was significant on the biological yield, Table (3).For example, the irrigation duration every ten days produced a biological yield of 16.899 tons ha -1 compared to the irrigation duration every fifteen days, 14.959 tons ha -1, and the irrigation duration every twenty days was 12.418 tons ha -1 .These differences in the irrigation durations affected the treatments because the water stress, generally the longer the drought duration, leads to a defect in the functional processes.Thus the supply of materials and elements needed by the photosynthesis process decreases.This causes abortion of grains and young shoots and atrophy of some of them, and thus a decrease in the yield, which is consistent with [25].
The dual interaction between irrigation and fungus durations was significant.Treatment F1R1 resulted in the highest overlap value, 17.249 ton ha -1, compared to the control F0R3, 11.827 ton ha -1 .The triple interaction between the study factors was also significant in the percentage of biological yield, and the treatment F1C1R1 resulted in the highest value of interaction, 17.926 ton ha -1, and F0C0R3 10.099 ton ha -1 .

The Impact of Applying Glomus Mosseae Fungus, Organic Residues, and Irrigation Durations on the Percentage of Protein (%) in the Flowering and Full Maturity Stages
The results of Tables (4 and 5) present a significant effect of inoculation with G.mosseae fungus on the grain protein content.The inoculation treatment resulted in 12.78 and 10.66 compared to the comparison treatment 11.54 and 9.12.The reason is attributed to the role played by the fungus in the roots, which is reflected positively in increasing the nitrogen in the plant parts and thus increasing the proportion of protein in the grain.The reason is also due to the positive relationship between mushrooms and nitrogen-fixing organisms, as the percentage of protein in seeds increases with an increase in the rate of nitrogen fixation [26].Tables 4 and 5 present that the effect of irrigation durations was also significant on the grain protein content.The irrigation duration every ten days resulted in the highest value, 13.20 and 10.76, compared to the irrigation duration every fifteen days, 12.96 and 10.59, and the irrigation duration every twenty days, 10.32 and 8.33.The decrease in the protein percentage at a duration of twenty days is due to the effect of water stress that caused the decrease in protein percentage [27].The two tables also show that compost had a significant effect, as the treatment C1 13.13 and 10.55 was significantly increased compared to C0 10.60 and 8.65.The interaction between fungus inoculum and watering duration in the flowering stage was significant, and F1R1 resulted in a value of 14.07 compared to the control F0R3 of 9.88.
In the full maturity stage, the F1R2 treatment was slightly increased to the F1R1 treatment, but they were significant as they resulted in an overlap value of 11.48 and 11.53, respectively, compared with the F0R3 treatment, which gave the lowest overlap value of 7.68.This is due to the role of the applied bio inoculum, as they provide many nutrients, especially potassium and nitrogen, which play an essential role in the manufacture of protein and increasing its percentage in grains.In addition, they are included in the synthesis of amino acids, which are essential in building proteins [28].
The triple interaction between the factors of the study was significant in the grain content of protein and for the stages of flowering and full maturity.The overlap treatment F1C1R1 resulted in the highest value, 16.10 and 13.16, compared to the control F0C0R3 which achieved the lowest value, 8.62 and 6.66.The results of Table 6 present a significant increase in the leaf content of proline when inoculated with G.mosseae fungus.The average value of the inoculation treatment was 1.055 mmol gm -1 compared to the non-inoculated treatment, which resulted in the highest value of 1.209 mmol gm -1 .The reason for the decrease in proline content in the treatment of mushroom inoculation is the increase in the water content of the leaves due to the beneficial effect played by the fungus in taking up water and nutrients and thus improving plant growth, which caused the decrease in the proline content in the leaves.The Table also presents that the organic materials achieved a significant effect when applied, and the value of C2 was 1.094 mmol gm -1 and C1 1.056 mmol gm -1 compared to the treatment of C0, which had an average highest value of 1.245 mmol gm -1 .The decrease (positive) in the proline content that occurred in the fertilization treatments was attributed to the increase in the water content of the leaves in the irrigation durations of less than twenty days.Table 6 also shows that the effect of irrigation duration was significant on the leaf content of proline for the treatments in which moisture stress increased, as the proline content in the leaves increased with the irrigation treatment every twenty days with an average of 1.423 mmol gm -1 compared to the IOP Publishing doi:10.1088/1755-1315/1259/1/0120268 irrigation duration every fifteen days 1.003 mmol gm -1 and the irrigation duration every ten days that resulted in the lowest value 0.969 mmol gm -1 .The bilateral and triple interactions between the studied factors did not achieve a significant effect when inoculating with fungus or applying compost.However, the values of the interactions for long irrigation duration (irrigation every twenty days) were the highest among the interactions.The value of the F0R3 binary interference was 1.532 mmol gm -1 , the C0R3 binary interference value was 1.528 mmol gm -1 , and the F0C0 binary interference value was 1.315 mmol gm -1 .
The triple overlap F0C0R3 also had the highest 1.617 mmol gm -1 .The reason for the high proline content of leaves exposed to water stress is attributed to the inability of plant tissues to build protein due to the increased activity of proteolytic enzymes such as Proteinase, which contributes to the increase of the amino acid (proline).Stress also causes a decrease in the pH value of the cytoplasm of the leaf tissue, which in turn increases the accumulation of proline [29].

Table 1 .
The field soil's physical, chemical, and biological characteristics (before planting).

Table 4 .
Protein content of grains -flowering.

Table 6 .
Proline content of leaves.