Growth and production of three wetland rice varieties on saline leached land with microbial consortium application

The study for investigate the level production and growth for several varieties of paddy rice on washed saline land with microbial consortium treatment. The environmental design used factorial Randomized Group Design. The microbial consortium application (no microbial application, microbial application A, microbial application B, microbial application C), while the second factor of paddy rice varieties (Pokkali, Biosalin 2 Agritan, IR 29) and repeated three times. The data obtained were analyzed with the F test. If significantly different, then further test was conducted using DMRT 5%. The results showed that bleaching using fresh water decreased the value of electrical conductivity. The interaction between the treatment of the type of microbial consortium and the variety of paddy rice did not affect all observed variables, but the application of the type of microbial consortium independently differed between treatments on the growth component, namely the variable plant height and the best yield shown by Pokkali, while the production component had no effect. The treatment of the type of paddy rice varieties differed between treatments on both growth and production components and the best was Biosalin 2 Agritan of 5.80 tons.ha−1, IR 29 4.37 tons.ha−1, and Pokkali 2.96 tons.ha−1.


Introduction
Saline land is suboptimal land that can inhibit and disrupt crop growth and production which is increasing in area and it assumption that 50% of the soil is affected by salinity in the next 50 years [1][2][3][4][5].Plants are affected by salinity as a complex interaction between morphological and biochemical and physiological processes including seed germination, plant growth, and nutrient carryng [2][3].The occurrence causes of osmotic and ionic pressure, an imbalance in the nutrient stability needed by plants, high electrical conductivity, and disrupting plant metabolic processes [2][3][4][5][6][7][8].However, this saline land has great potential to support increased crop production such as rice.Rice is the primary food by Indonesian people and most of the world's population [9][10][11][12][13].Meanwhile, Indonesia's population growth is always increasing and the world's population is experiencing the same thing, so paddy productivity must always be increased to needs of the community.From research result in Indonesia's population from the 2020 population census was 270.20 million at population growth rate of 1.25%/year while the world 1302 (2024) 012045 IOP Publishing doi:10.1088/1755-1315/1302/1/012045 2 population reached 8.5 billion in 2030 (an increase of 10%), in 2050 as many as 9.7 billion (an increase of 26%) and in 2100 it is estimated that 10.9 billion (an increase of 42%) [14][15].
Efforts to overcome the obstacles arising from saline land in order to support increased rice production can be made by washing using fresh water [16].Research results explained that drainage arrangements can cause salt leaching on saline soils [17].This activity can help to reduce the electrical conductivity by plant conditions so that the plant's metabolic processes run well which then supports plant growth and production.Such conditions can encourage the achievement of increased crop production by utilizing superior and adaptive rice varieties [18,19].The use of superior and adaptive varieties is expected to show a significant increase in yield because these varieties genetically have properties that can adjust and grow well in unfavorable environmental conditions.The rice varieties that have traits with genes tolerant/resistant to saline conditions can obtain sustainable yields by the mechanism of removing salt or accumulating salt in certain plant parts [18].The capacity of saline-tolerant plants make changes in gene expression patterns and changes in protein synthesis both qualitatively and quantitatively [19].From other study explained plant strategies to survive in saline conditions by producing osmolytes, antioxidant enzymes, and growth hormones [20].
Another alternative solution to overcome the disturbances caused by saline land is to apply microbes [17,21].Some research explained that microorganisms associated with plants key important role in providing to abiotic stresse resistances [18].These rhizoplane, rhizosphere, and endophytic bacteria with diverse mechanisms such as abnormal osmotic responses, providing hormones and nutrient uptake, act as bioindicator agents and inducing plant genetic.Beneficial microbes can grow in saline conditions by reducing electrical conductivity, helping to fix N, dissolve P and K, and produce hormones that help of the plant growth process [4], organic matter decomposition [20].Microbes that can adapt to saline land include halophilic bacteria such as Azospirillum, Pseudomonas, Klebsiella, Streptomyces, Rhizobium, Serratia, Alcaligenes, Bacillus, Thiobacillus, Clostridium, and Azotobacter [20][21][22][23].
The aim of this study was to investigate the growth and production from several varieties of paddy on washed saline land with microbial consortium treatment.

Experimental design
The study used a factorial Randomized Group Design.The main factor was of application the microbial consortium (M) consisting of four levels, namely without microbial application (M0), microbial application A (M1), microbial application B (M2), microbial application C (M3), while the second option factor was the paddy type variety (V) consisting of three levels, namely Pokkali rice variety (V1), Biosalin 2 Agritan rice variety (V2), IR 29 rice variety (V3).The treatment combination had 12 experimental units and was repeated three times.The microbial consortium used is listed in Table 1.The research procedure begins with the making of plots on the land used with a size of 2x1.5 meters with boundaries between plots made mounds as high as 60 cm with a width of 50 cm and left for 2 weeks to dry and strong then installed clear plastic as a barrier between the plots.Before making the plots, soil and water samples were taken to be analyzed for soil and water properties which were analyzed at the Soil Laboratory, Soil Research Institute, Bogor.Along with the making of the plots, pipes were installed on the right and left sides of the mounds, the length of which adjusted the size of the mounds with a diameter of 5.08 cm to regulate the entry and exit of water.The plots that have been dried and strong are then inundated with fresh water as high as 25 cm for 24 hours, then the fresh water is removed and replaced with new fresh water and inundated again as high as 25 cm and left for 24 hours and this is done for 3x24 hours.This is effectively done to reduce the electrical conductivity value to make it suitable for plant growth and production.Five days before planting, tillage is carried out until the soil is muddy and ready for planting.Before making the plots, seedling media preparation was carried out using red and non-saline soil that had been removed by gravel, stones, and other objects other than soil, then put into a 60x50 cm bucket as much as 25 kg.Applicate of manure at 20 tons.ha - dose the seedling media while stirring evenly and left for 1 week.Seed preparation was carried out by surface sterilization of rice seeds with 0.5% NaOCl and allowed to germinate until the radicle grew along 0.2-0.5 cm then soaked in microbial consortium according to the treatment for 1 hour, then sown on seedling media that had been prepared and the nursery was carried out for 30 days after sowing.Seedlings were transplanted to the prepared land by planting 5 stems per hole with a spacing of 25x25 cm.
The day before planting, manure was applied at dose 2 tons.ha - which was spread evenly on each plot.The application of microbial consortium according to the treatment was carried out 7 days form plating at a dose 5 liters.ha - with 100 times dilution.Ten days after planting, the application of Urea fertilizer was 125 kg.ha -1 , SP 36 100 kg.ha -1 , KCl 100 kg.ha -1 .The next fertilization was at the age of 30 days after planting with Urea by sprinkling evenly.For 7 days after planting, the plots were inundated with fresh water as high as +2 cm and then inundated with fresh water as high as +10 cm, and the inundation as high as +10 cm was maintained until the harvest by observing the inundation condition every day.If the inundation decreases, additional fresh water is added to the +10 cm level.Harvesting is done by seeing the condition of the grain has turned yellow about 90-95%.

Variables of observation
The observed variables are growth variables including plant hight (cm), root lenght (cm), root wet (g), and root weight (g), and yield variables are the number of productive stems, plant length (cm), filled grains per panicle (grains), number of hollow grains per panicle (grains), wet weight of grain per clump (g), clump weight of grain (g), wet panicle grain (g), dry weight of panicle grain (g).

4
Data collection for growth variables, namely observation of plant height, was carried out the day before harvest by measuring the height of the plant from the stem to the great of highest leaf using a 100 cm ruler.Root length was measured after harvest by measuring the roots using a ruler from the base to the tip of the longest root.Root wet weight observations were made after harvest by cleaning the roots from the soil and mud attached to the roots and then weighing the roots after the water was gone, while root dry weight observations were made by weighing the roots that had been baked at 80 o C until the weight was constant.The data on yield variables include the number of productive tillers obtained by counting tillers that produce panicles which is done the day before harvest.The observation of panicle length was done by taking the three longest panicles from each clump then measuring them with a ruler and averaged.The number of filled grains per panicle was observed by counting the filled grains after harvest, while the number of empty grains per panicle was observed after harvest by counting the empty grains from three panicles of each clump and then averaging.The wet weight of grain per clump was observed by taking wet grain from five clumps, each of which was weighed and then averaged, then the dry grain weight per clump was observed by drying the grain per clump of five clumps for 3x12 hours (12-14% moisture content) and the results were averaged.Data on the wet weight of ubinan grain were collected by taking wet grain from an experimental plot of 1 m -1 which was cleaned of leaves, twigs, and other objects and then weighed, while the dry weight of ubinan grain was obtained by taking wet grain from the 1 m 2 plot area and then drying it for 3x12 hours (12-14% moisture content) and weighed.

Data analysis
Dta analyzed by the F test.If there is a significant difference, then after tests are carried out using DMRT test with 5% test.Data analysis used DSAASTAT software version 1.514.

Results of water sample analysis
The results of the water analysis showed a high electrical conductivity value of 7,220 dS.m -1 and are listed in Table 2.The observation of the electrical conductivity value of water was not only analyzed in the laboratory but also checked using a portable EC meter.The electrical conductivity of water samples before washing was 6520-6690 µS.cm -1 (6.5-6.7 dS.m -1 ).After washing, the electrical conductivity value decreased to 1135-3567 µS.cm -1 (1.1-3.6 dS.m -1 ).This is in line with research reports that desalinization occurs in the upper soil layer and salt moves to the lower soil layer as a result of leaching [24].The result studies that leaching can reduce the value of electrical conductivity in saline soils so that it is effective for plant growth [25].

Aspects of plant growth
The results showed that the interaction between microbial application with the type of paddy rice varieties did not differ between treatments, but the treatment of microbial application types differed between treatments on the variable plant height.The best results were obtained in the treatment of microbial consortium type B which was 141.48 cm.When compared to the control treatment (without microbial application), all treatments with microbial application showed different values and provided information on better results, but among the microbial application treatments, the best data was microbial application type B. The treatment without microbes reached 135.62 cm in height, while the application with microbe type A 138.57 cm and type C 136.03 cm (Table 3).This difference occurs because microbes can associate with plants and assist in the provision and absorption of nutrients for plants such as inorganic and organic phosphates and produce growth regulators such as auxins and cytokinins [26][27][28][29].The microbes associate with plants to fix the N2 needed by plants [29].Microbes can produce siderophores that can chelate Fe, Zn, Mn, Cu, Ni, and other elements that help the plant growth process [29][30].Pseudomonas fluorescens as capable of producing siderophores that can growth promote for plant [31].In addition, microbes cooperate with plants by releasing root sampling such as organic acids, sugars, and secondary metabolites at all stages of development [32].As for other variables such as root length, root wet weight, and root dry weight, there is no effect between treatments, but the tendency is that the microbial application treatment gives a better picture of the results compared to the treatment without microbial application.This means that without microbial application, the results are lower than those given microbial consortium and between microbial treatments, the values are different with the best results shown by microbial consortium type B although statistically the effect is the same (Table 3).This is thought to be because planting media with saline conditions that are washed with fresh water results in relatively the same environmental conditions and the salinity goes down and is suitable for plant growth, thus providing the same effect on microbial life.The key success of rice cultivation in saline land must pay attention to good water management [33].Rice is one of the cereal crops recommended to be planted on saline land because it can grow and develop well in stagnant conditions as well as being able to wash salt in the upper layer to the lower layer of soil, so that the land is suitable for plant growth.Some research explained reported that communities of microorganisms that are taxonomically different but have the same function [34][35].From some research results describe microbes making physiological adjustments or genomic changes in anticipation of changes in certain environmental conditions [36][37][38].
The statistical resulyts showed that the treatment of paddy rice varieties differed among treatments.The best results were shown by the Pokkali variety in plant height (184.13 cm), root length (25.68 cm), root wet weight (91.75 g), and root dry weight (16.24 g) (Table 3).The saline conditions the root growth of Pokkali varieties is better than IR29 varieties [39].According to its description, the Pokkali variety reaches 160-200 cm in height, Biosalin 2 Agritan variety 109 cm, while IR 29 variety 100 cm [40].Furthermore, the Pokkali variety is a variety that is very tolerant of saline conditions [41][42][43] and genetically its plant height reaches 1.8 m and is saline resistant to 8 dSm -1 [42].The molecular mechanism of saline-tolerant varieties by storing salt in salt glands to a certain extent and then breaking and releasing it to the outside environment [19].Another mechanism is that plants produce phytohormones that help plant growth and production.

Crop production aspects
The interaction between the microbial consortium application with the type of paddy rice variety was not different, and the treatment of microbial consortium application independently on all production variables also had no effect between treatments, although all treatments with microbial consortium application had higher and better results compared to treatments without microbial application.The application of microbial consortium type B showed the best results compared to the application of microbial types A and C, although statistically there was no effect (Table 4).Such an occurrence arises because it is supported by the results of observations on growth components that show no effect between microbial application treatments, namely root variables, thus supporting and harmonizing with yield variables.The root is an organ that helps in finding and absorbing nutrients and water which are sent to the leaves to support and encourage crown growth [44][45].Frome some research say that long and deep roots can freely search for and absorb nutrients and water needed by plants [46].The water is very important for plants because most nutrients come from the soil and these nutrients become available due to water movement [47].This shows that if the growth component has no effect, it is likely to have the same impact on the observation of production elements.This is in line with the research that the treatment of increased daily temperature showed no effect on growth variables such as plant height, number of tillers, leaf area index, and plant growth rate and yield variables such as weight of filled grain per clump, total grain weight per clump, and crown dry weight also had no effect [48].
The statistical test showed that the treatment of paddy rice varieties differed among treatments for all observed production variables.The best results for the variable number of productive tillers were shown by the IR29 variety which was 25.32 stems, while in panicle length, the number of biologycal parameetrs by the Pokkali variety whose values were 29.78 cm, 118.95 grains, and 18.98 grains, respectively.As for the variables of wet weight of grain per clump, dry weight of grain per clump, wet weight of tinned grain, and dry weight of tinned grain, the best results were shown by the Biosalin 2 Agritan variety, respectively 33.99 g, 27.03 g, 743.38 g, and 580.07 g, followed by the IR 29 variety at 25.3 g, 21.26 g, 553.82 g, and 436.90 g, respectively, and the lowest weight was the Pokkali variety at 21.97 g, 19.36 g, 352.21 g, 295.58 g (Table 4).This is because the Biosalin 2 Agritan variety has a long and dense grain shape, and IR 29 has a long slender grain shape, while Pokkali is medium thick and sparse, so it affects the grain weight obtained [40].These results are also supported by the number of panicles per clump, the total number of grains per panicle, and the harvest index in the Biosalin 2 Agritan variety, each of which is 22.75 stems, 175.99 grains, and 0.522, the IR29 variety is 25.32 stems, 128.07 grains, and 0.460, while the Pokkali variety is 17.63 stems, 137.93 grains and 0.203.The harvest index has a direct and positive effect on grain weight [49].From after research explained that the IR29 variety is one of the saline-sensitive varieties but its production opportunities are high [50].
The results of this study are quite good and can be used as a reference for research in the field of agricultural engineering.This concept is also interesting to be explained further using different approach parameters.These results can also be modeled in practical agricultural applications.

Conclusions
The conclusion by this research to description of electrical conductivity value on saline land that is washed with fresh water from 6520-6690 µS.cm -1 (6.5-6.7 dS.m -1 ) to 1135-3567 µS.cm -1 (1.1-3.6 dS.m - 1 ), making it suitable for plant growth.The interaction between the treatment of microbial consortium types and paddy rice varieties did not affect on all observed variables, but the application of microbial consortium types independently differed between treatments on growth components, namely plant height variables, and the best yield was shown by the Pokkali variety, while the production component had no effect.The treatment of paddy rice varieties differed between treatments in both growth and production components and the best was the Biosalin 2 Agritan variety.The production of the Biosalin 2 Agritan variety was 5.80 tons.ha - , IR 29 4.37 tons.ha - , and Pokkali 2.96 tons.ha - .

Table 1 .
Microbial consortium applied

Table 2 .
Results of water sample analysis on the land used for research

Table 3 .
Mean effect of microbial species and paddy rice varieties on plant height, root length, root wet weight, root dry weight components Remarks: the numbers followed by the same letter in the same column are not significantly different with 5% DMRT test.

Table 4 .
Mean effect of microbial species and paddy rice varieties on production components : JAP= number of productive tillers; PM= panicle length; JGIM= number of filled grains per panicle; JGHM= number of empty grains per panicle; BBGR= wet weight of grain per clump; BKGR= dry weight of grain per clump; BBGU= wet weight of seedling grain; BKGU= dry weight of turbaned grain; numbers followed by the same letter in the same column are not significantly different with 5% DMRT test. Remarks