Impact of organic liquid fertilizers on growth and yield performance of Green Bean ( Phaseolus vulgaris L.) in non-circulating hydroponic system

Non-circulating hydroponic systems are a type of soilless production system that has been found to be extremely productive, low-cost, water, land efficient, and well-suited to avoid fertilizer leaching and groundwater contamination. The experiment was conducted to study the effect of liquid organic nutrient solutions on Green Bean (Phaseolus vulgaris L.) cultivation in non-circulating hydroponic system. The experiment was laid out in a Completely Randomized Design (CRD) with seven treatments having fifteen replicates. The treatments were recommended inorganic fertilizer application (T1), ½ doses of Albert’s solution with 0.5% vermiwash (T2), 1% vermiwash (T3), 1.5% vermiwash (T4), 0.5% vegetable waste solution (T5), 1% vegetable waste solution (T6), 1.5% vegetable waste solution (T7) was used as media. The results revealed that plant height, number of leaves and branches per plant, leaf area, dry weight of leaves and length of pods were significantly (P<0.05) varied at 6 th week after planting and it was high in T5. However, number of pods per plant, girth of pods, fresh and dry weight of pods and yield were high in T2 at 3 rd picking while yield at 1 st and 2 nd picking were high in T5. This result suggests that ½ doses of Albert’s solution with 0.5% vegetable waste solution (T5) and ½ doses of Albert’s solution with 0.5% vermiwash (T2) would be the potential source of plant nutrients for sustainable crop production of bean in Non-circulating Hydroponic system.


Introduction
Plant cultivation on soil has been devised and practiced since the beginning of civilization.However, because nutrients in many soil types are unpredictable and may be inaccessible to some plants, this traditional agricultural practice can cause problems with plant growth (Resh, 2012).Therefore, protected horticulture has recently transitioned away from soil-based system and toward soilless system.Hydroponics is a technique used to grow a wide range of crops in water-based closed systems without soil and using nutrient solutions, water, and other soilless media (Jan et al., 2020).Hydroponic agriculture produces higher yields, better quality, and more efficient water use, and it can be tailored to support production throughout the year.This is a valuable technology in places where land areas are limited, or climatic problem exist.
Hydroponic methods generally employ circulating systems, which rely on pumps to aerate the system for optimal oxygen and nutrient uptake (Arancon et al., 2015).Noncirculating hydroponic systems are a type of soilless production system that has been found to be extremely productive, low-cost, water or land efficient, and well-suited to reduce fertilizer loss and groundwater contamination (Mahlangu, 2016).Noncirculating hydroponic solutions minimize the added expenses and difficulties of mechanical aeration and circulation of the nutrient solution, as well as the use of electricity and pumps.In compared to traditional soil-based setups, non-circulating hydroponic systems provide better hygienic quality and are free of soil particles (Kratky, 1993).
Chemical fertilizers are a key component of hydroponic systems However, due to the accumulation of hazardous compounds in vegetables, employing large concentrations of chemical fertilizer may represent a risk to consumers (Garland et al., 1993).As a result, using Liquid Organic Fertilizer (LOF) as an alternative or complement to chemical fertilizer for hydroponic planting is a viable option (Phibunwatthanawong and Riddech, 2019).The advantages of liquid organic fertilizer include providing nutrients to plants, improving soil structure, suppressing harmful bacteria, and improving the physical, chemical, and biological activities over time and safe for the environment (Soeparjono, 2016).When compared to compact organic fertilizer, LOF application results in faster nutrients supply (Sopha and Uhan, 2013).
In todays society, use vermin technology to actively manage organic waste disposal crises and also using products of vermin technology as a nutrient source for modern agricultural technique (Ansari, and Sukhraj, 2010).Vermicompost improves the physical, chemical and biological properties of soil (Ansari, 2008).Vegetable waste is produced in great numbers in markets around the world; to make use of this waste and to prevent pollution, biofertilizers can be made.These wastes still have a lot of water in them and are full of organic components including carbohydrates, proteins, and lipids (Singh et al., 2012).This liquor would generate leachate which contain organic matters, contaminating underground and surface water.It is critical to treat vegetable waste in order to reduce greenhouse gas emissions (Monisha and Rameshaiah, 2016).Vegetable waste provides a significant amount of nutrients to occupy microorganisms; they are neither a pathogen nor a threat to human health (Cioabla et al., 2012).
Green bean is cultivated all over the world due to their nutritional and medicinal values (Adeyemi et al., 2012) and its adoptability.Beans provide dietary protein minerals such as ion, phosphorus, magnesium, manganese, and in lesser degree, Zinc, copper and calcium and important vitamins (Quintana et al., 1999) that plays an essential role in human nutrition.Several crops have been studied in hydroponics by several scientists, but there is no sufficient information on green bean cultivation in hydroponic with liquid organic fertilizers in Sri Lanka.Therefore, this study was aimed to study the impact of Organic liquid fertilizer on growth and yield of green bean in non-circulating hydroponic system.

Materials and Methods
The experiment was conducted in Bandarawela, Sri Lanka which is located at an elevation of 1300 m above mean sea level in the Uva province.Experimental site geographical coordinates are 6º 50´ N latitude and 80º 59´E longitudes and comes under the Agro Ecological Zone of Up-Country Intermediate Zone (UCIZ).The mean annual rainfall of this area varies from 1100 mm to 1400 mm.The annual mean temperature varies from 12 0 C to 32 0 C and Humidity level is 79%.The soil of experimental site is Red podzolic soil.This study was carried out using Completely Randomized Design (CRD) with seven treatments having fifteen replicates.Treatments are Recommended Albert's Solution as control (T1), ½ doses of Albert' Solution with 0.5% (T2), 1% (T3), 1.5% (T4) of vermiwash, 0.5% (T5), 1% (T6), 1.5% (T7) of vegetable waste solution.Green Beans, variety Sri Lankan Capri was used in this study.Two Liquid Organic Fertilizers such as vermiwash (VW) and vegetable waste solution (VS) were tested on Green Beans cultivation separately.

Preparation of vermiwash
Red earthworms, coarse sand, loam soil, broken bricks, and cow manure were gathered from the home garden.A vermiwash unit was set up in an open, empty barrel with a tap on one side.The tap was left open, and a 25 cm layer of broken bricks was laid at the bottom.After that, a 25 cm layer of coarse sand was added, followed by a layer of loam soil that was 30-45 cm thick and lightly wet.A barrel was filled with red earthworms.The barrel was then gently moistened after being filled with waste materials, including cow manure.Water was added every day to keep the unit moist.The tap remained open for a full week.After a week, the eighth day tap was shut, and the liquid was then poured into the barrel.Once more, on the ninth day, the tap was opened, and the gathered liquid was dumped into the barrel.This repeated for the remaining two weeks.Vermiwash was then collected through the tap after two weeks (Ansari, 2012 and Ismail).

Preparation of Vegetable waste solution
Effective Microorganisms (EM) solution was made utilizing natural ingredients as a first stage.A bottle with lid was taken.Two cups of water were combined with one cup of brown rice.Then it was properly shaken.An empty bottle was filled with the liquid solution, which was then covered with paper.After that, it was kept in a dark area for seven days.It was mixed with milk after seven days (1:100).Then, it was covered and stored in a dark area for seven days.Lactic Acid Bacteria (LAB) solution was collected after 7 days.
Vegetable waste solution was created after preparing the EM solution.Brown sugar, coconut water, brown rice, and fresh milk were gathered from home to make a vegetable waste solution.A bucket with a lid was properly cleaned and laundered.The leftover vegetables were then chopped up to a weight of 2 kg. 100 ml of EM and 5 liters of water were then added to the bucket.The bucket was filled with 1 liter of coconut water, 1/2 kg of brown sugar, and 100 ml of sugar solution.The liquid was then thoroughly mixed by swirling it.After that, 2 kg of chopped vegetable waste was added to the bucket and stirred until everything was combined.Following that, the bucket was covered for up to 15 days.The Liquid Organic Fertilizer (LOF) was ready to usage after 15 days of daily stirring for only 5 rounds of LOF (Faruq et al., 2021).

Non-circulating Hydroponic Installation
Fifteen Styrofoam boxes (46 x 40 x 35 cm) were prepared, and black polythene sheets were used as a coating material for the inner side of the boxes.Then five holes were made on the lid of the box.Then, the Nutrient solutions were added to each box according to the treatments.After that the coir dust was mixed with some amount of water and prepared a moistened mixture.Then the net pots were filled with above mixture as a medium.Two Bean seeds were planted in one pot.Later, the net pots with seeds were transferred into the holes of Styrofoam boxes with nutrient media.Poles were placed when, support is required.Readings were collected at 2 nd , 4 th , 6 th and 8 th weeks after planting by using destructive method in three plants.Plant height, number of leaves, branches and nodules per plant, leaf area, root length, number of flowers per plant, fresh and dry weight of plant, leaves, stem and root were measured at 2 nd , 4 th , 6 th , and 8 th weeks after planting.Picking was done at harvesting stage.Number of pods per plant, pod length and girth, fresh and dry weigh of pods, number of seeds per pod and weigh of 100 seeds were taken during harvesting.Total yield was calculated by the accumulation of yield per each picking.Statistical software such as SAS and Minitab were used to analyze the data.

Plant Height
The effect of Liquid Organic Fertilizer (LOF) and Albert's solution as a nutrient solution on average plant height of green bean from 2 nd WAP to 8 th WAP in hydroponic system is given in Table 1.

Table 1: Plant height (cm) of green bean with respect to treatment during the experiment period
Value represent means ± standard error of three replicates.F test: -ns: not significant; *: P<0.05.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.
There was no significant difference (P>0.05) in plant height at 4 th and 8 th WAP.However, significant difference (P<0.05) was observed in 2 nd and 6 th WAP.At 2 nd WAP and 6 th WAP, the tallest plants were recorded in T5.It may be due to provision of LOF contains nutrients that are ideal for the growth of plants, and it provides N, P, and K nutrients in the hydroponic system and also the activation of plant growth.Koesriharti and Istiqomah (2016)    plants grown under conventional hydroponic nutrient solution and under manure nutrient solution produced more flowers compared to those grown under tap water.

Root Length
There was significant variation (P<0.

Leaf Area
Plant photosynthesis determines by the rate of photosynthesis per unit leaf area, leaf area index, and leaf angle.The effect of LOF and Albert's solution on average leaf area of green bean from 2 nd WAP to 8 th WAP is given in Table 3.It was found that there was significant difference (P<0.05) at 2 nd , 6 th and 8 th WAP on average leaf area.At 2 nd WAP, the maximum value of 61.9 cm 2 was recorded in T2, while minimum value of 34.18 cm was recorded in T5.At 6 th and 8 th WAP, the highest leaf area value in T5 while low in T7.
It is due to the leaf area value depending on the genetic ability of the plant and the provision of nutrients.

Dry weight of leaves
There was significant difference (P<0.05) on average dry weight of leaves among the tested treatments due to nutrient medium with different concentration of LOF and Albert's solution (Table 4).At 2 nd and 4 th WAP, the highest dry weight of leaves was noted in T1 while lowest dry weight of leaves was noted in T7.At 6 th WAP, T5 (2.68 g) high value while low in T1 (0.52 g) and at 8 th WAP, the maximum value of dry leaf weight was recorded in T2 (6.43 g) and minimum value of dry leaf weight was noted in T7 (1.35 g).It may be due to the trend of plant height growth and number of leaves also caused an increase in the rate of dry weight accumulation, which was reflected in the relative growth rate variables.Arshad et al. (2018) reported that Lettuce plant produced leaves dry weight (LDW) as 15-25 g due to concentration of organic extracts in nutrient solution.

Dry weight of stem
There was significant difference (P<0.05) on average dry stem weight among the tested treatments (Table 5).At 2 nd and 4 th WAP, the maximum value of dry stem weight was recorded in T1 while minimum value was recorded in T4 and T7 at 2 nd WAP and T6 at 4 th WAP.At 6 th WAP, T2 highest value while low in T6.At 8 th WAP, the highest value of 1.32 g was recorded in T5 and low value of 0.59 g in T7.This is due to the presence of different water content in the plant tissue.The fresh weight reported by Kowalczyk et al. (2016) in a nutrient solution of N, P, K of 140, 50, and 300 mg/L, respectively, was 245 g and 175 g for two other lettuce cultivars.Furthermore, the increasing N concentration on a hydroponic culture of lettuce from 0 to 60 mg/L increased shoot weight from 68.7 to 129.7 g.

Dry weight of roots
The dry weight of roots is shown in Table 6.
There was no significant difference (P>0.05) in dry weight of roots at 2 nd , 4 th and 8 th WAP.
However, there was significant difference (P<0.05) at 6 th WAP.At 6 th WAP, the highest value of 1.10 g was observed in T3 and T5 while low value of 0.16 g was observed in T6.
It may be due to an increase in fresh production is accompanied by an increase in dry production.

Number of pods per plant
LOF application on nutrient medium was significantly influenced (P<0.05) the number of pods per plant at 1 st , 2 nd and 3 rd picking were confirmed with P values of 18.00, 21.00, 21.00 and chi square values of 0.006, 0.002, 0.002 is shown in Table 7.The maximum number of pods per plant was observed in T2 while minimum value in T7 at 1 st picking and T3, T6 at 2 nd and 3 rd picking.
It might be due to its vigor and the higher number of leaves per plant.Ekanayake et al.
(2020) stated that fish tonic treated plants produced the highest number of pods and the fresh weight while plants treated with compost tea produced the least number of pods and the fresh weight.
Table 7: Number of pods per plant of green bean with respect to treatment during the experiment period

Length of pods
The effect of nutrient medium with LOF and Albert's solution on average length of pods per plant from 1 st picking to 3 rd picking is shown in Table 8.There was significant difference (P<0.01) at 3 rd picking and also there was significant variation (P<0.05) at 2 nd picking.However, there was no significant difference (P>0.01) at 1 st picking.At 2 nd and 3 rd picking stage, the highest value of pod length was observed in T5 while low in T4.Jayawardana et al. (2016) stated that the terms of fruit parameters, simplified hydroponic system was better with significant increase in fruit length, fruit fresh weight and fruit firmness than that of non-circulating liquid hydroponic system supplied with either New Formula (NF) or Albert's nutrient solution.

Girth of pods
Girth of pod of green bean was significantly influenced by the nutrient medium with LOF and Albert's solution (Table 9).There was significant difference (P<0.05)among the tested treatments.At 1 st picking, maximum girth of pods of 3.40 cm was observed in T5 followed by 2.9 cm in T6, 2.85 cm in T1, 2.75 cm T2 while low value of 1.85 cm in T3.
At 2 nd and 3 rd picking, the highest value was observed in T2 while low value was observed in T3.It may be due to the relatively better nutrient uptake in this condition compared to other treatments.Where nutrient uptake and good translocation rates cause the relative growth rate to be good for the whole plant as well as for other plant parts.Ekanayake et al. (2020) showed that the highest stem girth was recorded in Albert's solution applied plants at flowering.However, it was not significantly different from the stem girth recorded in fish tonic treated plants.

Fresh weights of pods
The effect of nutrient medium with LOF and Albert's solution on average fresh pods weight of green bean from 1 st picking to 3 rd picking is given in Table 10.
There was significant difference (P<0.01) at 2 nd picking and at 3 rd picking, significant difference (P<0.05) was observed.At 2 nd and 3 rd picking, the maximum value of fresh pod weight was observed in T2 while minimum value in T7 at 2 nd picking and T3 at 3 rd picking.These results are agreed with Ekanayake et al. (2020) stated that Fish tonic treated plants produced the highest number of pods and the fresh weight while plants treated with compost tea produced the least number of pods and the fresh weight.

Dry weights of pods
The data on dry weight of pods per plant as influenced by nutrient medium with LOF and Albert's solution in Hydroponic system is presented in Table 11.There was significant difference (P<0.01) at 2 nd and 3 rd picking.It was significantly difference (P<0.05) at 1 st picking.At 1 st picking, T5 (3.38 g) high value while low in T3 (0.62 g).At 2 nd picking, the highest value of dry pod weight of 15.1 g was observed in T1.At 3 rd picking, the maximum value was observed in T2 (12.75 g) followed by T1, T5 (12.05 g) while minimum value was observed in T7 (6.05 g).

Total yield
The effect of nutrient medium with LOF and Albert's solution on total yield of green bean from 1 st picking to 3 rd picking is given in Table 12.There was significant difference (P<0.01)among the tested treatments on total yield.At 1 st and 2 nd picking, the highest value of yield was observed in T5 followed by T2, T1, T6, T4, T3 while low in T7.At 3 rd picking, T2 high value while low in T4.
Higher EC creates higher nutrient concentration of the solution which may lead to toxicities in plant nutrition.These results are agreed with Koesriharti and Istiqmah (2016) stated that the nutrient content also affects the growth and yield of pakcoy on hydroponic substrate, because the nutrient solution is one of the most important determining factors on the yield and quality in hydroponic system.Edgar et al. (2017) also noted increased growth and yield performance of tomato grown on goat manure.

Conclusion
There were significant differences (P<0.05) on plant height, number of branches per plant, leaf area, dry weight of leaves, length of pods and root length and highest performance were obtained from 1/2 doses of Albert's solution with 0.5% vegetable waste solution (T5) at 6 th WAP.Further, 1/2 doses of Albert's solution with 0.5% vermiwash (T2) increased number of pods per plant, girth of pods, fresh and dry weight of pods and yield at 3 rd picking.Therefore, 1/2 doses of Albert's solution with 0.5% vegetable waste solution (T5) and 1/2 doses of Albert's solution with 0.5% vermiwash (T2) would be more suitable for cultivation of green bean in non-circulating hydroponic system.Further studies are needed to investigate vermiwash and vegetable waste solution without Albert's solution at hydroponic.

Figure 2 .
Figure 2. Number of branches per plant with respect to treatment during the experiment period Number of flowers per plant

Figure 3 :
Figure 3: Number of flowers per plant with respect to treatment during the experiment period

Number of leaves per plant with respect to treatment during the experiment period Number of branches
stated that addition of nutrient solution is complete and available for plants to absorb for pakcoy (Brassica rapa L. Chinensis) in hydroponic.

Table 2 :
Root length with respect to treatment during the experiment periodValue represent means ± standard error of three replicates.F test: -ns: not significant; **: P<0.01.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 3 :
Leaf Area with respect to treatment during the experiment period Value represent means ± standard error of three replicates.F test: -ns: not significant; *: P<0.05; **: P<0.01.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 4 :
Dry weight of leaves per plant with respect to treatment during the experiment period Value represent means ± standard error of three replicates.F test: -*: P<0.05.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 5 :
Dry weight of stem per plant with respect to treatment during the experiment period Value represent means ± standard error of three replicates.F test: -*: P<0.05.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 6 :
Dry weight of roots per plant with respect to treatment during the experiment period

Table 8 :
Average length of pods per plant with respect to treatment during the experiment periodValue represent means ± standard error of three replicates.F test: -ns: not significant; *: P<0.05; **: P<0.01.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 9 : Girth of pods per plant with respect to treatment during the experiment period
Value represent means ± standard error of three replicates.F test: -*: P<0.05.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 10 :
Fresh weight of pods per plant with respect to treatment during the experiment period

Table 11 :
Dry weight of pods per plant with respect to treatment during the experiment period Value represent means ± standard error of three replicates.F test: -*: P<0.05; **: P<0.01.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.

Table 12 :
Total yield of green bean with respect to treatment during the experiment period Value represent means ± standard error of three replicates.F test: -**: P<0.01.Means followed by the same letter in each column are not significantly different according to the Duncan's Multiple Range Test at 5% level.