Response of Strawberry to Different Organic Fertilizers Application under Irrigation Levels

INTRODUCTION

The berry fruit strawberry (Fragaria ananassa Duch.) is one of the most frequently cultivated and consumed in the world. Strawberries were grown on 396.401 ha of land worldwide in 2019, and 8.885.028 tonnes were produced overall (FAO, 2019).Strawberry is a fruit that is popular throughout the year, can mostly be eaten fresh, and has a variety of uses in the food sector. Furthermore, due to its high antioxidant content, strawberries are a crucial part of daily nutrition meals (Wang, 2014). The globe produced over 8,861,381 tonnes of strawberries in 2020 on 384,668 ha of land, according to FAO (2020).

     Strawberry irrigation using a drip system, in which drip tapes are set up underneath plastic mulch after beds are prepared. During the first few weeks after transplanting, drip watering is combined with overhead aluminium sprinkler irrigation to help with transplant establishment and leach out salts from the root zone. The strawberry crop is vulnerable to salinity, although salt damage can be minimised or avoided via overhead aluminium sprinkler irrigation (Lozano et al., 2016; Morales-Quintana et al., 2022). Drought stress negatively impacted the accumulation of nutrients in strawberry leaves, resulting in a reduction in photosynthetic rates, growth, and yield output, but it also improved fruit quality, such as sugar content (Perin et al., 2019).

The growth, yield, and yield-related factors of many crops are significantly increased by organic fertilisers such chicken manure (Avetisyan et al., 2021). The organic matter in the soil is increased by using organic manures. In turn, organic matter makes plant nourishment readily available for use by crops. However, organic manures shouldn't be viewed as merely plant food transporters. These manures also assist clay soils drain better and allow a soil to hold more water.(Chagas et al. 2018 : Abou El-Goud and Yousry  2019 ; Abou El-Goud, 2020 and 2021).

        By adding plant compost to soil, soil properties such as water retention, aggregate formation, porosity, increased cation exchange capacity, and fertility are all improved. Additionally, the rhizosphere's biological and microbiological activity is growing(Abou-El-Hassan et al.,2014; Mona and Amal 2020; Abou El-Goud 2021 ).

Vermicompost is the end result of earth worms' biological breakdown of organic materials (Zuo et al., 2018). Vermicomposting is a technique that is frequently used to handle different kinds of organic waste. Vermicomposting is a cost-effective, environmentally responsible, and sustainable method for managing organic waste that yields organic fertiliser that is safe for use in sustainable farming practices(Abou El-Goud, 2020 and 2021 and Abou El-Goud et al., 2021)

Bokashi is one of the essentials for keeping the soil healthy so that plants may thrive and produce more and better-quality fruit and vegetables. Because humus compounds often take the form of hydrophilic compounds with the ability to bind water four to six times, they serve an important role in preserving water and reducing soil water evaporation. Increased nutrients and improved soil qualities such increased soil organic carbon, soil water content, cation exchange capacity, and pH can result from the high organic content. enhancing the aeration, water-holding capacity, soil structure, and soil temperatures to support plant growth. As a result of organic material fermenting with useful microbes, it is an organic material rich in various helpful microorganisms. In order to feed plants, promote growth, and improve crop yield, organic fertilisers are utilised. The usage of bookshi boosted the amount of N, P, and K as well as the quantity, diameter, and length of plant stems, all of which had an impact on the production's quality (Sri Anjar Lasmin et al., 2018 and Abou El-Goud 2020)

                In contrast to the use of inorganic triple phosphate fertilizer, Avetisyan et al. (2021) found that manure treatments (which contain favorable quantities of macro and micronutrients) increased fruit set and size in strawberries through forming carbohydrates. In many nations throughout the world, using organic fertilizers has proven to be an effective way to regulate soil fertility. In addition to increasing fruit quality, it also ensures long-term production sustainability (Kumar et al., 2018). Numerous earlier research have demonstrated that the use of organic fertilisers in strawberry fields increases the availability of nutrients to plants, which in turn encourages plant development (Khalil and Agah 2017).

The main objectives of this study are:

1. Increasing organic fertilization to produce a chemical-free strawberry crop

2. Raising the fair and marketing value of the strawberry crop

3. Rationalizing water consumption in poor sandy lands

MATERIALS AND METHODS

                Two field experiments were conducted at a private farm in Abdul Salam Aref, Badr Center, Beheira Governorate, Egypt, during the winter growing seasons of (2020/2021 and 2021/2022) to study organic strawberry production under different irrigation levels cultivated  in sandy soil.

Samples of soil were collected at a depth of 0-30 cm from the experimental orchard for all treatments, and some physical and chemical properties of the experimental soil were determined in 2020  are shown in Table (1).

Table (1). Some physical and chemical properties of the experimental soil in 2020 and 2021 growing seasons before planting.

Four kinds of organic manures were used in the experiments: plant compost (3.5 and 7 t/fed.), chicken manures (3.5 and 1.75 t/fed.), vermicompost (3.5 and 7 t/fed.) and Bokashi (3.5 and 7 t/fed.).

       The experiments were carried out in a split-plot design with three replicates, where the three irrigation levels (100, 75, and 50% of ET0) were arranged in the main plots, and then the four organic manures (control, plant compost, chicken manures, vermicompost and Bokashi) were arranged in the sub-plots on a strawberry plant, the Festival variety.

Strawberry transplants, Festival variety were  were planted in October in the first and second growing seasons, respectively. The fresh transplants were cultivated in four rows on terraces; the distance between the plants was 30 cm under the drip irrigation system.

Data recorded

A)   Vegetative growth

 Harvest was done on the 28^th of July in both seasons, and the following data were estimated:

• Plant height (cm)
• Total fresh weight (g)
• Number of leaves/plant
• Leaf area index (LAI)
• Total chlorophyll content was determined using the chlorophyll index meter (SPAD)

B)   Yield characters

• Fruit length (cm)
• Fruit weight (g)
• Yield/plant (kg/fed.)
• Yield (t/fed.)

C)     Chemical composition:

The percentages of NPK content in the dry leaves and fruits were calculated. According to Tandon (1995), their dry weights were calculated after drying to a constant weight at 75°C for 72 hours. The plant samples were pulverized and stored for examination as described after drying. However, according to the results of wet digestion of 0.5g of the tubers powder with an H2SO4-H2O2 mixture (Lowther, 1980) and the following determinations were carried out in the digested solution to determine the following:

• Nitrogen content (N %):

                Total nitrogen was determined in digested plant material colorimetrically by Nessler`smethod (Chapman and Pratt, 1978). Nessler’s solution (35 KI/100 ml d.w. + 20 g HgCl₂/500 ml d.w.) + 120 g NaOH / 250 ml d.w. Reading was achieved using a wave length of 420 nm, and N was determined as a percentage as follows:

                % N = NH4 % x 0.776485                                

• Phosphorus content (P %):

Phosphorus was determined by the Vanadomolyate yellow methodas given by Jackson (1973), and the intensity of the color developed was read in a spectrophotometer at 405nm wave length.

• Potassium content (K%):

Potassium was determined according to the method described by Jackson (1973) using a Beckman Flame photometer.

• Total soluble solids of fruits juice (TSS %):

The TSS% was determined using a Hand refractometer according to Chen and Mellenthin (1981).

• Total acidity (%):

Total acidity was determined by direct titration of 0.1 N sodium hydroxide using phenolphthalein 1% as an indicator and expressed as citric acid percentage according to the AOAC (1985).

• Total sugars (%):

Total sugars were determined in fresh fruit samples according to Malik and Singh (1980).

• Vitamin C (ascorbic acid):          

The ascorbic acid content of the juice was determined by titration with 2,6-dichlorophenol-indo-phenol (AOAC, 1985). and calculated as milligrams per 100 ml of juice.

Statistical analysis:

                The appropriate approach of statistical analysis of variance, as outlined by Gomez and Gomez (1984), was applied to the collected data. The least significant differences (L.S.D.) test was used to compare the treatment means at a 0.05 level of probability.

RESULTS AND DISCUSSIONS

A)     Vegetative growth

The effects of irrigation levels and various organic fertiliser rates on strawberry plant growth characteristics, including plant height (cm), plant fresh weight (g), number of leaves, leaf area (LA), and total chlorophyll content, were shown by the results in Table (2) and Fig. (1). However, results indicate that the highest mean values of all vegetative growth studied increasing gradually by increasing irrigation levels at 100% (24.05 and 26.94 cm, 45.05 and 50.46 g, 25.43 and 28.48, 3.82 and 4.27 cm² and 48.96 and 54.84 unit SPAD), followed by 75% (23.40 and 26.20 cm, 40.55 and 45.41 g, 21.81 and 24.42, 3.44 and 3.85 cm² and 44.07 and 49.36 unit SPAD), as compared with 50% which recorded the lowest mean values of this traits, respectively, during both seasons.

These findings are consistent with those of other researchers (Yuan et al., 2004), who found that strawberry plants grew noticeably taller when irrigation water was increased from Ep 0.75 to Ep 1.25. Although different strawberry cultivars had different leaf areas under ideal conditions, all of them showed a fall in leaf area to a comparable level when water supply was limited, according to Grant et al. (2010). When strawberry crops were severely deficient in water, the weight and wetness of the fruit after harvest decreased. From the outcomes produced by (Arash et .al., 2015: Mona et al.,2021; Abou El-Goud et al., 2021 and Abou El-Goud, 2020 and 2021)

Drought stress demonstrated detrimental impacts on leaf area, leaf number, and chlorophyll content on strawberry plants and beans.

On the other hand, results from the same table's analysis of the application of organic fertilizers showed that all of them significantly affected the vegetative growth characteristics of strawberries, including plant height (cm), plant fresh weight (g), number of leaves, leaf area (LA), and total chlorophyll content. In this respect, results cleared that the Vermicompost 7t/fed. recorded the higher values of plant height, plant fresh weight, leaf area and total chlorophyll (28.68 and 32.13 cm, 49.00 and 54.88 g, 4.48 and 5.02 cm² and 50.76 and 56.85 unit SPAD), while the higher number of leaves recorded with Chicken manure 3.5t/fed. (31.16 and 34.90), as compared to control treatments which recorded the lowest mean values of this traits, respectively, during both seasons.

The observed improvement in strawberry plant development with composted manure application could be related to enhanced nutrient availability for a longer length of time during the season, which would be predicted to improve soil physical and chemical qualities (Abou El-Goud et al., 2021).  Furthermore, Li et al. (2020) and Abou El-Goud (2020 a, b, and c) discovered that vermicompost not only improves soil texture, aeration, and compaction, thereby improving plant water and nutrient uptake, but it also produces hormones, vitamins, plant regulators, antibiotics, and beneficial microbes, all of which improve plant health. Similarly, Najar and Khan (2013) found that adding 6 t/ha vermicompost to tomato plots increased vegetative plant growth significantly. Vermicompost macronutrients increase crop output by activating enzymes involved in chlorophyll synthesis, growth, yield, and enzyme system maintenance (Piya et al., 2018; Abou El Goud, 2020 a, c). During both seasons, the interaction effect of irrigation levels and varied organic fertiliser rates was very significant on plant height and number of leaves, but not on plant fresh weight, leaf area, or total chlorophyll content.

Table (2): Effect of irrigation levels and different organic fertilizer rates on vegetative growth during the 2020/2021 and2021/2022 seasons.

*Means in the same column within a treatment that followed by the same letter(s), are not significantly different at P = 0.05.

Fig. (1): Effect of irrigation levels and different organic fertilizer rates on vegetative growth during the 2020/2021 and 2021/2022 seasons.

B)   Yield characters

                The results in Table (3) and Figs. (2 and 3) demonstrated the effect of irrigation levels and varied organic fertiliser rates on strawberry yield parameters (fruit length (cm), fruit weight (g), yield/plant, and yield/fed). However, results show that the highest mean values of all yield characteristics studied increased gradually by increasing irrigation levels at 100%, which recorded higher values of fruit length, fruit weight, yield/plant, and yield/fed. (3.25 and 3.65cm, 15.89 and 19.33 g, 755.73 and 906.87 kg/plant, and 24.01 and 26.38 t/fed.) during both seasons, as compared to irrigation levels at 50%, which recorded the lowest mean values of these traits, respectively.

                The moderate soil moisture level, which led to an increase in nutrient availability and uptake, as well as a reduction in soil salinity compared to low field capacity, may be linked to the positive influence of 100% or 75% of the reference evapotranspiration on fruit output and its components. Higher field capacity values enhanced growth parameters, resulting in higher rates of photosynthetic processes and carbohydrate generation, which increased final tuber yield. The drop in total yield due to water deficit, on the other hand, can be linked to a reduction in leaf area due to fewer and smaller leaves, an increase in stomatal resistance and gas exchange, and a decrease in transpiration rate, all of which resulted in a reduction in photosynthesis. (Ghosh et al., 2000).

                Better fruit size and weight under these irrigation treatments may have also contributed to higher total production in the current study. These findings are consistent with those of another author (Yuan et al., 2004), researchers also observed a considerable increase in strawberry fruit yield under higher levels of drip irrigation, which they attributed to optimal soil moisture conditions due to frequent water application. Earlier, similar results of increased strawberry yield under drip irrigation were reported. (Kachwaya et al., 2016).

                Water efficiency could be enhanced by using strawberry cultivars that are more resistant to water stress, resulting in better yield with more sustainability (Martinez-Ferri et al., 2016). According to Gomes et al. (2015), water consumption efficiency is directly connected to the irrigation system and the frequency of water application in strawberry plant production.

                In contrast, data from the same table show that organic fertilisers have an effect on strawberry production variables such as (fruit length (cm), fruit weight (g), yield/plant, and yield/fed. However, results show that vermi compost 7t/fed. recorded the highest mean values of fruit length (3.91 cm) in the second season and chicken manure 3.5t/fed. in the first season (3.39 cm), while fruit weight recorded the heaviest fruit weight with vermi compost 7t/fed (22.57 and 23.71 g), as well as yield/plant (826.15 and 998.46 kg/plant) and yield/fed (28.01 t/fed.

               The highest mean values for some new sweet melon lines were scored at 100% irrigation rate during the two seasons, followed by 70% irrigation rate treatment; while 40% irrigation rate treatment possessed the lowest mean values in this regard, as reported by (Abou Kamer et al., 2022).

                Increased production may be attributable to increased availability of N, P, and K levels in soil as a result of organic manure application (Zaman et al., 2011). According to Al-Balikh (2008), chicken manure produced the maximum numbers of tubers/plant, total tuber yield/ha, and marketable tuber yield/ha. The increase in tuber yield of potato plants as a result of using farmyard manure at various levels may be attributed to the positive effects of farmyard manure application on the vegetative growth characters of potato plants, which consequently increased photosynthesis efficiency and synthesis of carbohydrates such as starch content, resulting in an increase in plant tuber yield (Ahmed et al., 2009). Al-Hisnawy (2011) got similar results using organic manure, which induced the majority of yield components. Organic manure may have boosted soil organic matter, water holding capacity, nutrient availability, soil aggregation, root system, and microbial activity (John et al., 2002).     

                According to Mona and Amal 2020 on yield and quality of watermelon (cv. Skata F1 hyprid), the use of organic manure improves the yield and its components by improving soil productivity, soil organic carbon content, soil microorganisms, soil physical structure, soil nutrient status, and crop yield. Data also agreed with other researchers, who said that when basal farmyard manure was put on poor sandy soil with 0.3 to 0.5% humus content on Charleston Grey watermelon, the fruit yield was 42.4 t/ha (Audi et al., 2013).

                In the second season, the interaction effect of irrigation levels and varied organic fertilizer rates was highly significant on fruit length, yield/plant, yield/fed., and fruit weight, but not on fruit weight in the first season.

Table (3): Effect of irrigation levels and different organic fertilizer rates on yield characteristics of strawberries during the 2020/2021 and 2021/2022 seasons.

*Means in the same column within a treatment that followed by the same letter(s), are not significantly different at P = 0.05.

Fig. (2): Effect of irrigation levels and different organic fertilizer rates on fruit length and fruit weight of strawberries during the 2020/2021 and 2021/2022 seasons.

Fig. (3): Effect of irrigation levels and different organic fertilizer rates on yield/ plant and yield/ fed of strawberries during the 2020/2021 and 2021/2022seasons.

C) Chemical composition

                Table 4 and Figures 4-7 show the effect of irrigation levels and organic fertiliser rates on chemical composition (Acidity (%), TSS (%), VC (mg/100 g f.w.), and total sugar percentage). However, results showed that increasing irrigation levels to 100% (0.518 and 0.582%, 5.35 and 6.00%, 56.66 and 63.46 mg/100 g f.w., and 5.60 and 6.27%) resulted in the highest mean values of all these traits studied, as compared to 50%, which recorded the lowest mean values of these traits, respectively, during both seasons.

                On the other hand, results showed that organic fertiliser treatment had a substantial effect on chemical composition (Acidity (%), TSS (%), VC (mg/100 g f.w.) and total sugar percentage). However, the control treatment had the highest percentage of acidity (0.618 and 0.692%) compared to all organic treatments, which had the lowest percentage of acidity. Meanwhile, during both seasons, vermicompost at 7t/fed recorded the highest levels of TSS and VC (5.85 and 6.55% and 63.69 and 71.34 mg/100 g f.w., respectively), while chicken manure at 3.5t/fed recorded the greatest percentage of total sugar (6.13 and 6.86%).

       Organic fertilisers such as vermicompost and bokashi are commonly thought to play critical roles in reducing or eliminating chemical fertiliser inputs, which increase the production of active compounds such as enzymes, antibiotics, siderophores, and the plant hormone indole-1,3-acetic acid (Abou El-Goud et al., 2021; Abou El Goud, 2020a, b, c, and Mona and Amal 2020), which lead to increased total

                According to Odongo et al. (2008), FYM increased the TSS content of strawberry fruits; however, the major negative effect of FYM on TSS was due to K dilution caused by robust leaf development induced by a modest FYM rate. According to El-Hamid et al. (2006), such increases in total sugars, TSS, and titrable acidity resulted from the synergistic effect of the differential combination of inorganic fertiliser and organic manures.

                Gliessman et al. (1996b) and Cayuela et al. (1997) previously demonstrated greater quality and higher sugar contents in strawberry fruits in response to organic fertilizer treatment vs mineral fertilizer treatment. It was proposed that in an organic system, soil biotic life expands, causing plants to synthesise more vitamins and other useful compounds produced by these organisms. El-Sheikh and Salama (1997) showed similar results on tomatoes, where organic fertilizer boosted fruit vitamin C, acidity, and total sugars. During both seasons, the interaction effect of irrigation levels and varied organic fertilizer rates on acidity, TSS, and total sugars was highly significant.

                The observed increase in mineral composition in leaf tissue from organic manure treatment in general, and composted forms (PCM and FD) in particular, is consistent with the findings of Abou El-Goud and Yuosry (2019) and Abou El-Goud (2020 and 2021), who discovered that organic compost increased nutrient availability, cation exchange capacity, and micronutrients. Abou El-Goud et al. (2021) obtained similar results on potatoes. By increasing root length and root hairs in the rhizosphere, bokashi fertiliser benefits roots and plant growth. Organic matter can improve soil structure and increase N, P, and K nutrients as well as other microelements for improved root development, which reflects on nutrient uptake and can optimise the photosynthetic process.               

Table (4): Effect of irrigation levels and different organic fertilizer rates on Chemicalcomposition of strawberries during the 2020/2021 and 2021/2022 seasons.

*Means in the same column within a treatment that followed by the same letter(s), are not significantly different at P = 0.05.

Fig. (4): Effect of irrigation levels and different organic fertilizer rates on acidity

percentage of strawberries during the 2020/2021 and 2021/2022 seasons.

Fig. (5): Effect of irrigation levels and different organic fertilizer rates on TSS

               percentage of strawberries during the 2020/2021 and 2021/2022 seasons.

Fig. (6): Effect of irrigation levels and different organic fertilizer rates on VC (mg/ 100g f.w.) during the 2020/2021 and2021/2022 seasons.

Fig. (7): Effect of irrigation levels and different organic fertilizer rates on total sugar (%)during the 2020/2021 and2021/2022 seasons.

Table (5) and Figs. (8-10) show the effect of irrigation levels and different organic fertilizer rates on chemical composition (Acidity (%), TSS (%), VC (mg/100g f.w.) and total sugars percentage). However, the results showed that the highest mean values of all the traits studied increased gradually by increasing irrigation levels to 100% (0.518 and 0.582%, 5.35 and 6.00%, 56.66 and 63.46 mg/100g f.w. and 5.60 and 6.27%), as opposed to 50%, which recorded the lowest mean values of these traits during both seasons.

                These findings are consistent with, who showed that large concentrations of elements in fruits were caused by NH4+ ion adsorption on the surface of compost and became available for plant uptake. Similarly, said that applying organic fertiliser with organic manures increased both N mineralization and nitrification, which improved access to NH4+ and resulted in a greater number of viable cells of nitrifying bacteria, particularly when chemical fertilisation was used. Furthermore, chicken manure has an indirect effect on growth and mineral content by improving soil physical, chemical, and biological qualities, resulting in more vigorous squash development (Abou El-Goud and Yousry 2019).

                Organic material is utilised to avoid or enhance the negative effects of stress on plants and yield reduction. It is a substance used to reduce soil salinity. Root development in soil increases organic matter, improves soil structure, and increases water and air permeability. It is a popular fertilizer (Hassanpanah and Azimi, 2012).

Mona et al. 2021 discovered that varied amounts of irrigated water influenced the growth, productivity, and pod properties of Faba bean genotypes in different ways, indicating that Faba bean genotypes differed in their ability to survive different rates of water scarcity. This would aid in the discovery of additional growth and physiological markers associated with water deficit sensitivity. Due to the scarcity of irrigation water in semi-arid countries such as Egypt, advanced irrigation systems such as the drip irrigation system are required.

The interaction effect between irrigation levels and different organic fertilizers rates was highly significantly on potassium, while not significant on nitrogen and posphorus, during both seasons.