Biology EEI Effect of Inorganic and Organic Fertilisers on Yield and Growth of Tomatoes

ABSTRACT Aim: Laboratory experiments were carried out at Trinity Anglican School, Australia in 2010 to study the effect of various organic and inorganic fertilisers on the growth of tomato plants in the northern tropical region of Queensland, Australia during the winter season of 2010. Five pots with tomato seedlings were prepared for the experiment. Two pots were fertilised with inorganic fertilisers (IF), two with organic fertilisers (OF) and one without any fertilisers.

All pots were watered daily. Each week height, number of leaves, flowers and fruits were recorded on all pots. At the end of experiment, the heighest height was recorded with Powerfeed (OF) and maximum number of leaves with Seaweed (OF). Flowers started to appear in week six followed by fruit in week seven. Number of flowers and fruit were highest with Herb (IF). Plant with no fertiliser had minimum growth and late appearing flowering and fruits. From this experiment it is clear that fertilisers play an important in role of Tomato plants growth. Vegetative phase was longer with OF while fruits and flowers were earlier with IF.

HYPOTHESIS: I believe that the tomato plants grown with organic fertilisers will have a good growth compared to the plants grown with inorganic fertiliser and no added fertiliser.

INTRODUCTION The tomato is an herbaceous perennial plant, but is usually grown as an annual in temperate regions since it is killed by the frost. Tomato plants can be grown in fairly wide range of soil and climatic conditions, and they are also suitable for container growing. Tomato is one of the world’s most important vegetable crops. (Scholberg, J et al 2000)

Growth characteristics of tomato plants are governed by genetic traits, management practices, nitrogen content of soil and fertilisers, location and season, method of irrigation(sub and drip irrigation), type of fertilisers(organic or inorganic), salinization of soil and minerals. Some minerals are required by the plants for the normal development and growth stages which are met by foliar (e.g. leaf) absorption or by the uptake of solutes from the soil solution. The three primary macronutrients are nitrogen (N), phosphorus (P), and potassium (K). The three secondary macronutrients are calcium (Ca), sulphur (S), magnesium (Mg) and the micronutrients or trace minerals are boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo) and selenium (Se).

The growers of vegetable crops mainly add nutrients to plant roots zones at levels exceeding many times of those required for optimal growth because of the uptake of solutes from the soil solution and soil matrix. (Mawgoud A.M.R et al 2007). Groundwater for irrigation used by the growers must consider the amount of nitrogen in the water when deciding how much nitrogen fertiliser they should apply to crop as high amount of nitrogen in the irrigation water can have a preponderant influence on plant growth and development (Machado, R M.A et al 2008).

Central to the science of soil management and crop production is the topic of increasing crop yields and growing healthy plants that provide high nutritional value. When it comes to feeding a hungry world inorganic fertilizers (IF) are unsurpassed in their ability to provide high levels of nutrients to plants in an efficient and economical manner. Understanding their differences helps us all to understand their appropriate uses. Organic fertilizers (OF) are the result of the natural decomposition of plant and animal waste. Most common organic fertilisers contain animal manures, composts, sewage sludge and by-products from processed animal and vegetable materials. Inorganic fertilizers are mined or manufactured.

The primary difference between organic and inorganic fertilizers is the nutrient content. Organic fertilizers contain small concentrations of plant nutrients which mean they must be applied at high rates in order to provide the nutrient needs of plants. While it does contain nutrients, manures nutrient levels vary greatly from load to load. Nutrients in manure usually are not readily usable to the plants and are not properly balanced to provide all the nutrient needs the plant requires. Inorganic fertilizers on the other hand can be applied to the exact levels or nutrients required by the plants. ()

The benefits of organic fertilisers are that there is less danger of over fertilisation improves soil structure and vastly improves the water holding capacities of sandy soils. But at the same time disadvantages are that nutrients are not immediately available to the plants due to slow release and required to break down in the soil and convert to a fertilizer that plant can use. Also the exact amount of nutrients and exact elements in an organic fertiliser such as manure is not readily available to the home gardener. The benefit of inorganic fertilisers is that the nutrients are easily available to the plants. Also the exact amounts of a given element can be easily calculated and given to plants.

The organic systems of growing crops emphasizes the accumulation of soil organic matter and fertility over time through the use of cover crops, manures and composts and rely on the activity of a diverse soil ecosystem to make nitrogen and other nutrients available to plants. Farmyard manure which is an organic material can be considered as humus supplying and a soil improving agent. Enhancements of photosynthesis, chlorophyll density and plant root respiration have resulted in greater plant growth with humic acid application (Mawgoud A.M.R et al 2007). Comparing the organic fertilisers to the mineral fertilisers, it is said that the organic fertilisers are considered environment friendly than the mineral ones even though there is limited research on the use of organic fertilisers (Kaya S et al 2005).

The difference between two types of fertilisers is the release timing of the nutrients which is related to the nutrient solution characteristics and also to the substrate itself (Jian et al 2004). The organic matter content with substrate promotes microbial biomass and activity. The yield response of tomato to the added nitrogen through inorganic fertilizers is evident to a considerable level. However, the nitrates produced in the soil from the added N fertilizers can react with the organic matter of the soil and deplete even the native humus and may result in the fall of the crop production. This problem can be overcome by the application of additional amount of organic residues. (Douglas J. ezinearticles.com)

In relation to the above, the aim of this study was to investigate the response of tomato plants to two different organic and inorganic fertilisers as compared to tomato plants without any added fertilisers.

Procedure

Filled up five litre buckets of height 9.5cm and a diameter of 10cm with four litres of potting mix. Filled four litres of potting mix because the tomato plants require a minimum of 1-3 kgs of potting mix to get fruits.

Placed one seedling in each pot.

Watered the first pot with 0.4ml of seaweed concentrate in 1L of tap water. This was done on the basis of manufacturer’s recommendations and then calculations.

Watered the second pot with 0.6ml of Powerfeed in 1L of tap water. This was done on the basis of manufacturer’s recommendations and then calculations.

Watered the third pot with 1.5g of herb garden granules in 1L of water. This was done on the basis of manufacturer’s recommendations and then calculations.

Watered the fourth pot with 3.2g of tomato and vegetable granules in 1L of water. This was done on the basis of manufacturer’s recommendations and then calculations.

Watered the fifth pot with just 1L of water. To see the effect of no fertiliser on the growth of the plant

Measured the plants from the roots with a metre ruler every week, counted the leaves, the number of fruits and number of flowers. To see the effect of different types of fertilisers on the growth of tomato plants.

The plants had their height measured in the first week and it was found out that the plant with organic fertiliser (OF) powerfeed had the highest growth measuring 8cm, followed by inorganic fertiliser (IF) herb garden with a height of 7cm; Tomato and vegetable fertiliser (IF) with height of 3.5cm, and Seaweed (OF) with height of 3cm. The plant with no added fertiliser had the least growth of 2.5cm. By week four, the height of the five tomato plants was ranging in between 11-22cm but the plant with Powerfeed fertiliser (OF) was still leading at the height of 22cm. At the start of the eight week there was a marginal difference between the heights of all plants (28-31cm) including the plant with no added fertiliser. In the last week of data collection the height of all plants ranged from 29-39 with powerfeed fertiliser (OF) plant still having the highest height at 39cm and plant with no added fertiliser being shortest with height of 29cm.

*Tomato and Vegetable Fertiliser

In the first week of planting the tomato plants, the leaves on all plants ranged from 8-25 with the Tomato and Vegetable fertiliser (IF) having 25 leaves and the no added fertiliser plant had only 8 leaves. After four weeks the leaves of all five tomato plants ranged from 110 to 160, with seaweed fertilised (OF) plant having the highest number of leaves at 160 and plant with herb garden fertiliser (IF) having the lowest number of leaves at 110. In the eight week the range of the leaves was 210 to 300 leaves with seaweed fertilised (OF) plant having 300 leaves and the herb garden fertilised (IF) plant having 210 leaves.

The flowering on all five plants started after growing the tomato plants for 6 weeks with the flowers coming in the range of 1-6 in all plants except for the plant without any added fertiliser. The herb (IF) fertilised plant had the highest number of flowers (six).Two weeks later the number of flowers ranged between 0-9 with the highest number of flowers observed in the plant grown with herb garden fertiliser (IF). In the last week of data collection, the flowers ranged from 5-10 with the most flowers observed on the tomato plant with herb garden fertiliser (IF) and the least on the tomato plant with Tomato and vegetable fertiliser (IF).

The fruit on all plants started to arrive on the 7th week except for no added fertiliser. The range was between 1-6. The herb garden fertiliser (IO) plant had the highest number of fruits (6) while the other two fertilisers, Tomato and Vegetable (IF) and Seaweed (OF) had the least number of fruit (1). In week 9, the last week of data collection, there was no difference in the number of fruits on all the plants except for the plant grown with herb garden fertiliser which had 9 fruits instead of 6 fruits. This data is shown in Table 4.

FIGURE 4: FRUITS OF ALL PLANTS WITH DIFFERENT FOR EVERY WEEK

At the end of the investigation, the highest height of 39cm was observed in the tomato plant with the powerfeed (OF) fertiliser, the highest numbers of flowers (10) and fruits (9) were observed in plant with herb garden (IF) fertiliser. The highest numbers of leaves (300) were observed in plant fertilised with seaweed (OF) fertiliser. For pictures please refer to appendix 2

DISCUSSION Height, flowers, fruits and leaves were measured to determine the growth of the tomato plants to various fertilizers. Plant growth and yield is a function of nutrients supply providing that all other conditions are met. Tomato being heavy feeder and exhaustive crop requires large quantities of inorganic organic fertilizers (Shukla Y R et al, 2009). The production and productivity of crop are below due to lack of proper management practices, poor resource base of farmers and lack of knowledge to exploit the situation.

The earliest flowering was observed in pots applied with powerfeed, seaweed, herb and tomato & vegetable fertilisers in week five of experiment, while the pot with no added fertilisers had no flowerings. Highest flowers were in plants with Herb garden fertiliser (IF). At the same time TV fertiliser (IF) had two flowers in the beginning but picked up by week nine. Still the plant with herb garden fertiliser had ten flowers as compared to five flowers with TV (IF). This difference might be due to the different amounts of inorganic fertiliser applied which was 3.2g for TV and 1.5g for herb garden fertiliser.

This was probably related to the high nitrogen application associated with TV (IF). Delayed flowering due to the application of nitrogen at higher dose is responsible for increased nutrient uptake leading to longer vegetative phase and delayed flowering. Similar results have also been observed by Kumar et al (2004) and Shukla, Y.R. et al (2006). The treatment combination having all fertilisers and manures produces the highest number of fruits per plant. Both organic fertilisers had a similar number of flowers. Number of flowers with organic fertilisers was less than inorganic fertiliser (herb garden). This probably explained by the fact that the nitrogen has to be converted into the form by the plant that it can use easily (Kaya S et al 2005). No treatment caused reduction in number of fruits over the control.

The height of powerfeed fertilised (OF) plant picked up from the first week of plantation and continued the trend until the end of the experiment. Height of the powerfeed fertilised plant stayed the highest of all the other plants till the end of the experiment but the other plants nearly reached the height of powerfeed fertilised (OF) plant by the end of the experiment including the plant with no added fertiliser. The both plants with inorganic fertilisers nearly achieved the same height. At the same time, the plant with seaweed (OF) stayed at lower height compared to powerfeed (OF). This is probably due to the higher nitrogen, potassium and phosphorus content in powerfeed (OF). Similar results were observed by Abdel-Mawgoud A.M.R. et al (2007) and Machado, R.M.A et al (2008).

From the first week of planting all the tomato plants, the plant with TV (IF) fertiliser had the highest number of leaves but after there was no clear trend of number of leaves after that. The results of the all the five plants kept fluctuating but at the end of the experiment the seaweed fertilised (OF) plant was leading in the number of leaves that it produced. Similar results were observed by Abdel-Mawgoud A.M.R. et al (2007).

After seven weeks, the plants fed with fertilisers had some fruits appearing, with the herb garden (IF) fertiliser having the highest number of fruits. At the end of the experiment, both the organic fertilisers had the same number of fruits. Herb garden (IF) fertiliser still had the highest number of fruits by the end of the experiment. The plant with no added fertiliser had the first fruit appearing at the end of week eight as compared to fertilised plants. This means there was nearly a delay of eleven days. Number of fruits with no fertilised plant was lowest. Similar results were reported by Shukla Y.R et al (2006).

Nitrogen content of herb garden was 6.3% which is probably ideal nitrogen content for optimal growth (Machado R.M.A et al 2008). Although organic fertilisers had a higher nitrogen content compared to the inorganic fertilisers, they did not show high number of fruits. This maybe related due to the shorter duration of the current experiment. Other argument is that with the high N content, the vegetative phase is proloned and fruits appear late. Additional N may be beneficial later on, such as during fruit production, when demands for N are much higher (Rattin J E et al, 2003). Youssef et al (2001) reported that combination of organic and inorganic fertilizers increased the number of fruits per cluster and fruits per plant as compared to their individual application.

Other factors also may affect the Tomato plants. Soil volume plays a considerable role in plant response to N application. Roots undoubtedly explore more soil in the field than in pots. Soil N may have also migrated into the root zone from the area beyond that wetted by drip emitters ( Machado R M A et al 2008). Rippy et, al. (2004) determined that organic fertilizers did not significantly affect total yield and percentage of first class fruits. Although organic fertilization is the need of the day, but all of a sudden the tradition of applying inorganic fertilizers cannot be changed (Shukla Y R et al 2006). Temperature has a significant influence on many aspects of growth and development in tomato (E. Heuvelink 2005).

CONCLUSION Based on the results collected over the 8 week period, it may be concluded that the tomato plant grown with an organic fertiliser called Powerfeed (OF) had the highest growth of all the plants and its height had consistently stayed higher than any other tomato plant every week. Also the tomato plant grown with another organic fertiliser called Seaweed (OF) had a slow growth in the start but at the end of the experiment the tomato plant grown with Seaweed (OF) was just behind the tomato plant grown with Powerfeed (OF) fertiliser. At the end of the experiment the tomato plant grown with Seaweed (OF) had the highest number of leaves and the least in herb garden (IF) fertiliser, But the herb garden (IF) had the most number of flowers than any other tomato plant, as well as having the highest number of fruits. From this experiment, it is very difficult to determine whether organic and inorganic fertiliser is better to grow the tomato plants. Limitations in this experiment were time and pot with limited soil.

APPENDIX

1. Manufacturers recommendation for all fertilisers Powerfeed (Organic): 45ml per 9L of water every 2 weeks Seaweed (Organic): 30ml per 9L of water every 2 weeks Herb Garden (Inorganic): 75g per square metre and then water in Tomato and Vegetable (Inorganic): 150g per square metre and then water in.

2. Pictures of all tomato plants in week 3 and week 8.

PLANTS IN WEEK 3

Plants in week 8

ACKNOWLEDGEMENTS

I would like to thank my father for all his help in proof reading the article and suggestions, the lab assistant Mrs. Heather Law for allowing me to use the school’s equipment, Mr.Gupta for his help in getting access to a few articles and to my biology teacher Mrs.Elphick for all her suggestions when doing this experiment.

Annotated bibliography

TITLE OF ARTICLE: Effect of Inorganic and bio-fertilizers on yield and horticultural traits in tomato Author: Shukla Y.R., Thakur A.K., and Joshi A. Institution: University of Horticulture & Forestry Horticultural Research Station, India Date: 2006 URL: http://www.indianjournals.com/ijor.aspx?target=ijor:ijh&volume=66&issue=2&article=029 Aspect: Tomato plant growth

Summary: The authors are senior research scientists at University of Horticulture & Forestry Horticultural Research Station, who have investigated the effects of inorganic and bio-fertilisers to see the yield of tomato plants with different types of fertiliser and different amount of fertilisers applied. Their research findings are similar to previous scientists. The results are easily presented in a table so that the reader can easily interpret the effect of fertilisers on the growth and yield of tomato plants.

TITLE OF ARTICLE: Response of Tomato Plants to Organic Nutrition in Soilless Culture. Author: Kaya S., Tezel Y., Okur N., Caturano E., Leonardi C Institution: Ege University, Turkey & Catania University, Italy Date: 2005 URL: http://www.ecoponics.de/getfile.php?file=publications/2007Kayaetal.pdf Aspect: Tomato plant growth in soilless culture

Summary: The authors are researchers at Ege University & Catania University, who have been investigating ways to reduce the environmental impact of soilless culture particularly in open systems using organic nutrition. The results are easily presented in the form of tables and graphs. The object was to better understand the response of tomato plants fed with organic nutrient solution.

Responses of Tomato Plants to Different Rates of Humic-based Fertilizer and NPK Fertilization Author: Abdel-Mawgoud A.M.R, El-Greadly N.H.M., Helmy Y.I., Singer S.M. Institution: National Research Center, Dokki, Cairo, Egypt Date: 2007 URL: http://www.insipub.com/jasr/2007/169-174.pdf Aspect: Tomato plants growth with different rates of fertilisers

Summary: The authors are senior research scientists at NCR, who have been carrying out a field experiment during winter seasons of Egypt to see the response of tomato plants to different types of fertilisers. There were measurements of Plant height (cm), number of leaves; numbers of branches, total fresh and dry weights per plant were recorded in the end of the growing season. Weight and number of fruits in total and marketable yields were recorded from each replicate. Average individual fruit weight was also calculated from these data. There were also some chemical measurements to determine the Soluble Solids Contents (SSC) in fruit sap. The total content of some nutrients such as N, P, K and Ca were also determined in the leaves.

Summary: The authors are senior research scientists at the United States Department of Agriculture, who have been investigating the effect continuous application of small quantities of nitrogen in irrigation water as well as applying nitrogen as a starter on growth and development of processing tomato plants from transplantation to beginning of first fruits. The plant growth was unaffected by the nitrogen in the field trial and there was high residue of nitrogen in the soil and organic matter is high.

References

1. Abdel-Mawgoud, A.M.R, 2007. Responses of Tomato Plants to Different Rates of Humic-based Fertilizer and NPK Fertilization. _Journal of Applied Sciences Research_, [Online]. 3 (2), 169-174. Available at: http://www.insipub.com/jasr/2007/169-174.pdf [Accessed 07 July 2010].

2. Eraslan, F, 2008. Comparative Physiological and Growth Responses of Tomato and Pepper Plants to Fertilizer Induced Salinity and Salt Stress under Greenhouse Conditions. _International Meeting on Soil Fertility Land Management and Agroclimatology_, [Online] 687-696. Available at: http://www.dergi.adu.edu.tr/ziraatdergi/sp2009/077.pdf. [Accessed 27 May 2010].

3. HEUVELINK, E, 2005. Influence of sub-optimal temperature on tomato growth and yield: a review. _Journal of Horticultural Science & Biotechnology_, [Online]. 80 (6), 652-659. Available at: http://www.narcis.info/publication/RecordID/oai:library.wur.nl:wurpubs/341845 [Accessed 10 June 2010]

4. Hole, D.G, 2005. Does organic farming benefit biodiversity? Biological Conservation, [Online]. 122 (1), 113-130. Available at: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5X-4D67BFW-5&_user=10&_coverDate=03/31/2005&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1413692699&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=dd51ac5360cc4b591a1281c895a000e5[Accessed 09 June 2010].

5. John Douglas. 2010. _Organic vs. Inorganic Fertilizer_. [ONLINE] Available
at:http://ezinearticles.com/?Organic-vs.-Inorganic-Fertilizer&id=439310. [Accessed 01 June 10].

6. Kaya, S et al 2005. Response of Tomato Plants to Organic Nutrition in Soilless Culture. International Journal of Food, Agriculture and Environment, [Online]. 6/2, 303-305. Available at: http://www.ecoponics.de/getfile.php?file=publications/2007Kayaetal.pdf [Accessed 02 July 2010].

7. Machado, Rui M.A, 2008. Nitrogen requirements for growth and early fruit development of drip-irrigated processing tomato. Journal of Food, Agriculture & Environment, [Online]. 6 (3&4), 215-218. Available at:http://afrsweb.usda.gov/SP2UserFiles/person/34338/PDF/2008/2008JFooddAgriEnv6_215_218.pdf[Accessed 01 May 2010].

8. Mitchell, AE, 2007. Ten-Year Comparison of the Influence of Organic and Conventional Crop Management Practices on the Content of Flavonoids in Tomatoes. _Journal of Agricultural and Food Chemistry_, [Online]. 55(15), 6154-9. Available at:http://www.ncbi.nlm.nih.gov/pubmed/17590007 [Accessed 11 May 2010].

9. Scholberg, J, 2000. Field-Grown Tomato. _Agronomy Journal_, [Online]. 152-159. Available at: http://agron.scijournals.org/cgi/reprint/92/1/152.pdf [Accessed 17 June 2010].

10. Shukla, Y.R., 2006. Effect of Inorganic and bio-fertilizers on yield and horticultural traits in tomato. _Indian Journal of Horticulture_, [Online]. 66 /2, 285-287. Available at:http://www.indianjournals.com/ijor.aspx?target=ijor:ijh&volume=66&issue=2&article=029[Accessed 01 July 2010].

11. Shukla, Y.R., 2009. Effect of Inorganic and bio-fertilizers on yield and horticultural traits in tomato. _Indian Journal of Horticulture_, [Online]. 66 /2, 285-287. Available at:http://www.indianjournals.com/ijor.aspx?target=ijor:ijh&volume=66&issue=2&