Group 4 ProjectDetermining The Effects of Increasing Salinity Concentration on The Rate of Seed Germination

By: Sarbjit Masson, Debanila Talukdar, Hamna Amjad, Roger Li, David Hyatali and Mudit Kalia

Topic Question

What is the effect of increasing salinity on the rate of germination of crab grass seeds?

Reason this Topic was Chosen:

The single greatest profession in the world at the moment, is that of a subsistent farmer. While growing barely enough food to feed themselves and their families, they try to gather whatever is remaining to sell to gain some money in order to buy essentials. One problem is the low success rate of their farming. With low seeds germination rates and low yields from the ones that do grow, has led to a meager life styles for them. One of the problem that seeds fail to germinate is high soil salinities surrounding the seeds. Similarily in North America, municipalities rely heavily on road salt to improve winter driving conditions. But year after year use has led to accumulation of road salt on the soils nearby the roadways. As a result, this is having a profound effect on the vegetation that grows from these soils. Hence, for this project the effects of increased salt concentration on the germination ability of the Dactylis species will be examined.

Procedure

For this experiment, the scrolling method was used to determine what the effects of increasing salinity concentration on seed germination would be. Each trial had a different salinity concentration value. The initial value started from the controlled variable of 0.0g/L of road salt concentration and went up to 60.0g/L. The trials that were conducted were in one litre of tap water with 10 crab grass seeds in each trial. There were a total of four trials that were conducted. Each individual trial was placed in its own beaker, with Saran Wrap over it and was given a time period of three days to germinate.

Observations (Findings)

The following observations were recorded during this experiment.

Volume of Water (mL)

Salt Concentration (g/L)

Number of Seeds Germinated

Number of Seeds That Did Not Germinate

1000.0 0.0 10 2

1000.0 20.0 8 4

1000.0 40.0 0 12

1000.0 60.0 0 12

Pictures of Each Trial

0.0 g/L

20.0 g/L

40.0 g/L

60.0 g/L

Analysis

BAR GRAPH – SEED GERMINATION

0.0 20.0 40.0 60.002468

101214

24

12 1210

8

0 0

Effect of Seed Germination on the Change of Salt Concentrations

Number of Un-successful Ger-minations (±1)Number of Success-ful Germinations (±1)

Concentration of Salt Solutions (g/L)

Num

ber

of S

eeds

TABLE – GERMINATION %

Salt Concentration (g/L) Percentage of Successful Germinations (%)

Percentage of Unsuccessful Germinations (%)

0.0 83.3 ± 22.2 16.7 ± 11.1

20.0 66.7 ± 19.5 33.3 ± 13.9

40.0 0.0 ± 0.0 100.0 ± 25.0

60.0 0.0 ± 0.0 100.0 ± 25.0

SAMPLE CALCULATIONS

Percentage of Successful Germination → 0.0g/L Salt Solution

Uncertainty of Successful Germination → 0.0g/L Salt Solution

%= # of Successful Germination(# of Successful Germination)+(# of Unsuccessful Germination) *100

%= 10±1(10±1)+(2±1)*100

%=83.3ത

Uncertainty=( 110+ 212) * 83.3ത

Uncertainty= 22.2

SCATTER PLOT – GERMINATION %

0.0 20.0 40.0 60.00.0

10.020.030.040.050.060.070.080.090.0

100.0

16.7

33.3

100 100

83.3

66.7

0 0

Percentage of Successful and Unsuccessful Germinations

Percentage of Successful Germination (%)Linear (Percentage of Successful Germination (%))Percentage of Unsuccess-ful Germination (%)Linear (Percentage of Unsuccessful Germi-nation (%))

Concentrations of Salt Solutions (g/L)

Perc

ent

(%)

Conclusions

Thus in conclusion there were ten seeds that germinated in the paper towels soaked in 0.0 g/L, eight seeds that germinated in the paper towels soaked in 20.0g/L of salt and no seeds germinated in either the 40.0g/L solution or the 60.0g/L solution. As is obvious seeds are restricted in their germination if salt is found in their immediate vicinity. Salinity may also affect the germination of seeds by creating an external osmotic potential that prevents water uptake or due to the toxic effects of Na+ and Cl- ions on the germinating seed. The relative importance of the toxic effects of NaCl on seed germination of pea is not clear and will not be explored further in this experiment. This study was conducted to determine the effect of NaCl on seedling growth and germination, and to determine factors responsible for failure in seed germination under saline conditions comparing various levels of NaCl.

Evaluations Possible errors for this lab could include the time allotted to allow

germination. Only three days were given for the seeds to germinate. Since the purpose of this experiment is to monitor the success of the seed germination not at the speed at which the seeds germinated. Thus if another week had been provided for the germination then the seeds in the higher salt concentration may have also germinated. Also more seeds should have been used in each trial. The usual germination rate is around 90%. However since such a small number of seeds were used in each salt concentration every seed which did not germinate greatly affected the overall percentage. There are always a few seeds which are no longer viable for germination since they may be defective for a variety of reasons. If one of these seeds were placed in the trial it would greatly skew our perspective of the negative effect that concentration of salt has on germination success.

Implications

ECONOMICAL IMPLICATIONS

Usage of salts are common implications toward both plant growth and human activities

An example of salt are fertilizers Fertilizers promote plant growth and biomass when

used in the right amount Commonly used to treat maize fields, barley, sorghum,

rapeseed, soy and sunflower Human activity salts are ‘de-icing salts’ Promote safer passages on roads and highway Usually have negative impacts on the environment

ENVIRONMENTAL IMPLICATIONS

Changes in salinity levels pose risks to the environment ↑ concentrations of salt in soil causes osmosis in plant cells

Osmosis: Diffusion of free water molecules from an area of low solute concentration to an area of high solute concentration across a partially permeable membrane

The water moves out from the cell to equalize concentration between the two mediums

Decreased water concentration results in root and plant cell damage

May eventually kill plants Thus, as salt concentration increased, successful seed

germination decreased

Social Implications

Consequences of Salinity Detrimental effects on plant growth and yield Damage to infrastructure (roads, bricks, corrosion of pipes and

cables) Reduction of water quality for users, sedimentation problems Soil erosion ultimately, when crops are too strongly affected by

the amounts of salts

Salinity is an important land degradation problem. Soil salinity can be reduced by leaching soluble salts out of soil with excess irrigation water. High levels of soil salinity can be tolerated if salt-tolerant plants are grown.

Indirect Implications

PovertyHunger (malnourishment)Depleted EconomiesDisease

Poverty

Due to the salinity in the soils, it becomes impossible to yield a good and healthy crop. This then results in poverty, where communities are unable to feed, provide, and make a living for themselves. Poverty refers to the condition of not having the means to afford basic human needs. When a rural based community experiences salinity in the soils farmers are unable to feed their families and their incomes are hardly hit.

Hunger / Depleted Economies

Without the sufficient crops needed to feed and raise a family, both children and adults will eventually become malnourished unable to work the fields. This will then result in the inability to yield a crop for which is to be sold. With the limited supply of good crops, and with the limited amount of people who are able to harvest, rural communities will suffer as their major source of income, food, and employment will be damaged due to the soil salinity.

Disease

The salinity in the soils, eventually causing malnutrition amongst families will later result in diseases that could spread like wildfire in some rural communities.

Conclusion to Social Implications

As a result of soil salinity, a domino effect will occur; causing poor crop yields, then to malnutrition of families, decreased income and employment, therefore creating hunger and a damaged economy in rural areas, and these can also lead to disease. The social effects of soil salinity are mostly negative in rural communities. But in more advanced areas, where the population may not rely so dependently on the agricultural industry, the effects would not be felt so drastically.

Ethical Implications

Impact

The impact of salinity on agriculture and biodiversity has been identified recently as a major issue. Used in order to ease and increase the safety of road conditions, the effect of salt on the surrounding environment has dramatically increased as a result of annual deposition. Salinity is also a contributor to species extinctions and loss of ecosystem health. For example, in Australia, one of the most countries most affected by the effects of salinity, in the Western wheatbelt, salinity has caused a 50% decrease in the numbers of waterbird species using the wetlands and 450 plant species are threatened with extinction as a result of increasing salinity (Keighery et al. 2000). Nationally some 5.7 million hectares (are predicted to rise to 15 million by 2050) of land have been affected by or are at risk from salinity (NLWRA 2000).

AlternativesIn Canada, alternatives are readily available to combat this issue. Mark

Watson, the CEO of Earth Innovations Inc., introduced the EcoTraction product. EcoTraction is billed as an environmentally friendly alternative to road salt made from a volcanic mineral. Watson came up with the idea after his cocker spaniel, Grover, died from lymphoma cancer, which an oncologist suggested could have been caused from toxins in road salts. The product has been thoroughly tested to be non-toxic. However, the effectiveness of this product is questionable against the effectiveness readily available salt. When alternatives to road salt are available, it is difficult to weigh the effectiveness of the alternatives to the driving safety the salt provides during the winter. Therefore, it is important to consider both the degrees of damages that may occur as a result of all alternatives in comparison to road salt. Certain areas are more prone to damage than others, for example, river basins, streams and agricultural sites in which case, alternatives should be given more consideration.

Ethical Believes

An ethical belief that must be considered is the avoidance of brining harm to others. However, this belief can be argued both ways, in favour of farmers, and the environment in terms of agriculture. It may be argued that a community should not increase costs on farmers to use alternative means for example. Nevertheless, the affects of the salinity on the environment and biodiversity are priceless in this manner. Therefore, it is important to recognize the existence of alternative perspectives.

SolutionsA more desirable way of tackling the issue is establishing an ethical

position of the entire community. Communities should develop policies that limit the use of damaging chemicals on the environment and encourage the use of alternatives. For example, communities should address salinity in a balanced way and come to an effective conclusion that minimizes expenditures all while keeping in mind the immediate and future effects on the environment. Therefore, the responsibility for managing salinity rests with governments who will represent the whole community and future generations. It is up to these governments to establish policies that are effective against salinity. Only when policies become less based on the political need to do something quickly and more based on the ethical need to do something effective will we have any chance of substantially reducing the final area of saline land. The longer it takes to reach this point, the less effective the end response will be.