The aim of this investigation is to find out what effect acid rain has on crop growth. I will investigate this with the following experiment; I will put 2 crops named Wheat and Barley into three sealed bags with two different concentrations of acid in with them and one concentration of water. Each bag will contain one wheat plant, one Barley plant and a solution of either acid or water.

The two concentrations of acid and the concentration of H2o will each be transferred into a separate pot using a dropper, by using the dropper I can accurately measure how much of each solution goes into each tub; Each tub is lined with cotton wool to prevent spillages. The variables in this experiment are the concentrations of acid in each bag, the plant sizes and type e. g. in one plant a barley plant could measure 8cm this would make the test unfair because the smaller plant would be more easily effected. Also the plant type is another variable i. e.the barley plant could be immune to weak acid or it could effect barley more than the wheat plant.

This experiment is not very reliable so I would do it at least three times to get a clear set of results unfortunately I can only do the experiment once because of time restrictions. To evaluate if the experiment was a success and weather my results are reliable or not I will have to compare my results with another group. The safety aspects in this experiment, which I will have to take into consideration Will be wearing safety goggles when using the acids and I will also put cotton wool in the pots containing acids in case of spillages.

The equipment I will be using is as follows: 3x Polythene bags 3x Barley Plants 3x Wheat Plants 3x Plastic cups 3x Pieces of cotton wool 3x Universal indicator 10ml 2. 5% Sodium Metabi Sulphate 10ml 5% Sodium Metabi Sulphate To test the acidity of the atmosphere and soil in each bag I put six universal indicator strips in the bags 2 strips in each bag, one in the soil and one in the bag. After the experiment I will compare the colour which the universal indicator strips have turned to the Ph scale this will tell me how acidic the plants atmosphere is in each bag, this will determine which concentration of acid effects which plant worst.

To make this a fair test I will put the same amount of acid in each pot, I will ensure the same amount of acid will be put in each pot by using a dropper to measure the amount of acid I have put in each pot. I will use the same size plants (roughly), I will ensure the plants are (roughly) the same size by measuring them and comparing their sizes. I will put the same equipment in each bag e. g. each bag will contain 2 plants (one wheat, one barley) three universal indicator strips, one measurement of acid, one piece of cotton wool and a small pot/tub.

To make sure the results are accurate I recorded the size of each plant before and after I put it in a bag with the acid this will show if an acidic atmosphere effects crop growth, the measurements are as follows: Measurements before experiment Substance in pot-Water Plant type-Wheat Measurement-10. 0 Cm Observations-Healthy green colour, tall and quite thin Substance in pot-Water Plant type-Barley Measurement-11. 1 Cm Observations- Healthy green colour, tall and thicker than wheat Substance in pot-Weak acid Plant type-Wheat Measurement-8. 5 Cm Observations- Healthy green colour and thin Substance in pot-Weak acid.

Plant type- Barley Measurement-9. 0 Cm Observations-Healthy green colour thicker than wheat Substance in pot-Strong acid Plant type-Wheat Measurement-8. 5 Cm Observations-Healthy green colour quite tall and thin Substance in pot-Strong acid Plant type-Barley Measurement-6. 0cm Observations-Healthy green colour, small thicker than wheat My prediction is that I think the Bags with the strong and weak acid will have affected the crops growth and atmosphere.

I think this because this experiment is a simulation of what happens when plants come into contact with acid rainfall. Acid rain is caused as a result from burning fossil fuels e.g. coal, the scientific formula for acid rain is:  Plant-Wheat Substance in pot-Water Description- Strong, tall healthy plant Measurement-23. 2 Cm Plant-Barley Substance in pot-Weak acid Description-Short, droopy, white and shrivelled Measurement-20 Cm Plant-Wheat Substance in pot-Weak acid.

Description- Short, droopy, white and shrivelled Measurement-19. 1 Cm Plant-Barley Substance in pot-Strong acid Description-Quite tall, White tips and droopy Measurement-23. 0 Cm Plant-Wheat Substance in pot-Strong acid Description-short, weak and white in places Measurement-17. 5 Cm The universal indicator changed a variety of colours including white! The results are as follows: Substance-Water Plant-Wheat Colour-Green Ph-Ph 7 Neutral Substance-Water Plant-Barley Colour-Green Ph-Ph 7 Neutral Substance-Weak acid Plant-Wheat Colour-Bright yellow Ph-Ph 2 Substance-Weak acid Plant-Barley Colour-Bright yellow.

Ph-Ph 4 Substance-Strong acid Plant-Wheat Colour-Bright yellow Ph-Ph 3 Substance-Strong acid Plant-Barley Colour-Bright yellow Ph-Ph 3 Also there is a weak acidic atmosphere in the weak and strong acid bags and a green fungi was growing on the soil in the weak acid bag. Analysis What I Have found out is that the acid does affect crop growth and does damage plants I have proved this by using my results and observations. My prediction was correct and bags with strong and weak acid did affect the crops growth compared to the bag with the pot containing the water sample.