Question

In order to reduce individual carbon footprints on the planet, one great way to recycle food material is to compost

plant, fruit and vegetable organic waste and use it as fertilizer for plants. Students at the local High School Biology

class investigated the effect of composted material on plant growth. Each lab group decided to compare the effect of

different-aged compost on wheat plants. The composition of nutrients in composted material is a key element to

proper fertilizing potential so each group hypothesized that older composted material would contain more nutrients and

would therefore produce taller wheat plants. Five flats of wheat plants (30 plants/flat) were grown for 5 weeks. The

plants were then fertilized as follows: (a) Flat A: 450 g of 1-month-old compost, (b) Flat B: 450 g of 2 month-old compost,

(c) Flat C: 450 g of 4 month-old compost, (d) Flat B: 450 g of 6 month-old compost and (e) Flat C: 0 g compost. The

plants received the same amount of sunlight and water each day. At the end of 5 weeks, the group recorded the

height of the plants (cm).

Write a hypothesis that would be appropriate for the experiment scenario.

What would be the independent variable in the experiment?

What would be the dependent variable in the experiment?

What steps did the group take to ensure that the experiment would be controlled?

Answer 1

Hypothesis: Organic waste in the environment is ranged between 40-70 % . Due to large amount of organic waste in the environment it has become one of the global issues such as carbon footprint on the planet earth. There are a different methods are used for composting and management of organic waste such as use of landfill and incineration and decaying of organic waste by composting. Other methods such as of landfill and incineration are threatened to the environment as water pollution and air pollutions, respectively. Composting is considered as most suitable methods. Composting is one of the low cost biological decomposition processes. The composting processes is circulated by microbial activity, The physicochemical parameter including temperature, aeration, moisture content and carbon-nitrogen ration and pH. Composting process is considered to be most efficient, environmentally safe and agronomically better whereas compost can be used as soil conditioner, organic fertilisers as well as high nutrient for soils.

Independent variable in the experiment: Those paremters study should be neccessary to be observed afer using of same quantity of compost, water and sunlight. Such as slope of the area, water holding capacity before use of compost.

Dependent variable in the experiment: For the detailed analysis needs to be length of leave of plants, width of leave of plants, diameter of stems also should be measured based on age of compost fertilisers. Also obereved the grains of wheat in each plant along with size of grains.

The experiment enhance the results During the composting of organic waste the addition of animal manure can be enhance the degradation process whilist in compstiong becuase of animal manuremore content of Nitrogen than the vegetable compost. Nitrogen play an important role in the development and growth of the plants. After harvestiong of wheat quantitative and qualitative investigation should be suggested.