Project Name : Pesticides in agriculture
Theme Name : Natural Resource & their Conservation
Objective/Aim: Introduction of pesticides in agriculture is a major step in increasing plant yield. However these compounds have lead of gradual environment pollution and degradation and increase in health hazards like cancer.
Scientific Principle Involved: Allelopathy refers to the effect(s) both positive and negative of one plant over the other through release of chemical compounds (allelochemicals) in the environment, Research has shown that allelopathic vegetation can be used as effective herbicides.
Material Used: Questionaire, clavenger’s apparatus, test for alcohols, Ceric ammonium nitrate, ferric chloride, sodium nitronprusside, NaOH, sodium bicarbonate, red litmus solution, aluminum phosphate, HCL concentrated HNO3, NH4CL, K4FeCn6, ammonium, diphenly, CaCo3. Yellow colour confirms the presences of sulphates.
Investigation:
To study the existing practices of leaf litter disposal in residential area and public gardens
To compare the leaf litter of allelopathic and non allelopathic plants with respect to their physical and chemical composition. The differences in their pH, water, alcohol, magnesium, aldehydes, ketones and phenol content were tested by the students in the school laboratory.
One kg of lead litter gives 2.5 to 3 ml oil which can be used as herbicide.
Visit to P.U. to study working of clavenger’s apparatus and effect of oil and water extracts of leaf litter on plants.
Analysis of Data:
Around 124 people were surveyed in the tricity which included 74% residential garden, 20% public places and 6% schools.
Leaf litter was present in 85% of these cases.
Leaf litter was collected daily in 35% cases and weekly in 38% cases.
Inspite of 92% people being aware of the harmful effects caused burning of leaves nearly 34% still opted for this mode of disposal.
The season of maximum litter was found to be September – October.
Nearly 38% people depended on the collection of litter by municipal van and 58% people felt that fallen leaves could be used as organic manure.
Of all the samples taken Eucalyptus and Lantana were found to contain phenols thus making them appropriate choice as herbicides.
Majority of them contain nitrates, sulphates, phosphates, aldehydes, magnesium, ammonium and iron ions. Leaf litter of mango and Tecoma was found to be basic in nature where as the others were acidic.
Conclusions:
Leaf litter of both allelopathic and non – allelopathic plants can serve as effective compost due to their nutrient content.
Additionally the former can probably be used as natural herbicides due to their phenol content.
As well mulching can prove to be useful for retaining moisture content of the soil as well as growth of weeds can be checked.
This will be an environment friendly method of recycling leaf litter.
Utility and Further scope of the project: We can have a leaf litter processing unit to extract the herbicidal content from the leaves. The left over matter can be used as manure.
We are sure that, if our model is implemented it will not only solve as major problem of our city but also go a long way in creating ecobalance which is highly disturbed by excessive use of pesticides and fertilizers
Name of the School: Carmel Convent School, Chandigarh.
