NATURE'S PLANTING OF SEEDS TIME: WHEN GERMINATION BEGINS IN THE SPRING Object: To determine Nature's depth and rate of planting seeds. Material needed: Five shallow pans or boxes. DIRECTIONS 1. Select a spot of ground which has not been disturbed for one season. Mark off a space 12 inches square and from this remove a layer of soil, I inch deep, and place in a shallow pan or box. Repeat the process until you have removed six layers of soil to a depth of 6 inches. Care must be taken so that the surrounding soil shall not fall into the excavation while the soil is being removed. 2. Label the pans and put in a warm place. Keep moist and wait for the seeds to germinate. As the seedlings appear above the ground, pull them up and keep a record of the number. 3. Mark off another square by the side of the first one, and count the number of seedlings that appear. Watch from time to time and count the number that die. QUESTIONS 1. Which layer of soil contained the greatest number of seedlings? 2. Why did a number of seedlings die? 3. How many of the young plants could you identify? 4. Go into a forest and note all evidences of a struggle for existence among the trees and plants growing there. 5. Is the struggle greatest between plants of the same kind, or between those of different kinds? NUMBER OF SEEDS PRODUCED BY PLANT 1. The following data are given in Kerner's N ural History of Plants: a. An average hedge mustard plant (Sisymbriu sophia) yields 730,000 seeds. b. Fleabane (Erigeron canadense) yields 120,00 c. Shepherd's purse (Capsella bursa-pastoris yields 64,000 seeds. d. Plantain (Plantago major) yields 14,000 seed e. Henbane (Hyoscyamus niger) yields 10,00 seeds. 2. Starting with one plant of each of the specie mentioned, and supposing each seed to ripen an grow, how many seeds would be produced each yea up to and including the fifth? Allowing 40 plant to the square yard, at this rate of production hov long would it take each species to cover the State VALUE OF BIRDS TO THE FARMER TIME: WHENEVER CONVENIENT Object: To learn whether it pays to protect the birds. Material needed: Paper and pencil. Facts. Insects feed on the young and tender foliage of growing plants, but no part of the plant is entirely free from them-some insects attack the seed, others the fruit, stem, or roots. Birds prey largely upon injurious insects. Not only do they destroy great numbers of insects, but they eat great quantities of weed-seeds as well. The State of Illinois loses annually $20,000,000 by the ravages of insects. This means about 56 cents an acre. DIRECTIONS Suppose the damage done by insects in your State is 50 cents an acre, what would be the damage for the entire State? Suppose there are four birds to the acre, how many would there be in the State? If each bird eats 20 insects a day (a fair estimate), how many insects would be destroyed during the months of June, July, and August? Suppose one half of the birds in the State should eat one fourth of an ounce of seed each day for three months, how many pounds of weed-seeds would be destroyed? |