Theory question 106
Pasture and Forage Crops(a) Define pasture.
(b) List three features of natural pastures.
(c) A piece of land to be used to establish a pasture of Stylosanthes gracilis was surveyed to be circular. (i) If the radius of the land is 200 m and the spacing of the pasture legume is 1 m by 50 cm, what is the population of the legume at one seed per stand? (ii) If the germination percentage is 75, calculate the expected plant population. (iii) Give two ways in which Stylosanthes gracilis is important in agricultural production.
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(a) A pasture is an area of land covered with grasses and/or legumes on which livestock graze
(b) Any three: grows naturally without planting; mixture of many species, some unpalatable; low yield and quality; seasonal growth; weeds and shrubs present; low carrying capacity
(c)(i) Area = πr² = 22/7 × 200 × 200 ≈ 125,714 m² (125,600 m² with π = 3.14); area per stand = 1 m × 0.5 m = 0.5 m²; population ≈ 251,429 stands (251,200 with π = 3.14)
(ii) Expected plants = 75% of 251,429 ≈ 188,571 (188,400 with π = 3.14)
(iii) Any two: protein-rich forage for livestock; fixes nitrogen and improves soil fertility; cover crop controlling erosion and weeds; can be made into hay; drought tolerant
Find the circle's area, divide by area per stand, then take 75%.