North American Agroforestry. Группа авторов. Читать онлайн. Newlib. NEWLIB.NET

Автор: Группа авторов
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Биология
Год издания: 0
isbn: 9780891183839
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chemical and energy inputs required to reduce specific pest populations on specific hosts 18. Functional properties (such as community metabolism) are more robust (homeostatic‐resistant to stressors) than are species composition and other structural properties despite drastic reduction in biodiversity and simplification of structure, system continues to be productive
Indicator Definition Value indicating high sustainability Value indicating low sustainability Conventional farm Agroforestry farm
weight of harvested crops and livestock, kg ha−1 (lb acre−1) dry weight 7,952 (7,100) 0 3,805 (3,397) 3,923 (3,503)
total non‐solar energy inputs, MJ ha−1 (MJ acre−1) 0 59,259 (24,000) 17,264 (6,992) 14,091 (5,707)
ratio of energy in harvested crops to cultural energy inputs 5 <1 3.9 4.5
energy in harvested crops as proportion of growing season PAR,% 1.0 0 0.38 0.35
harvested biomass divided by AET (g m−1 mm−1) 1.15 0 0.61 0.61
N + P, kg ha−1 (lb acre−1) 0 151 (135) 44 (39) 26 (23)
losses through erosion and leaching), kg ha−1 (lb acre−1) 0 45 (40) 28 (25) 20 (18)
wind + water, Mg ha−1 (tons acre−1) 0 11 (8) 11 (5) 7.8 (2.5)
N inputs/N outputs 1 <0.8 or >1.2 0.6 0.64
P inputs/P outputs 1 <0.8 or >1.2 0.7 0.46
no. of crops per farm 12 1 2 7
h ha−1 (h acre−1) 0 5 (2) 1 (0.4) 5 (2)
US$ ha−1 (US$ acre−1) 235 (95) 89 (36) 99 (40) 249 (101)
debt/variable income 0 1 0.63 0.46
total skills and knowledge held by farm family high low medium high