GPHY 319 Lecture Notes - Lecture 8: The Takeaway, Living Mulch, Intercropping
Document Summary
Greater chilling tolerance (better for canada: photosynthesis continues after frost. Utilizes solar radiation effectively in spring and fall. Examples: rice, soybean, wheat, rye, oats, millet, barley, potto (85% of plants and trees are c3) Utilizes solar radiation effectively at high temperatures. Examples: maize (corn), switchgrass, pearl millet and sugar cane only 15% of plants and trees are c4) Agricultural soils either source or sink of ghg. Soil management changes ghg: soil climate (temp. moisture, physical/chemical environment soil, chemical composition organic residues. Ghg: carbon dioxide: co2, nitrous oxide: n2o, methane: ch4. Conversion forest to cropland: loss of soil organic c (most common, greater soil organic c (improved fertility, drainage( Drained organic soils lose about 10mg/ha/yr of c in cool climates. For eastern canada (on, qc, maritimes), historical loss: 10-20tg c (i. e 10-20 billion kg) Tillage: preparation of the soil by plowing. No-till: no disturbance of soil, may increase soil moisture, decrease erosion, increase soil biodiversity, requires more herbicide.
