GEOG M107 Lecture Notes - Lecture 16: Mulch, Crop Residue, Surfactant
Document Summary
50% of annual rainfall can be lost to evaporation, depending on environment/heat. Green in middle of storm: hail core. Uniform planting: humans regrowing forest for harvesting. Mass erosion can be spotted in differences in tree age. Natural disasters (landslides) leave indicators behind in soil. Winds are named by the direction they came from. Runoff is a loss to upstream farmers, but benefits those downstream. Mulches (decaying leaves, bark, or compost) can be applied to bare/unprotected fields. Produces miniature furrows/ridges across slopes that trap rainwater and give it time to infiltrate. Deep ripping/tilling can increase infiltration and reduce runoff. Level ridge-type terraces (combine ridge and level channel structures): allow ponding of water on flat surfaces. Conservation-bench (zingg) terraces: series of level benches with steep/narrow ridges; terraces separated by unleveled, runoff contributing areas, planting crop on bench. Mechanically generates micro-watersheds on degraded land is used to revegetated arid/desertified soils. Routes water to particular places where you want to plant.
