Biology 2485B Lecture Notes - Lecture 14: Mycorrhiza, Nitrate, Cash Crop
Document Summary
Lecture 14 - organic agriculture & climate change effects. We previously identified several negative impacts of modern agricultural practices: Fertilizer runoffs leads to algal blooms and poses human health risks. Irrigation can lead to waterlogging and salinization of soils: pesticides can affect non-target organisms and human health. There are many different approaches to "sustainable agriculture" Sustainable means an activity can meet our current needs without reducing about ability to meet our future needs. Sustainable agriculture is the production of agricultural products that does not deplete the soil or pollute the environment. No-till agriculture: depth and frequency of ploughing and tilling (turning over of the soil by mechanical means) are kept to a minimum to protect soil moisture and compaction. Conventional tillage: mechanical manipulation of the topsoil that leaves no more than 15% of the ground surface covered with crop residues.