Effects on Farmers
Until only a few decades ago, many farmers often saved seeds for re-planting for future crops, and many also bred seeds for more desirable traits. However, the advent of patent rules extending seed ownership and control has dramatically altered farmer-led seed breeding and free exchange of seed.
One of the central means of control over farmers’ ability to save seed is expressed through technology agreements that agrichemical companies now require farmers to sign upon seed purchases. These technology agreements are aggressively, and often questionably, enforced as illustrated by CFS investigations: 
Monsanto is not the only seed corporation engaging in lawsuits over “seed piracy” matters. Beginning in 2013, DuPont began sending dozens of retired police officers across Canada to search for illegal seed-saving and enforce patents.
Effects on the Environment
While little considered, seed patent and IPR systems have profound impacts upon the environment. Several examples illustrate this:
 Gwen Sharp, “Loss Of Genetic Diversity In U.S. Food Crops,” The Society Pages, July 19, 2011, accessed August 7, 2012, http://thesocietypages.org/socimages/2011/07/19/loss-of-genetic-diversity-in-u-s-food-crops
 Cary Fowler and Pat Mooney, Shattering: Food, Politics and the Loss of Genetic Diversity (Tucson: University of Arizona Press, 1990).
 Benbrook: Impacts of genetically engineered crops on pesticide use in the U.S. – the first sixteen years. Environmental Sciences Europe 2012 24:24. Supplemental Table 8.