Until about four decades ago, crop yields in agriculture depended mainly on internal resources, recycling of organic matter, built-in biological control mechanisms and rainfall intensity and frequency. At that time, agricultural yields were modest, but stable. Production was safeguarded by growing more than one crop. Inputs of nitrogen were gained by rotating major field crops with legumes. In turn rotations suppressed insects, weeds and diseases by effectively breaking the life cycles of these pests. Most …showed first 75 words of 440 total…

…showed last 75 words of 440 total…Quebec because wheater allows us to cultivate many types of crop. The climate breaks life cycles of many pests. In conclusion, modern agricultural structure and contemporary rules have certainly influenced the context of agricultural technology and production. This has led to environmental problems which are on the way to be solved. People now become to be concerned about resource-conserving practices. We know more than ever that this is the key for a long term profitability.