Tự nhiên Hệ thống Nông nghiệp Giới thiệu: Vấn đề môi trường Associated Nông nghiệp hiện đại Mô hình Prairie Một Nông nghiệp dựa trên các yếu tố của hệ sinh thái Prairie của Prairie Mô hình trồng cây lâu năm như ngũ cốc loài Chương trình nghị sự nghiên cứu đa dạng và phát hiện đó Hỗ trợ Câu hỏi Mô hình 1: Năng suất hạt lâu năm cũng như hạt một hàng năm ? Câu hỏi 2: Có thể một Overyield nuôi ghép lâu năm? Câu hỏi 3: nuôi ghép lâu năm có thể Cung cấp khả năng. | CHAPTER 10 Natural Systems Agriculture Jon K. Piper CONTENTS Introduction Environmental Problems Associated with Modern Agriculture The Prairie Model An Agriculture Modeled on the Prairie Ecosystem Elements of the Prairie Model Perennials as Grains Species Diversity Research Agenda and Findings That Support the Model Question 1 Can a Perennial Grain Yield As Well As an Annual Grain Question 2 Can a Perennial Polyculture Overyield Question 3 Can a Perennial Polyculture Provide Its Own Nitrogen Fertility Question 4 Can Perennial Polyculture Manage Weeds Herbivorous Insects and Plant Pathogens Weeds Insect Pests Plant Disease Community Assembly Concluding Remarks Acknowledgment References 1999 by CRC Press LLC. INTRODUCTION ENVIRONMENTAL PROBLEMS ASSOCIATED WITH MODERN AGRICULTURE One Kansas Farmer Feeds 101 People and You proclaims a billboard alongside Interstate 135 near Salina KS. Modern agriculture has been overwhelmingly successful in terms of output per farmer acre or hour worked. Agricultural productivity has steadily increased as a result of technological advances in machinery fertilizer and pesticides coupled with the intensive use of plant genetic diversity to improve yield through plant breeding. For example yields of corn and sorghum increased severalfold in the . between the 1930s and the 1980s Jordan et al. 1986 . In terms of return on labor industrial agriculture based on monocultures of annual grains is unquestionably a highly productive form of food and feed production. This productivity has arisen largely through simplifying agroecosystems into monocultures and tailoring them to maximize yield. In the process however many of the links between organisms and the soil that serve to regulate natural communities are ignored or disrupted. The following account surveys some of the more severe environmental effects deriving from large-scale monocultures. With the publication of Silent Spring 35 years ago Carson 1962 the public began to become aware of .
