IMPLICATIONS OF SUSTAINABLE AGRICULTURE FOR THE WORLD FOOD SITUATION

World population growth rate has slowed since the early 1970s, but gro wth in world grain production has slowed further. As a result, per cap ita grain production has declined since 1983. Conventional farming pra ctices that use heavy chemical applications and high-yielding varietie s have resulted in soil erosion, depletion of natural resources, conta mination of the environment, and reduced biodiversity; and threaten to diminish the world's ability to sustain life of all kinds. If these t rends persist, the earth may not sustain an adequate level of food pro duction. Transition to sustainable agricultural practices could presum ably prevent most of this degradation but may not produce adequate sup plies of food to meet the growing demand. Although yields from sustain able agricultural farms can be as high as those from conventional farm s, food production per acre of rotation generally declines because sus tainable farms need to incorporate green manure crops and forage legum es into their rotations. Therefore, food production must be increased, which can be done in two ways: either bring more land into cultivatio n or increase yields. Although there are large tracts of land still av ailable, their fragile ecosystems make it costly to bring them into pr oduction. Future grain production must come from higher yields. Howeve r, several studies indicate that the growth of major crop yields is le veling off, and that it has become increasingly difficult to increase crop yields. Therefore, to meet future world food demand, we need to c ontinue to invest in research to develop new technologies that are dir ected toward sustainable agriculture. Adoption of new technologies cou ld break through the yield ceiling characterized by previous technolog ies and enable the yield growth rate to outpace the population growth rate.