World population growth, soil erosion, and food security.
Global food insecuity is growing as the worldwide attempt to expand food production loses momentum. The grain surpluses that accumulated in the food exporting countries during the decades of the 1950s and the 1960s have disappeared. World food supplies are tightening and the slim excess of growth in food production over population is narrowing. Throughout the world pressures on the cropland are intensifying. Focus in this discussion of world population growth is on the loss of momentum, the return of famine, the North American breadbasket, declining food security, the conversion of cropland to nonfarm use, thinning topsoil, land productivity trends, and the loss of irrigated land. As the decade of 1980 begins, the growth in world food production is losing momentum, and its excess over population growth is narrowing. In Africa, if soils continue to deteriorate, the 10 year decline in food output per person there could become chronic. If soil erosion and the other forces that have slowed food production in the world as a whole continue to intensify, and the projected population increases occur, then growth in food production could drop below that of population for the world as a whole. Responding effectively to the cropland threats associated with mounting food demands creates a dilemma for both farmers and governmental planners. Economic forces and political instincts encourage short-term measures, yet pressures to wring too much from the land in the short run could destroy it over the long run. Wider public understanding of the longterm effect of cropland conversion and topsoil loss on food prices is the key to an effective worldwide response. The US Soil Conservation Service has outlined a national plan that would bring the annual loss of topsoil down to a tolerable level. Along with maintaining the conservation systems now in place, some 158 million acres of the 413 million acre cropland base need additional attention. Of this total, 17 million acres of cropland are eroding so rapidly that the Soil Conservation Service recommends that it be shifted from continuous row cropping and converted to either woodland, grassland, or longterm rotation. The remaining 141 million acres of cropland that are presently losing over 5 tons of soil per year are in need of the adoption of some form of conservation tillage. Officials in India are struggling with the same issues as officials and soil scientists in the US. Governments everywhere must consider the realignment of priorities that will allow soils to be stabilized.