00548    a2200133   4500020001800000082001700018100003100035245019700066260005600263300002300319650002500342650001900367650002800386  a9780309148962  a630.973bNAT  aNational research council   aToward sustainable agricultural systems in the 21st centurybcommittee on twenty-first century systems agriculture board on agriculture and nutural resources division on earth and life studies  aWashingtonbThe National Academic Pressc2010g2010  axxviii,570p.c25cm  aAgricultural systems  aSustainability  aSustainable agriculture