1. Effect of Changing the Rotation Sequence in a Long Term Tillage and Fertility Study

A continuous experiment was conducted fiom 1970 to 1999 to determine the long term effects of fertilizer application and tillage practices on soil acidity, organic matter and nutrient changes, and crop responses. Four tillage treatments were evaluated: continuous conventional: alternate till (two years no-till: one year conventional); continuous chisel till; and continuous no-till. Five fertilizer treatments were also evaluated (Ib ac-' N-P205-K20): check, 0-0-0; 175-0-0 broadcast; 160-0-0 broadcast...